1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Provide the ability to override linkage features of the interface.
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51#ifndef SQLITE_API
52# define SQLITE_API
53#endif
54#ifndef SQLITE_CDECL
55# define SQLITE_CDECL
56#endif
57#ifndef SQLITE_APICALL
58# define SQLITE_APICALL
59#endif
60#ifndef SQLITE_STDCALL
61# define SQLITE_STDCALL SQLITE_APICALL
62#endif
63#ifndef SQLITE_CALLBACK
64# define SQLITE_CALLBACK
65#endif
66#ifndef SQLITE_SYSAPI
67# define SQLITE_SYSAPI
68#endif
69
70/*
71** These no-op macros are used in front of interfaces to mark those
72** interfaces as either deprecated or experimental. New applications
73** should not use deprecated interfaces - they are supported for backwards
74** compatibility only. Application writers should be aware that
75** experimental interfaces are subject to change in point releases.
76**
77** These macros used to resolve to various kinds of compiler magic that
78** would generate warning messages when they were used. But that
79** compiler magic ended up generating such a flurry of bug reports
80** that we have taken it all out and gone back to using simple
81** noop macros.
82*/
83#define SQLITE_DEPRECATED
84#define SQLITE_EXPERIMENTAL
85
86/*
87** Ensure these symbols were not defined by some previous header file.
88*/
89#ifdef SQLITE_VERSION
90# undef SQLITE_VERSION
91#endif
92#ifdef SQLITE_VERSION_NUMBER
93# undef SQLITE_VERSION_NUMBER
94#endif
95
96/*
97** CAPI3REF: Compile-Time Library Version Numbers
98**
99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100** evaluates to a string literal that is the SQLite version in the
101** format "X.Y.Z" where X is the major version number (always 3 for
102** SQLite3) and Y is the minor version number and Z is the release number.)^
103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105** numbers used in [SQLITE_VERSION].)^
106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107** be larger than the release from which it is derived. Either Y will
108** be held constant and Z will be incremented or else Y will be incremented
109** and Z will be reset to zero.
110**
111** Since [version 3.6.18] ([dateof:3.6.18]),
112** SQLite source code has been stored in the
113** <a href="http://www.fossil-scm.org/">Fossil configuration management
114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115** a string which identifies a particular check-in of SQLite
116** within its configuration management system. ^The SQLITE_SOURCE_ID
117** string contains the date and time of the check-in (UTC) and a SHA1
118** or SHA3-256 hash of the entire source tree. If the source code has
119** been edited in any way since it was last checked in, then the last
120** four hexadecimal digits of the hash may be modified.
121**
122** See also: [sqlite3_libversion()],
123** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124** [sqlite_version()] and [sqlite_source_id()].
125*/
126#define SQLITE_VERSION "3.28.0"
127#define SQLITE_VERSION_NUMBER 3028000
128#define SQLITE_SOURCE_ID "2019-04-16 19:49:53 884b4b7e502b4e991677b53971277adfaf0a04a284f8e483e2553d0f83156b50"
129
130/*
131** CAPI3REF: Run-Time Library Version Numbers
132** KEYWORDS: sqlite3_version sqlite3_sourceid
133**
134** These interfaces provide the same information as the [SQLITE_VERSION],
135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
136** but are associated with the library instead of the header file. ^(Cautious
137** programmers might include assert() statements in their application to
138** verify that values returned by these interfaces match the macros in
139** the header, and thus ensure that the application is
140** compiled with matching library and header files.
141**
142** <blockquote><pre>
143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
146** </pre></blockquote>)^
147**
148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
149** macro. ^The sqlite3_libversion() function returns a pointer to the
150** to the sqlite3_version[] string constant. The sqlite3_libversion()
151** function is provided for use in DLLs since DLL users usually do not have
152** direct access to string constants within the DLL. ^The
153** sqlite3_libversion_number() function returns an integer equal to
154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
155** a pointer to a string constant whose value is the same as the
156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
157** using an edited copy of [the amalgamation], then the last four characters
158** of the hash might be different from [SQLITE_SOURCE_ID].)^
159**
160** See also: [sqlite_version()] and [sqlite_source_id()].
161*/
162SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
163SQLITE_API const char *sqlite3_libversion(void);
164SQLITE_API const char *sqlite3_sourceid(void);
165SQLITE_API int sqlite3_libversion_number(void);
166
167/*
168** CAPI3REF: Run-Time Library Compilation Options Diagnostics
169**
170** ^The sqlite3_compileoption_used() function returns 0 or 1
171** indicating whether the specified option was defined at
172** compile time. ^The SQLITE_ prefix may be omitted from the
173** option name passed to sqlite3_compileoption_used().
174**
175** ^The sqlite3_compileoption_get() function allows iterating
176** over the list of options that were defined at compile time by
177** returning the N-th compile time option string. ^If N is out of range,
178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
179** prefix is omitted from any strings returned by
180** sqlite3_compileoption_get().
181**
182** ^Support for the diagnostic functions sqlite3_compileoption_used()
183** and sqlite3_compileoption_get() may be omitted by specifying the
184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
185**
186** See also: SQL functions [sqlite_compileoption_used()] and
187** [sqlite_compileoption_get()] and the [compile_options pragma].
188*/
189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
190SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
191SQLITE_API const char *sqlite3_compileoption_get(int N);
192#else
193# define sqlite3_compileoption_used(X) 0
194# define sqlite3_compileoption_get(X) ((void*)0)
195#endif
196
197/*
198** CAPI3REF: Test To See If The Library Is Threadsafe
199**
200** ^The sqlite3_threadsafe() function returns zero if and only if
201** SQLite was compiled with mutexing code omitted due to the
202** [SQLITE_THREADSAFE] compile-time option being set to 0.
203**
204** SQLite can be compiled with or without mutexes. When
205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
206** are enabled and SQLite is threadsafe. When the
207** [SQLITE_THREADSAFE] macro is 0,
208** the mutexes are omitted. Without the mutexes, it is not safe
209** to use SQLite concurrently from more than one thread.
210**
211** Enabling mutexes incurs a measurable performance penalty.
212** So if speed is of utmost importance, it makes sense to disable
213** the mutexes. But for maximum safety, mutexes should be enabled.
214** ^The default behavior is for mutexes to be enabled.
215**
216** This interface can be used by an application to make sure that the
217** version of SQLite that it is linking against was compiled with
218** the desired setting of the [SQLITE_THREADSAFE] macro.
219**
220** This interface only reports on the compile-time mutex setting
221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
223** can be fully or partially disabled using a call to [sqlite3_config()]
224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
226** sqlite3_threadsafe() function shows only the compile-time setting of
227** thread safety, not any run-time changes to that setting made by
228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
229** is unchanged by calls to sqlite3_config().)^
230**
231** See the [threading mode] documentation for additional information.
232*/
233SQLITE_API int sqlite3_threadsafe(void);
234
235/*
236** CAPI3REF: Database Connection Handle
237** KEYWORDS: {database connection} {database connections}
238**
239** Each open SQLite database is represented by a pointer to an instance of
240** the opaque structure named "sqlite3". It is useful to think of an sqlite3
241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
243** and [sqlite3_close_v2()] are its destructors. There are many other
244** interfaces (such as
245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
246** [sqlite3_busy_timeout()] to name but three) that are methods on an
247** sqlite3 object.
248*/
249typedef struct sqlite3 sqlite3;
250
251/*
252** CAPI3REF: 64-Bit Integer Types
253** KEYWORDS: sqlite_int64 sqlite_uint64
254**
255** Because there is no cross-platform way to specify 64-bit integer types
256** SQLite includes typedefs for 64-bit signed and unsigned integers.
257**
258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
259** The sqlite_int64 and sqlite_uint64 types are supported for backwards
260** compatibility only.
261**
262** ^The sqlite3_int64 and sqlite_int64 types can store integer values
263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
264** sqlite3_uint64 and sqlite_uint64 types can store integer values
265** between 0 and +18446744073709551615 inclusive.
266*/
267#ifdef SQLITE_INT64_TYPE
268 typedef SQLITE_INT64_TYPE sqlite_int64;
269# ifdef SQLITE_UINT64_TYPE
270 typedef SQLITE_UINT64_TYPE sqlite_uint64;
271# else
272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
273# endif
274#elif defined(_MSC_VER) || defined(__BORLANDC__)
275 typedef __int64 sqlite_int64;
276 typedef unsigned __int64 sqlite_uint64;
277#else
278 typedef long long int sqlite_int64;
279 typedef unsigned long long int sqlite_uint64;
280#endif
281typedef sqlite_int64 sqlite3_int64;
282typedef sqlite_uint64 sqlite3_uint64;
283
284/*
285** If compiling for a processor that lacks floating point support,
286** substitute integer for floating-point.
287*/
288#ifdef SQLITE_OMIT_FLOATING_POINT
289# define double sqlite3_int64
290#endif
291
292/*
293** CAPI3REF: Closing A Database Connection
294** DESTRUCTOR: sqlite3
295**
296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
297** for the [sqlite3] object.
298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
299** the [sqlite3] object is successfully destroyed and all associated
300** resources are deallocated.
301**
302** ^If the database connection is associated with unfinalized prepared
303** statements or unfinished sqlite3_backup objects then sqlite3_close()
304** will leave the database connection open and return [SQLITE_BUSY].
305** ^If sqlite3_close_v2() is called with unfinalized prepared statements
306** and/or unfinished sqlite3_backups, then the database connection becomes
307** an unusable "zombie" which will automatically be deallocated when the
308** last prepared statement is finalized or the last sqlite3_backup is
309** finished. The sqlite3_close_v2() interface is intended for use with
310** host languages that are garbage collected, and where the order in which
311** destructors are called is arbitrary.
312**
313** Applications should [sqlite3_finalize | finalize] all [prepared statements],
314** [sqlite3_blob_close | close] all [BLOB handles], and
315** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
316** with the [sqlite3] object prior to attempting to close the object. ^If
317** sqlite3_close_v2() is called on a [database connection] that still has
318** outstanding [prepared statements], [BLOB handles], and/or
319** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
320** of resources is deferred until all [prepared statements], [BLOB handles],
321** and [sqlite3_backup] objects are also destroyed.
322**
323** ^If an [sqlite3] object is destroyed while a transaction is open,
324** the transaction is automatically rolled back.
325**
326** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
327** must be either a NULL
328** pointer or an [sqlite3] object pointer obtained
329** from [sqlite3_open()], [sqlite3_open16()], or
330** [sqlite3_open_v2()], and not previously closed.
331** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
332** argument is a harmless no-op.
333*/
334SQLITE_API int sqlite3_close(sqlite3*);
335SQLITE_API int sqlite3_close_v2(sqlite3*);
336
337/*
338** The type for a callback function.
339** This is legacy and deprecated. It is included for historical
340** compatibility and is not documented.
341*/
342typedef int (*sqlite3_callback)(void*,int,char**, char**);
343
344/*
345** CAPI3REF: One-Step Query Execution Interface
346** METHOD: sqlite3
347**
348** The sqlite3_exec() interface is a convenience wrapper around
349** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
350** that allows an application to run multiple statements of SQL
351** without having to use a lot of C code.
352**
353** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
354** semicolon-separate SQL statements passed into its 2nd argument,
355** in the context of the [database connection] passed in as its 1st
356** argument. ^If the callback function of the 3rd argument to
357** sqlite3_exec() is not NULL, then it is invoked for each result row
358** coming out of the evaluated SQL statements. ^The 4th argument to
359** sqlite3_exec() is relayed through to the 1st argument of each
360** callback invocation. ^If the callback pointer to sqlite3_exec()
361** is NULL, then no callback is ever invoked and result rows are
362** ignored.
363**
364** ^If an error occurs while evaluating the SQL statements passed into
365** sqlite3_exec(), then execution of the current statement stops and
366** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
367** is not NULL then any error message is written into memory obtained
368** from [sqlite3_malloc()] and passed back through the 5th parameter.
369** To avoid memory leaks, the application should invoke [sqlite3_free()]
370** on error message strings returned through the 5th parameter of
371** sqlite3_exec() after the error message string is no longer needed.
372** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
373** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
374** NULL before returning.
375**
376** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
377** routine returns SQLITE_ABORT without invoking the callback again and
378** without running any subsequent SQL statements.
379**
380** ^The 2nd argument to the sqlite3_exec() callback function is the
381** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
382** callback is an array of pointers to strings obtained as if from
383** [sqlite3_column_text()], one for each column. ^If an element of a
384** result row is NULL then the corresponding string pointer for the
385** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
386** sqlite3_exec() callback is an array of pointers to strings where each
387** entry represents the name of corresponding result column as obtained
388** from [sqlite3_column_name()].
389**
390** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
391** to an empty string, or a pointer that contains only whitespace and/or
392** SQL comments, then no SQL statements are evaluated and the database
393** is not changed.
394**
395** Restrictions:
396**
397** <ul>
398** <li> The application must ensure that the 1st parameter to sqlite3_exec()
399** is a valid and open [database connection].
400** <li> The application must not close the [database connection] specified by
401** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
402** <li> The application must not modify the SQL statement text passed into
403** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
404** </ul>
405*/
406SQLITE_API int sqlite3_exec(
407 sqlite3*, /* An open database */
408 const char *sql, /* SQL to be evaluated */
409 int (*callback)(void*,int,char**,char**), /* Callback function */
410 void *, /* 1st argument to callback */
411 char **errmsg /* Error msg written here */
412);
413
414/*
415** CAPI3REF: Result Codes
416** KEYWORDS: {result code definitions}
417**
418** Many SQLite functions return an integer result code from the set shown
419** here in order to indicate success or failure.
420**
421** New error codes may be added in future versions of SQLite.
422**
423** See also: [extended result code definitions]
424*/
425#define SQLITE_OK 0 /* Successful result */
426/* beginning-of-error-codes */
427#define SQLITE_ERROR 1 /* Generic error */
428#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
429#define SQLITE_PERM 3 /* Access permission denied */
430#define SQLITE_ABORT 4 /* Callback routine requested an abort */
431#define SQLITE_BUSY 5 /* The database file is locked */
432#define SQLITE_LOCKED 6 /* A table in the database is locked */
433#define SQLITE_NOMEM 7 /* A malloc() failed */
434#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
435#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
436#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
437#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
438#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
439#define SQLITE_FULL 13 /* Insertion failed because database is full */
440#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
441#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
442#define SQLITE_EMPTY 16 /* Internal use only */
443#define SQLITE_SCHEMA 17 /* The database schema changed */
444#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
445#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
446#define SQLITE_MISMATCH 20 /* Data type mismatch */
447#define SQLITE_MISUSE 21 /* Library used incorrectly */
448#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
449#define SQLITE_AUTH 23 /* Authorization denied */
450#define SQLITE_FORMAT 24 /* Not used */
451#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
452#define SQLITE_NOTADB 26 /* File opened that is not a database file */
453#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
454#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
455#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
456#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
457/* end-of-error-codes */
458
459/*
460** CAPI3REF: Extended Result Codes
461** KEYWORDS: {extended result code definitions}
462**
463** In its default configuration, SQLite API routines return one of 30 integer
464** [result codes]. However, experience has shown that many of
465** these result codes are too coarse-grained. They do not provide as
466** much information about problems as programmers might like. In an effort to
467** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
468** and later) include
469** support for additional result codes that provide more detailed information
470** about errors. These [extended result codes] are enabled or disabled
471** on a per database connection basis using the
472** [sqlite3_extended_result_codes()] API. Or, the extended code for
473** the most recent error can be obtained using
474** [sqlite3_extended_errcode()].
475*/
476#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
477#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
478#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
479#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
480#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
481#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
482#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
483#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
484#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
485#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
486#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
487#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
488#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
489#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
490#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
491#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
492#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
493#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
494#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
495#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
496#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
497#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
498#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
499#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
500#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
501#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
502#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
503#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
504#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
505#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
506#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
507#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
508#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
509#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
510#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
511#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
512#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
513#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
514#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
515#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
516#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
517#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
518#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
519#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
520#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
521#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
522#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
523#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
524#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
525#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
526#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
527#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
528#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
529#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
530#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
531#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
532#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
533#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
534#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
535#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
536#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
537#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
538#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
539#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
540#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
541#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
542#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
543
544/*
545** CAPI3REF: Flags For File Open Operations
546**
547** These bit values are intended for use in the
548** 3rd parameter to the [sqlite3_open_v2()] interface and
549** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
550*/
551#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
552#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
553#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
554#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
555#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
556#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
557#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
558#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
559#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
560#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
561#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
562#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
563#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
564#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
565#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
566#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
567#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
568#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
569#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
570#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
571
572/* Reserved: 0x00F00000 */
573
574/*
575** CAPI3REF: Device Characteristics
576**
577** The xDeviceCharacteristics method of the [sqlite3_io_methods]
578** object returns an integer which is a vector of these
579** bit values expressing I/O characteristics of the mass storage
580** device that holds the file that the [sqlite3_io_methods]
581** refers to.
582**
583** The SQLITE_IOCAP_ATOMIC property means that all writes of
584** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
585** mean that writes of blocks that are nnn bytes in size and
586** are aligned to an address which is an integer multiple of
587** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
588** that when data is appended to a file, the data is appended
589** first then the size of the file is extended, never the other
590** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
591** information is written to disk in the same order as calls
592** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
593** after reboot following a crash or power loss, the only bytes in a
594** file that were written at the application level might have changed
595** and that adjacent bytes, even bytes within the same sector are
596** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
597** flag indicates that a file cannot be deleted when open. The
598** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
599** read-only media and cannot be changed even by processes with
600** elevated privileges.
601**
602** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
603** filesystem supports doing multiple write operations atomically when those
604** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
605** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
606*/
607#define SQLITE_IOCAP_ATOMIC 0x00000001
608#define SQLITE_IOCAP_ATOMIC512 0x00000002
609#define SQLITE_IOCAP_ATOMIC1K 0x00000004
610#define SQLITE_IOCAP_ATOMIC2K 0x00000008
611#define SQLITE_IOCAP_ATOMIC4K 0x00000010
612#define SQLITE_IOCAP_ATOMIC8K 0x00000020
613#define SQLITE_IOCAP_ATOMIC16K 0x00000040
614#define SQLITE_IOCAP_ATOMIC32K 0x00000080
615#define SQLITE_IOCAP_ATOMIC64K 0x00000100
616#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
617#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
618#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
619#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
620#define SQLITE_IOCAP_IMMUTABLE 0x00002000
621#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
622
623/*
624** CAPI3REF: File Locking Levels
625**
626** SQLite uses one of these integer values as the second
627** argument to calls it makes to the xLock() and xUnlock() methods
628** of an [sqlite3_io_methods] object.
629*/
630#define SQLITE_LOCK_NONE 0
631#define SQLITE_LOCK_SHARED 1
632#define SQLITE_LOCK_RESERVED 2
633#define SQLITE_LOCK_PENDING 3
634#define SQLITE_LOCK_EXCLUSIVE 4
635
636/*
637** CAPI3REF: Synchronization Type Flags
638**
639** When SQLite invokes the xSync() method of an
640** [sqlite3_io_methods] object it uses a combination of
641** these integer values as the second argument.
642**
643** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
644** sync operation only needs to flush data to mass storage. Inode
645** information need not be flushed. If the lower four bits of the flag
646** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
647** If the lower four bits equal SQLITE_SYNC_FULL, that means
648** to use Mac OS X style fullsync instead of fsync().
649**
650** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
651** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
652** settings. The [synchronous pragma] determines when calls to the
653** xSync VFS method occur and applies uniformly across all platforms.
654** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
655** energetic or rigorous or forceful the sync operations are and
656** only make a difference on Mac OSX for the default SQLite code.
657** (Third-party VFS implementations might also make the distinction
658** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
659** operating systems natively supported by SQLite, only Mac OSX
660** cares about the difference.)
661*/
662#define SQLITE_SYNC_NORMAL 0x00002
663#define SQLITE_SYNC_FULL 0x00003
664#define SQLITE_SYNC_DATAONLY 0x00010
665
666/*
667** CAPI3REF: OS Interface Open File Handle
668**
669** An [sqlite3_file] object represents an open file in the
670** [sqlite3_vfs | OS interface layer]. Individual OS interface
671** implementations will
672** want to subclass this object by appending additional fields
673** for their own use. The pMethods entry is a pointer to an
674** [sqlite3_io_methods] object that defines methods for performing
675** I/O operations on the open file.
676*/
677typedef struct sqlite3_file sqlite3_file;
678struct sqlite3_file {
679 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
680};
681
682/*
683** CAPI3REF: OS Interface File Virtual Methods Object
684**
685** Every file opened by the [sqlite3_vfs.xOpen] method populates an
686** [sqlite3_file] object (or, more commonly, a subclass of the
687** [sqlite3_file] object) with a pointer to an instance of this object.
688** This object defines the methods used to perform various operations
689** against the open file represented by the [sqlite3_file] object.
690**
691** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
692** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
693** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
694** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
695** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
696** to NULL.
697**
698** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
699** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
700** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
701** flag may be ORed in to indicate that only the data of the file
702** and not its inode needs to be synced.
703**
704** The integer values to xLock() and xUnlock() are one of
705** <ul>
706** <li> [SQLITE_LOCK_NONE],
707** <li> [SQLITE_LOCK_SHARED],
708** <li> [SQLITE_LOCK_RESERVED],
709** <li> [SQLITE_LOCK_PENDING], or
710** <li> [SQLITE_LOCK_EXCLUSIVE].
711** </ul>
712** xLock() increases the lock. xUnlock() decreases the lock.
713** The xCheckReservedLock() method checks whether any database connection,
714** either in this process or in some other process, is holding a RESERVED,
715** PENDING, or EXCLUSIVE lock on the file. It returns true
716** if such a lock exists and false otherwise.
717**
718** The xFileControl() method is a generic interface that allows custom
719** VFS implementations to directly control an open file using the
720** [sqlite3_file_control()] interface. The second "op" argument is an
721** integer opcode. The third argument is a generic pointer intended to
722** point to a structure that may contain arguments or space in which to
723** write return values. Potential uses for xFileControl() might be
724** functions to enable blocking locks with timeouts, to change the
725** locking strategy (for example to use dot-file locks), to inquire
726** about the status of a lock, or to break stale locks. The SQLite
727** core reserves all opcodes less than 100 for its own use.
728** A [file control opcodes | list of opcodes] less than 100 is available.
729** Applications that define a custom xFileControl method should use opcodes
730** greater than 100 to avoid conflicts. VFS implementations should
731** return [SQLITE_NOTFOUND] for file control opcodes that they do not
732** recognize.
733**
734** The xSectorSize() method returns the sector size of the
735** device that underlies the file. The sector size is the
736** minimum write that can be performed without disturbing
737** other bytes in the file. The xDeviceCharacteristics()
738** method returns a bit vector describing behaviors of the
739** underlying device:
740**
741** <ul>
742** <li> [SQLITE_IOCAP_ATOMIC]
743** <li> [SQLITE_IOCAP_ATOMIC512]
744** <li> [SQLITE_IOCAP_ATOMIC1K]
745** <li> [SQLITE_IOCAP_ATOMIC2K]
746** <li> [SQLITE_IOCAP_ATOMIC4K]
747** <li> [SQLITE_IOCAP_ATOMIC8K]
748** <li> [SQLITE_IOCAP_ATOMIC16K]
749** <li> [SQLITE_IOCAP_ATOMIC32K]
750** <li> [SQLITE_IOCAP_ATOMIC64K]
751** <li> [SQLITE_IOCAP_SAFE_APPEND]
752** <li> [SQLITE_IOCAP_SEQUENTIAL]
753** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
754** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
755** <li> [SQLITE_IOCAP_IMMUTABLE]
756** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
757** </ul>
758**
759** The SQLITE_IOCAP_ATOMIC property means that all writes of
760** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
761** mean that writes of blocks that are nnn bytes in size and
762** are aligned to an address which is an integer multiple of
763** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
764** that when data is appended to a file, the data is appended
765** first then the size of the file is extended, never the other
766** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
767** information is written to disk in the same order as calls
768** to xWrite().
769**
770** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
771** in the unread portions of the buffer with zeros. A VFS that
772** fails to zero-fill short reads might seem to work. However,
773** failure to zero-fill short reads will eventually lead to
774** database corruption.
775*/
776typedef struct sqlite3_io_methods sqlite3_io_methods;
777struct sqlite3_io_methods {
778 int iVersion;
779 int (*xClose)(sqlite3_file*);
780 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
781 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
782 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
783 int (*xSync)(sqlite3_file*, int flags);
784 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
785 int (*xLock)(sqlite3_file*, int);
786 int (*xUnlock)(sqlite3_file*, int);
787 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
788 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
789 int (*xSectorSize)(sqlite3_file*);
790 int (*xDeviceCharacteristics)(sqlite3_file*);
791 /* Methods above are valid for version 1 */
792 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
793 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
794 void (*xShmBarrier)(sqlite3_file*);
795 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
796 /* Methods above are valid for version 2 */
797 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
798 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
799 /* Methods above are valid for version 3 */
800 /* Additional methods may be added in future releases */
801};
802
803/*
804** CAPI3REF: Standard File Control Opcodes
805** KEYWORDS: {file control opcodes} {file control opcode}
806**
807** These integer constants are opcodes for the xFileControl method
808** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
809** interface.
810**
811** <ul>
812** <li>[[SQLITE_FCNTL_LOCKSTATE]]
813** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
814** opcode causes the xFileControl method to write the current state of
815** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
816** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
817** into an integer that the pArg argument points to. This capability
818** is used during testing and is only available when the SQLITE_TEST
819** compile-time option is used.
820**
821** <li>[[SQLITE_FCNTL_SIZE_HINT]]
822** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
823** layer a hint of how large the database file will grow to be during the
824** current transaction. This hint is not guaranteed to be accurate but it
825** is often close. The underlying VFS might choose to preallocate database
826** file space based on this hint in order to help writes to the database
827** file run faster.
828**
829** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
830** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
831** implements [sqlite3_deserialize()] to set an upper bound on the size
832** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
833** If the integer pointed to is negative, then it is filled in with the
834** current limit. Otherwise the limit is set to the larger of the value
835** of the integer pointed to and the current database size. The integer
836** pointed to is set to the new limit.
837**
838** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
839** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
840** extends and truncates the database file in chunks of a size specified
841** by the user. The fourth argument to [sqlite3_file_control()] should
842** point to an integer (type int) containing the new chunk-size to use
843** for the nominated database. Allocating database file space in large
844** chunks (say 1MB at a time), may reduce file-system fragmentation and
845** improve performance on some systems.
846**
847** <li>[[SQLITE_FCNTL_FILE_POINTER]]
848** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
849** to the [sqlite3_file] object associated with a particular database
850** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
851**
852** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
853** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
854** to the [sqlite3_file] object associated with the journal file (either
855** the [rollback journal] or the [write-ahead log]) for a particular database
856** connection. See also [SQLITE_FCNTL_FILE_POINTER].
857**
858** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
859** No longer in use.
860**
861** <li>[[SQLITE_FCNTL_SYNC]]
862** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
863** sent to the VFS immediately before the xSync method is invoked on a
864** database file descriptor. Or, if the xSync method is not invoked
865** because the user has configured SQLite with
866** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
867** of the xSync method. In most cases, the pointer argument passed with
868** this file-control is NULL. However, if the database file is being synced
869** as part of a multi-database commit, the argument points to a nul-terminated
870** string containing the transactions master-journal file name. VFSes that
871** do not need this signal should silently ignore this opcode. Applications
872** should not call [sqlite3_file_control()] with this opcode as doing so may
873** disrupt the operation of the specialized VFSes that do require it.
874**
875** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
876** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
877** and sent to the VFS after a transaction has been committed immediately
878** but before the database is unlocked. VFSes that do not need this signal
879** should silently ignore this opcode. Applications should not call
880** [sqlite3_file_control()] with this opcode as doing so may disrupt the
881** operation of the specialized VFSes that do require it.
882**
883** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
884** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
885** retry counts and intervals for certain disk I/O operations for the
886** windows [VFS] in order to provide robustness in the presence of
887** anti-virus programs. By default, the windows VFS will retry file read,
888** file write, and file delete operations up to 10 times, with a delay
889** of 25 milliseconds before the first retry and with the delay increasing
890** by an additional 25 milliseconds with each subsequent retry. This
891** opcode allows these two values (10 retries and 25 milliseconds of delay)
892** to be adjusted. The values are changed for all database connections
893** within the same process. The argument is a pointer to an array of two
894** integers where the first integer is the new retry count and the second
895** integer is the delay. If either integer is negative, then the setting
896** is not changed but instead the prior value of that setting is written
897** into the array entry, allowing the current retry settings to be
898** interrogated. The zDbName parameter is ignored.
899**
900** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
901** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
902** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
903** write ahead log ([WAL file]) and shared memory
904** files used for transaction control
905** are automatically deleted when the latest connection to the database
906** closes. Setting persistent WAL mode causes those files to persist after
907** close. Persisting the files is useful when other processes that do not
908** have write permission on the directory containing the database file want
909** to read the database file, as the WAL and shared memory files must exist
910** in order for the database to be readable. The fourth parameter to
911** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
912** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
913** WAL mode. If the integer is -1, then it is overwritten with the current
914** WAL persistence setting.
915**
916** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
917** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
918** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
919** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
920** xDeviceCharacteristics methods. The fourth parameter to
921** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
922** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
923** mode. If the integer is -1, then it is overwritten with the current
924** zero-damage mode setting.
925**
926** <li>[[SQLITE_FCNTL_OVERWRITE]]
927** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
928** a write transaction to indicate that, unless it is rolled back for some
929** reason, the entire database file will be overwritten by the current
930** transaction. This is used by VACUUM operations.
931**
932** <li>[[SQLITE_FCNTL_VFSNAME]]
933** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
934** all [VFSes] in the VFS stack. The names are of all VFS shims and the
935** final bottom-level VFS are written into memory obtained from
936** [sqlite3_malloc()] and the result is stored in the char* variable
937** that the fourth parameter of [sqlite3_file_control()] points to.
938** The caller is responsible for freeing the memory when done. As with
939** all file-control actions, there is no guarantee that this will actually
940** do anything. Callers should initialize the char* variable to a NULL
941** pointer in case this file-control is not implemented. This file-control
942** is intended for diagnostic use only.
943**
944** <li>[[SQLITE_FCNTL_VFS_POINTER]]
945** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
946** [VFSes] currently in use. ^(The argument X in
947** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
948** of type "[sqlite3_vfs] **". This opcodes will set *X
949** to a pointer to the top-level VFS.)^
950** ^When there are multiple VFS shims in the stack, this opcode finds the
951** upper-most shim only.
952**
953** <li>[[SQLITE_FCNTL_PRAGMA]]
954** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
955** file control is sent to the open [sqlite3_file] object corresponding
956** to the database file to which the pragma statement refers. ^The argument
957** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
958** pointers to strings (char**) in which the second element of the array
959** is the name of the pragma and the third element is the argument to the
960** pragma or NULL if the pragma has no argument. ^The handler for an
961** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
962** of the char** argument point to a string obtained from [sqlite3_mprintf()]
963** or the equivalent and that string will become the result of the pragma or
964** the error message if the pragma fails. ^If the
965** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
966** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
967** file control returns [SQLITE_OK], then the parser assumes that the
968** VFS has handled the PRAGMA itself and the parser generates a no-op
969** prepared statement if result string is NULL, or that returns a copy
970** of the result string if the string is non-NULL.
971** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
972** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
973** that the VFS encountered an error while handling the [PRAGMA] and the
974** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
975** file control occurs at the beginning of pragma statement analysis and so
976** it is able to override built-in [PRAGMA] statements.
977**
978** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
979** ^The [SQLITE_FCNTL_BUSYHANDLER]
980** file-control may be invoked by SQLite on the database file handle
981** shortly after it is opened in order to provide a custom VFS with access
982** to the connections busy-handler callback. The argument is of type (void **)
983** - an array of two (void *) values. The first (void *) actually points
984** to a function of type (int (*)(void *)). In order to invoke the connections
985** busy-handler, this function should be invoked with the second (void *) in
986** the array as the only argument. If it returns non-zero, then the operation
987** should be retried. If it returns zero, the custom VFS should abandon the
988** current operation.
989**
990** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
991** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
992** to have SQLite generate a
993** temporary filename using the same algorithm that is followed to generate
994** temporary filenames for TEMP tables and other internal uses. The
995** argument should be a char** which will be filled with the filename
996** written into memory obtained from [sqlite3_malloc()]. The caller should
997** invoke [sqlite3_free()] on the result to avoid a memory leak.
998**
999** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1000** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1001** maximum number of bytes that will be used for memory-mapped I/O.
1002** The argument is a pointer to a value of type sqlite3_int64 that
1003** is an advisory maximum number of bytes in the file to memory map. The
1004** pointer is overwritten with the old value. The limit is not changed if
1005** the value originally pointed to is negative, and so the current limit
1006** can be queried by passing in a pointer to a negative number. This
1007** file-control is used internally to implement [PRAGMA mmap_size].
1008**
1009** <li>[[SQLITE_FCNTL_TRACE]]
1010** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1011** to the VFS about what the higher layers of the SQLite stack are doing.
1012** This file control is used by some VFS activity tracing [shims].
1013** The argument is a zero-terminated string. Higher layers in the
1014** SQLite stack may generate instances of this file control if
1015** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1016**
1017** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1018** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1019** pointer to an integer and it writes a boolean into that integer depending
1020** on whether or not the file has been renamed, moved, or deleted since it
1021** was first opened.
1022**
1023** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1024** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1025** underlying native file handle associated with a file handle. This file
1026** control interprets its argument as a pointer to a native file handle and
1027** writes the resulting value there.
1028**
1029** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1030** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1031** opcode causes the xFileControl method to swap the file handle with the one
1032** pointed to by the pArg argument. This capability is used during testing
1033** and only needs to be supported when SQLITE_TEST is defined.
1034**
1035** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1036** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1037** be advantageous to block on the next WAL lock if the lock is not immediately
1038** available. The WAL subsystem issues this signal during rare
1039** circumstances in order to fix a problem with priority inversion.
1040** Applications should <em>not</em> use this file-control.
1041**
1042** <li>[[SQLITE_FCNTL_ZIPVFS]]
1043** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1044** VFS should return SQLITE_NOTFOUND for this opcode.
1045**
1046** <li>[[SQLITE_FCNTL_RBU]]
1047** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1048** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1049** this opcode.
1050**
1051** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1052** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1053** the file descriptor is placed in "batch write mode", which
1054** means all subsequent write operations will be deferred and done
1055** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1056** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1057** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1058** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1059** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1060** no VFS interface calls on the same [sqlite3_file] file descriptor
1061** except for calls to the xWrite method and the xFileControl method
1062** with [SQLITE_FCNTL_SIZE_HINT].
1063**
1064** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1065** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1066** operations since the previous successful call to
1067** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1068** This file control returns [SQLITE_OK] if and only if the writes were
1069** all performed successfully and have been committed to persistent storage.
1070** ^Regardless of whether or not it is successful, this file control takes
1071** the file descriptor out of batch write mode so that all subsequent
1072** write operations are independent.
1073** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1074** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1075**
1076** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1077** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1078** operations since the previous successful call to
1079** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1080** ^This file control takes the file descriptor out of batch write mode
1081** so that all subsequent write operations are independent.
1082** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1083** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1084**
1085** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1086** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
1087** a file lock using the xLock or xShmLock methods of the VFS to wait
1088** for up to M milliseconds before failing, where M is the single
1089** unsigned integer parameter.
1090**
1091** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1092** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1093** a database file. The argument is a pointer to a 32-bit unsigned integer.
1094** The "data version" for the pager is written into the pointer. The
1095** "data version" changes whenever any change occurs to the corresponding
1096** database file, either through SQL statements on the same database
1097** connection or through transactions committed by separate database
1098** connections possibly in other processes. The [sqlite3_total_changes()]
1099** interface can be used to find if any database on the connection has changed,
1100** but that interface responds to changes on TEMP as well as MAIN and does
1101** not provide a mechanism to detect changes to MAIN only. Also, the
1102** [sqlite3_total_changes()] interface responds to internal changes only and
1103** omits changes made by other database connections. The
1104** [PRAGMA data_version] command provide a mechanism to detect changes to
1105** a single attached database that occur due to other database connections,
1106** but omits changes implemented by the database connection on which it is
1107** called. This file control is the only mechanism to detect changes that
1108** happen either internally or externally and that are associated with
1109** a particular attached database.
1110** </ul>
1111*/
1112#define SQLITE_FCNTL_LOCKSTATE 1
1113#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1114#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1115#define SQLITE_FCNTL_LAST_ERRNO 4
1116#define SQLITE_FCNTL_SIZE_HINT 5
1117#define SQLITE_FCNTL_CHUNK_SIZE 6
1118#define SQLITE_FCNTL_FILE_POINTER 7
1119#define SQLITE_FCNTL_SYNC_OMITTED 8
1120#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1121#define SQLITE_FCNTL_PERSIST_WAL 10
1122#define SQLITE_FCNTL_OVERWRITE 11
1123#define SQLITE_FCNTL_VFSNAME 12
1124#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1125#define SQLITE_FCNTL_PRAGMA 14
1126#define SQLITE_FCNTL_BUSYHANDLER 15
1127#define SQLITE_FCNTL_TEMPFILENAME 16
1128#define SQLITE_FCNTL_MMAP_SIZE 18
1129#define SQLITE_FCNTL_TRACE 19
1130#define SQLITE_FCNTL_HAS_MOVED 20
1131#define SQLITE_FCNTL_SYNC 21
1132#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1133#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1134#define SQLITE_FCNTL_WAL_BLOCK 24
1135#define SQLITE_FCNTL_ZIPVFS 25
1136#define SQLITE_FCNTL_RBU 26
1137#define SQLITE_FCNTL_VFS_POINTER 27
1138#define SQLITE_FCNTL_JOURNAL_POINTER 28
1139#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1140#define SQLITE_FCNTL_PDB 30
1141#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1142#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1143#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1144#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1145#define SQLITE_FCNTL_DATA_VERSION 35
1146#define SQLITE_FCNTL_SIZE_LIMIT 36
1147
1148/* deprecated names */
1149#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1150#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1151#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1152
1153
1154/*
1155** CAPI3REF: Mutex Handle
1156**
1157** The mutex module within SQLite defines [sqlite3_mutex] to be an
1158** abstract type for a mutex object. The SQLite core never looks
1159** at the internal representation of an [sqlite3_mutex]. It only
1160** deals with pointers to the [sqlite3_mutex] object.
1161**
1162** Mutexes are created using [sqlite3_mutex_alloc()].
1163*/
1164typedef struct sqlite3_mutex sqlite3_mutex;
1165
1166/*
1167** CAPI3REF: Loadable Extension Thunk
1168**
1169** A pointer to the opaque sqlite3_api_routines structure is passed as
1170** the third parameter to entry points of [loadable extensions]. This
1171** structure must be typedefed in order to work around compiler warnings
1172** on some platforms.
1173*/
1174typedef struct sqlite3_api_routines sqlite3_api_routines;
1175
1176/*
1177** CAPI3REF: OS Interface Object
1178**
1179** An instance of the sqlite3_vfs object defines the interface between
1180** the SQLite core and the underlying operating system. The "vfs"
1181** in the name of the object stands for "virtual file system". See
1182** the [VFS | VFS documentation] for further information.
1183**
1184** The VFS interface is sometimes extended by adding new methods onto
1185** the end. Each time such an extension occurs, the iVersion field
1186** is incremented. The iVersion value started out as 1 in
1187** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1188** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1189** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1190** may be appended to the sqlite3_vfs object and the iVersion value
1191** may increase again in future versions of SQLite.
1192** Note that the structure
1193** of the sqlite3_vfs object changes in the transition from
1194** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1195** and yet the iVersion field was not modified.
1196**
1197** The szOsFile field is the size of the subclassed [sqlite3_file]
1198** structure used by this VFS. mxPathname is the maximum length of
1199** a pathname in this VFS.
1200**
1201** Registered sqlite3_vfs objects are kept on a linked list formed by
1202** the pNext pointer. The [sqlite3_vfs_register()]
1203** and [sqlite3_vfs_unregister()] interfaces manage this list
1204** in a thread-safe way. The [sqlite3_vfs_find()] interface
1205** searches the list. Neither the application code nor the VFS
1206** implementation should use the pNext pointer.
1207**
1208** The pNext field is the only field in the sqlite3_vfs
1209** structure that SQLite will ever modify. SQLite will only access
1210** or modify this field while holding a particular static mutex.
1211** The application should never modify anything within the sqlite3_vfs
1212** object once the object has been registered.
1213**
1214** The zName field holds the name of the VFS module. The name must
1215** be unique across all VFS modules.
1216**
1217** [[sqlite3_vfs.xOpen]]
1218** ^SQLite guarantees that the zFilename parameter to xOpen
1219** is either a NULL pointer or string obtained
1220** from xFullPathname() with an optional suffix added.
1221** ^If a suffix is added to the zFilename parameter, it will
1222** consist of a single "-" character followed by no more than
1223** 11 alphanumeric and/or "-" characters.
1224** ^SQLite further guarantees that
1225** the string will be valid and unchanged until xClose() is
1226** called. Because of the previous sentence,
1227** the [sqlite3_file] can safely store a pointer to the
1228** filename if it needs to remember the filename for some reason.
1229** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1230** must invent its own temporary name for the file. ^Whenever the
1231** xFilename parameter is NULL it will also be the case that the
1232** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1233**
1234** The flags argument to xOpen() includes all bits set in
1235** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1236** or [sqlite3_open16()] is used, then flags includes at least
1237** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1238** If xOpen() opens a file read-only then it sets *pOutFlags to
1239** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1240**
1241** ^(SQLite will also add one of the following flags to the xOpen()
1242** call, depending on the object being opened:
1243**
1244** <ul>
1245** <li> [SQLITE_OPEN_MAIN_DB]
1246** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1247** <li> [SQLITE_OPEN_TEMP_DB]
1248** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1249** <li> [SQLITE_OPEN_TRANSIENT_DB]
1250** <li> [SQLITE_OPEN_SUBJOURNAL]
1251** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1252** <li> [SQLITE_OPEN_WAL]
1253** </ul>)^
1254**
1255** The file I/O implementation can use the object type flags to
1256** change the way it deals with files. For example, an application
1257** that does not care about crash recovery or rollback might make
1258** the open of a journal file a no-op. Writes to this journal would
1259** also be no-ops, and any attempt to read the journal would return
1260** SQLITE_IOERR. Or the implementation might recognize that a database
1261** file will be doing page-aligned sector reads and writes in a random
1262** order and set up its I/O subsystem accordingly.
1263**
1264** SQLite might also add one of the following flags to the xOpen method:
1265**
1266** <ul>
1267** <li> [SQLITE_OPEN_DELETEONCLOSE]
1268** <li> [SQLITE_OPEN_EXCLUSIVE]
1269** </ul>
1270**
1271** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1272** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1273** will be set for TEMP databases and their journals, transient
1274** databases, and subjournals.
1275**
1276** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1277** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1278** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1279** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1280** SQLITE_OPEN_CREATE, is used to indicate that file should always
1281** be created, and that it is an error if it already exists.
1282** It is <i>not</i> used to indicate the file should be opened
1283** for exclusive access.
1284**
1285** ^At least szOsFile bytes of memory are allocated by SQLite
1286** to hold the [sqlite3_file] structure passed as the third
1287** argument to xOpen. The xOpen method does not have to
1288** allocate the structure; it should just fill it in. Note that
1289** the xOpen method must set the sqlite3_file.pMethods to either
1290** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1291** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1292** element will be valid after xOpen returns regardless of the success
1293** or failure of the xOpen call.
1294**
1295** [[sqlite3_vfs.xAccess]]
1296** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1297** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1298** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1299** to test whether a file is at least readable. The file can be a
1300** directory.
1301**
1302** ^SQLite will always allocate at least mxPathname+1 bytes for the
1303** output buffer xFullPathname. The exact size of the output buffer
1304** is also passed as a parameter to both methods. If the output buffer
1305** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1306** handled as a fatal error by SQLite, vfs implementations should endeavor
1307** to prevent this by setting mxPathname to a sufficiently large value.
1308**
1309** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1310** interfaces are not strictly a part of the filesystem, but they are
1311** included in the VFS structure for completeness.
1312** The xRandomness() function attempts to return nBytes bytes
1313** of good-quality randomness into zOut. The return value is
1314** the actual number of bytes of randomness obtained.
1315** The xSleep() method causes the calling thread to sleep for at
1316** least the number of microseconds given. ^The xCurrentTime()
1317** method returns a Julian Day Number for the current date and time as
1318** a floating point value.
1319** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1320** Day Number multiplied by 86400000 (the number of milliseconds in
1321** a 24-hour day).
1322** ^SQLite will use the xCurrentTimeInt64() method to get the current
1323** date and time if that method is available (if iVersion is 2 or
1324** greater and the function pointer is not NULL) and will fall back
1325** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1326**
1327** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1328** are not used by the SQLite core. These optional interfaces are provided
1329** by some VFSes to facilitate testing of the VFS code. By overriding
1330** system calls with functions under its control, a test program can
1331** simulate faults and error conditions that would otherwise be difficult
1332** or impossible to induce. The set of system calls that can be overridden
1333** varies from one VFS to another, and from one version of the same VFS to the
1334** next. Applications that use these interfaces must be prepared for any
1335** or all of these interfaces to be NULL or for their behavior to change
1336** from one release to the next. Applications must not attempt to access
1337** any of these methods if the iVersion of the VFS is less than 3.
1338*/
1339typedef struct sqlite3_vfs sqlite3_vfs;
1340typedef void (*sqlite3_syscall_ptr)(void);
1341struct sqlite3_vfs {
1342 int iVersion; /* Structure version number (currently 3) */
1343 int szOsFile; /* Size of subclassed sqlite3_file */
1344 int mxPathname; /* Maximum file pathname length */
1345 sqlite3_vfs *pNext; /* Next registered VFS */
1346 const char *zName; /* Name of this virtual file system */
1347 void *pAppData; /* Pointer to application-specific data */
1348 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1349 int flags, int *pOutFlags);
1350 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1351 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1352 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1353 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1354 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1355 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1356 void (*xDlClose)(sqlite3_vfs*, void*);
1357 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1358 int (*xSleep)(sqlite3_vfs*, int microseconds);
1359 int (*xCurrentTime)(sqlite3_vfs*, double*);
1360 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1361 /*
1362 ** The methods above are in version 1 of the sqlite_vfs object
1363 ** definition. Those that follow are added in version 2 or later
1364 */
1365 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1366 /*
1367 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1368 ** Those below are for version 3 and greater.
1369 */
1370 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1371 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1372 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1373 /*
1374 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1375 ** New fields may be appended in future versions. The iVersion
1376 ** value will increment whenever this happens.
1377 */
1378};
1379
1380/*
1381** CAPI3REF: Flags for the xAccess VFS method
1382**
1383** These integer constants can be used as the third parameter to
1384** the xAccess method of an [sqlite3_vfs] object. They determine
1385** what kind of permissions the xAccess method is looking for.
1386** With SQLITE_ACCESS_EXISTS, the xAccess method
1387** simply checks whether the file exists.
1388** With SQLITE_ACCESS_READWRITE, the xAccess method
1389** checks whether the named directory is both readable and writable
1390** (in other words, if files can be added, removed, and renamed within
1391** the directory).
1392** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1393** [temp_store_directory pragma], though this could change in a future
1394** release of SQLite.
1395** With SQLITE_ACCESS_READ, the xAccess method
1396** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1397** currently unused, though it might be used in a future release of
1398** SQLite.
1399*/
1400#define SQLITE_ACCESS_EXISTS 0
1401#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1402#define SQLITE_ACCESS_READ 2 /* Unused */
1403
1404/*
1405** CAPI3REF: Flags for the xShmLock VFS method
1406**
1407** These integer constants define the various locking operations
1408** allowed by the xShmLock method of [sqlite3_io_methods]. The
1409** following are the only legal combinations of flags to the
1410** xShmLock method:
1411**
1412** <ul>
1413** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1414** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1415** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1416** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1417** </ul>
1418**
1419** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1420** was given on the corresponding lock.
1421**
1422** The xShmLock method can transition between unlocked and SHARED or
1423** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1424** and EXCLUSIVE.
1425*/
1426#define SQLITE_SHM_UNLOCK 1
1427#define SQLITE_SHM_LOCK 2
1428#define SQLITE_SHM_SHARED 4
1429#define SQLITE_SHM_EXCLUSIVE 8
1430
1431/*
1432** CAPI3REF: Maximum xShmLock index
1433**
1434** The xShmLock method on [sqlite3_io_methods] may use values
1435** between 0 and this upper bound as its "offset" argument.
1436** The SQLite core will never attempt to acquire or release a
1437** lock outside of this range
1438*/
1439#define SQLITE_SHM_NLOCK 8
1440
1441
1442/*
1443** CAPI3REF: Initialize The SQLite Library
1444**
1445** ^The sqlite3_initialize() routine initializes the
1446** SQLite library. ^The sqlite3_shutdown() routine
1447** deallocates any resources that were allocated by sqlite3_initialize().
1448** These routines are designed to aid in process initialization and
1449** shutdown on embedded systems. Workstation applications using
1450** SQLite normally do not need to invoke either of these routines.
1451**
1452** A call to sqlite3_initialize() is an "effective" call if it is
1453** the first time sqlite3_initialize() is invoked during the lifetime of
1454** the process, or if it is the first time sqlite3_initialize() is invoked
1455** following a call to sqlite3_shutdown(). ^(Only an effective call
1456** of sqlite3_initialize() does any initialization. All other calls
1457** are harmless no-ops.)^
1458**
1459** A call to sqlite3_shutdown() is an "effective" call if it is the first
1460** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1461** an effective call to sqlite3_shutdown() does any deinitialization.
1462** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1463**
1464** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1465** is not. The sqlite3_shutdown() interface must only be called from a
1466** single thread. All open [database connections] must be closed and all
1467** other SQLite resources must be deallocated prior to invoking
1468** sqlite3_shutdown().
1469**
1470** Among other things, ^sqlite3_initialize() will invoke
1471** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1472** will invoke sqlite3_os_end().
1473**
1474** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1475** ^If for some reason, sqlite3_initialize() is unable to initialize
1476** the library (perhaps it is unable to allocate a needed resource such
1477** as a mutex) it returns an [error code] other than [SQLITE_OK].
1478**
1479** ^The sqlite3_initialize() routine is called internally by many other
1480** SQLite interfaces so that an application usually does not need to
1481** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1482** calls sqlite3_initialize() so the SQLite library will be automatically
1483** initialized when [sqlite3_open()] is called if it has not be initialized
1484** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1485** compile-time option, then the automatic calls to sqlite3_initialize()
1486** are omitted and the application must call sqlite3_initialize() directly
1487** prior to using any other SQLite interface. For maximum portability,
1488** it is recommended that applications always invoke sqlite3_initialize()
1489** directly prior to using any other SQLite interface. Future releases
1490** of SQLite may require this. In other words, the behavior exhibited
1491** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1492** default behavior in some future release of SQLite.
1493**
1494** The sqlite3_os_init() routine does operating-system specific
1495** initialization of the SQLite library. The sqlite3_os_end()
1496** routine undoes the effect of sqlite3_os_init(). Typical tasks
1497** performed by these routines include allocation or deallocation
1498** of static resources, initialization of global variables,
1499** setting up a default [sqlite3_vfs] module, or setting up
1500** a default configuration using [sqlite3_config()].
1501**
1502** The application should never invoke either sqlite3_os_init()
1503** or sqlite3_os_end() directly. The application should only invoke
1504** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1505** interface is called automatically by sqlite3_initialize() and
1506** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1507** implementations for sqlite3_os_init() and sqlite3_os_end()
1508** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1509** When [custom builds | built for other platforms]
1510** (using the [SQLITE_OS_OTHER=1] compile-time
1511** option) the application must supply a suitable implementation for
1512** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1513** implementation of sqlite3_os_init() or sqlite3_os_end()
1514** must return [SQLITE_OK] on success and some other [error code] upon
1515** failure.
1516*/
1517SQLITE_API int sqlite3_initialize(void);
1518SQLITE_API int sqlite3_shutdown(void);
1519SQLITE_API int sqlite3_os_init(void);
1520SQLITE_API int sqlite3_os_end(void);
1521
1522/*
1523** CAPI3REF: Configuring The SQLite Library
1524**
1525** The sqlite3_config() interface is used to make global configuration
1526** changes to SQLite in order to tune SQLite to the specific needs of
1527** the application. The default configuration is recommended for most
1528** applications and so this routine is usually not necessary. It is
1529** provided to support rare applications with unusual needs.
1530**
1531** <b>The sqlite3_config() interface is not threadsafe. The application
1532** must ensure that no other SQLite interfaces are invoked by other
1533** threads while sqlite3_config() is running.</b>
1534**
1535** The sqlite3_config() interface
1536** may only be invoked prior to library initialization using
1537** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1538** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1539** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1540** Note, however, that ^sqlite3_config() can be called as part of the
1541** implementation of an application-defined [sqlite3_os_init()].
1542**
1543** The first argument to sqlite3_config() is an integer
1544** [configuration option] that determines
1545** what property of SQLite is to be configured. Subsequent arguments
1546** vary depending on the [configuration option]
1547** in the first argument.
1548**
1549** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1550** ^If the option is unknown or SQLite is unable to set the option
1551** then this routine returns a non-zero [error code].
1552*/
1553SQLITE_API int sqlite3_config(int, ...);
1554
1555/*
1556** CAPI3REF: Configure database connections
1557** METHOD: sqlite3
1558**
1559** The sqlite3_db_config() interface is used to make configuration
1560** changes to a [database connection]. The interface is similar to
1561** [sqlite3_config()] except that the changes apply to a single
1562** [database connection] (specified in the first argument).
1563**
1564** The second argument to sqlite3_db_config(D,V,...) is the
1565** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1566** that indicates what aspect of the [database connection] is being configured.
1567** Subsequent arguments vary depending on the configuration verb.
1568**
1569** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1570** the call is considered successful.
1571*/
1572SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1573
1574/*
1575** CAPI3REF: Memory Allocation Routines
1576**
1577** An instance of this object defines the interface between SQLite
1578** and low-level memory allocation routines.
1579**
1580** This object is used in only one place in the SQLite interface.
1581** A pointer to an instance of this object is the argument to
1582** [sqlite3_config()] when the configuration option is
1583** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1584** By creating an instance of this object
1585** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1586** during configuration, an application can specify an alternative
1587** memory allocation subsystem for SQLite to use for all of its
1588** dynamic memory needs.
1589**
1590** Note that SQLite comes with several [built-in memory allocators]
1591** that are perfectly adequate for the overwhelming majority of applications
1592** and that this object is only useful to a tiny minority of applications
1593** with specialized memory allocation requirements. This object is
1594** also used during testing of SQLite in order to specify an alternative
1595** memory allocator that simulates memory out-of-memory conditions in
1596** order to verify that SQLite recovers gracefully from such
1597** conditions.
1598**
1599** The xMalloc, xRealloc, and xFree methods must work like the
1600** malloc(), realloc() and free() functions from the standard C library.
1601** ^SQLite guarantees that the second argument to
1602** xRealloc is always a value returned by a prior call to xRoundup.
1603**
1604** xSize should return the allocated size of a memory allocation
1605** previously obtained from xMalloc or xRealloc. The allocated size
1606** is always at least as big as the requested size but may be larger.
1607**
1608** The xRoundup method returns what would be the allocated size of
1609** a memory allocation given a particular requested size. Most memory
1610** allocators round up memory allocations at least to the next multiple
1611** of 8. Some allocators round up to a larger multiple or to a power of 2.
1612** Every memory allocation request coming in through [sqlite3_malloc()]
1613** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1614** that causes the corresponding memory allocation to fail.
1615**
1616** The xInit method initializes the memory allocator. For example,
1617** it might allocate any require mutexes or initialize internal data
1618** structures. The xShutdown method is invoked (indirectly) by
1619** [sqlite3_shutdown()] and should deallocate any resources acquired
1620** by xInit. The pAppData pointer is used as the only parameter to
1621** xInit and xShutdown.
1622**
1623** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1624** the xInit method, so the xInit method need not be threadsafe. The
1625** xShutdown method is only called from [sqlite3_shutdown()] so it does
1626** not need to be threadsafe either. For all other methods, SQLite
1627** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1628** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1629** it is by default) and so the methods are automatically serialized.
1630** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1631** methods must be threadsafe or else make their own arrangements for
1632** serialization.
1633**
1634** SQLite will never invoke xInit() more than once without an intervening
1635** call to xShutdown().
1636*/
1637typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1638struct sqlite3_mem_methods {
1639 void *(*xMalloc)(int); /* Memory allocation function */
1640 void (*xFree)(void*); /* Free a prior allocation */
1641 void *(*xRealloc)(void*,int); /* Resize an allocation */
1642 int (*xSize)(void*); /* Return the size of an allocation */
1643 int (*xRoundup)(int); /* Round up request size to allocation size */
1644 int (*xInit)(void*); /* Initialize the memory allocator */
1645 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1646 void *pAppData; /* Argument to xInit() and xShutdown() */
1647};
1648
1649/*
1650** CAPI3REF: Configuration Options
1651** KEYWORDS: {configuration option}
1652**
1653** These constants are the available integer configuration options that
1654** can be passed as the first argument to the [sqlite3_config()] interface.
1655**
1656** New configuration options may be added in future releases of SQLite.
1657** Existing configuration options might be discontinued. Applications
1658** should check the return code from [sqlite3_config()] to make sure that
1659** the call worked. The [sqlite3_config()] interface will return a
1660** non-zero [error code] if a discontinued or unsupported configuration option
1661** is invoked.
1662**
1663** <dl>
1664** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1665** <dd>There are no arguments to this option. ^This option sets the
1666** [threading mode] to Single-thread. In other words, it disables
1667** all mutexing and puts SQLite into a mode where it can only be used
1668** by a single thread. ^If SQLite is compiled with
1669** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1670** it is not possible to change the [threading mode] from its default
1671** value of Single-thread and so [sqlite3_config()] will return
1672** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1673** configuration option.</dd>
1674**
1675** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1676** <dd>There are no arguments to this option. ^This option sets the
1677** [threading mode] to Multi-thread. In other words, it disables
1678** mutexing on [database connection] and [prepared statement] objects.
1679** The application is responsible for serializing access to
1680** [database connections] and [prepared statements]. But other mutexes
1681** are enabled so that SQLite will be safe to use in a multi-threaded
1682** environment as long as no two threads attempt to use the same
1683** [database connection] at the same time. ^If SQLite is compiled with
1684** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1685** it is not possible to set the Multi-thread [threading mode] and
1686** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1687** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1688**
1689** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1690** <dd>There are no arguments to this option. ^This option sets the
1691** [threading mode] to Serialized. In other words, this option enables
1692** all mutexes including the recursive
1693** mutexes on [database connection] and [prepared statement] objects.
1694** In this mode (which is the default when SQLite is compiled with
1695** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1696** to [database connections] and [prepared statements] so that the
1697** application is free to use the same [database connection] or the
1698** same [prepared statement] in different threads at the same time.
1699** ^If SQLite is compiled with
1700** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1701** it is not possible to set the Serialized [threading mode] and
1702** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1703** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1704**
1705** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1706** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1707** a pointer to an instance of the [sqlite3_mem_methods] structure.
1708** The argument specifies
1709** alternative low-level memory allocation routines to be used in place of
1710** the memory allocation routines built into SQLite.)^ ^SQLite makes
1711** its own private copy of the content of the [sqlite3_mem_methods] structure
1712** before the [sqlite3_config()] call returns.</dd>
1713**
1714** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1715** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1716** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1717** The [sqlite3_mem_methods]
1718** structure is filled with the currently defined memory allocation routines.)^
1719** This option can be used to overload the default memory allocation
1720** routines with a wrapper that simulations memory allocation failure or
1721** tracks memory usage, for example. </dd>
1722**
1723** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1724** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1725** type int, interpreted as a boolean, which if true provides a hint to
1726** SQLite that it should avoid large memory allocations if possible.
1727** SQLite will run faster if it is free to make large memory allocations,
1728** but some application might prefer to run slower in exchange for
1729** guarantees about memory fragmentation that are possible if large
1730** allocations are avoided. This hint is normally off.
1731** </dd>
1732**
1733** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1734** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1735** interpreted as a boolean, which enables or disables the collection of
1736** memory allocation statistics. ^(When memory allocation statistics are
1737** disabled, the following SQLite interfaces become non-operational:
1738** <ul>
1739** <li> [sqlite3_memory_used()]
1740** <li> [sqlite3_memory_highwater()]
1741** <li> [sqlite3_soft_heap_limit64()]
1742** <li> [sqlite3_status64()]
1743** </ul>)^
1744** ^Memory allocation statistics are enabled by default unless SQLite is
1745** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1746** allocation statistics are disabled by default.
1747** </dd>
1748**
1749** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1750** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1751** </dd>
1752**
1753** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1754** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1755** that SQLite can use for the database page cache with the default page
1756** cache implementation.
1757** This configuration option is a no-op if an application-define page
1758** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1759** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1760** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1761** and the number of cache lines (N).
1762** The sz argument should be the size of the largest database page
1763** (a power of two between 512 and 65536) plus some extra bytes for each
1764** page header. ^The number of extra bytes needed by the page header
1765** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1766** ^It is harmless, apart from the wasted memory,
1767** for the sz parameter to be larger than necessary. The pMem
1768** argument must be either a NULL pointer or a pointer to an 8-byte
1769** aligned block of memory of at least sz*N bytes, otherwise
1770** subsequent behavior is undefined.
1771** ^When pMem is not NULL, SQLite will strive to use the memory provided
1772** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1773** a page cache line is larger than sz bytes or if all of the pMem buffer
1774** is exhausted.
1775** ^If pMem is NULL and N is non-zero, then each database connection
1776** does an initial bulk allocation for page cache memory
1777** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1778** of -1024*N bytes if N is negative, . ^If additional
1779** page cache memory is needed beyond what is provided by the initial
1780** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1781** additional cache line. </dd>
1782**
1783** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1784** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1785** that SQLite will use for all of its dynamic memory allocation needs
1786** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1787** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1788** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1789** [SQLITE_ERROR] if invoked otherwise.
1790** ^There are three arguments to SQLITE_CONFIG_HEAP:
1791** An 8-byte aligned pointer to the memory,
1792** the number of bytes in the memory buffer, and the minimum allocation size.
1793** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1794** to using its default memory allocator (the system malloc() implementation),
1795** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1796** memory pointer is not NULL then the alternative memory
1797** allocator is engaged to handle all of SQLites memory allocation needs.
1798** The first pointer (the memory pointer) must be aligned to an 8-byte
1799** boundary or subsequent behavior of SQLite will be undefined.
1800** The minimum allocation size is capped at 2**12. Reasonable values
1801** for the minimum allocation size are 2**5 through 2**8.</dd>
1802**
1803** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1804** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1805** pointer to an instance of the [sqlite3_mutex_methods] structure.
1806** The argument specifies alternative low-level mutex routines to be used
1807** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1808** the content of the [sqlite3_mutex_methods] structure before the call to
1809** [sqlite3_config()] returns. ^If SQLite is compiled with
1810** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1811** the entire mutexing subsystem is omitted from the build and hence calls to
1812** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1813** return [SQLITE_ERROR].</dd>
1814**
1815** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1816** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1817** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1818** [sqlite3_mutex_methods]
1819** structure is filled with the currently defined mutex routines.)^
1820** This option can be used to overload the default mutex allocation
1821** routines with a wrapper used to track mutex usage for performance
1822** profiling or testing, for example. ^If SQLite is compiled with
1823** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1824** the entire mutexing subsystem is omitted from the build and hence calls to
1825** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1826** return [SQLITE_ERROR].</dd>
1827**
1828** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1829** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1830** the default size of lookaside memory on each [database connection].
1831** The first argument is the
1832** size of each lookaside buffer slot and the second is the number of
1833** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1834** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1835** option to [sqlite3_db_config()] can be used to change the lookaside
1836** configuration on individual connections.)^ </dd>
1837**
1838** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1839** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1840** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1841** the interface to a custom page cache implementation.)^
1842** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1843**
1844** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1845** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1846** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1847** the current page cache implementation into that object.)^ </dd>
1848**
1849** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1850** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1851** global [error log].
1852** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1853** function with a call signature of void(*)(void*,int,const char*),
1854** and a pointer to void. ^If the function pointer is not NULL, it is
1855** invoked by [sqlite3_log()] to process each logging event. ^If the
1856** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1857** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1858** passed through as the first parameter to the application-defined logger
1859** function whenever that function is invoked. ^The second parameter to
1860** the logger function is a copy of the first parameter to the corresponding
1861** [sqlite3_log()] call and is intended to be a [result code] or an
1862** [extended result code]. ^The third parameter passed to the logger is
1863** log message after formatting via [sqlite3_snprintf()].
1864** The SQLite logging interface is not reentrant; the logger function
1865** supplied by the application must not invoke any SQLite interface.
1866** In a multi-threaded application, the application-defined logger
1867** function must be threadsafe. </dd>
1868**
1869** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1870** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1871** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1872** then URI handling is globally disabled.)^ ^If URI handling is globally
1873** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1874** [sqlite3_open16()] or
1875** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1876** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1877** connection is opened. ^If it is globally disabled, filenames are
1878** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1879** database connection is opened. ^(By default, URI handling is globally
1880** disabled. The default value may be changed by compiling with the
1881** [SQLITE_USE_URI] symbol defined.)^
1882**
1883** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1884** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1885** argument which is interpreted as a boolean in order to enable or disable
1886** the use of covering indices for full table scans in the query optimizer.
1887** ^The default setting is determined
1888** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1889** if that compile-time option is omitted.
1890** The ability to disable the use of covering indices for full table scans
1891** is because some incorrectly coded legacy applications might malfunction
1892** when the optimization is enabled. Providing the ability to
1893** disable the optimization allows the older, buggy application code to work
1894** without change even with newer versions of SQLite.
1895**
1896** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1897** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1898** <dd> These options are obsolete and should not be used by new code.
1899** They are retained for backwards compatibility but are now no-ops.
1900** </dd>
1901**
1902** [[SQLITE_CONFIG_SQLLOG]]
1903** <dt>SQLITE_CONFIG_SQLLOG
1904** <dd>This option is only available if sqlite is compiled with the
1905** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1906** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1907** The second should be of type (void*). The callback is invoked by the library
1908** in three separate circumstances, identified by the value passed as the
1909** fourth parameter. If the fourth parameter is 0, then the database connection
1910** passed as the second argument has just been opened. The third argument
1911** points to a buffer containing the name of the main database file. If the
1912** fourth parameter is 1, then the SQL statement that the third parameter
1913** points to has just been executed. Or, if the fourth parameter is 2, then
1914** the connection being passed as the second parameter is being closed. The
1915** third parameter is passed NULL In this case. An example of using this
1916** configuration option can be seen in the "test_sqllog.c" source file in
1917** the canonical SQLite source tree.</dd>
1918**
1919** [[SQLITE_CONFIG_MMAP_SIZE]]
1920** <dt>SQLITE_CONFIG_MMAP_SIZE
1921** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1922** that are the default mmap size limit (the default setting for
1923** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1924** ^The default setting can be overridden by each database connection using
1925** either the [PRAGMA mmap_size] command, or by using the
1926** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1927** will be silently truncated if necessary so that it does not exceed the
1928** compile-time maximum mmap size set by the
1929** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1930** ^If either argument to this option is negative, then that argument is
1931** changed to its compile-time default.
1932**
1933** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1934** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1935** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1936** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1937** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1938** that specifies the maximum size of the created heap.
1939**
1940** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1941** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1942** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1943** is a pointer to an integer and writes into that integer the number of extra
1944** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1945** The amount of extra space required can change depending on the compiler,
1946** target platform, and SQLite version.
1947**
1948** [[SQLITE_CONFIG_PMASZ]]
1949** <dt>SQLITE_CONFIG_PMASZ
1950** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1951** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1952** sorter to that integer. The default minimum PMA Size is set by the
1953** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1954** to help with sort operations when multithreaded sorting
1955** is enabled (using the [PRAGMA threads] command) and the amount of content
1956** to be sorted exceeds the page size times the minimum of the
1957** [PRAGMA cache_size] setting and this value.
1958**
1959** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1960** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1961** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1962** becomes the [statement journal] spill-to-disk threshold.
1963** [Statement journals] are held in memory until their size (in bytes)
1964** exceeds this threshold, at which point they are written to disk.
1965** Or if the threshold is -1, statement journals are always held
1966** exclusively in memory.
1967** Since many statement journals never become large, setting the spill
1968** threshold to a value such as 64KiB can greatly reduce the amount of
1969** I/O required to support statement rollback.
1970** The default value for this setting is controlled by the
1971** [SQLITE_STMTJRNL_SPILL] compile-time option.
1972**
1973** [[SQLITE_CONFIG_SORTERREF_SIZE]]
1974** <dt>SQLITE_CONFIG_SORTERREF_SIZE
1975** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
1976** of type (int) - the new value of the sorter-reference size threshold.
1977** Usually, when SQLite uses an external sort to order records according
1978** to an ORDER BY clause, all fields required by the caller are present in the
1979** sorted records. However, if SQLite determines based on the declared type
1980** of a table column that its values are likely to be very large - larger
1981** than the configured sorter-reference size threshold - then a reference
1982** is stored in each sorted record and the required column values loaded
1983** from the database as records are returned in sorted order. The default
1984** value for this option is to never use this optimization. Specifying a
1985** negative value for this option restores the default behaviour.
1986** This option is only available if SQLite is compiled with the
1987** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
1988**
1989** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
1990** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
1991** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
1992** [sqlite3_int64] parameter which is the default maximum size for an in-memory
1993** database created using [sqlite3_deserialize()]. This default maximum
1994** size can be adjusted up or down for individual databases using the
1995** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
1996** configuration setting is never used, then the default maximum is determined
1997** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
1998** compile-time option is not set, then the default maximum is 1073741824.
1999** </dl>
2000*/
2001#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2002#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2003#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2004#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2005#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2006#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2007#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2008#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2009#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2010#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2011#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2012/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2013#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2014#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2015#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2016#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2017#define SQLITE_CONFIG_URI 17 /* int */
2018#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2019#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2020#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2021#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2022#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2023#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2024#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2025#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2026#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2027#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2028#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2029#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2030
2031/*
2032** CAPI3REF: Database Connection Configuration Options
2033**
2034** These constants are the available integer configuration options that
2035** can be passed as the second argument to the [sqlite3_db_config()] interface.
2036**
2037** New configuration options may be added in future releases of SQLite.
2038** Existing configuration options might be discontinued. Applications
2039** should check the return code from [sqlite3_db_config()] to make sure that
2040** the call worked. ^The [sqlite3_db_config()] interface will return a
2041** non-zero [error code] if a discontinued or unsupported configuration option
2042** is invoked.
2043**
2044** <dl>
2045** [[SQLITE_DBCONFIG_LOOKASIDE]]
2046** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2047** <dd> ^This option takes three additional arguments that determine the
2048** [lookaside memory allocator] configuration for the [database connection].
2049** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2050** pointer to a memory buffer to use for lookaside memory.
2051** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2052** may be NULL in which case SQLite will allocate the
2053** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2054** size of each lookaside buffer slot. ^The third argument is the number of
2055** slots. The size of the buffer in the first argument must be greater than
2056** or equal to the product of the second and third arguments. The buffer
2057** must be aligned to an 8-byte boundary. ^If the second argument to
2058** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2059** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2060** configuration for a database connection can only be changed when that
2061** connection is not currently using lookaside memory, or in other words
2062** when the "current value" returned by
2063** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2064** Any attempt to change the lookaside memory configuration when lookaside
2065** memory is in use leaves the configuration unchanged and returns
2066** [SQLITE_BUSY].)^</dd>
2067**
2068** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2069** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2070** <dd> ^This option is used to enable or disable the enforcement of
2071** [foreign key constraints]. There should be two additional arguments.
2072** The first argument is an integer which is 0 to disable FK enforcement,
2073** positive to enable FK enforcement or negative to leave FK enforcement
2074** unchanged. The second parameter is a pointer to an integer into which
2075** is written 0 or 1 to indicate whether FK enforcement is off or on
2076** following this call. The second parameter may be a NULL pointer, in
2077** which case the FK enforcement setting is not reported back. </dd>
2078**
2079** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2080** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2081** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2082** There should be two additional arguments.
2083** The first argument is an integer which is 0 to disable triggers,
2084** positive to enable triggers or negative to leave the setting unchanged.
2085** The second parameter is a pointer to an integer into which
2086** is written 0 or 1 to indicate whether triggers are disabled or enabled
2087** following this call. The second parameter may be a NULL pointer, in
2088** which case the trigger setting is not reported back. </dd>
2089**
2090** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2091** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2092** <dd> ^This option is used to enable or disable the
2093** [fts3_tokenizer()] function which is part of the
2094** [FTS3] full-text search engine extension.
2095** There should be two additional arguments.
2096** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2097** positive to enable fts3_tokenizer() or negative to leave the setting
2098** unchanged.
2099** The second parameter is a pointer to an integer into which
2100** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2101** following this call. The second parameter may be a NULL pointer, in
2102** which case the new setting is not reported back. </dd>
2103**
2104** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2105** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2106** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2107** interface independently of the [load_extension()] SQL function.
2108** The [sqlite3_enable_load_extension()] API enables or disables both the
2109** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2110** There should be two additional arguments.
2111** When the first argument to this interface is 1, then only the C-API is
2112** enabled and the SQL function remains disabled. If the first argument to
2113** this interface is 0, then both the C-API and the SQL function are disabled.
2114** If the first argument is -1, then no changes are made to state of either the
2115** C-API or the SQL function.
2116** The second parameter is a pointer to an integer into which
2117** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2118** is disabled or enabled following this call. The second parameter may
2119** be a NULL pointer, in which case the new setting is not reported back.
2120** </dd>
2121**
2122** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2123** <dd> ^This option is used to change the name of the "main" database
2124** schema. ^The sole argument is a pointer to a constant UTF8 string
2125** which will become the new schema name in place of "main". ^SQLite
2126** does not make a copy of the new main schema name string, so the application
2127** must ensure that the argument passed into this DBCONFIG option is unchanged
2128** until after the database connection closes.
2129** </dd>
2130**
2131** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2132** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2133** <dd> Usually, when a database in wal mode is closed or detached from a
2134** database handle, SQLite checks if this will mean that there are now no
2135** connections at all to the database. If so, it performs a checkpoint
2136** operation before closing the connection. This option may be used to
2137** override this behaviour. The first parameter passed to this operation
2138** is an integer - positive to disable checkpoints-on-close, or zero (the
2139** default) to enable them, and negative to leave the setting unchanged.
2140** The second parameter is a pointer to an integer
2141** into which is written 0 or 1 to indicate whether checkpoints-on-close
2142** have been disabled - 0 if they are not disabled, 1 if they are.
2143** </dd>
2144**
2145** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2146** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2147** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2148** a single SQL query statement will always use the same algorithm regardless
2149** of values of [bound parameters].)^ The QPSG disables some query optimizations
2150** that look at the values of bound parameters, which can make some queries
2151** slower. But the QPSG has the advantage of more predictable behavior. With
2152** the QPSG active, SQLite will always use the same query plan in the field as
2153** was used during testing in the lab.
2154** The first argument to this setting is an integer which is 0 to disable
2155** the QPSG, positive to enable QPSG, or negative to leave the setting
2156** unchanged. The second parameter is a pointer to an integer into which
2157** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2158** following this call.
2159** </dd>
2160**
2161** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2162** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2163** include output for any operations performed by trigger programs. This
2164** option is used to set or clear (the default) a flag that governs this
2165** behavior. The first parameter passed to this operation is an integer -
2166** positive to enable output for trigger programs, or zero to disable it,
2167** or negative to leave the setting unchanged.
2168** The second parameter is a pointer to an integer into which is written
2169** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2170** it is not disabled, 1 if it is.
2171** </dd>
2172**
2173** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2174** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2175** [VACUUM] in order to reset a database back to an empty database
2176** with no schema and no content. The following process works even for
2177** a badly corrupted database file:
2178** <ol>
2179** <li> If the database connection is newly opened, make sure it has read the
2180** database schema by preparing then discarding some query against the
2181** database, or calling sqlite3_table_column_metadata(), ignoring any
2182** errors. This step is only necessary if the application desires to keep
2183** the database in WAL mode after the reset if it was in WAL mode before
2184** the reset.
2185** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2186** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2187** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2188** </ol>
2189** Because resetting a database is destructive and irreversible, the
2190** process requires the use of this obscure API and multiple steps to help
2191** ensure that it does not happen by accident.
2192**
2193** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2194** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2195** "defensive" flag for a database connection. When the defensive
2196** flag is enabled, language features that allow ordinary SQL to
2197** deliberately corrupt the database file are disabled. The disabled
2198** features include but are not limited to the following:
2199** <ul>
2200** <li> The [PRAGMA writable_schema=ON] statement.
2201** <li> Writes to the [sqlite_dbpage] virtual table.
2202** <li> Direct writes to [shadow tables].
2203** </ul>
2204** </dd>
2205**
2206** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2207** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2208** "writable_schema" flag. This has the same effect and is logically equivalent
2209** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2210** The first argument to this setting is an integer which is 0 to disable
2211** the writable_schema, positive to enable writable_schema, or negative to
2212** leave the setting unchanged. The second parameter is a pointer to an
2213** integer into which is written 0 or 1 to indicate whether the writable_schema
2214** is enabled or disabled following this call.
2215** </dd>
2216** </dl>
2217*/
2218#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2219#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2220#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2221#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2222#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2223#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2224#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2225#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2226#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2227#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2228#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2229#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2230#define SQLITE_DBCONFIG_MAX 1011 /* Largest DBCONFIG */
2231
2232/*
2233** CAPI3REF: Enable Or Disable Extended Result Codes
2234** METHOD: sqlite3
2235**
2236** ^The sqlite3_extended_result_codes() routine enables or disables the
2237** [extended result codes] feature of SQLite. ^The extended result
2238** codes are disabled by default for historical compatibility.
2239*/
2240SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2241
2242/*
2243** CAPI3REF: Last Insert Rowid
2244** METHOD: sqlite3
2245**
2246** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2247** has a unique 64-bit signed
2248** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2249** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2250** names are not also used by explicitly declared columns. ^If
2251** the table has a column of type [INTEGER PRIMARY KEY] then that column
2252** is another alias for the rowid.
2253**
2254** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2255** the most recent successful [INSERT] into a rowid table or [virtual table]
2256** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2257** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2258** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2259** zero.
2260**
2261** As well as being set automatically as rows are inserted into database
2262** tables, the value returned by this function may be set explicitly by
2263** [sqlite3_set_last_insert_rowid()]
2264**
2265** Some virtual table implementations may INSERT rows into rowid tables as
2266** part of committing a transaction (e.g. to flush data accumulated in memory
2267** to disk). In this case subsequent calls to this function return the rowid
2268** associated with these internal INSERT operations, which leads to
2269** unintuitive results. Virtual table implementations that do write to rowid
2270** tables in this way can avoid this problem by restoring the original
2271** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2272** control to the user.
2273**
2274** ^(If an [INSERT] occurs within a trigger then this routine will
2275** return the [rowid] of the inserted row as long as the trigger is
2276** running. Once the trigger program ends, the value returned
2277** by this routine reverts to what it was before the trigger was fired.)^
2278**
2279** ^An [INSERT] that fails due to a constraint violation is not a
2280** successful [INSERT] and does not change the value returned by this
2281** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2282** and INSERT OR ABORT make no changes to the return value of this
2283** routine when their insertion fails. ^(When INSERT OR REPLACE
2284** encounters a constraint violation, it does not fail. The
2285** INSERT continues to completion after deleting rows that caused
2286** the constraint problem so INSERT OR REPLACE will always change
2287** the return value of this interface.)^
2288**
2289** ^For the purposes of this routine, an [INSERT] is considered to
2290** be successful even if it is subsequently rolled back.
2291**
2292** This function is accessible to SQL statements via the
2293** [last_insert_rowid() SQL function].
2294**
2295** If a separate thread performs a new [INSERT] on the same
2296** database connection while the [sqlite3_last_insert_rowid()]
2297** function is running and thus changes the last insert [rowid],
2298** then the value returned by [sqlite3_last_insert_rowid()] is
2299** unpredictable and might not equal either the old or the new
2300** last insert [rowid].
2301*/
2302SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2303
2304/*
2305** CAPI3REF: Set the Last Insert Rowid value.
2306** METHOD: sqlite3
2307**
2308** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2309** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2310** without inserting a row into the database.
2311*/
2312SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2313
2314/*
2315** CAPI3REF: Count The Number Of Rows Modified
2316** METHOD: sqlite3
2317**
2318** ^This function returns the number of rows modified, inserted or
2319** deleted by the most recently completed INSERT, UPDATE or DELETE
2320** statement on the database connection specified by the only parameter.
2321** ^Executing any other type of SQL statement does not modify the value
2322** returned by this function.
2323**
2324** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2325** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2326** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2327**
2328** Changes to a view that are intercepted by
2329** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2330** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2331** DELETE statement run on a view is always zero. Only changes made to real
2332** tables are counted.
2333**
2334** Things are more complicated if the sqlite3_changes() function is
2335** executed while a trigger program is running. This may happen if the
2336** program uses the [changes() SQL function], or if some other callback
2337** function invokes sqlite3_changes() directly. Essentially:
2338**
2339** <ul>
2340** <li> ^(Before entering a trigger program the value returned by
2341** sqlite3_changes() function is saved. After the trigger program
2342** has finished, the original value is restored.)^
2343**
2344** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2345** statement sets the value returned by sqlite3_changes()
2346** upon completion as normal. Of course, this value will not include
2347** any changes performed by sub-triggers, as the sqlite3_changes()
2348** value will be saved and restored after each sub-trigger has run.)^
2349** </ul>
2350**
2351** ^This means that if the changes() SQL function (or similar) is used
2352** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2353** returns the value as set when the calling statement began executing.
2354** ^If it is used by the second or subsequent such statement within a trigger
2355** program, the value returned reflects the number of rows modified by the
2356** previous INSERT, UPDATE or DELETE statement within the same trigger.
2357**
2358** If a separate thread makes changes on the same database connection
2359** while [sqlite3_changes()] is running then the value returned
2360** is unpredictable and not meaningful.
2361**
2362** See also:
2363** <ul>
2364** <li> the [sqlite3_total_changes()] interface
2365** <li> the [count_changes pragma]
2366** <li> the [changes() SQL function]
2367** <li> the [data_version pragma]
2368** </ul>
2369*/
2370SQLITE_API int sqlite3_changes(sqlite3*);
2371
2372/*
2373** CAPI3REF: Total Number Of Rows Modified
2374** METHOD: sqlite3
2375**
2376** ^This function returns the total number of rows inserted, modified or
2377** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2378** since the database connection was opened, including those executed as
2379** part of trigger programs. ^Executing any other type of SQL statement
2380** does not affect the value returned by sqlite3_total_changes().
2381**
2382** ^Changes made as part of [foreign key actions] are included in the
2383** count, but those made as part of REPLACE constraint resolution are
2384** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2385** are not counted.
2386**
2387** The [sqlite3_total_changes(D)] interface only reports the number
2388** of rows that changed due to SQL statement run against database
2389** connection D. Any changes by other database connections are ignored.
2390** To detect changes against a database file from other database
2391** connections use the [PRAGMA data_version] command or the
2392** [SQLITE_FCNTL_DATA_VERSION] [file control].
2393**
2394** If a separate thread makes changes on the same database connection
2395** while [sqlite3_total_changes()] is running then the value
2396** returned is unpredictable and not meaningful.
2397**
2398** See also:
2399** <ul>
2400** <li> the [sqlite3_changes()] interface
2401** <li> the [count_changes pragma]
2402** <li> the [changes() SQL function]
2403** <li> the [data_version pragma]
2404** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2405** </ul>
2406*/
2407SQLITE_API int sqlite3_total_changes(sqlite3*);
2408
2409/*
2410** CAPI3REF: Interrupt A Long-Running Query
2411** METHOD: sqlite3
2412**
2413** ^This function causes any pending database operation to abort and
2414** return at its earliest opportunity. This routine is typically
2415** called in response to a user action such as pressing "Cancel"
2416** or Ctrl-C where the user wants a long query operation to halt
2417** immediately.
2418**
2419** ^It is safe to call this routine from a thread different from the
2420** thread that is currently running the database operation. But it
2421** is not safe to call this routine with a [database connection] that
2422** is closed or might close before sqlite3_interrupt() returns.
2423**
2424** ^If an SQL operation is very nearly finished at the time when
2425** sqlite3_interrupt() is called, then it might not have an opportunity
2426** to be interrupted and might continue to completion.
2427**
2428** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2429** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2430** that is inside an explicit transaction, then the entire transaction
2431** will be rolled back automatically.
2432**
2433** ^The sqlite3_interrupt(D) call is in effect until all currently running
2434** SQL statements on [database connection] D complete. ^Any new SQL statements
2435** that are started after the sqlite3_interrupt() call and before the
2436** running statements reaches zero are interrupted as if they had been
2437** running prior to the sqlite3_interrupt() call. ^New SQL statements
2438** that are started after the running statement count reaches zero are
2439** not effected by the sqlite3_interrupt().
2440** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2441** SQL statements is a no-op and has no effect on SQL statements
2442** that are started after the sqlite3_interrupt() call returns.
2443*/
2444SQLITE_API void sqlite3_interrupt(sqlite3*);
2445
2446/*
2447** CAPI3REF: Determine If An SQL Statement Is Complete
2448**
2449** These routines are useful during command-line input to determine if the
2450** currently entered text seems to form a complete SQL statement or
2451** if additional input is needed before sending the text into
2452** SQLite for parsing. ^These routines return 1 if the input string
2453** appears to be a complete SQL statement. ^A statement is judged to be
2454** complete if it ends with a semicolon token and is not a prefix of a
2455** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2456** string literals or quoted identifier names or comments are not
2457** independent tokens (they are part of the token in which they are
2458** embedded) and thus do not count as a statement terminator. ^Whitespace
2459** and comments that follow the final semicolon are ignored.
2460**
2461** ^These routines return 0 if the statement is incomplete. ^If a
2462** memory allocation fails, then SQLITE_NOMEM is returned.
2463**
2464** ^These routines do not parse the SQL statements thus
2465** will not detect syntactically incorrect SQL.
2466**
2467** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2468** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2469** automatically by sqlite3_complete16(). If that initialization fails,
2470** then the return value from sqlite3_complete16() will be non-zero
2471** regardless of whether or not the input SQL is complete.)^
2472**
2473** The input to [sqlite3_complete()] must be a zero-terminated
2474** UTF-8 string.
2475**
2476** The input to [sqlite3_complete16()] must be a zero-terminated
2477** UTF-16 string in native byte order.
2478*/
2479SQLITE_API int sqlite3_complete(const char *sql);
2480SQLITE_API int sqlite3_complete16(const void *sql);
2481
2482/*
2483** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2484** KEYWORDS: {busy-handler callback} {busy handler}
2485** METHOD: sqlite3
2486**
2487** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2488** that might be invoked with argument P whenever
2489** an attempt is made to access a database table associated with
2490** [database connection] D when another thread
2491** or process has the table locked.
2492** The sqlite3_busy_handler() interface is used to implement
2493** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2494**
2495** ^If the busy callback is NULL, then [SQLITE_BUSY]
2496** is returned immediately upon encountering the lock. ^If the busy callback
2497** is not NULL, then the callback might be invoked with two arguments.
2498**
2499** ^The first argument to the busy handler is a copy of the void* pointer which
2500** is the third argument to sqlite3_busy_handler(). ^The second argument to
2501** the busy handler callback is the number of times that the busy handler has
2502** been invoked previously for the same locking event. ^If the
2503** busy callback returns 0, then no additional attempts are made to
2504** access the database and [SQLITE_BUSY] is returned
2505** to the application.
2506** ^If the callback returns non-zero, then another attempt
2507** is made to access the database and the cycle repeats.
2508**
2509** The presence of a busy handler does not guarantee that it will be invoked
2510** when there is lock contention. ^If SQLite determines that invoking the busy
2511** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2512** to the application instead of invoking the
2513** busy handler.
2514** Consider a scenario where one process is holding a read lock that
2515** it is trying to promote to a reserved lock and
2516** a second process is holding a reserved lock that it is trying
2517** to promote to an exclusive lock. The first process cannot proceed
2518** because it is blocked by the second and the second process cannot
2519** proceed because it is blocked by the first. If both processes
2520** invoke the busy handlers, neither will make any progress. Therefore,
2521** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2522** will induce the first process to release its read lock and allow
2523** the second process to proceed.
2524**
2525** ^The default busy callback is NULL.
2526**
2527** ^(There can only be a single busy handler defined for each
2528** [database connection]. Setting a new busy handler clears any
2529** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2530** or evaluating [PRAGMA busy_timeout=N] will change the
2531** busy handler and thus clear any previously set busy handler.
2532**
2533** The busy callback should not take any actions which modify the
2534** database connection that invoked the busy handler. In other words,
2535** the busy handler is not reentrant. Any such actions
2536** result in undefined behavior.
2537**
2538** A busy handler must not close the database connection
2539** or [prepared statement] that invoked the busy handler.
2540*/
2541SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2542
2543/*
2544** CAPI3REF: Set A Busy Timeout
2545** METHOD: sqlite3
2546**
2547** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2548** for a specified amount of time when a table is locked. ^The handler
2549** will sleep multiple times until at least "ms" milliseconds of sleeping
2550** have accumulated. ^After at least "ms" milliseconds of sleeping,
2551** the handler returns 0 which causes [sqlite3_step()] to return
2552** [SQLITE_BUSY].
2553**
2554** ^Calling this routine with an argument less than or equal to zero
2555** turns off all busy handlers.
2556**
2557** ^(There can only be a single busy handler for a particular
2558** [database connection] at any given moment. If another busy handler
2559** was defined (using [sqlite3_busy_handler()]) prior to calling
2560** this routine, that other busy handler is cleared.)^
2561**
2562** See also: [PRAGMA busy_timeout]
2563*/
2564SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2565
2566/*
2567** CAPI3REF: Convenience Routines For Running Queries
2568** METHOD: sqlite3
2569**
2570** This is a legacy interface that is preserved for backwards compatibility.
2571** Use of this interface is not recommended.
2572**
2573** Definition: A <b>result table</b> is memory data structure created by the
2574** [sqlite3_get_table()] interface. A result table records the
2575** complete query results from one or more queries.
2576**
2577** The table conceptually has a number of rows and columns. But
2578** these numbers are not part of the result table itself. These
2579** numbers are obtained separately. Let N be the number of rows
2580** and M be the number of columns.
2581**
2582** A result table is an array of pointers to zero-terminated UTF-8 strings.
2583** There are (N+1)*M elements in the array. The first M pointers point
2584** to zero-terminated strings that contain the names of the columns.
2585** The remaining entries all point to query results. NULL values result
2586** in NULL pointers. All other values are in their UTF-8 zero-terminated
2587** string representation as returned by [sqlite3_column_text()].
2588**
2589** A result table might consist of one or more memory allocations.
2590** It is not safe to pass a result table directly to [sqlite3_free()].
2591** A result table should be deallocated using [sqlite3_free_table()].
2592**
2593** ^(As an example of the result table format, suppose a query result
2594** is as follows:
2595**
2596** <blockquote><pre>
2597** Name | Age
2598** -----------------------
2599** Alice | 43
2600** Bob | 28
2601** Cindy | 21
2602** </pre></blockquote>
2603**
2604** There are two column (M==2) and three rows (N==3). Thus the
2605** result table has 8 entries. Suppose the result table is stored
2606** in an array names azResult. Then azResult holds this content:
2607**
2608** <blockquote><pre>
2609** azResult&#91;0] = "Name";
2610** azResult&#91;1] = "Age";
2611** azResult&#91;2] = "Alice";
2612** azResult&#91;3] = "43";
2613** azResult&#91;4] = "Bob";
2614** azResult&#91;5] = "28";
2615** azResult&#91;6] = "Cindy";
2616** azResult&#91;7] = "21";
2617** </pre></blockquote>)^
2618**
2619** ^The sqlite3_get_table() function evaluates one or more
2620** semicolon-separated SQL statements in the zero-terminated UTF-8
2621** string of its 2nd parameter and returns a result table to the
2622** pointer given in its 3rd parameter.
2623**
2624** After the application has finished with the result from sqlite3_get_table(),
2625** it must pass the result table pointer to sqlite3_free_table() in order to
2626** release the memory that was malloced. Because of the way the
2627** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2628** function must not try to call [sqlite3_free()] directly. Only
2629** [sqlite3_free_table()] is able to release the memory properly and safely.
2630**
2631** The sqlite3_get_table() interface is implemented as a wrapper around
2632** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2633** to any internal data structures of SQLite. It uses only the public
2634** interface defined here. As a consequence, errors that occur in the
2635** wrapper layer outside of the internal [sqlite3_exec()] call are not
2636** reflected in subsequent calls to [sqlite3_errcode()] or
2637** [sqlite3_errmsg()].
2638*/
2639SQLITE_API int sqlite3_get_table(
2640 sqlite3 *db, /* An open database */
2641 const char *zSql, /* SQL to be evaluated */
2642 char ***pazResult, /* Results of the query */
2643 int *pnRow, /* Number of result rows written here */
2644 int *pnColumn, /* Number of result columns written here */
2645 char **pzErrmsg /* Error msg written here */
2646);
2647SQLITE_API void sqlite3_free_table(char **result);
2648
2649/*
2650** CAPI3REF: Formatted String Printing Functions
2651**
2652** These routines are work-alikes of the "printf()" family of functions
2653** from the standard C library.
2654** These routines understand most of the common formatting options from
2655** the standard library printf()
2656** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2657** See the [built-in printf()] documentation for details.
2658**
2659** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2660** results into memory obtained from [sqlite3_malloc64()].
2661** The strings returned by these two routines should be
2662** released by [sqlite3_free()]. ^Both routines return a
2663** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2664** memory to hold the resulting string.
2665**
2666** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2667** the standard C library. The result is written into the
2668** buffer supplied as the second parameter whose size is given by
2669** the first parameter. Note that the order of the
2670** first two parameters is reversed from snprintf().)^ This is an
2671** historical accident that cannot be fixed without breaking
2672** backwards compatibility. ^(Note also that sqlite3_snprintf()
2673** returns a pointer to its buffer instead of the number of
2674** characters actually written into the buffer.)^ We admit that
2675** the number of characters written would be a more useful return
2676** value but we cannot change the implementation of sqlite3_snprintf()
2677** now without breaking compatibility.
2678**
2679** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2680** guarantees that the buffer is always zero-terminated. ^The first
2681** parameter "n" is the total size of the buffer, including space for
2682** the zero terminator. So the longest string that can be completely
2683** written will be n-1 characters.
2684**
2685** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2686**
2687** See also: [built-in printf()], [printf() SQL function]
2688*/
2689SQLITE_API char *sqlite3_mprintf(const char*,...);
2690SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2691SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2692SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2693
2694/*
2695** CAPI3REF: Memory Allocation Subsystem
2696**
2697** The SQLite core uses these three routines for all of its own
2698** internal memory allocation needs. "Core" in the previous sentence
2699** does not include operating-system specific VFS implementation. The
2700** Windows VFS uses native malloc() and free() for some operations.
2701**
2702** ^The sqlite3_malloc() routine returns a pointer to a block
2703** of memory at least N bytes in length, where N is the parameter.
2704** ^If sqlite3_malloc() is unable to obtain sufficient free
2705** memory, it returns a NULL pointer. ^If the parameter N to
2706** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2707** a NULL pointer.
2708**
2709** ^The sqlite3_malloc64(N) routine works just like
2710** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2711** of a signed 32-bit integer.
2712**
2713** ^Calling sqlite3_free() with a pointer previously returned
2714** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2715** that it might be reused. ^The sqlite3_free() routine is
2716** a no-op if is called with a NULL pointer. Passing a NULL pointer
2717** to sqlite3_free() is harmless. After being freed, memory
2718** should neither be read nor written. Even reading previously freed
2719** memory might result in a segmentation fault or other severe error.
2720** Memory corruption, a segmentation fault, or other severe error
2721** might result if sqlite3_free() is called with a non-NULL pointer that
2722** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2723**
2724** ^The sqlite3_realloc(X,N) interface attempts to resize a
2725** prior memory allocation X to be at least N bytes.
2726** ^If the X parameter to sqlite3_realloc(X,N)
2727** is a NULL pointer then its behavior is identical to calling
2728** sqlite3_malloc(N).
2729** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2730** negative then the behavior is exactly the same as calling
2731** sqlite3_free(X).
2732** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2733** of at least N bytes in size or NULL if insufficient memory is available.
2734** ^If M is the size of the prior allocation, then min(N,M) bytes
2735** of the prior allocation are copied into the beginning of buffer returned
2736** by sqlite3_realloc(X,N) and the prior allocation is freed.
2737** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2738** prior allocation is not freed.
2739**
2740** ^The sqlite3_realloc64(X,N) interfaces works the same as
2741** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2742** of a 32-bit signed integer.
2743**
2744** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2745** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2746** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2747** ^The value returned by sqlite3_msize(X) might be larger than the number
2748** of bytes requested when X was allocated. ^If X is a NULL pointer then
2749** sqlite3_msize(X) returns zero. If X points to something that is not
2750** the beginning of memory allocation, or if it points to a formerly
2751** valid memory allocation that has now been freed, then the behavior
2752** of sqlite3_msize(X) is undefined and possibly harmful.
2753**
2754** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2755** sqlite3_malloc64(), and sqlite3_realloc64()
2756** is always aligned to at least an 8 byte boundary, or to a
2757** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2758** option is used.
2759**
2760** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2761** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2762** implementation of these routines to be omitted. That capability
2763** is no longer provided. Only built-in memory allocators can be used.
2764**
2765** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2766** the system malloc() and free() directly when converting
2767** filenames between the UTF-8 encoding used by SQLite
2768** and whatever filename encoding is used by the particular Windows
2769** installation. Memory allocation errors were detected, but
2770** they were reported back as [SQLITE_CANTOPEN] or
2771** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2772**
2773** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2774** must be either NULL or else pointers obtained from a prior
2775** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2776** not yet been released.
2777**
2778** The application must not read or write any part of
2779** a block of memory after it has been released using
2780** [sqlite3_free()] or [sqlite3_realloc()].
2781*/
2782SQLITE_API void *sqlite3_malloc(int);
2783SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2784SQLITE_API void *sqlite3_realloc(void*, int);
2785SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2786SQLITE_API void sqlite3_free(void*);
2787SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2788
2789/*
2790** CAPI3REF: Memory Allocator Statistics
2791**
2792** SQLite provides these two interfaces for reporting on the status
2793** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2794** routines, which form the built-in memory allocation subsystem.
2795**
2796** ^The [sqlite3_memory_used()] routine returns the number of bytes
2797** of memory currently outstanding (malloced but not freed).
2798** ^The [sqlite3_memory_highwater()] routine returns the maximum
2799** value of [sqlite3_memory_used()] since the high-water mark
2800** was last reset. ^The values returned by [sqlite3_memory_used()] and
2801** [sqlite3_memory_highwater()] include any overhead
2802** added by SQLite in its implementation of [sqlite3_malloc()],
2803** but not overhead added by the any underlying system library
2804** routines that [sqlite3_malloc()] may call.
2805**
2806** ^The memory high-water mark is reset to the current value of
2807** [sqlite3_memory_used()] if and only if the parameter to
2808** [sqlite3_memory_highwater()] is true. ^The value returned
2809** by [sqlite3_memory_highwater(1)] is the high-water mark
2810** prior to the reset.
2811*/
2812SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2813SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2814
2815/*
2816** CAPI3REF: Pseudo-Random Number Generator
2817**
2818** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2819** select random [ROWID | ROWIDs] when inserting new records into a table that
2820** already uses the largest possible [ROWID]. The PRNG is also used for
2821** the build-in random() and randomblob() SQL functions. This interface allows
2822** applications to access the same PRNG for other purposes.
2823**
2824** ^A call to this routine stores N bytes of randomness into buffer P.
2825** ^The P parameter can be a NULL pointer.
2826**
2827** ^If this routine has not been previously called or if the previous
2828** call had N less than one or a NULL pointer for P, then the PRNG is
2829** seeded using randomness obtained from the xRandomness method of
2830** the default [sqlite3_vfs] object.
2831** ^If the previous call to this routine had an N of 1 or more and a
2832** non-NULL P then the pseudo-randomness is generated
2833** internally and without recourse to the [sqlite3_vfs] xRandomness
2834** method.
2835*/
2836SQLITE_API void sqlite3_randomness(int N, void *P);
2837
2838/*
2839** CAPI3REF: Compile-Time Authorization Callbacks
2840** METHOD: sqlite3
2841** KEYWORDS: {authorizer callback}
2842**
2843** ^This routine registers an authorizer callback with a particular
2844** [database connection], supplied in the first argument.
2845** ^The authorizer callback is invoked as SQL statements are being compiled
2846** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2847** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2848** and [sqlite3_prepare16_v3()]. ^At various
2849** points during the compilation process, as logic is being created
2850** to perform various actions, the authorizer callback is invoked to
2851** see if those actions are allowed. ^The authorizer callback should
2852** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2853** specific action but allow the SQL statement to continue to be
2854** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2855** rejected with an error. ^If the authorizer callback returns
2856** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2857** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2858** the authorizer will fail with an error message.
2859**
2860** When the callback returns [SQLITE_OK], that means the operation
2861** requested is ok. ^When the callback returns [SQLITE_DENY], the
2862** [sqlite3_prepare_v2()] or equivalent call that triggered the
2863** authorizer will fail with an error message explaining that
2864** access is denied.
2865**
2866** ^The first parameter to the authorizer callback is a copy of the third
2867** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2868** to the callback is an integer [SQLITE_COPY | action code] that specifies
2869** the particular action to be authorized. ^The third through sixth parameters
2870** to the callback are either NULL pointers or zero-terminated strings
2871** that contain additional details about the action to be authorized.
2872** Applications must always be prepared to encounter a NULL pointer in any
2873** of the third through the sixth parameters of the authorization callback.
2874**
2875** ^If the action code is [SQLITE_READ]
2876** and the callback returns [SQLITE_IGNORE] then the
2877** [prepared statement] statement is constructed to substitute
2878** a NULL value in place of the table column that would have
2879** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2880** return can be used to deny an untrusted user access to individual
2881** columns of a table.
2882** ^When a table is referenced by a [SELECT] but no column values are
2883** extracted from that table (for example in a query like
2884** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2885** is invoked once for that table with a column name that is an empty string.
2886** ^If the action code is [SQLITE_DELETE] and the callback returns
2887** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2888** [truncate optimization] is disabled and all rows are deleted individually.
2889**
2890** An authorizer is used when [sqlite3_prepare | preparing]
2891** SQL statements from an untrusted source, to ensure that the SQL statements
2892** do not try to access data they are not allowed to see, or that they do not
2893** try to execute malicious statements that damage the database. For
2894** example, an application may allow a user to enter arbitrary
2895** SQL queries for evaluation by a database. But the application does
2896** not want the user to be able to make arbitrary changes to the
2897** database. An authorizer could then be put in place while the
2898** user-entered SQL is being [sqlite3_prepare | prepared] that
2899** disallows everything except [SELECT] statements.
2900**
2901** Applications that need to process SQL from untrusted sources
2902** might also consider lowering resource limits using [sqlite3_limit()]
2903** and limiting database size using the [max_page_count] [PRAGMA]
2904** in addition to using an authorizer.
2905**
2906** ^(Only a single authorizer can be in place on a database connection
2907** at a time. Each call to sqlite3_set_authorizer overrides the
2908** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2909** The authorizer is disabled by default.
2910**
2911** The authorizer callback must not do anything that will modify
2912** the database connection that invoked the authorizer callback.
2913** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2914** database connections for the meaning of "modify" in this paragraph.
2915**
2916** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2917** statement might be re-prepared during [sqlite3_step()] due to a
2918** schema change. Hence, the application should ensure that the
2919** correct authorizer callback remains in place during the [sqlite3_step()].
2920**
2921** ^Note that the authorizer callback is invoked only during
2922** [sqlite3_prepare()] or its variants. Authorization is not
2923** performed during statement evaluation in [sqlite3_step()], unless
2924** as stated in the previous paragraph, sqlite3_step() invokes
2925** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2926*/
2927SQLITE_API int sqlite3_set_authorizer(
2928 sqlite3*,
2929 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2930 void *pUserData
2931);
2932
2933/*
2934** CAPI3REF: Authorizer Return Codes
2935**
2936** The [sqlite3_set_authorizer | authorizer callback function] must
2937** return either [SQLITE_OK] or one of these two constants in order
2938** to signal SQLite whether or not the action is permitted. See the
2939** [sqlite3_set_authorizer | authorizer documentation] for additional
2940** information.
2941**
2942** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2943** returned from the [sqlite3_vtab_on_conflict()] interface.
2944*/
2945#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2946#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2947
2948/*
2949** CAPI3REF: Authorizer Action Codes
2950**
2951** The [sqlite3_set_authorizer()] interface registers a callback function
2952** that is invoked to authorize certain SQL statement actions. The
2953** second parameter to the callback is an integer code that specifies
2954** what action is being authorized. These are the integer action codes that
2955** the authorizer callback may be passed.
2956**
2957** These action code values signify what kind of operation is to be
2958** authorized. The 3rd and 4th parameters to the authorization
2959** callback function will be parameters or NULL depending on which of these
2960** codes is used as the second parameter. ^(The 5th parameter to the
2961** authorizer callback is the name of the database ("main", "temp",
2962** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2963** is the name of the inner-most trigger or view that is responsible for
2964** the access attempt or NULL if this access attempt is directly from
2965** top-level SQL code.
2966*/
2967/******************************************* 3rd ************ 4th ***********/
2968#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2969#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2970#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2971#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2972#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2973#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2974#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2975#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2976#define SQLITE_DELETE 9 /* Table Name NULL */
2977#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2978#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2979#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2980#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2981#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2982#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2983#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2984#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2985#define SQLITE_INSERT 18 /* Table Name NULL */
2986#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2987#define SQLITE_READ 20 /* Table Name Column Name */
2988#define SQLITE_SELECT 21 /* NULL NULL */
2989#define SQLITE_TRANSACTION 22 /* Operation NULL */
2990#define SQLITE_UPDATE 23 /* Table Name Column Name */
2991#define SQLITE_ATTACH 24 /* Filename NULL */
2992#define SQLITE_DETACH 25 /* Database Name NULL */
2993#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2994#define SQLITE_REINDEX 27 /* Index Name NULL */
2995#define SQLITE_ANALYZE 28 /* Table Name NULL */
2996#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2997#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2998#define SQLITE_FUNCTION 31 /* NULL Function Name */
2999#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3000#define SQLITE_COPY 0 /* No longer used */
3001#define SQLITE_RECURSIVE 33 /* NULL NULL */
3002
3003/*
3004** CAPI3REF: Tracing And Profiling Functions
3005** METHOD: sqlite3
3006**
3007** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3008** instead of the routines described here.
3009**
3010** These routines register callback functions that can be used for
3011** tracing and profiling the execution of SQL statements.
3012**
3013** ^The callback function registered by sqlite3_trace() is invoked at
3014** various times when an SQL statement is being run by [sqlite3_step()].
3015** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3016** SQL statement text as the statement first begins executing.
3017** ^(Additional sqlite3_trace() callbacks might occur
3018** as each triggered subprogram is entered. The callbacks for triggers
3019** contain a UTF-8 SQL comment that identifies the trigger.)^
3020**
3021** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3022** the length of [bound parameter] expansion in the output of sqlite3_trace().
3023**
3024** ^The callback function registered by sqlite3_profile() is invoked
3025** as each SQL statement finishes. ^The profile callback contains
3026** the original statement text and an estimate of wall-clock time
3027** of how long that statement took to run. ^The profile callback
3028** time is in units of nanoseconds, however the current implementation
3029** is only capable of millisecond resolution so the six least significant
3030** digits in the time are meaningless. Future versions of SQLite
3031** might provide greater resolution on the profiler callback. Invoking
3032** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3033** profile callback.
3034*/
3035SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3036 void(*xTrace)(void*,const char*), void*);
3037SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3038 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3039
3040/*
3041** CAPI3REF: SQL Trace Event Codes
3042** KEYWORDS: SQLITE_TRACE
3043**
3044** These constants identify classes of events that can be monitored
3045** using the [sqlite3_trace_v2()] tracing logic. The M argument
3046** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3047** the following constants. ^The first argument to the trace callback
3048** is one of the following constants.
3049**
3050** New tracing constants may be added in future releases.
3051**
3052** ^A trace callback has four arguments: xCallback(T,C,P,X).
3053** ^The T argument is one of the integer type codes above.
3054** ^The C argument is a copy of the context pointer passed in as the
3055** fourth argument to [sqlite3_trace_v2()].
3056** The P and X arguments are pointers whose meanings depend on T.
3057**
3058** <dl>
3059** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3060** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3061** first begins running and possibly at other times during the
3062** execution of the prepared statement, such as at the start of each
3063** trigger subprogram. ^The P argument is a pointer to the
3064** [prepared statement]. ^The X argument is a pointer to a string which
3065** is the unexpanded SQL text of the prepared statement or an SQL comment
3066** that indicates the invocation of a trigger. ^The callback can compute
3067** the same text that would have been returned by the legacy [sqlite3_trace()]
3068** interface by using the X argument when X begins with "--" and invoking
3069** [sqlite3_expanded_sql(P)] otherwise.
3070**
3071** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3072** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3073** information as is provided by the [sqlite3_profile()] callback.
3074** ^The P argument is a pointer to the [prepared statement] and the
3075** X argument points to a 64-bit integer which is the estimated of
3076** the number of nanosecond that the prepared statement took to run.
3077** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3078**
3079** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3080** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3081** statement generates a single row of result.
3082** ^The P argument is a pointer to the [prepared statement] and the
3083** X argument is unused.
3084**
3085** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3086** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3087** connection closes.
3088** ^The P argument is a pointer to the [database connection] object
3089** and the X argument is unused.
3090** </dl>
3091*/
3092#define SQLITE_TRACE_STMT 0x01
3093#define SQLITE_TRACE_PROFILE 0x02
3094#define SQLITE_TRACE_ROW 0x04
3095#define SQLITE_TRACE_CLOSE 0x08
3096
3097/*
3098** CAPI3REF: SQL Trace Hook
3099** METHOD: sqlite3
3100**
3101** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3102** function X against [database connection] D, using property mask M
3103** and context pointer P. ^If the X callback is
3104** NULL or if the M mask is zero, then tracing is disabled. The
3105** M argument should be the bitwise OR-ed combination of
3106** zero or more [SQLITE_TRACE] constants.
3107**
3108** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3109** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3110**
3111** ^The X callback is invoked whenever any of the events identified by
3112** mask M occur. ^The integer return value from the callback is currently
3113** ignored, though this may change in future releases. Callback
3114** implementations should return zero to ensure future compatibility.
3115**
3116** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3117** ^The T argument is one of the [SQLITE_TRACE]
3118** constants to indicate why the callback was invoked.
3119** ^The C argument is a copy of the context pointer.
3120** The P and X arguments are pointers whose meanings depend on T.
3121**
3122** The sqlite3_trace_v2() interface is intended to replace the legacy
3123** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3124** are deprecated.
3125*/
3126SQLITE_API int sqlite3_trace_v2(
3127 sqlite3*,
3128 unsigned uMask,
3129 int(*xCallback)(unsigned,void*,void*,void*),
3130 void *pCtx
3131);
3132
3133/*
3134** CAPI3REF: Query Progress Callbacks
3135** METHOD: sqlite3
3136**
3137** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3138** function X to be invoked periodically during long running calls to
3139** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3140** database connection D. An example use for this
3141** interface is to keep a GUI updated during a large query.
3142**
3143** ^The parameter P is passed through as the only parameter to the
3144** callback function X. ^The parameter N is the approximate number of
3145** [virtual machine instructions] that are evaluated between successive
3146** invocations of the callback X. ^If N is less than one then the progress
3147** handler is disabled.
3148**
3149** ^Only a single progress handler may be defined at one time per
3150** [database connection]; setting a new progress handler cancels the
3151** old one. ^Setting parameter X to NULL disables the progress handler.
3152** ^The progress handler is also disabled by setting N to a value less
3153** than 1.
3154**
3155** ^If the progress callback returns non-zero, the operation is
3156** interrupted. This feature can be used to implement a
3157** "Cancel" button on a GUI progress dialog box.
3158**
3159** The progress handler callback must not do anything that will modify
3160** the database connection that invoked the progress handler.
3161** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3162** database connections for the meaning of "modify" in this paragraph.
3163**
3164*/
3165SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3166
3167/*
3168** CAPI3REF: Opening A New Database Connection
3169** CONSTRUCTOR: sqlite3
3170**
3171** ^These routines open an SQLite database file as specified by the
3172** filename argument. ^The filename argument is interpreted as UTF-8 for
3173** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3174** order for sqlite3_open16(). ^(A [database connection] handle is usually
3175** returned in *ppDb, even if an error occurs. The only exception is that
3176** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3177** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3178** object.)^ ^(If the database is opened (and/or created) successfully, then
3179** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3180** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3181** an English language description of the error following a failure of any
3182** of the sqlite3_open() routines.
3183**
3184** ^The default encoding will be UTF-8 for databases created using
3185** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3186** created using sqlite3_open16() will be UTF-16 in the native byte order.
3187**
3188** Whether or not an error occurs when it is opened, resources
3189** associated with the [database connection] handle should be released by
3190** passing it to [sqlite3_close()] when it is no longer required.
3191**
3192** The sqlite3_open_v2() interface works like sqlite3_open()
3193** except that it accepts two additional parameters for additional control
3194** over the new database connection. ^(The flags parameter to
3195** sqlite3_open_v2() can take one of
3196** the following three values, optionally combined with the
3197** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3198** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3199**
3200** <dl>
3201** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3202** <dd>The database is opened in read-only mode. If the database does not
3203** already exist, an error is returned.</dd>)^
3204**
3205** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3206** <dd>The database is opened for reading and writing if possible, or reading
3207** only if the file is write protected by the operating system. In either
3208** case the database must already exist, otherwise an error is returned.</dd>)^
3209**
3210** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3211** <dd>The database is opened for reading and writing, and is created if
3212** it does not already exist. This is the behavior that is always used for
3213** sqlite3_open() and sqlite3_open16().</dd>)^
3214** </dl>
3215**
3216** If the 3rd parameter to sqlite3_open_v2() is not one of the
3217** combinations shown above optionally combined with other
3218** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3219** then the behavior is undefined.
3220**
3221** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3222** opens in the multi-thread [threading mode] as long as the single-thread
3223** mode has not been set at compile-time or start-time. ^If the
3224** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3225** in the serialized [threading mode] unless single-thread was
3226** previously selected at compile-time or start-time.
3227** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3228** eligible to use [shared cache mode], regardless of whether or not shared
3229** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3230** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3231** participate in [shared cache mode] even if it is enabled.
3232**
3233** ^The fourth parameter to sqlite3_open_v2() is the name of the
3234** [sqlite3_vfs] object that defines the operating system interface that
3235** the new database connection should use. ^If the fourth parameter is
3236** a NULL pointer then the default [sqlite3_vfs] object is used.
3237**
3238** ^If the filename is ":memory:", then a private, temporary in-memory database
3239** is created for the connection. ^This in-memory database will vanish when
3240** the database connection is closed. Future versions of SQLite might
3241** make use of additional special filenames that begin with the ":" character.
3242** It is recommended that when a database filename actually does begin with
3243** a ":" character you should prefix the filename with a pathname such as
3244** "./" to avoid ambiguity.
3245**
3246** ^If the filename is an empty string, then a private, temporary
3247** on-disk database will be created. ^This private database will be
3248** automatically deleted as soon as the database connection is closed.
3249**
3250** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3251**
3252** ^If [URI filename] interpretation is enabled, and the filename argument
3253** begins with "file:", then the filename is interpreted as a URI. ^URI
3254** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3255** set in the third argument to sqlite3_open_v2(), or if it has
3256** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3257** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3258** URI filename interpretation is turned off
3259** by default, but future releases of SQLite might enable URI filename
3260** interpretation by default. See "[URI filenames]" for additional
3261** information.
3262**
3263** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3264** authority, then it must be either an empty string or the string
3265** "localhost". ^If the authority is not an empty string or "localhost", an
3266** error is returned to the caller. ^The fragment component of a URI, if
3267** present, is ignored.
3268**
3269** ^SQLite uses the path component of the URI as the name of the disk file
3270** which contains the database. ^If the path begins with a '/' character,
3271** then it is interpreted as an absolute path. ^If the path does not begin
3272** with a '/' (meaning that the authority section is omitted from the URI)
3273** then the path is interpreted as a relative path.
3274** ^(On windows, the first component of an absolute path
3275** is a drive specification (e.g. "C:").)^
3276**
3277** [[core URI query parameters]]
3278** The query component of a URI may contain parameters that are interpreted
3279** either by SQLite itself, or by a [VFS | custom VFS implementation].
3280** SQLite and its built-in [VFSes] interpret the
3281** following query parameters:
3282**
3283** <ul>
3284** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3285** a VFS object that provides the operating system interface that should
3286** be used to access the database file on disk. ^If this option is set to
3287** an empty string the default VFS object is used. ^Specifying an unknown
3288** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3289** present, then the VFS specified by the option takes precedence over
3290** the value passed as the fourth parameter to sqlite3_open_v2().
3291**
3292** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3293** "rwc", or "memory". Attempting to set it to any other value is
3294** an error)^.
3295** ^If "ro" is specified, then the database is opened for read-only
3296** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3297** third argument to sqlite3_open_v2(). ^If the mode option is set to
3298** "rw", then the database is opened for read-write (but not create)
3299** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3300** been set. ^Value "rwc" is equivalent to setting both
3301** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3302** set to "memory" then a pure [in-memory database] that never reads
3303** or writes from disk is used. ^It is an error to specify a value for
3304** the mode parameter that is less restrictive than that specified by
3305** the flags passed in the third parameter to sqlite3_open_v2().
3306**
3307** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3308** "private". ^Setting it to "shared" is equivalent to setting the
3309** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3310** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3311** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3312** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3313** a URI filename, its value overrides any behavior requested by setting
3314** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3315**
3316** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3317** [powersafe overwrite] property does or does not apply to the
3318** storage media on which the database file resides.
3319**
3320** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3321** which if set disables file locking in rollback journal modes. This
3322** is useful for accessing a database on a filesystem that does not
3323** support locking. Caution: Database corruption might result if two
3324** or more processes write to the same database and any one of those
3325** processes uses nolock=1.
3326**
3327** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3328** parameter that indicates that the database file is stored on
3329** read-only media. ^When immutable is set, SQLite assumes that the
3330** database file cannot be changed, even by a process with higher
3331** privilege, and so the database is opened read-only and all locking
3332** and change detection is disabled. Caution: Setting the immutable
3333** property on a database file that does in fact change can result
3334** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3335** See also: [SQLITE_IOCAP_IMMUTABLE].
3336**
3337** </ul>
3338**
3339** ^Specifying an unknown parameter in the query component of a URI is not an
3340** error. Future versions of SQLite might understand additional query
3341** parameters. See "[query parameters with special meaning to SQLite]" for
3342** additional information.
3343**
3344** [[URI filename examples]] <h3>URI filename examples</h3>
3345**
3346** <table border="1" align=center cellpadding=5>
3347** <tr><th> URI filenames <th> Results
3348** <tr><td> file:data.db <td>
3349** Open the file "data.db" in the current directory.
3350** <tr><td> file:/home/fred/data.db<br>
3351** file:///home/fred/data.db <br>
3352** file://localhost/home/fred/data.db <br> <td>
3353** Open the database file "/home/fred/data.db".
3354** <tr><td> file://darkstar/home/fred/data.db <td>
3355** An error. "darkstar" is not a recognized authority.
3356** <tr><td style="white-space:nowrap">
3357** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3358** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3359** C:. Note that the %20 escaping in this example is not strictly
3360** necessary - space characters can be used literally
3361** in URI filenames.
3362** <tr><td> file:data.db?mode=ro&cache=private <td>
3363** Open file "data.db" in the current directory for read-only access.
3364** Regardless of whether or not shared-cache mode is enabled by
3365** default, use a private cache.
3366** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3367** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3368** that uses dot-files in place of posix advisory locking.
3369** <tr><td> file:data.db?mode=readonly <td>
3370** An error. "readonly" is not a valid option for the "mode" parameter.
3371** </table>
3372**
3373** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3374** query components of a URI. A hexadecimal escape sequence consists of a
3375** percent sign - "%" - followed by exactly two hexadecimal digits
3376** specifying an octet value. ^Before the path or query components of a
3377** URI filename are interpreted, they are encoded using UTF-8 and all
3378** hexadecimal escape sequences replaced by a single byte containing the
3379** corresponding octet. If this process generates an invalid UTF-8 encoding,
3380** the results are undefined.
3381**
3382** <b>Note to Windows users:</b> The encoding used for the filename argument
3383** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3384** codepage is currently defined. Filenames containing international
3385** characters must be converted to UTF-8 prior to passing them into
3386** sqlite3_open() or sqlite3_open_v2().
3387**
3388** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3389** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3390** features that require the use of temporary files may fail.
3391**
3392** See also: [sqlite3_temp_directory]
3393*/
3394SQLITE_API int sqlite3_open(
3395 const char *filename, /* Database filename (UTF-8) */
3396 sqlite3 **ppDb /* OUT: SQLite db handle */
3397);
3398SQLITE_API int sqlite3_open16(
3399 const void *filename, /* Database filename (UTF-16) */
3400 sqlite3 **ppDb /* OUT: SQLite db handle */
3401);
3402SQLITE_API int sqlite3_open_v2(
3403 const char *filename, /* Database filename (UTF-8) */
3404 sqlite3 **ppDb, /* OUT: SQLite db handle */
3405 int flags, /* Flags */
3406 const char *zVfs /* Name of VFS module to use */
3407);
3408
3409/*
3410** CAPI3REF: Obtain Values For URI Parameters
3411**
3412** These are utility routines, useful to VFS implementations, that check
3413** to see if a database file was a URI that contained a specific query
3414** parameter, and if so obtains the value of that query parameter.
3415**
3416** If F is the database filename pointer passed into the xOpen() method of
3417** a VFS implementation when the flags parameter to xOpen() has one or
3418** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3419** P is the name of the query parameter, then
3420** sqlite3_uri_parameter(F,P) returns the value of the P
3421** parameter if it exists or a NULL pointer if P does not appear as a
3422** query parameter on F. If P is a query parameter of F
3423** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3424** a pointer to an empty string.
3425**
3426** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3427** parameter and returns true (1) or false (0) according to the value
3428** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3429** value of query parameter P is one of "yes", "true", or "on" in any
3430** case or if the value begins with a non-zero number. The
3431** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3432** query parameter P is one of "no", "false", or "off" in any case or
3433** if the value begins with a numeric zero. If P is not a query
3434** parameter on F or if the value of P is does not match any of the
3435** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3436**
3437** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3438** 64-bit signed integer and returns that integer, or D if P does not
3439** exist. If the value of P is something other than an integer, then
3440** zero is returned.
3441**
3442** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3443** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3444** is not a database file pathname pointer that SQLite passed into the xOpen
3445** VFS method, then the behavior of this routine is undefined and probably
3446** undesirable.
3447**
3448** See the [URI filename] documentation for additional information.
3449*/
3450SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3451SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3452SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3453
3454
3455/*
3456** CAPI3REF: Error Codes And Messages
3457** METHOD: sqlite3
3458**
3459** ^If the most recent sqlite3_* API call associated with
3460** [database connection] D failed, then the sqlite3_errcode(D) interface
3461** returns the numeric [result code] or [extended result code] for that
3462** API call.
3463** ^The sqlite3_extended_errcode()
3464** interface is the same except that it always returns the
3465** [extended result code] even when extended result codes are
3466** disabled.
3467**
3468** The values returned by sqlite3_errcode() and/or
3469** sqlite3_extended_errcode() might change with each API call.
3470** Except, there are some interfaces that are guaranteed to never
3471** change the value of the error code. The error-code preserving
3472** interfaces are:
3473**
3474** <ul>
3475** <li> sqlite3_errcode()
3476** <li> sqlite3_extended_errcode()
3477** <li> sqlite3_errmsg()
3478** <li> sqlite3_errmsg16()
3479** </ul>
3480**
3481** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3482** text that describes the error, as either UTF-8 or UTF-16 respectively.
3483** ^(Memory to hold the error message string is managed internally.
3484** The application does not need to worry about freeing the result.
3485** However, the error string might be overwritten or deallocated by
3486** subsequent calls to other SQLite interface functions.)^
3487**
3488** ^The sqlite3_errstr() interface returns the English-language text
3489** that describes the [result code], as UTF-8.
3490** ^(Memory to hold the error message string is managed internally
3491** and must not be freed by the application)^.
3492**
3493** When the serialized [threading mode] is in use, it might be the
3494** case that a second error occurs on a separate thread in between
3495** the time of the first error and the call to these interfaces.
3496** When that happens, the second error will be reported since these
3497** interfaces always report the most recent result. To avoid
3498** this, each thread can obtain exclusive use of the [database connection] D
3499** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3500** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3501** all calls to the interfaces listed here are completed.
3502**
3503** If an interface fails with SQLITE_MISUSE, that means the interface
3504** was invoked incorrectly by the application. In that case, the
3505** error code and message may or may not be set.
3506*/
3507SQLITE_API int sqlite3_errcode(sqlite3 *db);
3508SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3509SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3510SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3511SQLITE_API const char *sqlite3_errstr(int);
3512
3513/*
3514** CAPI3REF: Prepared Statement Object
3515** KEYWORDS: {prepared statement} {prepared statements}
3516**
3517** An instance of this object represents a single SQL statement that
3518** has been compiled into binary form and is ready to be evaluated.
3519**
3520** Think of each SQL statement as a separate computer program. The
3521** original SQL text is source code. A prepared statement object
3522** is the compiled object code. All SQL must be converted into a
3523** prepared statement before it can be run.
3524**
3525** The life-cycle of a prepared statement object usually goes like this:
3526**
3527** <ol>
3528** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3529** <li> Bind values to [parameters] using the sqlite3_bind_*()
3530** interfaces.
3531** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3532** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3533** to step 2. Do this zero or more times.
3534** <li> Destroy the object using [sqlite3_finalize()].
3535** </ol>
3536*/
3537typedef struct sqlite3_stmt sqlite3_stmt;
3538
3539/*
3540** CAPI3REF: Run-time Limits
3541** METHOD: sqlite3
3542**
3543** ^(This interface allows the size of various constructs to be limited
3544** on a connection by connection basis. The first parameter is the
3545** [database connection] whose limit is to be set or queried. The
3546** second parameter is one of the [limit categories] that define a
3547** class of constructs to be size limited. The third parameter is the
3548** new limit for that construct.)^
3549**
3550** ^If the new limit is a negative number, the limit is unchanged.
3551** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3552** [limits | hard upper bound]
3553** set at compile-time by a C preprocessor macro called
3554** [limits | SQLITE_MAX_<i>NAME</i>].
3555** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3556** ^Attempts to increase a limit above its hard upper bound are
3557** silently truncated to the hard upper bound.
3558**
3559** ^Regardless of whether or not the limit was changed, the
3560** [sqlite3_limit()] interface returns the prior value of the limit.
3561** ^Hence, to find the current value of a limit without changing it,
3562** simply invoke this interface with the third parameter set to -1.
3563**
3564** Run-time limits are intended for use in applications that manage
3565** both their own internal database and also databases that are controlled
3566** by untrusted external sources. An example application might be a
3567** web browser that has its own databases for storing history and
3568** separate databases controlled by JavaScript applications downloaded
3569** off the Internet. The internal databases can be given the
3570** large, default limits. Databases managed by external sources can
3571** be given much smaller limits designed to prevent a denial of service
3572** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3573** interface to further control untrusted SQL. The size of the database
3574** created by an untrusted script can be contained using the
3575** [max_page_count] [PRAGMA].
3576**
3577** New run-time limit categories may be added in future releases.
3578*/
3579SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3580
3581/*
3582** CAPI3REF: Run-Time Limit Categories
3583** KEYWORDS: {limit category} {*limit categories}
3584**
3585** These constants define various performance limits
3586** that can be lowered at run-time using [sqlite3_limit()].
3587** The synopsis of the meanings of the various limits is shown below.
3588** Additional information is available at [limits | Limits in SQLite].
3589**
3590** <dl>
3591** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3592** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3593**
3594** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3595** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3596**
3597** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3598** <dd>The maximum number of columns in a table definition or in the
3599** result set of a [SELECT] or the maximum number of columns in an index
3600** or in an ORDER BY or GROUP BY clause.</dd>)^
3601**
3602** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3603** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3604**
3605** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3606** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3607**
3608** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3609** <dd>The maximum number of instructions in a virtual machine program
3610** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3611** the equivalent tries to allocate space for more than this many opcodes
3612** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3613**
3614** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3615** <dd>The maximum number of arguments on a function.</dd>)^
3616**
3617** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3618** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3619**
3620** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3621** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3622** <dd>The maximum length of the pattern argument to the [LIKE] or
3623** [GLOB] operators.</dd>)^
3624**
3625** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3626** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3627** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3628**
3629** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3630** <dd>The maximum depth of recursion for triggers.</dd>)^
3631**
3632** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3633** <dd>The maximum number of auxiliary worker threads that a single
3634** [prepared statement] may start.</dd>)^
3635** </dl>
3636*/
3637#define SQLITE_LIMIT_LENGTH 0
3638#define SQLITE_LIMIT_SQL_LENGTH 1
3639#define SQLITE_LIMIT_COLUMN 2
3640#define SQLITE_LIMIT_EXPR_DEPTH 3
3641#define SQLITE_LIMIT_COMPOUND_SELECT 4
3642#define SQLITE_LIMIT_VDBE_OP 5
3643#define SQLITE_LIMIT_FUNCTION_ARG 6
3644#define SQLITE_LIMIT_ATTACHED 7
3645#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3646#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3647#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3648#define SQLITE_LIMIT_WORKER_THREADS 11
3649
3650/*
3651** CAPI3REF: Prepare Flags
3652**
3653** These constants define various flags that can be passed into
3654** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3655** [sqlite3_prepare16_v3()] interfaces.
3656**
3657** New flags may be added in future releases of SQLite.
3658**
3659** <dl>
3660** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3661** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3662** that the prepared statement will be retained for a long time and
3663** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3664** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3665** be used just once or at most a few times and then destroyed using
3666** [sqlite3_finalize()] relatively soon. The current implementation acts
3667** on this hint by avoiding the use of [lookaside memory] so as not to
3668** deplete the limited store of lookaside memory. Future versions of
3669** SQLite may act on this hint differently.
3670**
3671** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
3672** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
3673** to be required for any prepared statement that wanted to use the
3674** [sqlite3_normalized_sql()] interface. However, the
3675** [sqlite3_normalized_sql()] interface is now available to all
3676** prepared statements, regardless of whether or not they use this
3677** flag.
3678**
3679** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
3680** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
3681** to return an error (error code SQLITE_ERROR) if the statement uses
3682** any virtual tables.
3683** </dl>
3684*/
3685#define SQLITE_PREPARE_PERSISTENT 0x01
3686#define SQLITE_PREPARE_NORMALIZE 0x02
3687#define SQLITE_PREPARE_NO_VTAB 0x04
3688
3689/*
3690** CAPI3REF: Compiling An SQL Statement
3691** KEYWORDS: {SQL statement compiler}
3692** METHOD: sqlite3
3693** CONSTRUCTOR: sqlite3_stmt
3694**
3695** To execute an SQL statement, it must first be compiled into a byte-code
3696** program using one of these routines. Or, in other words, these routines
3697** are constructors for the [prepared statement] object.
3698**
3699** The preferred routine to use is [sqlite3_prepare_v2()]. The
3700** [sqlite3_prepare()] interface is legacy and should be avoided.
3701** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3702** for special purposes.
3703**
3704** The use of the UTF-8 interfaces is preferred, as SQLite currently
3705** does all parsing using UTF-8. The UTF-16 interfaces are provided
3706** as a convenience. The UTF-16 interfaces work by converting the
3707** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3708**
3709** The first argument, "db", is a [database connection] obtained from a
3710** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3711** [sqlite3_open16()]. The database connection must not have been closed.
3712**
3713** The second argument, "zSql", is the statement to be compiled, encoded
3714** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3715** and sqlite3_prepare_v3()
3716** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3717** and sqlite3_prepare16_v3() use UTF-16.
3718**
3719** ^If the nByte argument is negative, then zSql is read up to the
3720** first zero terminator. ^If nByte is positive, then it is the
3721** number of bytes read from zSql. ^If nByte is zero, then no prepared
3722** statement is generated.
3723** If the caller knows that the supplied string is nul-terminated, then
3724** there is a small performance advantage to passing an nByte parameter that
3725** is the number of bytes in the input string <i>including</i>
3726** the nul-terminator.
3727**
3728** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3729** past the end of the first SQL statement in zSql. These routines only
3730** compile the first statement in zSql, so *pzTail is left pointing to
3731** what remains uncompiled.
3732**
3733** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3734** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3735** to NULL. ^If the input text contains no SQL (if the input is an empty
3736** string or a comment) then *ppStmt is set to NULL.
3737** The calling procedure is responsible for deleting the compiled
3738** SQL statement using [sqlite3_finalize()] after it has finished with it.
3739** ppStmt may not be NULL.
3740**
3741** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3742** otherwise an [error code] is returned.
3743**
3744** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
3745** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
3746** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
3747** are retained for backwards compatibility, but their use is discouraged.
3748** ^In the "vX" interfaces, the prepared statement
3749** that is returned (the [sqlite3_stmt] object) contains a copy of the
3750** original SQL text. This causes the [sqlite3_step()] interface to
3751** behave differently in three ways:
3752**
3753** <ol>
3754** <li>
3755** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3756** always used to do, [sqlite3_step()] will automatically recompile the SQL
3757** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3758** retries will occur before sqlite3_step() gives up and returns an error.
3759** </li>
3760**
3761** <li>
3762** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3763** [error codes] or [extended error codes]. ^The legacy behavior was that
3764** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3765** and the application would have to make a second call to [sqlite3_reset()]
3766** in order to find the underlying cause of the problem. With the "v2" prepare
3767** interfaces, the underlying reason for the error is returned immediately.
3768** </li>
3769**
3770** <li>
3771** ^If the specific value bound to [parameter | host parameter] in the
3772** WHERE clause might influence the choice of query plan for a statement,
3773** then the statement will be automatically recompiled, as if there had been
3774** a schema change, on the first [sqlite3_step()] call following any change
3775** to the [sqlite3_bind_text | bindings] of that [parameter].
3776** ^The specific value of WHERE-clause [parameter] might influence the
3777** choice of query plan if the parameter is the left-hand side of a [LIKE]
3778** or [GLOB] operator or if the parameter is compared to an indexed column
3779** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3780** </li>
3781** </ol>
3782**
3783** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
3784** the extra prepFlags parameter, which is a bit array consisting of zero or
3785** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
3786** sqlite3_prepare_v2() interface works exactly the same as
3787** sqlite3_prepare_v3() with a zero prepFlags parameter.
3788*/
3789SQLITE_API int sqlite3_prepare(
3790 sqlite3 *db, /* Database handle */
3791 const char *zSql, /* SQL statement, UTF-8 encoded */
3792 int nByte, /* Maximum length of zSql in bytes. */
3793 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3794 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3795);
3796SQLITE_API int sqlite3_prepare_v2(
3797 sqlite3 *db, /* Database handle */
3798 const char *zSql, /* SQL statement, UTF-8 encoded */
3799 int nByte, /* Maximum length of zSql in bytes. */
3800 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3801 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3802);
3803SQLITE_API int sqlite3_prepare_v3(
3804 sqlite3 *db, /* Database handle */
3805 const char *zSql, /* SQL statement, UTF-8 encoded */
3806 int nByte, /* Maximum length of zSql in bytes. */
3807 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3808 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3809 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3810);
3811SQLITE_API int sqlite3_prepare16(
3812 sqlite3 *db, /* Database handle */
3813 const void *zSql, /* SQL statement, UTF-16 encoded */
3814 int nByte, /* Maximum length of zSql in bytes. */
3815 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3816 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3817);
3818SQLITE_API int sqlite3_prepare16_v2(
3819 sqlite3 *db, /* Database handle */
3820 const void *zSql, /* SQL statement, UTF-16 encoded */
3821 int nByte, /* Maximum length of zSql in bytes. */
3822 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3823 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3824);
3825SQLITE_API int sqlite3_prepare16_v3(
3826 sqlite3 *db, /* Database handle */
3827 const void *zSql, /* SQL statement, UTF-16 encoded */
3828 int nByte, /* Maximum length of zSql in bytes. */
3829 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3830 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3831 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3832);
3833
3834/*
3835** CAPI3REF: Retrieving Statement SQL
3836** METHOD: sqlite3_stmt
3837**
3838** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3839** SQL text used to create [prepared statement] P if P was
3840** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
3841** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
3842** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3843** string containing the SQL text of prepared statement P with
3844** [bound parameters] expanded.
3845** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
3846** string containing the normalized SQL text of prepared statement P. The
3847** semantics used to normalize a SQL statement are unspecified and subject
3848** to change. At a minimum, literal values will be replaced with suitable
3849** placeholders.
3850**
3851** ^(For example, if a prepared statement is created using the SQL
3852** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3853** and parameter :xyz is unbound, then sqlite3_sql() will return
3854** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3855** will return "SELECT 2345,NULL".)^
3856**
3857** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3858** is available to hold the result, or if the result would exceed the
3859** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3860**
3861** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3862** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3863** option causes sqlite3_expanded_sql() to always return NULL.
3864**
3865** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
3866** are managed by SQLite and are automatically freed when the prepared
3867** statement is finalized.
3868** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3869** is obtained from [sqlite3_malloc()] and must be free by the application
3870** by passing it to [sqlite3_free()].
3871*/
3872SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3873SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3874SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
3875
3876/*
3877** CAPI3REF: Determine If An SQL Statement Writes The Database
3878** METHOD: sqlite3_stmt
3879**
3880** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3881** and only if the [prepared statement] X makes no direct changes to
3882** the content of the database file.
3883**
3884** Note that [application-defined SQL functions] or
3885** [virtual tables] might change the database indirectly as a side effect.
3886** ^(For example, if an application defines a function "eval()" that
3887** calls [sqlite3_exec()], then the following SQL statement would
3888** change the database file through side-effects:
3889**
3890** <blockquote><pre>
3891** SELECT eval('DELETE FROM t1') FROM t2;
3892** </pre></blockquote>
3893**
3894** But because the [SELECT] statement does not change the database file
3895** directly, sqlite3_stmt_readonly() would still return true.)^
3896**
3897** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3898** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3899** since the statements themselves do not actually modify the database but
3900** rather they control the timing of when other statements modify the
3901** database. ^The [ATTACH] and [DETACH] statements also cause
3902** sqlite3_stmt_readonly() to return true since, while those statements
3903** change the configuration of a database connection, they do not make
3904** changes to the content of the database files on disk.
3905** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3906** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3907** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3908** sqlite3_stmt_readonly() returns false for those commands.
3909*/
3910SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3911
3912/*
3913** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
3914** METHOD: sqlite3_stmt
3915**
3916** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
3917** prepared statement S is an EXPLAIN statement, or 2 if the
3918** statement S is an EXPLAIN QUERY PLAN.
3919** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
3920** an ordinary statement or a NULL pointer.
3921*/
3922SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
3923
3924/*
3925** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3926** METHOD: sqlite3_stmt
3927**
3928** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3929** [prepared statement] S has been stepped at least once using
3930** [sqlite3_step(S)] but has neither run to completion (returned
3931** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3932** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3933** interface returns false if S is a NULL pointer. If S is not a
3934** NULL pointer and is not a pointer to a valid [prepared statement]
3935** object, then the behavior is undefined and probably undesirable.
3936**
3937** This interface can be used in combination [sqlite3_next_stmt()]
3938** to locate all prepared statements associated with a database
3939** connection that are in need of being reset. This can be used,
3940** for example, in diagnostic routines to search for prepared
3941** statements that are holding a transaction open.
3942*/
3943SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3944
3945/*
3946** CAPI3REF: Dynamically Typed Value Object
3947** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3948**
3949** SQLite uses the sqlite3_value object to represent all values
3950** that can be stored in a database table. SQLite uses dynamic typing
3951** for the values it stores. ^Values stored in sqlite3_value objects
3952** can be integers, floating point values, strings, BLOBs, or NULL.
3953**
3954** An sqlite3_value object may be either "protected" or "unprotected".
3955** Some interfaces require a protected sqlite3_value. Other interfaces
3956** will accept either a protected or an unprotected sqlite3_value.
3957** Every interface that accepts sqlite3_value arguments specifies
3958** whether or not it requires a protected sqlite3_value. The
3959** [sqlite3_value_dup()] interface can be used to construct a new
3960** protected sqlite3_value from an unprotected sqlite3_value.
3961**
3962** The terms "protected" and "unprotected" refer to whether or not
3963** a mutex is held. An internal mutex is held for a protected
3964** sqlite3_value object but no mutex is held for an unprotected
3965** sqlite3_value object. If SQLite is compiled to be single-threaded
3966** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3967** or if SQLite is run in one of reduced mutex modes
3968** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3969** then there is no distinction between protected and unprotected
3970** sqlite3_value objects and they can be used interchangeably. However,
3971** for maximum code portability it is recommended that applications
3972** still make the distinction between protected and unprotected
3973** sqlite3_value objects even when not strictly required.
3974**
3975** ^The sqlite3_value objects that are passed as parameters into the
3976** implementation of [application-defined SQL functions] are protected.
3977** ^The sqlite3_value object returned by
3978** [sqlite3_column_value()] is unprotected.
3979** Unprotected sqlite3_value objects may only be used as arguments
3980** to [sqlite3_result_value()], [sqlite3_bind_value()], and
3981** [sqlite3_value_dup()].
3982** The [sqlite3_value_blob | sqlite3_value_type()] family of
3983** interfaces require protected sqlite3_value objects.
3984*/
3985typedef struct sqlite3_value sqlite3_value;
3986
3987/*
3988** CAPI3REF: SQL Function Context Object
3989**
3990** The context in which an SQL function executes is stored in an
3991** sqlite3_context object. ^A pointer to an sqlite3_context object
3992** is always first parameter to [application-defined SQL functions].
3993** The application-defined SQL function implementation will pass this
3994** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3995** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3996** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3997** and/or [sqlite3_set_auxdata()].
3998*/
3999typedef struct sqlite3_context sqlite3_context;
4000
4001/*
4002** CAPI3REF: Binding Values To Prepared Statements
4003** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4004** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4005** METHOD: sqlite3_stmt
4006**
4007** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4008** literals may be replaced by a [parameter] that matches one of following
4009** templates:
4010**
4011** <ul>
4012** <li> ?
4013** <li> ?NNN
4014** <li> :VVV
4015** <li> @VVV
4016** <li> $VVV
4017** </ul>
4018**
4019** In the templates above, NNN represents an integer literal,
4020** and VVV represents an alphanumeric identifier.)^ ^The values of these
4021** parameters (also called "host parameter names" or "SQL parameters")
4022** can be set using the sqlite3_bind_*() routines defined here.
4023**
4024** ^The first argument to the sqlite3_bind_*() routines is always
4025** a pointer to the [sqlite3_stmt] object returned from
4026** [sqlite3_prepare_v2()] or its variants.
4027**
4028** ^The second argument is the index of the SQL parameter to be set.
4029** ^The leftmost SQL parameter has an index of 1. ^When the same named
4030** SQL parameter is used more than once, second and subsequent
4031** occurrences have the same index as the first occurrence.
4032** ^The index for named parameters can be looked up using the
4033** [sqlite3_bind_parameter_index()] API if desired. ^The index
4034** for "?NNN" parameters is the value of NNN.
4035** ^The NNN value must be between 1 and the [sqlite3_limit()]
4036** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
4037**
4038** ^The third argument is the value to bind to the parameter.
4039** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4040** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4041** is ignored and the end result is the same as sqlite3_bind_null().
4042**
4043** ^(In those routines that have a fourth argument, its value is the
4044** number of bytes in the parameter. To be clear: the value is the
4045** number of <u>bytes</u> in the value, not the number of characters.)^
4046** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4047** is negative, then the length of the string is
4048** the number of bytes up to the first zero terminator.
4049** If the fourth parameter to sqlite3_bind_blob() is negative, then
4050** the behavior is undefined.
4051** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4052** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4053** that parameter must be the byte offset
4054** where the NUL terminator would occur assuming the string were NUL
4055** terminated. If any NUL characters occur at byte offsets less than
4056** the value of the fourth parameter then the resulting string value will
4057** contain embedded NULs. The result of expressions involving strings
4058** with embedded NULs is undefined.
4059**
4060** ^The fifth argument to the BLOB and string binding interfaces
4061** is a destructor used to dispose of the BLOB or
4062** string after SQLite has finished with it. ^The destructor is called
4063** to dispose of the BLOB or string even if the call to the bind API fails,
4064** except the destructor is not called if the third parameter is a NULL
4065** pointer or the fourth parameter is negative.
4066** ^If the fifth argument is
4067** the special value [SQLITE_STATIC], then SQLite assumes that the
4068** information is in static, unmanaged space and does not need to be freed.
4069** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
4070** SQLite makes its own private copy of the data immediately, before
4071** the sqlite3_bind_*() routine returns.
4072**
4073** ^The sixth argument to sqlite3_bind_text64() must be one of
4074** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4075** to specify the encoding of the text in the third parameter. If
4076** the sixth argument to sqlite3_bind_text64() is not one of the
4077** allowed values shown above, or if the text encoding is different
4078** from the encoding specified by the sixth parameter, then the behavior
4079** is undefined.
4080**
4081** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4082** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4083** (just an integer to hold its size) while it is being processed.
4084** Zeroblobs are intended to serve as placeholders for BLOBs whose
4085** content is later written using
4086** [sqlite3_blob_open | incremental BLOB I/O] routines.
4087** ^A negative value for the zeroblob results in a zero-length BLOB.
4088**
4089** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4090** [prepared statement] S to have an SQL value of NULL, but to also be
4091** associated with the pointer P of type T. ^D is either a NULL pointer or
4092** a pointer to a destructor function for P. ^SQLite will invoke the
4093** destructor D with a single argument of P when it is finished using
4094** P. The T parameter should be a static string, preferably a string
4095** literal. The sqlite3_bind_pointer() routine is part of the
4096** [pointer passing interface] added for SQLite 3.20.0.
4097**
4098** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4099** for the [prepared statement] or with a prepared statement for which
4100** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4101** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4102** routine is passed a [prepared statement] that has been finalized, the
4103** result is undefined and probably harmful.
4104**
4105** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4106** ^Unbound parameters are interpreted as NULL.
4107**
4108** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4109** [error code] if anything goes wrong.
4110** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4111** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4112** [SQLITE_MAX_LENGTH].
4113** ^[SQLITE_RANGE] is returned if the parameter
4114** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4115**
4116** See also: [sqlite3_bind_parameter_count()],
4117** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4118*/
4119SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4120SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4121 void(*)(void*));
4122SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4123SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4124SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4125SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4126SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4127SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4128SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4129 void(*)(void*), unsigned char encoding);
4130SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4131SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4132SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4133SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4134
4135/*
4136** CAPI3REF: Number Of SQL Parameters
4137** METHOD: sqlite3_stmt
4138**
4139** ^This routine can be used to find the number of [SQL parameters]
4140** in a [prepared statement]. SQL parameters are tokens of the
4141** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4142** placeholders for values that are [sqlite3_bind_blob | bound]
4143** to the parameters at a later time.
4144**
4145** ^(This routine actually returns the index of the largest (rightmost)
4146** parameter. For all forms except ?NNN, this will correspond to the
4147** number of unique parameters. If parameters of the ?NNN form are used,
4148** there may be gaps in the list.)^
4149**
4150** See also: [sqlite3_bind_blob|sqlite3_bind()],
4151** [sqlite3_bind_parameter_name()], and
4152** [sqlite3_bind_parameter_index()].
4153*/
4154SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4155
4156/*
4157** CAPI3REF: Name Of A Host Parameter
4158** METHOD: sqlite3_stmt
4159**
4160** ^The sqlite3_bind_parameter_name(P,N) interface returns
4161** the name of the N-th [SQL parameter] in the [prepared statement] P.
4162** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4163** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4164** respectively.
4165** In other words, the initial ":" or "$" or "@" or "?"
4166** is included as part of the name.)^
4167** ^Parameters of the form "?" without a following integer have no name
4168** and are referred to as "nameless" or "anonymous parameters".
4169**
4170** ^The first host parameter has an index of 1, not 0.
4171**
4172** ^If the value N is out of range or if the N-th parameter is
4173** nameless, then NULL is returned. ^The returned string is
4174** always in UTF-8 encoding even if the named parameter was
4175** originally specified as UTF-16 in [sqlite3_prepare16()],
4176** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4177**
4178** See also: [sqlite3_bind_blob|sqlite3_bind()],
4179** [sqlite3_bind_parameter_count()], and
4180** [sqlite3_bind_parameter_index()].
4181*/
4182SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4183
4184/*
4185** CAPI3REF: Index Of A Parameter With A Given Name
4186** METHOD: sqlite3_stmt
4187**
4188** ^Return the index of an SQL parameter given its name. ^The
4189** index value returned is suitable for use as the second
4190** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4191** is returned if no matching parameter is found. ^The parameter
4192** name must be given in UTF-8 even if the original statement
4193** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4194** [sqlite3_prepare16_v3()].
4195**
4196** See also: [sqlite3_bind_blob|sqlite3_bind()],
4197** [sqlite3_bind_parameter_count()], and
4198** [sqlite3_bind_parameter_name()].
4199*/
4200SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4201
4202/*
4203** CAPI3REF: Reset All Bindings On A Prepared Statement
4204** METHOD: sqlite3_stmt
4205**
4206** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4207** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4208** ^Use this routine to reset all host parameters to NULL.
4209*/
4210SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4211
4212/*
4213** CAPI3REF: Number Of Columns In A Result Set
4214** METHOD: sqlite3_stmt
4215**
4216** ^Return the number of columns in the result set returned by the
4217** [prepared statement]. ^If this routine returns 0, that means the
4218** [prepared statement] returns no data (for example an [UPDATE]).
4219** ^However, just because this routine returns a positive number does not
4220** mean that one or more rows of data will be returned. ^A SELECT statement
4221** will always have a positive sqlite3_column_count() but depending on the
4222** WHERE clause constraints and the table content, it might return no rows.
4223**
4224** See also: [sqlite3_data_count()]
4225*/
4226SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4227
4228/*
4229** CAPI3REF: Column Names In A Result Set
4230** METHOD: sqlite3_stmt
4231**
4232** ^These routines return the name assigned to a particular column
4233** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4234** interface returns a pointer to a zero-terminated UTF-8 string
4235** and sqlite3_column_name16() returns a pointer to a zero-terminated
4236** UTF-16 string. ^The first parameter is the [prepared statement]
4237** that implements the [SELECT] statement. ^The second parameter is the
4238** column number. ^The leftmost column is number 0.
4239**
4240** ^The returned string pointer is valid until either the [prepared statement]
4241** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4242** reprepared by the first call to [sqlite3_step()] for a particular run
4243** or until the next call to
4244** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4245**
4246** ^If sqlite3_malloc() fails during the processing of either routine
4247** (for example during a conversion from UTF-8 to UTF-16) then a
4248** NULL pointer is returned.
4249**
4250** ^The name of a result column is the value of the "AS" clause for
4251** that column, if there is an AS clause. If there is no AS clause
4252** then the name of the column is unspecified and may change from
4253** one release of SQLite to the next.
4254*/
4255SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4256SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4257
4258/*
4259** CAPI3REF: Source Of Data In A Query Result
4260** METHOD: sqlite3_stmt
4261**
4262** ^These routines provide a means to determine the database, table, and
4263** table column that is the origin of a particular result column in
4264** [SELECT] statement.
4265** ^The name of the database or table or column can be returned as
4266** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4267** the database name, the _table_ routines return the table name, and
4268** the origin_ routines return the column name.
4269** ^The returned string is valid until the [prepared statement] is destroyed
4270** using [sqlite3_finalize()] or until the statement is automatically
4271** reprepared by the first call to [sqlite3_step()] for a particular run
4272** or until the same information is requested
4273** again in a different encoding.
4274**
4275** ^The names returned are the original un-aliased names of the
4276** database, table, and column.
4277**
4278** ^The first argument to these interfaces is a [prepared statement].
4279** ^These functions return information about the Nth result column returned by
4280** the statement, where N is the second function argument.
4281** ^The left-most column is column 0 for these routines.
4282**
4283** ^If the Nth column returned by the statement is an expression or
4284** subquery and is not a column value, then all of these functions return
4285** NULL. ^These routine might also return NULL if a memory allocation error
4286** occurs. ^Otherwise, they return the name of the attached database, table,
4287** or column that query result column was extracted from.
4288**
4289** ^As with all other SQLite APIs, those whose names end with "16" return
4290** UTF-16 encoded strings and the other functions return UTF-8.
4291**
4292** ^These APIs are only available if the library was compiled with the
4293** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4294**
4295** If two or more threads call one or more of these routines against the same
4296** prepared statement and column at the same time then the results are
4297** undefined.
4298**
4299** If two or more threads call one or more
4300** [sqlite3_column_database_name | column metadata interfaces]
4301** for the same [prepared statement] and result column
4302** at the same time then the results are undefined.
4303*/
4304SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4305SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4306SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4307SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4308SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4309SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4310
4311/*
4312** CAPI3REF: Declared Datatype Of A Query Result
4313** METHOD: sqlite3_stmt
4314**
4315** ^(The first parameter is a [prepared statement].
4316** If this statement is a [SELECT] statement and the Nth column of the
4317** returned result set of that [SELECT] is a table column (not an
4318** expression or subquery) then the declared type of the table
4319** column is returned.)^ ^If the Nth column of the result set is an
4320** expression or subquery, then a NULL pointer is returned.
4321** ^The returned string is always UTF-8 encoded.
4322**
4323** ^(For example, given the database schema:
4324**
4325** CREATE TABLE t1(c1 VARIANT);
4326**
4327** and the following statement to be compiled:
4328**
4329** SELECT c1 + 1, c1 FROM t1;
4330**
4331** this routine would return the string "VARIANT" for the second result
4332** column (i==1), and a NULL pointer for the first result column (i==0).)^
4333**
4334** ^SQLite uses dynamic run-time typing. ^So just because a column
4335** is declared to contain a particular type does not mean that the
4336** data stored in that column is of the declared type. SQLite is
4337** strongly typed, but the typing is dynamic not static. ^Type
4338** is associated with individual values, not with the containers
4339** used to hold those values.
4340*/
4341SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4342SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4343
4344/*
4345** CAPI3REF: Evaluate An SQL Statement
4346** METHOD: sqlite3_stmt
4347**
4348** After a [prepared statement] has been prepared using any of
4349** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4350** or [sqlite3_prepare16_v3()] or one of the legacy
4351** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4352** must be called one or more times to evaluate the statement.
4353**
4354** The details of the behavior of the sqlite3_step() interface depend
4355** on whether the statement was prepared using the newer "vX" interfaces
4356** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4357** [sqlite3_prepare16_v2()] or the older legacy
4358** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4359** new "vX" interface is recommended for new applications but the legacy
4360** interface will continue to be supported.
4361**
4362** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4363** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4364** ^With the "v2" interface, any of the other [result codes] or
4365** [extended result codes] might be returned as well.
4366**
4367** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4368** database locks it needs to do its job. ^If the statement is a [COMMIT]
4369** or occurs outside of an explicit transaction, then you can retry the
4370** statement. If the statement is not a [COMMIT] and occurs within an
4371** explicit transaction then you should rollback the transaction before
4372** continuing.
4373**
4374** ^[SQLITE_DONE] means that the statement has finished executing
4375** successfully. sqlite3_step() should not be called again on this virtual
4376** machine without first calling [sqlite3_reset()] to reset the virtual
4377** machine back to its initial state.
4378**
4379** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4380** is returned each time a new row of data is ready for processing by the
4381** caller. The values may be accessed using the [column access functions].
4382** sqlite3_step() is called again to retrieve the next row of data.
4383**
4384** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4385** violation) has occurred. sqlite3_step() should not be called again on
4386** the VM. More information may be found by calling [sqlite3_errmsg()].
4387** ^With the legacy interface, a more specific error code (for example,
4388** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4389** can be obtained by calling [sqlite3_reset()] on the
4390** [prepared statement]. ^In the "v2" interface,
4391** the more specific error code is returned directly by sqlite3_step().
4392**
4393** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4394** Perhaps it was called on a [prepared statement] that has
4395** already been [sqlite3_finalize | finalized] or on one that had
4396** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4397** be the case that the same database connection is being used by two or
4398** more threads at the same moment in time.
4399**
4400** For all versions of SQLite up to and including 3.6.23.1, a call to
4401** [sqlite3_reset()] was required after sqlite3_step() returned anything
4402** other than [SQLITE_ROW] before any subsequent invocation of
4403** sqlite3_step(). Failure to reset the prepared statement using
4404** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4405** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4406** sqlite3_step() began
4407** calling [sqlite3_reset()] automatically in this circumstance rather
4408** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4409** break because any application that ever receives an SQLITE_MISUSE error
4410** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4411** can be used to restore the legacy behavior.
4412**
4413** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4414** API always returns a generic error code, [SQLITE_ERROR], following any
4415** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4416** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4417** specific [error codes] that better describes the error.
4418** We admit that this is a goofy design. The problem has been fixed
4419** with the "v2" interface. If you prepare all of your SQL statements
4420** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4421** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4422** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4423** then the more specific [error codes] are returned directly
4424** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4425*/
4426SQLITE_API int sqlite3_step(sqlite3_stmt*);
4427
4428/*
4429** CAPI3REF: Number of columns in a result set
4430** METHOD: sqlite3_stmt
4431**
4432** ^The sqlite3_data_count(P) interface returns the number of columns in the
4433** current row of the result set of [prepared statement] P.
4434** ^If prepared statement P does not have results ready to return
4435** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4436** interfaces) then sqlite3_data_count(P) returns 0.
4437** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4438** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4439** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4440** will return non-zero if previous call to [sqlite3_step](P) returned
4441** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4442** where it always returns zero since each step of that multi-step
4443** pragma returns 0 columns of data.
4444**
4445** See also: [sqlite3_column_count()]
4446*/
4447SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4448
4449/*
4450** CAPI3REF: Fundamental Datatypes
4451** KEYWORDS: SQLITE_TEXT
4452**
4453** ^(Every value in SQLite has one of five fundamental datatypes:
4454**
4455** <ul>
4456** <li> 64-bit signed integer
4457** <li> 64-bit IEEE floating point number
4458** <li> string
4459** <li> BLOB
4460** <li> NULL
4461** </ul>)^
4462**
4463** These constants are codes for each of those types.
4464**
4465** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4466** for a completely different meaning. Software that links against both
4467** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4468** SQLITE_TEXT.
4469*/
4470#define SQLITE_INTEGER 1
4471#define SQLITE_FLOAT 2
4472#define SQLITE_BLOB 4
4473#define SQLITE_NULL 5
4474#ifdef SQLITE_TEXT
4475# undef SQLITE_TEXT
4476#else
4477# define SQLITE_TEXT 3
4478#endif
4479#define SQLITE3_TEXT 3
4480
4481/*
4482** CAPI3REF: Result Values From A Query
4483** KEYWORDS: {column access functions}
4484** METHOD: sqlite3_stmt
4485**
4486** <b>Summary:</b>
4487** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4488** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4489** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4490** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4491** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4492** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4493** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4494** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4495** [sqlite3_value|unprotected sqlite3_value] object.
4496** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4497** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4498** or a UTF-8 TEXT result in bytes
4499** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4500** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4501** TEXT in bytes
4502** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4503** datatype of the result
4504** </table></blockquote>
4505**
4506** <b>Details:</b>
4507**
4508** ^These routines return information about a single column of the current
4509** result row of a query. ^In every case the first argument is a pointer
4510** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4511** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4512** and the second argument is the index of the column for which information
4513** should be returned. ^The leftmost column of the result set has the index 0.
4514** ^The number of columns in the result can be determined using
4515** [sqlite3_column_count()].
4516**
4517** If the SQL statement does not currently point to a valid row, or if the
4518** column index is out of range, the result is undefined.
4519** These routines may only be called when the most recent call to
4520** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4521** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4522** If any of these routines are called after [sqlite3_reset()] or
4523** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4524** something other than [SQLITE_ROW], the results are undefined.
4525** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4526** are called from a different thread while any of these routines
4527** are pending, then the results are undefined.
4528**
4529** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4530** each return the value of a result column in a specific data format. If
4531** the result column is not initially in the requested format (for example,
4532** if the query returns an integer but the sqlite3_column_text() interface
4533** is used to extract the value) then an automatic type conversion is performed.
4534**
4535** ^The sqlite3_column_type() routine returns the
4536** [SQLITE_INTEGER | datatype code] for the initial data type
4537** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4538** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4539** The return value of sqlite3_column_type() can be used to decide which
4540** of the first six interface should be used to extract the column value.
4541** The value returned by sqlite3_column_type() is only meaningful if no
4542** automatic type conversions have occurred for the value in question.
4543** After a type conversion, the result of calling sqlite3_column_type()
4544** is undefined, though harmless. Future
4545** versions of SQLite may change the behavior of sqlite3_column_type()
4546** following a type conversion.
4547**
4548** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4549** or sqlite3_column_bytes16() interfaces can be used to determine the size
4550** of that BLOB or string.
4551**
4552** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4553** routine returns the number of bytes in that BLOB or string.
4554** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4555** the string to UTF-8 and then returns the number of bytes.
4556** ^If the result is a numeric value then sqlite3_column_bytes() uses
4557** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4558** the number of bytes in that string.
4559** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4560**
4561** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4562** routine returns the number of bytes in that BLOB or string.
4563** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4564** the string to UTF-16 and then returns the number of bytes.
4565** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4566** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4567** the number of bytes in that string.
4568** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4569**
4570** ^The values returned by [sqlite3_column_bytes()] and
4571** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4572** of the string. ^For clarity: the values returned by
4573** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4574** bytes in the string, not the number of characters.
4575**
4576** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4577** even empty strings, are always zero-terminated. ^The return
4578** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4579**
4580** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4581** [unprotected sqlite3_value] object. In a multithreaded environment,
4582** an unprotected sqlite3_value object may only be used safely with
4583** [sqlite3_bind_value()] and [sqlite3_result_value()].
4584** If the [unprotected sqlite3_value] object returned by
4585** [sqlite3_column_value()] is used in any other way, including calls
4586** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4587** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4588** Hence, the sqlite3_column_value() interface
4589** is normally only useful within the implementation of
4590** [application-defined SQL functions] or [virtual tables], not within
4591** top-level application code.
4592**
4593** The these routines may attempt to convert the datatype of the result.
4594** ^For example, if the internal representation is FLOAT and a text result
4595** is requested, [sqlite3_snprintf()] is used internally to perform the
4596** conversion automatically. ^(The following table details the conversions
4597** that are applied:
4598**
4599** <blockquote>
4600** <table border="1">
4601** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4602**
4603** <tr><td> NULL <td> INTEGER <td> Result is 0
4604** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4605** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4606** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4607** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4608** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4609** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4610** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4611** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4612** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4613** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4614** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4615** <tr><td> TEXT <td> BLOB <td> No change
4616** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4617** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4618** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4619** </table>
4620** </blockquote>)^
4621**
4622** Note that when type conversions occur, pointers returned by prior
4623** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4624** sqlite3_column_text16() may be invalidated.
4625** Type conversions and pointer invalidations might occur
4626** in the following cases:
4627**
4628** <ul>
4629** <li> The initial content is a BLOB and sqlite3_column_text() or
4630** sqlite3_column_text16() is called. A zero-terminator might
4631** need to be added to the string.</li>
4632** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4633** sqlite3_column_text16() is called. The content must be converted
4634** to UTF-16.</li>
4635** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4636** sqlite3_column_text() is called. The content must be converted
4637** to UTF-8.</li>
4638** </ul>
4639**
4640** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4641** not invalidate a prior pointer, though of course the content of the buffer
4642** that the prior pointer references will have been modified. Other kinds
4643** of conversion are done in place when it is possible, but sometimes they
4644** are not possible and in those cases prior pointers are invalidated.
4645**
4646** The safest policy is to invoke these routines
4647** in one of the following ways:
4648**
4649** <ul>
4650** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4651** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4652** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4653** </ul>
4654**
4655** In other words, you should call sqlite3_column_text(),
4656** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4657** into the desired format, then invoke sqlite3_column_bytes() or
4658** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4659** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4660** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4661** with calls to sqlite3_column_bytes().
4662**
4663** ^The pointers returned are valid until a type conversion occurs as
4664** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4665** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4666** and BLOBs is freed automatically. Do not pass the pointers returned
4667** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4668** [sqlite3_free()].
4669**
4670** As long as the input parameters are correct, these routines will only
4671** fail if an out-of-memory error occurs during a format conversion.
4672** Only the following subset of interfaces are subject to out-of-memory
4673** errors:
4674**
4675** <ul>
4676** <li> sqlite3_column_blob()
4677** <li> sqlite3_column_text()
4678** <li> sqlite3_column_text16()
4679** <li> sqlite3_column_bytes()
4680** <li> sqlite3_column_bytes16()
4681** </ul>
4682**
4683** If an out-of-memory error occurs, then the return value from these
4684** routines is the same as if the column had contained an SQL NULL value.
4685** Valid SQL NULL returns can be distinguished from out-of-memory errors
4686** by invoking the [sqlite3_errcode()] immediately after the suspect
4687** return value is obtained and before any
4688** other SQLite interface is called on the same [database connection].
4689*/
4690SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4691SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4692SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4693SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4694SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4695SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4696SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4697SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4698SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4699SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4700
4701/*
4702** CAPI3REF: Destroy A Prepared Statement Object
4703** DESTRUCTOR: sqlite3_stmt
4704**
4705** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4706** ^If the most recent evaluation of the statement encountered no errors
4707** or if the statement is never been evaluated, then sqlite3_finalize() returns
4708** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4709** sqlite3_finalize(S) returns the appropriate [error code] or
4710** [extended error code].
4711**
4712** ^The sqlite3_finalize(S) routine can be called at any point during
4713** the life cycle of [prepared statement] S:
4714** before statement S is ever evaluated, after
4715** one or more calls to [sqlite3_reset()], or after any call
4716** to [sqlite3_step()] regardless of whether or not the statement has
4717** completed execution.
4718**
4719** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4720**
4721** The application must finalize every [prepared statement] in order to avoid
4722** resource leaks. It is a grievous error for the application to try to use
4723** a prepared statement after it has been finalized. Any use of a prepared
4724** statement after it has been finalized can result in undefined and
4725** undesirable behavior such as segfaults and heap corruption.
4726*/
4727SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4728
4729/*
4730** CAPI3REF: Reset A Prepared Statement Object
4731** METHOD: sqlite3_stmt
4732**
4733** The sqlite3_reset() function is called to reset a [prepared statement]
4734** object back to its initial state, ready to be re-executed.
4735** ^Any SQL statement variables that had values bound to them using
4736** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4737** Use [sqlite3_clear_bindings()] to reset the bindings.
4738**
4739** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4740** back to the beginning of its program.
4741**
4742** ^If the most recent call to [sqlite3_step(S)] for the
4743** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4744** or if [sqlite3_step(S)] has never before been called on S,
4745** then [sqlite3_reset(S)] returns [SQLITE_OK].
4746**
4747** ^If the most recent call to [sqlite3_step(S)] for the
4748** [prepared statement] S indicated an error, then
4749** [sqlite3_reset(S)] returns an appropriate [error code].
4750**
4751** ^The [sqlite3_reset(S)] interface does not change the values
4752** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4753*/
4754SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4755
4756/*
4757** CAPI3REF: Create Or Redefine SQL Functions
4758** KEYWORDS: {function creation routines}
4759** KEYWORDS: {application-defined SQL function}
4760** KEYWORDS: {application-defined SQL functions}
4761** METHOD: sqlite3
4762**
4763** ^These functions (collectively known as "function creation routines")
4764** are used to add SQL functions or aggregates or to redefine the behavior
4765** of existing SQL functions or aggregates. The only differences between
4766** the three "sqlite3_create_function*" routines are the text encoding
4767** expected for the second parameter (the name of the function being
4768** created) and the presence or absence of a destructor callback for
4769** the application data pointer. Function sqlite3_create_window_function()
4770** is similar, but allows the user to supply the extra callback functions
4771** needed by [aggregate window functions].
4772**
4773** ^The first parameter is the [database connection] to which the SQL
4774** function is to be added. ^If an application uses more than one database
4775** connection then application-defined SQL functions must be added
4776** to each database connection separately.
4777**
4778** ^The second parameter is the name of the SQL function to be created or
4779** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4780** representation, exclusive of the zero-terminator. ^Note that the name
4781** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4782** ^Any attempt to create a function with a longer name
4783** will result in [SQLITE_MISUSE] being returned.
4784**
4785** ^The third parameter (nArg)
4786** is the number of arguments that the SQL function or
4787** aggregate takes. ^If this parameter is -1, then the SQL function or
4788** aggregate may take any number of arguments between 0 and the limit
4789** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4790** parameter is less than -1 or greater than 127 then the behavior is
4791** undefined.
4792**
4793** ^The fourth parameter, eTextRep, specifies what
4794** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4795** its parameters. The application should set this parameter to
4796** [SQLITE_UTF16LE] if the function implementation invokes
4797** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4798** implementation invokes [sqlite3_value_text16be()] on an input, or
4799** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4800** otherwise. ^The same SQL function may be registered multiple times using
4801** different preferred text encodings, with different implementations for
4802** each encoding.
4803** ^When multiple implementations of the same function are available, SQLite
4804** will pick the one that involves the least amount of data conversion.
4805**
4806** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4807** to signal that the function will always return the same result given
4808** the same inputs within a single SQL statement. Most SQL functions are
4809** deterministic. The built-in [random()] SQL function is an example of a
4810** function that is not deterministic. The SQLite query planner is able to
4811** perform additional optimizations on deterministic functions, so use
4812** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4813**
4814** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4815** function can gain access to this pointer using [sqlite3_user_data()].)^
4816**
4817** ^The sixth, seventh and eighth parameters passed to the three
4818** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
4819** pointers to C-language functions that implement the SQL function or
4820** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4821** callback only; NULL pointers must be passed as the xStep and xFinal
4822** parameters. ^An aggregate SQL function requires an implementation of xStep
4823** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4824** SQL function or aggregate, pass NULL pointers for all three function
4825** callbacks.
4826**
4827** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
4828** and xInverse) passed to sqlite3_create_window_function are pointers to
4829** C-language callbacks that implement the new function. xStep and xFinal
4830** must both be non-NULL. xValue and xInverse may either both be NULL, in
4831** which case a regular aggregate function is created, or must both be
4832** non-NULL, in which case the new function may be used as either an aggregate
4833** or aggregate window function. More details regarding the implementation
4834** of aggregate window functions are
4835** [user-defined window functions|available here].
4836**
4837** ^(If the final parameter to sqlite3_create_function_v2() or
4838** sqlite3_create_window_function() is not NULL, then it is destructor for
4839** the application data pointer. The destructor is invoked when the function
4840** is deleted, either by being overloaded or when the database connection
4841** closes.)^ ^The destructor is also invoked if the call to
4842** sqlite3_create_function_v2() fails. ^When the destructor callback is
4843** invoked, it is passed a single argument which is a copy of the application
4844** data pointer which was the fifth parameter to sqlite3_create_function_v2().
4845**
4846** ^It is permitted to register multiple implementations of the same
4847** functions with the same name but with either differing numbers of
4848** arguments or differing preferred text encodings. ^SQLite will use
4849** the implementation that most closely matches the way in which the
4850** SQL function is used. ^A function implementation with a non-negative
4851** nArg parameter is a better match than a function implementation with
4852** a negative nArg. ^A function where the preferred text encoding
4853** matches the database encoding is a better
4854** match than a function where the encoding is different.
4855** ^A function where the encoding difference is between UTF16le and UTF16be
4856** is a closer match than a function where the encoding difference is
4857** between UTF8 and UTF16.
4858**
4859** ^Built-in functions may be overloaded by new application-defined functions.
4860**
4861** ^An application-defined function is permitted to call other
4862** SQLite interfaces. However, such calls must not
4863** close the database connection nor finalize or reset the prepared
4864** statement in which the function is running.
4865*/
4866SQLITE_API int sqlite3_create_function(
4867 sqlite3 *db,
4868 const char *zFunctionName,
4869 int nArg,
4870 int eTextRep,
4871 void *pApp,
4872 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4873 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4874 void (*xFinal)(sqlite3_context*)
4875);
4876SQLITE_API int sqlite3_create_function16(
4877 sqlite3 *db,
4878 const void *zFunctionName,
4879 int nArg,
4880 int eTextRep,
4881 void *pApp,
4882 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4883 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4884 void (*xFinal)(sqlite3_context*)
4885);
4886SQLITE_API int sqlite3_create_function_v2(
4887 sqlite3 *db,
4888 const char *zFunctionName,
4889 int nArg,
4890 int eTextRep,
4891 void *pApp,
4892 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4893 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4894 void (*xFinal)(sqlite3_context*),
4895 void(*xDestroy)(void*)
4896);
4897SQLITE_API int sqlite3_create_window_function(
4898 sqlite3 *db,
4899 const char *zFunctionName,
4900 int nArg,
4901 int eTextRep,
4902 void *pApp,
4903 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4904 void (*xFinal)(sqlite3_context*),
4905 void (*xValue)(sqlite3_context*),
4906 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
4907 void(*xDestroy)(void*)
4908);
4909
4910/*
4911** CAPI3REF: Text Encodings
4912**
4913** These constant define integer codes that represent the various
4914** text encodings supported by SQLite.
4915*/
4916#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4917#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4918#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4919#define SQLITE_UTF16 4 /* Use native byte order */
4920#define SQLITE_ANY 5 /* Deprecated */
4921#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4922
4923/*
4924** CAPI3REF: Function Flags
4925**
4926** These constants may be ORed together with the
4927** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4928** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4929** [sqlite3_create_function_v2()].
4930*/
4931#define SQLITE_DETERMINISTIC 0x800
4932
4933/*
4934** CAPI3REF: Deprecated Functions
4935** DEPRECATED
4936**
4937** These functions are [deprecated]. In order to maintain
4938** backwards compatibility with older code, these functions continue
4939** to be supported. However, new applications should avoid
4940** the use of these functions. To encourage programmers to avoid
4941** these functions, we will not explain what they do.
4942*/
4943#ifndef SQLITE_OMIT_DEPRECATED
4944SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4945SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4946SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4947SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4948SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4949SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4950 void*,sqlite3_int64);
4951#endif
4952
4953/*
4954** CAPI3REF: Obtaining SQL Values
4955** METHOD: sqlite3_value
4956**
4957** <b>Summary:</b>
4958** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4959** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
4960** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
4961** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
4962** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
4963** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
4964** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
4965** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
4966** the native byteorder
4967** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
4968** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
4969** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4970** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
4971** or a UTF-8 TEXT in bytes
4972** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
4973** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4974** TEXT in bytes
4975** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
4976** datatype of the value
4977** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
4978** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
4979** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
4980** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
4981** against a virtual table.
4982** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
4983** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
4984** </table></blockquote>
4985**
4986** <b>Details:</b>
4987**
4988** These routines extract type, size, and content information from
4989** [protected sqlite3_value] objects. Protected sqlite3_value objects
4990** are used to pass parameter information into implementation of
4991** [application-defined SQL functions] and [virtual tables].
4992**
4993** These routines work only with [protected sqlite3_value] objects.
4994** Any attempt to use these routines on an [unprotected sqlite3_value]
4995** is not threadsafe.
4996**
4997** ^These routines work just like the corresponding [column access functions]
4998** except that these routines take a single [protected sqlite3_value] object
4999** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5000**
5001** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5002** in the native byte-order of the host machine. ^The
5003** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5004** extract UTF-16 strings as big-endian and little-endian respectively.
5005**
5006** ^If [sqlite3_value] object V was initialized
5007** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5008** and if X and Y are strings that compare equal according to strcmp(X,Y),
5009** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5010** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5011** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5012**
5013** ^(The sqlite3_value_type(V) interface returns the
5014** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5015** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5016** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5017** Other interfaces might change the datatype for an sqlite3_value object.
5018** For example, if the datatype is initially SQLITE_INTEGER and
5019** sqlite3_value_text(V) is called to extract a text value for that
5020** integer, then subsequent calls to sqlite3_value_type(V) might return
5021** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5022** occurs is undefined and may change from one release of SQLite to the next.
5023**
5024** ^(The sqlite3_value_numeric_type() interface attempts to apply
5025** numeric affinity to the value. This means that an attempt is
5026** made to convert the value to an integer or floating point. If
5027** such a conversion is possible without loss of information (in other
5028** words, if the value is a string that looks like a number)
5029** then the conversion is performed. Otherwise no conversion occurs.
5030** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5031**
5032** ^Within the [xUpdate] method of a [virtual table], the
5033** sqlite3_value_nochange(X) interface returns true if and only if
5034** the column corresponding to X is unchanged by the UPDATE operation
5035** that the xUpdate method call was invoked to implement and if
5036** and the prior [xColumn] method call that was invoked to extracted
5037** the value for that column returned without setting a result (probably
5038** because it queried [sqlite3_vtab_nochange()] and found that the column
5039** was unchanging). ^Within an [xUpdate] method, any value for which
5040** sqlite3_value_nochange(X) is true will in all other respects appear
5041** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5042** than within an [xUpdate] method call for an UPDATE statement, then
5043** the return value is arbitrary and meaningless.
5044**
5045** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5046** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5047** interfaces. ^If X comes from an SQL literal value, or a table column,
5048** and expression, then sqlite3_value_frombind(X) returns zero.
5049**
5050** Please pay particular attention to the fact that the pointer returned
5051** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5052** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5053** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5054** or [sqlite3_value_text16()].
5055**
5056** These routines must be called from the same thread as
5057** the SQL function that supplied the [sqlite3_value*] parameters.
5058**
5059** As long as the input parameter is correct, these routines can only
5060** fail if an out-of-memory error occurs during a format conversion.
5061** Only the following subset of interfaces are subject to out-of-memory
5062** errors:
5063**
5064** <ul>
5065** <li> sqlite3_value_blob()
5066** <li> sqlite3_value_text()
5067** <li> sqlite3_value_text16()
5068** <li> sqlite3_value_text16le()
5069** <li> sqlite3_value_text16be()
5070** <li> sqlite3_value_bytes()
5071** <li> sqlite3_value_bytes16()
5072** </ul>
5073**
5074** If an out-of-memory error occurs, then the return value from these
5075** routines is the same as if the column had contained an SQL NULL value.
5076** Valid SQL NULL returns can be distinguished from out-of-memory errors
5077** by invoking the [sqlite3_errcode()] immediately after the suspect
5078** return value is obtained and before any
5079** other SQLite interface is called on the same [database connection].
5080*/
5081SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5082SQLITE_API double sqlite3_value_double(sqlite3_value*);
5083SQLITE_API int sqlite3_value_int(sqlite3_value*);
5084SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5085SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5086SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5087SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5088SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5089SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5090SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5091SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5092SQLITE_API int sqlite3_value_type(sqlite3_value*);
5093SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5094SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5095SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5096
5097/*
5098** CAPI3REF: Finding The Subtype Of SQL Values
5099** METHOD: sqlite3_value
5100**
5101** The sqlite3_value_subtype(V) function returns the subtype for
5102** an [application-defined SQL function] argument V. The subtype
5103** information can be used to pass a limited amount of context from
5104** one SQL function to another. Use the [sqlite3_result_subtype()]
5105** routine to set the subtype for the return value of an SQL function.
5106*/
5107SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5108
5109/*
5110** CAPI3REF: Copy And Free SQL Values
5111** METHOD: sqlite3_value
5112**
5113** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5114** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5115** is a [protected sqlite3_value] object even if the input is not.
5116** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5117** memory allocation fails.
5118**
5119** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5120** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5121** then sqlite3_value_free(V) is a harmless no-op.
5122*/
5123SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5124SQLITE_API void sqlite3_value_free(sqlite3_value*);
5125
5126/*
5127** CAPI3REF: Obtain Aggregate Function Context
5128** METHOD: sqlite3_context
5129**
5130** Implementations of aggregate SQL functions use this
5131** routine to allocate memory for storing their state.
5132**
5133** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5134** for a particular aggregate function, SQLite
5135** allocates N of memory, zeroes out that memory, and returns a pointer
5136** to the new memory. ^On second and subsequent calls to
5137** sqlite3_aggregate_context() for the same aggregate function instance,
5138** the same buffer is returned. Sqlite3_aggregate_context() is normally
5139** called once for each invocation of the xStep callback and then one
5140** last time when the xFinal callback is invoked. ^(When no rows match
5141** an aggregate query, the xStep() callback of the aggregate function
5142** implementation is never called and xFinal() is called exactly once.
5143** In those cases, sqlite3_aggregate_context() might be called for the
5144** first time from within xFinal().)^
5145**
5146** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5147** when first called if N is less than or equal to zero or if a memory
5148** allocate error occurs.
5149**
5150** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5151** determined by the N parameter on first successful call. Changing the
5152** value of N in subsequent call to sqlite3_aggregate_context() within
5153** the same aggregate function instance will not resize the memory
5154** allocation.)^ Within the xFinal callback, it is customary to set
5155** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5156** pointless memory allocations occur.
5157**
5158** ^SQLite automatically frees the memory allocated by
5159** sqlite3_aggregate_context() when the aggregate query concludes.
5160**
5161** The first parameter must be a copy of the
5162** [sqlite3_context | SQL function context] that is the first parameter
5163** to the xStep or xFinal callback routine that implements the aggregate
5164** function.
5165**
5166** This routine must be called from the same thread in which
5167** the aggregate SQL function is running.
5168*/
5169SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5170
5171/*
5172** CAPI3REF: User Data For Functions
5173** METHOD: sqlite3_context
5174**
5175** ^The sqlite3_user_data() interface returns a copy of
5176** the pointer that was the pUserData parameter (the 5th parameter)
5177** of the [sqlite3_create_function()]
5178** and [sqlite3_create_function16()] routines that originally
5179** registered the application defined function.
5180**
5181** This routine must be called from the same thread in which
5182** the application-defined function is running.
5183*/
5184SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5185
5186/*
5187** CAPI3REF: Database Connection For Functions
5188** METHOD: sqlite3_context
5189**
5190** ^The sqlite3_context_db_handle() interface returns a copy of
5191** the pointer to the [database connection] (the 1st parameter)
5192** of the [sqlite3_create_function()]
5193** and [sqlite3_create_function16()] routines that originally
5194** registered the application defined function.
5195*/
5196SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5197
5198/*
5199** CAPI3REF: Function Auxiliary Data
5200** METHOD: sqlite3_context
5201**
5202** These functions may be used by (non-aggregate) SQL functions to
5203** associate metadata with argument values. If the same value is passed to
5204** multiple invocations of the same SQL function during query execution, under
5205** some circumstances the associated metadata may be preserved. An example
5206** of where this might be useful is in a regular-expression matching
5207** function. The compiled version of the regular expression can be stored as
5208** metadata associated with the pattern string.
5209** Then as long as the pattern string remains the same,
5210** the compiled regular expression can be reused on multiple
5211** invocations of the same function.
5212**
5213** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5214** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5215** value to the application-defined function. ^N is zero for the left-most
5216** function argument. ^If there is no metadata
5217** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5218** returns a NULL pointer.
5219**
5220** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5221** argument of the application-defined function. ^Subsequent
5222** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5223** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5224** NULL if the metadata has been discarded.
5225** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5226** SQLite will invoke the destructor function X with parameter P exactly
5227** once, when the metadata is discarded.
5228** SQLite is free to discard the metadata at any time, including: <ul>
5229** <li> ^(when the corresponding function parameter changes)^, or
5230** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5231** SQL statement)^, or
5232** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5233** parameter)^, or
5234** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5235** allocation error occurs.)^ </ul>
5236**
5237** Note the last bullet in particular. The destructor X in
5238** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5239** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5240** should be called near the end of the function implementation and the
5241** function implementation should not make any use of P after
5242** sqlite3_set_auxdata() has been called.
5243**
5244** ^(In practice, metadata is preserved between function calls for
5245** function parameters that are compile-time constants, including literal
5246** values and [parameters] and expressions composed from the same.)^
5247**
5248** The value of the N parameter to these interfaces should be non-negative.
5249** Future enhancements may make use of negative N values to define new
5250** kinds of function caching behavior.
5251**
5252** These routines must be called from the same thread in which
5253** the SQL function is running.
5254*/
5255SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5256SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5257
5258
5259/*
5260** CAPI3REF: Constants Defining Special Destructor Behavior
5261**
5262** These are special values for the destructor that is passed in as the
5263** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5264** argument is SQLITE_STATIC, it means that the content pointer is constant
5265** and will never change. It does not need to be destroyed. ^The
5266** SQLITE_TRANSIENT value means that the content will likely change in
5267** the near future and that SQLite should make its own private copy of
5268** the content before returning.
5269**
5270** The typedef is necessary to work around problems in certain
5271** C++ compilers.
5272*/
5273typedef void (*sqlite3_destructor_type)(void*);
5274#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5275#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5276
5277/*
5278** CAPI3REF: Setting The Result Of An SQL Function
5279** METHOD: sqlite3_context
5280**
5281** These routines are used by the xFunc or xFinal callbacks that
5282** implement SQL functions and aggregates. See
5283** [sqlite3_create_function()] and [sqlite3_create_function16()]
5284** for additional information.
5285**
5286** These functions work very much like the [parameter binding] family of
5287** functions used to bind values to host parameters in prepared statements.
5288** Refer to the [SQL parameter] documentation for additional information.
5289**
5290** ^The sqlite3_result_blob() interface sets the result from
5291** an application-defined function to be the BLOB whose content is pointed
5292** to by the second parameter and which is N bytes long where N is the
5293** third parameter.
5294**
5295** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5296** interfaces set the result of the application-defined function to be
5297** a BLOB containing all zero bytes and N bytes in size.
5298**
5299** ^The sqlite3_result_double() interface sets the result from
5300** an application-defined function to be a floating point value specified
5301** by its 2nd argument.
5302**
5303** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5304** cause the implemented SQL function to throw an exception.
5305** ^SQLite uses the string pointed to by the
5306** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5307** as the text of an error message. ^SQLite interprets the error
5308** message string from sqlite3_result_error() as UTF-8. ^SQLite
5309** interprets the string from sqlite3_result_error16() as UTF-16 in native
5310** byte order. ^If the third parameter to sqlite3_result_error()
5311** or sqlite3_result_error16() is negative then SQLite takes as the error
5312** message all text up through the first zero character.
5313** ^If the third parameter to sqlite3_result_error() or
5314** sqlite3_result_error16() is non-negative then SQLite takes that many
5315** bytes (not characters) from the 2nd parameter as the error message.
5316** ^The sqlite3_result_error() and sqlite3_result_error16()
5317** routines make a private copy of the error message text before
5318** they return. Hence, the calling function can deallocate or
5319** modify the text after they return without harm.
5320** ^The sqlite3_result_error_code() function changes the error code
5321** returned by SQLite as a result of an error in a function. ^By default,
5322** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5323** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5324**
5325** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5326** error indicating that a string or BLOB is too long to represent.
5327**
5328** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5329** error indicating that a memory allocation failed.
5330**
5331** ^The sqlite3_result_int() interface sets the return value
5332** of the application-defined function to be the 32-bit signed integer
5333** value given in the 2nd argument.
5334** ^The sqlite3_result_int64() interface sets the return value
5335** of the application-defined function to be the 64-bit signed integer
5336** value given in the 2nd argument.
5337**
5338** ^The sqlite3_result_null() interface sets the return value
5339** of the application-defined function to be NULL.
5340**
5341** ^The sqlite3_result_text(), sqlite3_result_text16(),
5342** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5343** set the return value of the application-defined function to be
5344** a text string which is represented as UTF-8, UTF-16 native byte order,
5345** UTF-16 little endian, or UTF-16 big endian, respectively.
5346** ^The sqlite3_result_text64() interface sets the return value of an
5347** application-defined function to be a text string in an encoding
5348** specified by the fifth (and last) parameter, which must be one
5349** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5350** ^SQLite takes the text result from the application from
5351** the 2nd parameter of the sqlite3_result_text* interfaces.
5352** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5353** is negative, then SQLite takes result text from the 2nd parameter
5354** through the first zero character.
5355** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5356** is non-negative, then as many bytes (not characters) of the text
5357** pointed to by the 2nd parameter are taken as the application-defined
5358** function result. If the 3rd parameter is non-negative, then it
5359** must be the byte offset into the string where the NUL terminator would
5360** appear if the string where NUL terminated. If any NUL characters occur
5361** in the string at a byte offset that is less than the value of the 3rd
5362** parameter, then the resulting string will contain embedded NULs and the
5363** result of expressions operating on strings with embedded NULs is undefined.
5364** ^If the 4th parameter to the sqlite3_result_text* interfaces
5365** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5366** function as the destructor on the text or BLOB result when it has
5367** finished using that result.
5368** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5369** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5370** assumes that the text or BLOB result is in constant space and does not
5371** copy the content of the parameter nor call a destructor on the content
5372** when it has finished using that result.
5373** ^If the 4th parameter to the sqlite3_result_text* interfaces
5374** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5375** then SQLite makes a copy of the result into space obtained
5376** from [sqlite3_malloc()] before it returns.
5377**
5378** ^The sqlite3_result_value() interface sets the result of
5379** the application-defined function to be a copy of the
5380** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5381** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5382** so that the [sqlite3_value] specified in the parameter may change or
5383** be deallocated after sqlite3_result_value() returns without harm.
5384** ^A [protected sqlite3_value] object may always be used where an
5385** [unprotected sqlite3_value] object is required, so either
5386** kind of [sqlite3_value] object can be used with this interface.
5387**
5388** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5389** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5390** also associates the host-language pointer P or type T with that
5391** NULL value such that the pointer can be retrieved within an
5392** [application-defined SQL function] using [sqlite3_value_pointer()].
5393** ^If the D parameter is not NULL, then it is a pointer to a destructor
5394** for the P parameter. ^SQLite invokes D with P as its only argument
5395** when SQLite is finished with P. The T parameter should be a static
5396** string and preferably a string literal. The sqlite3_result_pointer()
5397** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5398**
5399** If these routines are called from within the different thread
5400** than the one containing the application-defined function that received
5401** the [sqlite3_context] pointer, the results are undefined.
5402*/
5403SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5404SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5405 sqlite3_uint64,void(*)(void*));
5406SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5407SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5408SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5409SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5410SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5411SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5412SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5413SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5414SQLITE_API void sqlite3_result_null(sqlite3_context*);
5415SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5416SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5417 void(*)(void*), unsigned char encoding);
5418SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5419SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5420SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5421SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5422SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5423SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5424SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5425
5426
5427/*
5428** CAPI3REF: Setting The Subtype Of An SQL Function
5429** METHOD: sqlite3_context
5430**
5431** The sqlite3_result_subtype(C,T) function causes the subtype of
5432** the result from the [application-defined SQL function] with
5433** [sqlite3_context] C to be the value T. Only the lower 8 bits
5434** of the subtype T are preserved in current versions of SQLite;
5435** higher order bits are discarded.
5436** The number of subtype bytes preserved by SQLite might increase
5437** in future releases of SQLite.
5438*/
5439SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5440
5441/*
5442** CAPI3REF: Define New Collating Sequences
5443** METHOD: sqlite3
5444**
5445** ^These functions add, remove, or modify a [collation] associated
5446** with the [database connection] specified as the first argument.
5447**
5448** ^The name of the collation is a UTF-8 string
5449** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5450** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5451** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5452** considered to be the same name.
5453**
5454** ^(The third argument (eTextRep) must be one of the constants:
5455** <ul>
5456** <li> [SQLITE_UTF8],
5457** <li> [SQLITE_UTF16LE],
5458** <li> [SQLITE_UTF16BE],
5459** <li> [SQLITE_UTF16], or
5460** <li> [SQLITE_UTF16_ALIGNED].
5461** </ul>)^
5462** ^The eTextRep argument determines the encoding of strings passed
5463** to the collating function callback, xCallback.
5464** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5465** force strings to be UTF16 with native byte order.
5466** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5467** on an even byte address.
5468**
5469** ^The fourth argument, pArg, is an application data pointer that is passed
5470** through as the first argument to the collating function callback.
5471**
5472** ^The fifth argument, xCallback, is a pointer to the collating function.
5473** ^Multiple collating functions can be registered using the same name but
5474** with different eTextRep parameters and SQLite will use whichever
5475** function requires the least amount of data transformation.
5476** ^If the xCallback argument is NULL then the collating function is
5477** deleted. ^When all collating functions having the same name are deleted,
5478** that collation is no longer usable.
5479**
5480** ^The collating function callback is invoked with a copy of the pArg
5481** application data pointer and with two strings in the encoding specified
5482** by the eTextRep argument. The collating function must return an
5483** integer that is negative, zero, or positive
5484** if the first string is less than, equal to, or greater than the second,
5485** respectively. A collating function must always return the same answer
5486** given the same inputs. If two or more collating functions are registered
5487** to the same collation name (using different eTextRep values) then all
5488** must give an equivalent answer when invoked with equivalent strings.
5489** The collating function must obey the following properties for all
5490** strings A, B, and C:
5491**
5492** <ol>
5493** <li> If A==B then B==A.
5494** <li> If A==B and B==C then A==C.
5495** <li> If A&lt;B THEN B&gt;A.
5496** <li> If A&lt;B and B&lt;C then A&lt;C.
5497** </ol>
5498**
5499** If a collating function fails any of the above constraints and that
5500** collating function is registered and used, then the behavior of SQLite
5501** is undefined.
5502**
5503** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5504** with the addition that the xDestroy callback is invoked on pArg when
5505** the collating function is deleted.
5506** ^Collating functions are deleted when they are overridden by later
5507** calls to the collation creation functions or when the
5508** [database connection] is closed using [sqlite3_close()].
5509**
5510** ^The xDestroy callback is <u>not</u> called if the
5511** sqlite3_create_collation_v2() function fails. Applications that invoke
5512** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5513** check the return code and dispose of the application data pointer
5514** themselves rather than expecting SQLite to deal with it for them.
5515** This is different from every other SQLite interface. The inconsistency
5516** is unfortunate but cannot be changed without breaking backwards
5517** compatibility.
5518**
5519** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5520*/
5521SQLITE_API int sqlite3_create_collation(
5522 sqlite3*,
5523 const char *zName,
5524 int eTextRep,
5525 void *pArg,
5526 int(*xCompare)(void*,int,const void*,int,const void*)
5527);
5528SQLITE_API int sqlite3_create_collation_v2(
5529 sqlite3*,
5530 const char *zName,
5531 int eTextRep,
5532 void *pArg,
5533 int(*xCompare)(void*,int,const void*,int,const void*),
5534 void(*xDestroy)(void*)
5535);
5536SQLITE_API int sqlite3_create_collation16(
5537 sqlite3*,
5538 const void *zName,
5539 int eTextRep,
5540 void *pArg,
5541 int(*xCompare)(void*,int,const void*,int,const void*)
5542);
5543
5544/*
5545** CAPI3REF: Collation Needed Callbacks
5546** METHOD: sqlite3
5547**
5548** ^To avoid having to register all collation sequences before a database
5549** can be used, a single callback function may be registered with the
5550** [database connection] to be invoked whenever an undefined collation
5551** sequence is required.
5552**
5553** ^If the function is registered using the sqlite3_collation_needed() API,
5554** then it is passed the names of undefined collation sequences as strings
5555** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5556** the names are passed as UTF-16 in machine native byte order.
5557** ^A call to either function replaces the existing collation-needed callback.
5558**
5559** ^(When the callback is invoked, the first argument passed is a copy
5560** of the second argument to sqlite3_collation_needed() or
5561** sqlite3_collation_needed16(). The second argument is the database
5562** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5563** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5564** sequence function required. The fourth parameter is the name of the
5565** required collation sequence.)^
5566**
5567** The callback function should register the desired collation using
5568** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5569** [sqlite3_create_collation_v2()].
5570*/
5571SQLITE_API int sqlite3_collation_needed(
5572 sqlite3*,
5573 void*,
5574 void(*)(void*,sqlite3*,int eTextRep,const char*)
5575);
5576SQLITE_API int sqlite3_collation_needed16(
5577 sqlite3*,
5578 void*,
5579 void(*)(void*,sqlite3*,int eTextRep,const void*)
5580);
5581
5582#ifdef SQLITE_HAS_CODEC
5583/*
5584** Specify the key for an encrypted database. This routine should be
5585** called right after sqlite3_open().
5586**
5587** The code to implement this API is not available in the public release
5588** of SQLite.
5589*/
5590SQLITE_API int sqlite3_key(
5591 sqlite3 *db, /* Database to be rekeyed */
5592 const void *pKey, int nKey /* The key */
5593);
5594SQLITE_API int sqlite3_key_v2(
5595 sqlite3 *db, /* Database to be rekeyed */
5596 const char *zDbName, /* Name of the database */
5597 const void *pKey, int nKey /* The key */
5598);
5599
5600/*
5601** Change the key on an open database. If the current database is not
5602** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5603** database is decrypted.
5604**
5605** The code to implement this API is not available in the public release
5606** of SQLite.
5607*/
5608SQLITE_API int sqlite3_rekey(
5609 sqlite3 *db, /* Database to be rekeyed */
5610 const void *pKey, int nKey /* The new key */
5611);
5612SQLITE_API int sqlite3_rekey_v2(
5613 sqlite3 *db, /* Database to be rekeyed */
5614 const char *zDbName, /* Name of the database */
5615 const void *pKey, int nKey /* The new key */
5616);
5617
5618/*
5619** Specify the activation key for a SEE database. Unless
5620** activated, none of the SEE routines will work.
5621*/
5622SQLITE_API void sqlite3_activate_see(
5623 const char *zPassPhrase /* Activation phrase */
5624);
5625#endif
5626
5627#ifdef SQLITE_ENABLE_CEROD
5628/*
5629** Specify the activation key for a CEROD database. Unless
5630** activated, none of the CEROD routines will work.
5631*/
5632SQLITE_API void sqlite3_activate_cerod(
5633 const char *zPassPhrase /* Activation phrase */
5634);
5635#endif
5636
5637/*
5638** CAPI3REF: Suspend Execution For A Short Time
5639**
5640** The sqlite3_sleep() function causes the current thread to suspend execution
5641** for at least a number of milliseconds specified in its parameter.
5642**
5643** If the operating system does not support sleep requests with
5644** millisecond time resolution, then the time will be rounded up to
5645** the nearest second. The number of milliseconds of sleep actually
5646** requested from the operating system is returned.
5647**
5648** ^SQLite implements this interface by calling the xSleep()
5649** method of the default [sqlite3_vfs] object. If the xSleep() method
5650** of the default VFS is not implemented correctly, or not implemented at
5651** all, then the behavior of sqlite3_sleep() may deviate from the description
5652** in the previous paragraphs.
5653*/
5654SQLITE_API int sqlite3_sleep(int);
5655
5656/*
5657** CAPI3REF: Name Of The Folder Holding Temporary Files
5658**
5659** ^(If this global variable is made to point to a string which is
5660** the name of a folder (a.k.a. directory), then all temporary files
5661** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5662** will be placed in that directory.)^ ^If this variable
5663** is a NULL pointer, then SQLite performs a search for an appropriate
5664** temporary file directory.
5665**
5666** Applications are strongly discouraged from using this global variable.
5667** It is required to set a temporary folder on Windows Runtime (WinRT).
5668** But for all other platforms, it is highly recommended that applications
5669** neither read nor write this variable. This global variable is a relic
5670** that exists for backwards compatibility of legacy applications and should
5671** be avoided in new projects.
5672**
5673** It is not safe to read or modify this variable in more than one
5674** thread at a time. It is not safe to read or modify this variable
5675** if a [database connection] is being used at the same time in a separate
5676** thread.
5677** It is intended that this variable be set once
5678** as part of process initialization and before any SQLite interface
5679** routines have been called and that this variable remain unchanged
5680** thereafter.
5681**
5682** ^The [temp_store_directory pragma] may modify this variable and cause
5683** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5684** the [temp_store_directory pragma] always assumes that any string
5685** that this variable points to is held in memory obtained from
5686** [sqlite3_malloc] and the pragma may attempt to free that memory
5687** using [sqlite3_free].
5688** Hence, if this variable is modified directly, either it should be
5689** made NULL or made to point to memory obtained from [sqlite3_malloc]
5690** or else the use of the [temp_store_directory pragma] should be avoided.
5691** Except when requested by the [temp_store_directory pragma], SQLite
5692** does not free the memory that sqlite3_temp_directory points to. If
5693** the application wants that memory to be freed, it must do
5694** so itself, taking care to only do so after all [database connection]
5695** objects have been destroyed.
5696**
5697** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5698** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5699** features that require the use of temporary files may fail. Here is an
5700** example of how to do this using C++ with the Windows Runtime:
5701**
5702** <blockquote><pre>
5703** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5704** &nbsp; TemporaryFolder->Path->Data();
5705** char zPathBuf&#91;MAX_PATH + 1&#93;;
5706** memset(zPathBuf, 0, sizeof(zPathBuf));
5707** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5708** &nbsp; NULL, NULL);
5709** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5710** </pre></blockquote>
5711*/
5712SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5713
5714/*
5715** CAPI3REF: Name Of The Folder Holding Database Files
5716**
5717** ^(If this global variable is made to point to a string which is
5718** the name of a folder (a.k.a. directory), then all database files
5719** specified with a relative pathname and created or accessed by
5720** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5721** to be relative to that directory.)^ ^If this variable is a NULL
5722** pointer, then SQLite assumes that all database files specified
5723** with a relative pathname are relative to the current directory
5724** for the process. Only the windows VFS makes use of this global
5725** variable; it is ignored by the unix VFS.
5726**
5727** Changing the value of this variable while a database connection is
5728** open can result in a corrupt database.
5729**
5730** It is not safe to read or modify this variable in more than one
5731** thread at a time. It is not safe to read or modify this variable
5732** if a [database connection] is being used at the same time in a separate
5733** thread.
5734** It is intended that this variable be set once
5735** as part of process initialization and before any SQLite interface
5736** routines have been called and that this variable remain unchanged
5737** thereafter.
5738**
5739** ^The [data_store_directory pragma] may modify this variable and cause
5740** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5741** the [data_store_directory pragma] always assumes that any string
5742** that this variable points to is held in memory obtained from
5743** [sqlite3_malloc] and the pragma may attempt to free that memory
5744** using [sqlite3_free].
5745** Hence, if this variable is modified directly, either it should be
5746** made NULL or made to point to memory obtained from [sqlite3_malloc]
5747** or else the use of the [data_store_directory pragma] should be avoided.
5748*/
5749SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5750
5751/*
5752** CAPI3REF: Win32 Specific Interface
5753**
5754** These interfaces are available only on Windows. The
5755** [sqlite3_win32_set_directory] interface is used to set the value associated
5756** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
5757** zValue, depending on the value of the type parameter. The zValue parameter
5758** should be NULL to cause the previous value to be freed via [sqlite3_free];
5759** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
5760** prior to being used. The [sqlite3_win32_set_directory] interface returns
5761** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
5762** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
5763** [sqlite3_data_directory] variable is intended to act as a replacement for
5764** the current directory on the sub-platforms of Win32 where that concept is
5765** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
5766** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
5767** sqlite3_win32_set_directory interface except the string parameter must be
5768** UTF-8 or UTF-16, respectively.
5769*/
5770SQLITE_API int sqlite3_win32_set_directory(
5771 unsigned long type, /* Identifier for directory being set or reset */
5772 void *zValue /* New value for directory being set or reset */
5773);
5774SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
5775SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
5776
5777/*
5778** CAPI3REF: Win32 Directory Types
5779**
5780** These macros are only available on Windows. They define the allowed values
5781** for the type argument to the [sqlite3_win32_set_directory] interface.
5782*/
5783#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
5784#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
5785
5786/*
5787** CAPI3REF: Test For Auto-Commit Mode
5788** KEYWORDS: {autocommit mode}
5789** METHOD: sqlite3
5790**
5791** ^The sqlite3_get_autocommit() interface returns non-zero or
5792** zero if the given database connection is or is not in autocommit mode,
5793** respectively. ^Autocommit mode is on by default.
5794** ^Autocommit mode is disabled by a [BEGIN] statement.
5795** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5796**
5797** If certain kinds of errors occur on a statement within a multi-statement
5798** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5799** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5800** transaction might be rolled back automatically. The only way to
5801** find out whether SQLite automatically rolled back the transaction after
5802** an error is to use this function.
5803**
5804** If another thread changes the autocommit status of the database
5805** connection while this routine is running, then the return value
5806** is undefined.
5807*/
5808SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5809
5810/*
5811** CAPI3REF: Find The Database Handle Of A Prepared Statement
5812** METHOD: sqlite3_stmt
5813**
5814** ^The sqlite3_db_handle interface returns the [database connection] handle
5815** to which a [prepared statement] belongs. ^The [database connection]
5816** returned by sqlite3_db_handle is the same [database connection]
5817** that was the first argument
5818** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5819** create the statement in the first place.
5820*/
5821SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5822
5823/*
5824** CAPI3REF: Return The Filename For A Database Connection
5825** METHOD: sqlite3
5826**
5827** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5828** associated with database N of connection D. ^The main database file
5829** has the name "main". If there is no attached database N on the database
5830** connection D, or if database N is a temporary or in-memory database, then
5831** this function will return either a NULL pointer or an empty string.
5832**
5833** ^The filename returned by this function is the output of the
5834** xFullPathname method of the [VFS]. ^In other words, the filename
5835** will be an absolute pathname, even if the filename used
5836** to open the database originally was a URI or relative pathname.
5837*/
5838SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5839
5840/*
5841** CAPI3REF: Determine if a database is read-only
5842** METHOD: sqlite3
5843**
5844** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5845** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5846** the name of a database on connection D.
5847*/
5848SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5849
5850/*
5851** CAPI3REF: Find the next prepared statement
5852** METHOD: sqlite3
5853**
5854** ^This interface returns a pointer to the next [prepared statement] after
5855** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5856** then this interface returns a pointer to the first prepared statement
5857** associated with the database connection pDb. ^If no prepared statement
5858** satisfies the conditions of this routine, it returns NULL.
5859**
5860** The [database connection] pointer D in a call to
5861** [sqlite3_next_stmt(D,S)] must refer to an open database
5862** connection and in particular must not be a NULL pointer.
5863*/
5864SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5865
5866/*
5867** CAPI3REF: Commit And Rollback Notification Callbacks
5868** METHOD: sqlite3
5869**
5870** ^The sqlite3_commit_hook() interface registers a callback
5871** function to be invoked whenever a transaction is [COMMIT | committed].
5872** ^Any callback set by a previous call to sqlite3_commit_hook()
5873** for the same database connection is overridden.
5874** ^The sqlite3_rollback_hook() interface registers a callback
5875** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5876** ^Any callback set by a previous call to sqlite3_rollback_hook()
5877** for the same database connection is overridden.
5878** ^The pArg argument is passed through to the callback.
5879** ^If the callback on a commit hook function returns non-zero,
5880** then the commit is converted into a rollback.
5881**
5882** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5883** return the P argument from the previous call of the same function
5884** on the same [database connection] D, or NULL for
5885** the first call for each function on D.
5886**
5887** The commit and rollback hook callbacks are not reentrant.
5888** The callback implementation must not do anything that will modify
5889** the database connection that invoked the callback. Any actions
5890** to modify the database connection must be deferred until after the
5891** completion of the [sqlite3_step()] call that triggered the commit
5892** or rollback hook in the first place.
5893** Note that running any other SQL statements, including SELECT statements,
5894** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5895** the database connections for the meaning of "modify" in this paragraph.
5896**
5897** ^Registering a NULL function disables the callback.
5898**
5899** ^When the commit hook callback routine returns zero, the [COMMIT]
5900** operation is allowed to continue normally. ^If the commit hook
5901** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5902** ^The rollback hook is invoked on a rollback that results from a commit
5903** hook returning non-zero, just as it would be with any other rollback.
5904**
5905** ^For the purposes of this API, a transaction is said to have been
5906** rolled back if an explicit "ROLLBACK" statement is executed, or
5907** an error or constraint causes an implicit rollback to occur.
5908** ^The rollback callback is not invoked if a transaction is
5909** automatically rolled back because the database connection is closed.
5910**
5911** See also the [sqlite3_update_hook()] interface.
5912*/
5913SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5914SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5915
5916/*
5917** CAPI3REF: Data Change Notification Callbacks
5918** METHOD: sqlite3
5919**
5920** ^The sqlite3_update_hook() interface registers a callback function
5921** with the [database connection] identified by the first argument
5922** to be invoked whenever a row is updated, inserted or deleted in
5923** a [rowid table].
5924** ^Any callback set by a previous call to this function
5925** for the same database connection is overridden.
5926**
5927** ^The second argument is a pointer to the function to invoke when a
5928** row is updated, inserted or deleted in a rowid table.
5929** ^The first argument to the callback is a copy of the third argument
5930** to sqlite3_update_hook().
5931** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5932** or [SQLITE_UPDATE], depending on the operation that caused the callback
5933** to be invoked.
5934** ^The third and fourth arguments to the callback contain pointers to the
5935** database and table name containing the affected row.
5936** ^The final callback parameter is the [rowid] of the row.
5937** ^In the case of an update, this is the [rowid] after the update takes place.
5938**
5939** ^(The update hook is not invoked when internal system tables are
5940** modified (i.e. sqlite_master and sqlite_sequence).)^
5941** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5942**
5943** ^In the current implementation, the update hook
5944** is not invoked when conflicting rows are deleted because of an
5945** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5946** invoked when rows are deleted using the [truncate optimization].
5947** The exceptions defined in this paragraph might change in a future
5948** release of SQLite.
5949**
5950** The update hook implementation must not do anything that will modify
5951** the database connection that invoked the update hook. Any actions
5952** to modify the database connection must be deferred until after the
5953** completion of the [sqlite3_step()] call that triggered the update hook.
5954** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5955** database connections for the meaning of "modify" in this paragraph.
5956**
5957** ^The sqlite3_update_hook(D,C,P) function
5958** returns the P argument from the previous call
5959** on the same [database connection] D, or NULL for
5960** the first call on D.
5961**
5962** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5963** and [sqlite3_preupdate_hook()] interfaces.
5964*/
5965SQLITE_API void *sqlite3_update_hook(
5966 sqlite3*,
5967 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5968 void*
5969);
5970
5971/*
5972** CAPI3REF: Enable Or Disable Shared Pager Cache
5973**
5974** ^(This routine enables or disables the sharing of the database cache
5975** and schema data structures between [database connection | connections]
5976** to the same database. Sharing is enabled if the argument is true
5977** and disabled if the argument is false.)^
5978**
5979** ^Cache sharing is enabled and disabled for an entire process.
5980** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5981** In prior versions of SQLite,
5982** sharing was enabled or disabled for each thread separately.
5983**
5984** ^(The cache sharing mode set by this interface effects all subsequent
5985** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5986** Existing database connections continue use the sharing mode
5987** that was in effect at the time they were opened.)^
5988**
5989** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5990** successfully. An [error code] is returned otherwise.)^
5991**
5992** ^Shared cache is disabled by default. But this might change in
5993** future releases of SQLite. Applications that care about shared
5994** cache setting should set it explicitly.
5995**
5996** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5997** and will always return SQLITE_MISUSE. On those systems,
5998** shared cache mode should be enabled per-database connection via
5999** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6000**
6001** This interface is threadsafe on processors where writing a
6002** 32-bit integer is atomic.
6003**
6004** See Also: [SQLite Shared-Cache Mode]
6005*/
6006SQLITE_API int sqlite3_enable_shared_cache(int);
6007
6008/*
6009** CAPI3REF: Attempt To Free Heap Memory
6010**
6011** ^The sqlite3_release_memory() interface attempts to free N bytes
6012** of heap memory by deallocating non-essential memory allocations
6013** held by the database library. Memory used to cache database
6014** pages to improve performance is an example of non-essential memory.
6015** ^sqlite3_release_memory() returns the number of bytes actually freed,
6016** which might be more or less than the amount requested.
6017** ^The sqlite3_release_memory() routine is a no-op returning zero
6018** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6019**
6020** See also: [sqlite3_db_release_memory()]
6021*/
6022SQLITE_API int sqlite3_release_memory(int);
6023
6024/*
6025** CAPI3REF: Free Memory Used By A Database Connection
6026** METHOD: sqlite3
6027**
6028** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6029** memory as possible from database connection D. Unlike the
6030** [sqlite3_release_memory()] interface, this interface is in effect even
6031** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6032** omitted.
6033**
6034** See also: [sqlite3_release_memory()]
6035*/
6036SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6037
6038/*
6039** CAPI3REF: Impose A Limit On Heap Size
6040**
6041** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6042** soft limit on the amount of heap memory that may be allocated by SQLite.
6043** ^SQLite strives to keep heap memory utilization below the soft heap
6044** limit by reducing the number of pages held in the page cache
6045** as heap memory usages approaches the limit.
6046** ^The soft heap limit is "soft" because even though SQLite strives to stay
6047** below the limit, it will exceed the limit rather than generate
6048** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6049** is advisory only.
6050**
6051** ^The return value from sqlite3_soft_heap_limit64() is the size of
6052** the soft heap limit prior to the call, or negative in the case of an
6053** error. ^If the argument N is negative
6054** then no change is made to the soft heap limit. Hence, the current
6055** size of the soft heap limit can be determined by invoking
6056** sqlite3_soft_heap_limit64() with a negative argument.
6057**
6058** ^If the argument N is zero then the soft heap limit is disabled.
6059**
6060** ^(The soft heap limit is not enforced in the current implementation
6061** if one or more of following conditions are true:
6062**
6063** <ul>
6064** <li> The soft heap limit is set to zero.
6065** <li> Memory accounting is disabled using a combination of the
6066** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6067** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6068** <li> An alternative page cache implementation is specified using
6069** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6070** <li> The page cache allocates from its own memory pool supplied
6071** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6072** from the heap.
6073** </ul>)^
6074**
6075** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
6076** the soft heap limit is enforced
6077** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
6078** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
6079** the soft heap limit is enforced on every memory allocation. Without
6080** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
6081** when memory is allocated by the page cache. Testing suggests that because
6082** the page cache is the predominate memory user in SQLite, most
6083** applications will achieve adequate soft heap limit enforcement without
6084** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6085**
6086** The circumstances under which SQLite will enforce the soft heap limit may
6087** changes in future releases of SQLite.
6088*/
6089SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6090
6091/*
6092** CAPI3REF: Deprecated Soft Heap Limit Interface
6093** DEPRECATED
6094**
6095** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6096** interface. This routine is provided for historical compatibility
6097** only. All new applications should use the
6098** [sqlite3_soft_heap_limit64()] interface rather than this one.
6099*/
6100SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6101
6102
6103/*
6104** CAPI3REF: Extract Metadata About A Column Of A Table
6105** METHOD: sqlite3
6106**
6107** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6108** information about column C of table T in database D
6109** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6110** interface returns SQLITE_OK and fills in the non-NULL pointers in
6111** the final five arguments with appropriate values if the specified
6112** column exists. ^The sqlite3_table_column_metadata() interface returns
6113** SQLITE_ERROR and if the specified column does not exist.
6114** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6115** NULL pointer, then this routine simply checks for the existence of the
6116** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6117** does not. If the table name parameter T in a call to
6118** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6119** undefined behavior.
6120**
6121** ^The column is identified by the second, third and fourth parameters to
6122** this function. ^(The second parameter is either the name of the database
6123** (i.e. "main", "temp", or an attached database) containing the specified
6124** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6125** for the table using the same algorithm used by the database engine to
6126** resolve unqualified table references.
6127**
6128** ^The third and fourth parameters to this function are the table and column
6129** name of the desired column, respectively.
6130**
6131** ^Metadata is returned by writing to the memory locations passed as the 5th
6132** and subsequent parameters to this function. ^Any of these arguments may be
6133** NULL, in which case the corresponding element of metadata is omitted.
6134**
6135** ^(<blockquote>
6136** <table border="1">
6137** <tr><th> Parameter <th> Output<br>Type <th> Description
6138**
6139** <tr><td> 5th <td> const char* <td> Data type
6140** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6141** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6142** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6143** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6144** </table>
6145** </blockquote>)^
6146**
6147** ^The memory pointed to by the character pointers returned for the
6148** declaration type and collation sequence is valid until the next
6149** call to any SQLite API function.
6150**
6151** ^If the specified table is actually a view, an [error code] is returned.
6152**
6153** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6154** is not a [WITHOUT ROWID] table and an
6155** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6156** parameters are set for the explicitly declared column. ^(If there is no
6157** [INTEGER PRIMARY KEY] column, then the outputs
6158** for the [rowid] are set as follows:
6159**
6160** <pre>
6161** data type: "INTEGER"
6162** collation sequence: "BINARY"
6163** not null: 0
6164** primary key: 1
6165** auto increment: 0
6166** </pre>)^
6167**
6168** ^This function causes all database schemas to be read from disk and
6169** parsed, if that has not already been done, and returns an error if
6170** any errors are encountered while loading the schema.
6171*/
6172SQLITE_API int sqlite3_table_column_metadata(
6173 sqlite3 *db, /* Connection handle */
6174 const char *zDbName, /* Database name or NULL */
6175 const char *zTableName, /* Table name */
6176 const char *zColumnName, /* Column name */
6177 char const **pzDataType, /* OUTPUT: Declared data type */
6178 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6179 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6180 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6181 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6182);
6183
6184/*
6185** CAPI3REF: Load An Extension
6186** METHOD: sqlite3
6187**
6188** ^This interface loads an SQLite extension library from the named file.
6189**
6190** ^The sqlite3_load_extension() interface attempts to load an
6191** [SQLite extension] library contained in the file zFile. If
6192** the file cannot be loaded directly, attempts are made to load
6193** with various operating-system specific extensions added.
6194** So for example, if "samplelib" cannot be loaded, then names like
6195** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6196** be tried also.
6197**
6198** ^The entry point is zProc.
6199** ^(zProc may be 0, in which case SQLite will try to come up with an
6200** entry point name on its own. It first tries "sqlite3_extension_init".
6201** If that does not work, it constructs a name "sqlite3_X_init" where the
6202** X is consists of the lower-case equivalent of all ASCII alphabetic
6203** characters in the filename from the last "/" to the first following
6204** "." and omitting any initial "lib".)^
6205** ^The sqlite3_load_extension() interface returns
6206** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6207** ^If an error occurs and pzErrMsg is not 0, then the
6208** [sqlite3_load_extension()] interface shall attempt to
6209** fill *pzErrMsg with error message text stored in memory
6210** obtained from [sqlite3_malloc()]. The calling function
6211** should free this memory by calling [sqlite3_free()].
6212**
6213** ^Extension loading must be enabled using
6214** [sqlite3_enable_load_extension()] or
6215** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6216** prior to calling this API,
6217** otherwise an error will be returned.
6218**
6219** <b>Security warning:</b> It is recommended that the
6220** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6221** interface. The use of the [sqlite3_enable_load_extension()] interface
6222** should be avoided. This will keep the SQL function [load_extension()]
6223** disabled and prevent SQL injections from giving attackers
6224** access to extension loading capabilities.
6225**
6226** See also the [load_extension() SQL function].
6227*/
6228SQLITE_API int sqlite3_load_extension(
6229 sqlite3 *db, /* Load the extension into this database connection */
6230 const char *zFile, /* Name of the shared library containing extension */
6231 const char *zProc, /* Entry point. Derived from zFile if 0 */
6232 char **pzErrMsg /* Put error message here if not 0 */
6233);
6234
6235/*
6236** CAPI3REF: Enable Or Disable Extension Loading
6237** METHOD: sqlite3
6238**
6239** ^So as not to open security holes in older applications that are
6240** unprepared to deal with [extension loading], and as a means of disabling
6241** [extension loading] while evaluating user-entered SQL, the following API
6242** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6243**
6244** ^Extension loading is off by default.
6245** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6246** to turn extension loading on and call it with onoff==0 to turn
6247** it back off again.
6248**
6249** ^This interface enables or disables both the C-API
6250** [sqlite3_load_extension()] and the SQL function [load_extension()].
6251** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6252** to enable or disable only the C-API.)^
6253**
6254** <b>Security warning:</b> It is recommended that extension loading
6255** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6256** rather than this interface, so the [load_extension()] SQL function
6257** remains disabled. This will prevent SQL injections from giving attackers
6258** access to extension loading capabilities.
6259*/
6260SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6261
6262/*
6263** CAPI3REF: Automatically Load Statically Linked Extensions
6264**
6265** ^This interface causes the xEntryPoint() function to be invoked for
6266** each new [database connection] that is created. The idea here is that
6267** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6268** that is to be automatically loaded into all new database connections.
6269**
6270** ^(Even though the function prototype shows that xEntryPoint() takes
6271** no arguments and returns void, SQLite invokes xEntryPoint() with three
6272** arguments and expects an integer result as if the signature of the
6273** entry point where as follows:
6274**
6275** <blockquote><pre>
6276** &nbsp; int xEntryPoint(
6277** &nbsp; sqlite3 *db,
6278** &nbsp; const char **pzErrMsg,
6279** &nbsp; const struct sqlite3_api_routines *pThunk
6280** &nbsp; );
6281** </pre></blockquote>)^
6282**
6283** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6284** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6285** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6286** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6287** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6288** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6289** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6290**
6291** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6292** on the list of automatic extensions is a harmless no-op. ^No entry point
6293** will be called more than once for each database connection that is opened.
6294**
6295** See also: [sqlite3_reset_auto_extension()]
6296** and [sqlite3_cancel_auto_extension()]
6297*/
6298SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6299
6300/*
6301** CAPI3REF: Cancel Automatic Extension Loading
6302**
6303** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6304** initialization routine X that was registered using a prior call to
6305** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6306** routine returns 1 if initialization routine X was successfully
6307** unregistered and it returns 0 if X was not on the list of initialization
6308** routines.
6309*/
6310SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6311
6312/*
6313** CAPI3REF: Reset Automatic Extension Loading
6314**
6315** ^This interface disables all automatic extensions previously
6316** registered using [sqlite3_auto_extension()].
6317*/
6318SQLITE_API void sqlite3_reset_auto_extension(void);
6319
6320/*
6321** The interface to the virtual-table mechanism is currently considered
6322** to be experimental. The interface might change in incompatible ways.
6323** If this is a problem for you, do not use the interface at this time.
6324**
6325** When the virtual-table mechanism stabilizes, we will declare the
6326** interface fixed, support it indefinitely, and remove this comment.
6327*/
6328
6329/*
6330** Structures used by the virtual table interface
6331*/
6332typedef struct sqlite3_vtab sqlite3_vtab;
6333typedef struct sqlite3_index_info sqlite3_index_info;
6334typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6335typedef struct sqlite3_module sqlite3_module;
6336
6337/*
6338** CAPI3REF: Virtual Table Object
6339** KEYWORDS: sqlite3_module {virtual table module}
6340**
6341** This structure, sometimes called a "virtual table module",
6342** defines the implementation of a [virtual tables].
6343** This structure consists mostly of methods for the module.
6344**
6345** ^A virtual table module is created by filling in a persistent
6346** instance of this structure and passing a pointer to that instance
6347** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6348** ^The registration remains valid until it is replaced by a different
6349** module or until the [database connection] closes. The content
6350** of this structure must not change while it is registered with
6351** any database connection.
6352*/
6353struct sqlite3_module {
6354 int iVersion;
6355 int (*xCreate)(sqlite3*, void *pAux,
6356 int argc, const char *const*argv,
6357 sqlite3_vtab **ppVTab, char**);
6358 int (*xConnect)(sqlite3*, void *pAux,
6359 int argc, const char *const*argv,
6360 sqlite3_vtab **ppVTab, char**);
6361 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6362 int (*xDisconnect)(sqlite3_vtab *pVTab);
6363 int (*xDestroy)(sqlite3_vtab *pVTab);
6364 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6365 int (*xClose)(sqlite3_vtab_cursor*);
6366 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6367 int argc, sqlite3_value **argv);
6368 int (*xNext)(sqlite3_vtab_cursor*);
6369 int (*xEof)(sqlite3_vtab_cursor*);
6370 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6371 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6372 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6373 int (*xBegin)(sqlite3_vtab *pVTab);
6374 int (*xSync)(sqlite3_vtab *pVTab);
6375 int (*xCommit)(sqlite3_vtab *pVTab);
6376 int (*xRollback)(sqlite3_vtab *pVTab);
6377 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6378 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6379 void **ppArg);
6380 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6381 /* The methods above are in version 1 of the sqlite_module object. Those
6382 ** below are for version 2 and greater. */
6383 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6384 int (*xRelease)(sqlite3_vtab *pVTab, int);
6385 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6386 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6387 ** Those below are for version 3 and greater. */
6388 int (*xShadowName)(const char*);
6389};
6390
6391/*
6392** CAPI3REF: Virtual Table Indexing Information
6393** KEYWORDS: sqlite3_index_info
6394**
6395** The sqlite3_index_info structure and its substructures is used as part
6396** of the [virtual table] interface to
6397** pass information into and receive the reply from the [xBestIndex]
6398** method of a [virtual table module]. The fields under **Inputs** are the
6399** inputs to xBestIndex and are read-only. xBestIndex inserts its
6400** results into the **Outputs** fields.
6401**
6402** ^(The aConstraint[] array records WHERE clause constraints of the form:
6403**
6404** <blockquote>column OP expr</blockquote>
6405**
6406** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6407** stored in aConstraint[].op using one of the
6408** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6409** ^(The index of the column is stored in
6410** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6411** expr on the right-hand side can be evaluated (and thus the constraint
6412** is usable) and false if it cannot.)^
6413**
6414** ^The optimizer automatically inverts terms of the form "expr OP column"
6415** and makes other simplifications to the WHERE clause in an attempt to
6416** get as many WHERE clause terms into the form shown above as possible.
6417** ^The aConstraint[] array only reports WHERE clause terms that are
6418** relevant to the particular virtual table being queried.
6419**
6420** ^Information about the ORDER BY clause is stored in aOrderBy[].
6421** ^Each term of aOrderBy records a column of the ORDER BY clause.
6422**
6423** The colUsed field indicates which columns of the virtual table may be
6424** required by the current scan. Virtual table columns are numbered from
6425** zero in the order in which they appear within the CREATE TABLE statement
6426** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6427** the corresponding bit is set within the colUsed mask if the column may be
6428** required by SQLite. If the table has at least 64 columns and any column
6429** to the right of the first 63 is required, then bit 63 of colUsed is also
6430** set. In other words, column iCol may be required if the expression
6431** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6432** non-zero.
6433**
6434** The [xBestIndex] method must fill aConstraintUsage[] with information
6435** about what parameters to pass to xFilter. ^If argvIndex>0 then
6436** the right-hand side of the corresponding aConstraint[] is evaluated
6437** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6438** is true, then the constraint is assumed to be fully handled by the
6439** virtual table and is not checked again by SQLite.)^
6440**
6441** ^The idxNum and idxPtr values are recorded and passed into the
6442** [xFilter] method.
6443** ^[sqlite3_free()] is used to free idxPtr if and only if
6444** needToFreeIdxPtr is true.
6445**
6446** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6447** the correct order to satisfy the ORDER BY clause so that no separate
6448** sorting step is required.
6449**
6450** ^The estimatedCost value is an estimate of the cost of a particular
6451** strategy. A cost of N indicates that the cost of the strategy is similar
6452** to a linear scan of an SQLite table with N rows. A cost of log(N)
6453** indicates that the expense of the operation is similar to that of a
6454** binary search on a unique indexed field of an SQLite table with N rows.
6455**
6456** ^The estimatedRows value is an estimate of the number of rows that
6457** will be returned by the strategy.
6458**
6459** The xBestIndex method may optionally populate the idxFlags field with a
6460** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6461** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6462** assumes that the strategy may visit at most one row.
6463**
6464** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6465** SQLite also assumes that if a call to the xUpdate() method is made as
6466** part of the same statement to delete or update a virtual table row and the
6467** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6468** any database changes. In other words, if the xUpdate() returns
6469** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6470** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6471** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6472** the xUpdate method are automatically rolled back by SQLite.
6473**
6474** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6475** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6476** If a virtual table extension is
6477** used with an SQLite version earlier than 3.8.2, the results of attempting
6478** to read or write the estimatedRows field are undefined (but are likely
6479** to included crashing the application). The estimatedRows field should
6480** therefore only be used if [sqlite3_libversion_number()] returns a
6481** value greater than or equal to 3008002. Similarly, the idxFlags field
6482** was added for [version 3.9.0] ([dateof:3.9.0]).
6483** It may therefore only be used if
6484** sqlite3_libversion_number() returns a value greater than or equal to
6485** 3009000.
6486*/
6487struct sqlite3_index_info {
6488 /* Inputs */
6489 int nConstraint; /* Number of entries in aConstraint */
6490 struct sqlite3_index_constraint {
6491 int iColumn; /* Column constrained. -1 for ROWID */
6492 unsigned char op; /* Constraint operator */
6493 unsigned char usable; /* True if this constraint is usable */
6494 int iTermOffset; /* Used internally - xBestIndex should ignore */
6495 } *aConstraint; /* Table of WHERE clause constraints */
6496 int nOrderBy; /* Number of terms in the ORDER BY clause */
6497 struct sqlite3_index_orderby {
6498 int iColumn; /* Column number */
6499 unsigned char desc; /* True for DESC. False for ASC. */
6500 } *aOrderBy; /* The ORDER BY clause */
6501 /* Outputs */
6502 struct sqlite3_index_constraint_usage {
6503 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6504 unsigned char omit; /* Do not code a test for this constraint */
6505 } *aConstraintUsage;
6506 int idxNum; /* Number used to identify the index */
6507 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6508 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6509 int orderByConsumed; /* True if output is already ordered */
6510 double estimatedCost; /* Estimated cost of using this index */
6511 /* Fields below are only available in SQLite 3.8.2 and later */
6512 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6513 /* Fields below are only available in SQLite 3.9.0 and later */
6514 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6515 /* Fields below are only available in SQLite 3.10.0 and later */
6516 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6517};
6518
6519/*
6520** CAPI3REF: Virtual Table Scan Flags
6521**
6522** Virtual table implementations are allowed to set the
6523** [sqlite3_index_info].idxFlags field to some combination of
6524** these bits.
6525*/
6526#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6527
6528/*
6529** CAPI3REF: Virtual Table Constraint Operator Codes
6530**
6531** These macros defined the allowed values for the
6532** [sqlite3_index_info].aConstraint[].op field. Each value represents
6533** an operator that is part of a constraint term in the wHERE clause of
6534** a query that uses a [virtual table].
6535*/
6536#define SQLITE_INDEX_CONSTRAINT_EQ 2
6537#define SQLITE_INDEX_CONSTRAINT_GT 4
6538#define SQLITE_INDEX_CONSTRAINT_LE 8
6539#define SQLITE_INDEX_CONSTRAINT_LT 16
6540#define SQLITE_INDEX_CONSTRAINT_GE 32
6541#define SQLITE_INDEX_CONSTRAINT_MATCH 64
6542#define SQLITE_INDEX_CONSTRAINT_LIKE 65
6543#define SQLITE_INDEX_CONSTRAINT_GLOB 66
6544#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6545#define SQLITE_INDEX_CONSTRAINT_NE 68
6546#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6547#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6548#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6549#define SQLITE_INDEX_CONSTRAINT_IS 72
6550#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
6551
6552/*
6553** CAPI3REF: Register A Virtual Table Implementation
6554** METHOD: sqlite3
6555**
6556** ^These routines are used to register a new [virtual table module] name.
6557** ^Module names must be registered before
6558** creating a new [virtual table] using the module and before using a
6559** preexisting [virtual table] for the module.
6560**
6561** ^The module name is registered on the [database connection] specified
6562** by the first parameter. ^The name of the module is given by the
6563** second parameter. ^The third parameter is a pointer to
6564** the implementation of the [virtual table module]. ^The fourth
6565** parameter is an arbitrary client data pointer that is passed through
6566** into the [xCreate] and [xConnect] methods of the virtual table module
6567** when a new virtual table is be being created or reinitialized.
6568**
6569** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6570** is a pointer to a destructor for the pClientData. ^SQLite will
6571** invoke the destructor function (if it is not NULL) when SQLite
6572** no longer needs the pClientData pointer. ^The destructor will also
6573** be invoked if the call to sqlite3_create_module_v2() fails.
6574** ^The sqlite3_create_module()
6575** interface is equivalent to sqlite3_create_module_v2() with a NULL
6576** destructor.
6577*/
6578SQLITE_API int sqlite3_create_module(
6579 sqlite3 *db, /* SQLite connection to register module with */
6580 const char *zName, /* Name of the module */
6581 const sqlite3_module *p, /* Methods for the module */
6582 void *pClientData /* Client data for xCreate/xConnect */
6583);
6584SQLITE_API int sqlite3_create_module_v2(
6585 sqlite3 *db, /* SQLite connection to register module with */
6586 const char *zName, /* Name of the module */
6587 const sqlite3_module *p, /* Methods for the module */
6588 void *pClientData, /* Client data for xCreate/xConnect */
6589 void(*xDestroy)(void*) /* Module destructor function */
6590);
6591
6592/*
6593** CAPI3REF: Virtual Table Instance Object
6594** KEYWORDS: sqlite3_vtab
6595**
6596** Every [virtual table module] implementation uses a subclass
6597** of this object to describe a particular instance
6598** of the [virtual table]. Each subclass will
6599** be tailored to the specific needs of the module implementation.
6600** The purpose of this superclass is to define certain fields that are
6601** common to all module implementations.
6602**
6603** ^Virtual tables methods can set an error message by assigning a
6604** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6605** take care that any prior string is freed by a call to [sqlite3_free()]
6606** prior to assigning a new string to zErrMsg. ^After the error message
6607** is delivered up to the client application, the string will be automatically
6608** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6609*/
6610struct sqlite3_vtab {
6611 const sqlite3_module *pModule; /* The module for this virtual table */
6612 int nRef; /* Number of open cursors */
6613 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6614 /* Virtual table implementations will typically add additional fields */
6615};
6616
6617/*
6618** CAPI3REF: Virtual Table Cursor Object
6619** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6620**
6621** Every [virtual table module] implementation uses a subclass of the
6622** following structure to describe cursors that point into the
6623** [virtual table] and are used
6624** to loop through the virtual table. Cursors are created using the
6625** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6626** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6627** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6628** of the module. Each module implementation will define
6629** the content of a cursor structure to suit its own needs.
6630**
6631** This superclass exists in order to define fields of the cursor that
6632** are common to all implementations.
6633*/
6634struct sqlite3_vtab_cursor {
6635 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6636 /* Virtual table implementations will typically add additional fields */
6637};
6638
6639/*
6640** CAPI3REF: Declare The Schema Of A Virtual Table
6641**
6642** ^The [xCreate] and [xConnect] methods of a
6643** [virtual table module] call this interface
6644** to declare the format (the names and datatypes of the columns) of
6645** the virtual tables they implement.
6646*/
6647SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6648
6649/*
6650** CAPI3REF: Overload A Function For A Virtual Table
6651** METHOD: sqlite3
6652**
6653** ^(Virtual tables can provide alternative implementations of functions
6654** using the [xFindFunction] method of the [virtual table module].
6655** But global versions of those functions
6656** must exist in order to be overloaded.)^
6657**
6658** ^(This API makes sure a global version of a function with a particular
6659** name and number of parameters exists. If no such function exists
6660** before this API is called, a new function is created.)^ ^The implementation
6661** of the new function always causes an exception to be thrown. So
6662** the new function is not good for anything by itself. Its only
6663** purpose is to be a placeholder function that can be overloaded
6664** by a [virtual table].
6665*/
6666SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6667
6668/*
6669** The interface to the virtual-table mechanism defined above (back up
6670** to a comment remarkably similar to this one) is currently considered
6671** to be experimental. The interface might change in incompatible ways.
6672** If this is a problem for you, do not use the interface at this time.
6673**
6674** When the virtual-table mechanism stabilizes, we will declare the
6675** interface fixed, support it indefinitely, and remove this comment.
6676*/
6677
6678/*
6679** CAPI3REF: A Handle To An Open BLOB
6680** KEYWORDS: {BLOB handle} {BLOB handles}
6681**
6682** An instance of this object represents an open BLOB on which
6683** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6684** ^Objects of this type are created by [sqlite3_blob_open()]
6685** and destroyed by [sqlite3_blob_close()].
6686** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6687** can be used to read or write small subsections of the BLOB.
6688** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6689*/
6690typedef struct sqlite3_blob sqlite3_blob;
6691
6692/*
6693** CAPI3REF: Open A BLOB For Incremental I/O
6694** METHOD: sqlite3
6695** CONSTRUCTOR: sqlite3_blob
6696**
6697** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6698** in row iRow, column zColumn, table zTable in database zDb;
6699** in other words, the same BLOB that would be selected by:
6700**
6701** <pre>
6702** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6703** </pre>)^
6704**
6705** ^(Parameter zDb is not the filename that contains the database, but
6706** rather the symbolic name of the database. For attached databases, this is
6707** the name that appears after the AS keyword in the [ATTACH] statement.
6708** For the main database file, the database name is "main". For TEMP
6709** tables, the database name is "temp".)^
6710**
6711** ^If the flags parameter is non-zero, then the BLOB is opened for read
6712** and write access. ^If the flags parameter is zero, the BLOB is opened for
6713** read-only access.
6714**
6715** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6716** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6717** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6718** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6719** on *ppBlob after this function it returns.
6720**
6721** This function fails with SQLITE_ERROR if any of the following are true:
6722** <ul>
6723** <li> ^(Database zDb does not exist)^,
6724** <li> ^(Table zTable does not exist within database zDb)^,
6725** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6726** <li> ^(Column zColumn does not exist)^,
6727** <li> ^(Row iRow is not present in the table)^,
6728** <li> ^(The specified column of row iRow contains a value that is not
6729** a TEXT or BLOB value)^,
6730** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6731** constraint and the blob is being opened for read/write access)^,
6732** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6733** column zColumn is part of a [child key] definition and the blob is
6734** being opened for read/write access)^.
6735** </ul>
6736**
6737** ^Unless it returns SQLITE_MISUSE, this function sets the
6738** [database connection] error code and message accessible via
6739** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6740**
6741** A BLOB referenced by sqlite3_blob_open() may be read using the
6742** [sqlite3_blob_read()] interface and modified by using
6743** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6744** different row of the same table using the [sqlite3_blob_reopen()]
6745** interface. However, the column, table, or database of a [BLOB handle]
6746** cannot be changed after the [BLOB handle] is opened.
6747**
6748** ^(If the row that a BLOB handle points to is modified by an
6749** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6750** then the BLOB handle is marked as "expired".
6751** This is true if any column of the row is changed, even a column
6752** other than the one the BLOB handle is open on.)^
6753** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6754** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6755** ^(Changes written into a BLOB prior to the BLOB expiring are not
6756** rolled back by the expiration of the BLOB. Such changes will eventually
6757** commit if the transaction continues to completion.)^
6758**
6759** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6760** the opened blob. ^The size of a blob may not be changed by this
6761** interface. Use the [UPDATE] SQL command to change the size of a
6762** blob.
6763**
6764** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6765** and the built-in [zeroblob] SQL function may be used to create a
6766** zero-filled blob to read or write using the incremental-blob interface.
6767**
6768** To avoid a resource leak, every open [BLOB handle] should eventually
6769** be released by a call to [sqlite3_blob_close()].
6770**
6771** See also: [sqlite3_blob_close()],
6772** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6773** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6774*/
6775SQLITE_API int sqlite3_blob_open(
6776 sqlite3*,
6777 const char *zDb,
6778 const char *zTable,
6779 const char *zColumn,
6780 sqlite3_int64 iRow,
6781 int flags,
6782 sqlite3_blob **ppBlob
6783);
6784
6785/*
6786** CAPI3REF: Move a BLOB Handle to a New Row
6787** METHOD: sqlite3_blob
6788**
6789** ^This function is used to move an existing [BLOB handle] so that it points
6790** to a different row of the same database table. ^The new row is identified
6791** by the rowid value passed as the second argument. Only the row can be
6792** changed. ^The database, table and column on which the blob handle is open
6793** remain the same. Moving an existing [BLOB handle] to a new row is
6794** faster than closing the existing handle and opening a new one.
6795**
6796** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6797** it must exist and there must be either a blob or text value stored in
6798** the nominated column.)^ ^If the new row is not present in the table, or if
6799** it does not contain a blob or text value, or if another error occurs, an
6800** SQLite error code is returned and the blob handle is considered aborted.
6801** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6802** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6803** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6804** always returns zero.
6805**
6806** ^This function sets the database handle error code and message.
6807*/
6808SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6809
6810/*
6811** CAPI3REF: Close A BLOB Handle
6812** DESTRUCTOR: sqlite3_blob
6813**
6814** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6815** unconditionally. Even if this routine returns an error code, the
6816** handle is still closed.)^
6817**
6818** ^If the blob handle being closed was opened for read-write access, and if
6819** the database is in auto-commit mode and there are no other open read-write
6820** blob handles or active write statements, the current transaction is
6821** committed. ^If an error occurs while committing the transaction, an error
6822** code is returned and the transaction rolled back.
6823**
6824** Calling this function with an argument that is not a NULL pointer or an
6825** open blob handle results in undefined behaviour. ^Calling this routine
6826** with a null pointer (such as would be returned by a failed call to
6827** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6828** is passed a valid open blob handle, the values returned by the
6829** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6830*/
6831SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6832
6833/*
6834** CAPI3REF: Return The Size Of An Open BLOB
6835** METHOD: sqlite3_blob
6836**
6837** ^Returns the size in bytes of the BLOB accessible via the
6838** successfully opened [BLOB handle] in its only argument. ^The
6839** incremental blob I/O routines can only read or overwriting existing
6840** blob content; they cannot change the size of a blob.
6841**
6842** This routine only works on a [BLOB handle] which has been created
6843** by a prior successful call to [sqlite3_blob_open()] and which has not
6844** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6845** to this routine results in undefined and probably undesirable behavior.
6846*/
6847SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6848
6849/*
6850** CAPI3REF: Read Data From A BLOB Incrementally
6851** METHOD: sqlite3_blob
6852**
6853** ^(This function is used to read data from an open [BLOB handle] into a
6854** caller-supplied buffer. N bytes of data are copied into buffer Z
6855** from the open BLOB, starting at offset iOffset.)^
6856**
6857** ^If offset iOffset is less than N bytes from the end of the BLOB,
6858** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6859** less than zero, [SQLITE_ERROR] is returned and no data is read.
6860** ^The size of the blob (and hence the maximum value of N+iOffset)
6861** can be determined using the [sqlite3_blob_bytes()] interface.
6862**
6863** ^An attempt to read from an expired [BLOB handle] fails with an
6864** error code of [SQLITE_ABORT].
6865**
6866** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6867** Otherwise, an [error code] or an [extended error code] is returned.)^
6868**
6869** This routine only works on a [BLOB handle] which has been created
6870** by a prior successful call to [sqlite3_blob_open()] and which has not
6871** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6872** to this routine results in undefined and probably undesirable behavior.
6873**
6874** See also: [sqlite3_blob_write()].
6875*/
6876SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6877
6878/*
6879** CAPI3REF: Write Data Into A BLOB Incrementally
6880** METHOD: sqlite3_blob
6881**
6882** ^(This function is used to write data into an open [BLOB handle] from a
6883** caller-supplied buffer. N bytes of data are copied from the buffer Z
6884** into the open BLOB, starting at offset iOffset.)^
6885**
6886** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6887** Otherwise, an [error code] or an [extended error code] is returned.)^
6888** ^Unless SQLITE_MISUSE is returned, this function sets the
6889** [database connection] error code and message accessible via
6890** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6891**
6892** ^If the [BLOB handle] passed as the first argument was not opened for
6893** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6894** this function returns [SQLITE_READONLY].
6895**
6896** This function may only modify the contents of the BLOB; it is
6897** not possible to increase the size of a BLOB using this API.
6898** ^If offset iOffset is less than N bytes from the end of the BLOB,
6899** [SQLITE_ERROR] is returned and no data is written. The size of the
6900** BLOB (and hence the maximum value of N+iOffset) can be determined
6901** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6902** than zero [SQLITE_ERROR] is returned and no data is written.
6903**
6904** ^An attempt to write to an expired [BLOB handle] fails with an
6905** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6906** before the [BLOB handle] expired are not rolled back by the
6907** expiration of the handle, though of course those changes might
6908** have been overwritten by the statement that expired the BLOB handle
6909** or by other independent statements.
6910**
6911** This routine only works on a [BLOB handle] which has been created
6912** by a prior successful call to [sqlite3_blob_open()] and which has not
6913** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6914** to this routine results in undefined and probably undesirable behavior.
6915**
6916** See also: [sqlite3_blob_read()].
6917*/
6918SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6919
6920/*
6921** CAPI3REF: Virtual File System Objects
6922**
6923** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6924** that SQLite uses to interact
6925** with the underlying operating system. Most SQLite builds come with a
6926** single default VFS that is appropriate for the host computer.
6927** New VFSes can be registered and existing VFSes can be unregistered.
6928** The following interfaces are provided.
6929**
6930** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6931** ^Names are case sensitive.
6932** ^Names are zero-terminated UTF-8 strings.
6933** ^If there is no match, a NULL pointer is returned.
6934** ^If zVfsName is NULL then the default VFS is returned.
6935**
6936** ^New VFSes are registered with sqlite3_vfs_register().
6937** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6938** ^The same VFS can be registered multiple times without injury.
6939** ^To make an existing VFS into the default VFS, register it again
6940** with the makeDflt flag set. If two different VFSes with the
6941** same name are registered, the behavior is undefined. If a
6942** VFS is registered with a name that is NULL or an empty string,
6943** then the behavior is undefined.
6944**
6945** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6946** ^(If the default VFS is unregistered, another VFS is chosen as
6947** the default. The choice for the new VFS is arbitrary.)^
6948*/
6949SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6950SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6951SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6952
6953/*
6954** CAPI3REF: Mutexes
6955**
6956** The SQLite core uses these routines for thread
6957** synchronization. Though they are intended for internal
6958** use by SQLite, code that links against SQLite is
6959** permitted to use any of these routines.
6960**
6961** The SQLite source code contains multiple implementations
6962** of these mutex routines. An appropriate implementation
6963** is selected automatically at compile-time. The following
6964** implementations are available in the SQLite core:
6965**
6966** <ul>
6967** <li> SQLITE_MUTEX_PTHREADS
6968** <li> SQLITE_MUTEX_W32
6969** <li> SQLITE_MUTEX_NOOP
6970** </ul>
6971**
6972** The SQLITE_MUTEX_NOOP implementation is a set of routines
6973** that does no real locking and is appropriate for use in
6974** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6975** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6976** and Windows.
6977**
6978** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6979** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6980** implementation is included with the library. In this case the
6981** application must supply a custom mutex implementation using the
6982** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6983** before calling sqlite3_initialize() or any other public sqlite3_
6984** function that calls sqlite3_initialize().
6985**
6986** ^The sqlite3_mutex_alloc() routine allocates a new
6987** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6988** routine returns NULL if it is unable to allocate the requested
6989** mutex. The argument to sqlite3_mutex_alloc() must one of these
6990** integer constants:
6991**
6992** <ul>
6993** <li> SQLITE_MUTEX_FAST
6994** <li> SQLITE_MUTEX_RECURSIVE
6995** <li> SQLITE_MUTEX_STATIC_MASTER
6996** <li> SQLITE_MUTEX_STATIC_MEM
6997** <li> SQLITE_MUTEX_STATIC_OPEN
6998** <li> SQLITE_MUTEX_STATIC_PRNG
6999** <li> SQLITE_MUTEX_STATIC_LRU
7000** <li> SQLITE_MUTEX_STATIC_PMEM
7001** <li> SQLITE_MUTEX_STATIC_APP1
7002** <li> SQLITE_MUTEX_STATIC_APP2
7003** <li> SQLITE_MUTEX_STATIC_APP3
7004** <li> SQLITE_MUTEX_STATIC_VFS1
7005** <li> SQLITE_MUTEX_STATIC_VFS2
7006** <li> SQLITE_MUTEX_STATIC_VFS3
7007** </ul>
7008**
7009** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7010** cause sqlite3_mutex_alloc() to create
7011** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7012** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7013** The mutex implementation does not need to make a distinction
7014** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7015** not want to. SQLite will only request a recursive mutex in
7016** cases where it really needs one. If a faster non-recursive mutex
7017** implementation is available on the host platform, the mutex subsystem
7018** might return such a mutex in response to SQLITE_MUTEX_FAST.
7019**
7020** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7021** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7022** a pointer to a static preexisting mutex. ^Nine static mutexes are
7023** used by the current version of SQLite. Future versions of SQLite
7024** may add additional static mutexes. Static mutexes are for internal
7025** use by SQLite only. Applications that use SQLite mutexes should
7026** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7027** SQLITE_MUTEX_RECURSIVE.
7028**
7029** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7030** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7031** returns a different mutex on every call. ^For the static
7032** mutex types, the same mutex is returned on every call that has
7033** the same type number.
7034**
7035** ^The sqlite3_mutex_free() routine deallocates a previously
7036** allocated dynamic mutex. Attempting to deallocate a static
7037** mutex results in undefined behavior.
7038**
7039** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7040** to enter a mutex. ^If another thread is already within the mutex,
7041** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7042** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7043** upon successful entry. ^(Mutexes created using
7044** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7045** In such cases, the
7046** mutex must be exited an equal number of times before another thread
7047** can enter.)^ If the same thread tries to enter any mutex other
7048** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7049**
7050** ^(Some systems (for example, Windows 95) do not support the operation
7051** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7052** will always return SQLITE_BUSY. The SQLite core only ever uses
7053** sqlite3_mutex_try() as an optimization so this is acceptable
7054** behavior.)^
7055**
7056** ^The sqlite3_mutex_leave() routine exits a mutex that was
7057** previously entered by the same thread. The behavior
7058** is undefined if the mutex is not currently entered by the
7059** calling thread or is not currently allocated.
7060**
7061** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7062** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7063** behave as no-ops.
7064**
7065** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7066*/
7067SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7068SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7069SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7070SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7071SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7072
7073/*
7074** CAPI3REF: Mutex Methods Object
7075**
7076** An instance of this structure defines the low-level routines
7077** used to allocate and use mutexes.
7078**
7079** Usually, the default mutex implementations provided by SQLite are
7080** sufficient, however the application has the option of substituting a custom
7081** implementation for specialized deployments or systems for which SQLite
7082** does not provide a suitable implementation. In this case, the application
7083** creates and populates an instance of this structure to pass
7084** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7085** Additionally, an instance of this structure can be used as an
7086** output variable when querying the system for the current mutex
7087** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7088**
7089** ^The xMutexInit method defined by this structure is invoked as
7090** part of system initialization by the sqlite3_initialize() function.
7091** ^The xMutexInit routine is called by SQLite exactly once for each
7092** effective call to [sqlite3_initialize()].
7093**
7094** ^The xMutexEnd method defined by this structure is invoked as
7095** part of system shutdown by the sqlite3_shutdown() function. The
7096** implementation of this method is expected to release all outstanding
7097** resources obtained by the mutex methods implementation, especially
7098** those obtained by the xMutexInit method. ^The xMutexEnd()
7099** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7100**
7101** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7102** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7103** xMutexNotheld) implement the following interfaces (respectively):
7104**
7105** <ul>
7106** <li> [sqlite3_mutex_alloc()] </li>
7107** <li> [sqlite3_mutex_free()] </li>
7108** <li> [sqlite3_mutex_enter()] </li>
7109** <li> [sqlite3_mutex_try()] </li>
7110** <li> [sqlite3_mutex_leave()] </li>
7111** <li> [sqlite3_mutex_held()] </li>
7112** <li> [sqlite3_mutex_notheld()] </li>
7113** </ul>)^
7114**
7115** The only difference is that the public sqlite3_XXX functions enumerated
7116** above silently ignore any invocations that pass a NULL pointer instead
7117** of a valid mutex handle. The implementations of the methods defined
7118** by this structure are not required to handle this case, the results
7119** of passing a NULL pointer instead of a valid mutex handle are undefined
7120** (i.e. it is acceptable to provide an implementation that segfaults if
7121** it is passed a NULL pointer).
7122**
7123** The xMutexInit() method must be threadsafe. It must be harmless to
7124** invoke xMutexInit() multiple times within the same process and without
7125** intervening calls to xMutexEnd(). Second and subsequent calls to
7126** xMutexInit() must be no-ops.
7127**
7128** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7129** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7130** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7131** memory allocation for a fast or recursive mutex.
7132**
7133** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7134** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7135** If xMutexInit fails in any way, it is expected to clean up after itself
7136** prior to returning.
7137*/
7138typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7139struct sqlite3_mutex_methods {
7140 int (*xMutexInit)(void);
7141 int (*xMutexEnd)(void);
7142 sqlite3_mutex *(*xMutexAlloc)(int);
7143 void (*xMutexFree)(sqlite3_mutex *);
7144 void (*xMutexEnter)(sqlite3_mutex *);
7145 int (*xMutexTry)(sqlite3_mutex *);
7146 void (*xMutexLeave)(sqlite3_mutex *);
7147 int (*xMutexHeld)(sqlite3_mutex *);
7148 int (*xMutexNotheld)(sqlite3_mutex *);
7149};
7150
7151/*
7152** CAPI3REF: Mutex Verification Routines
7153**
7154** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7155** are intended for use inside assert() statements. The SQLite core
7156** never uses these routines except inside an assert() and applications
7157** are advised to follow the lead of the core. The SQLite core only
7158** provides implementations for these routines when it is compiled
7159** with the SQLITE_DEBUG flag. External mutex implementations
7160** are only required to provide these routines if SQLITE_DEBUG is
7161** defined and if NDEBUG is not defined.
7162**
7163** These routines should return true if the mutex in their argument
7164** is held or not held, respectively, by the calling thread.
7165**
7166** The implementation is not required to provide versions of these
7167** routines that actually work. If the implementation does not provide working
7168** versions of these routines, it should at least provide stubs that always
7169** return true so that one does not get spurious assertion failures.
7170**
7171** If the argument to sqlite3_mutex_held() is a NULL pointer then
7172** the routine should return 1. This seems counter-intuitive since
7173** clearly the mutex cannot be held if it does not exist. But
7174** the reason the mutex does not exist is because the build is not
7175** using mutexes. And we do not want the assert() containing the
7176** call to sqlite3_mutex_held() to fail, so a non-zero return is
7177** the appropriate thing to do. The sqlite3_mutex_notheld()
7178** interface should also return 1 when given a NULL pointer.
7179*/
7180#ifndef NDEBUG
7181SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7182SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7183#endif
7184
7185/*
7186** CAPI3REF: Mutex Types
7187**
7188** The [sqlite3_mutex_alloc()] interface takes a single argument
7189** which is one of these integer constants.
7190**
7191** The set of static mutexes may change from one SQLite release to the
7192** next. Applications that override the built-in mutex logic must be
7193** prepared to accommodate additional static mutexes.
7194*/
7195#define SQLITE_MUTEX_FAST 0
7196#define SQLITE_MUTEX_RECURSIVE 1
7197#define SQLITE_MUTEX_STATIC_MASTER 2
7198#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7199#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7200#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7201#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7202#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7203#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7204#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7205#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7206#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7207#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7208#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7209#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7210#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7211
7212/*
7213** CAPI3REF: Retrieve the mutex for a database connection
7214** METHOD: sqlite3
7215**
7216** ^This interface returns a pointer the [sqlite3_mutex] object that
7217** serializes access to the [database connection] given in the argument
7218** when the [threading mode] is Serialized.
7219** ^If the [threading mode] is Single-thread or Multi-thread then this
7220** routine returns a NULL pointer.
7221*/
7222SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7223
7224/*
7225** CAPI3REF: Low-Level Control Of Database Files
7226** METHOD: sqlite3
7227** KEYWORDS: {file control}
7228**
7229** ^The [sqlite3_file_control()] interface makes a direct call to the
7230** xFileControl method for the [sqlite3_io_methods] object associated
7231** with a particular database identified by the second argument. ^The
7232** name of the database is "main" for the main database or "temp" for the
7233** TEMP database, or the name that appears after the AS keyword for
7234** databases that are added using the [ATTACH] SQL command.
7235** ^A NULL pointer can be used in place of "main" to refer to the
7236** main database file.
7237** ^The third and fourth parameters to this routine
7238** are passed directly through to the second and third parameters of
7239** the xFileControl method. ^The return value of the xFileControl
7240** method becomes the return value of this routine.
7241**
7242** A few opcodes for [sqlite3_file_control()] are handled directly
7243** by the SQLite core and never invoke the
7244** sqlite3_io_methods.xFileControl method.
7245** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7246** a pointer to the underlying [sqlite3_file] object to be written into
7247** the space pointed to by the 4th parameter. The
7248** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7249** the [sqlite3_file] object associated with the journal file instead of
7250** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7251** a pointer to the underlying [sqlite3_vfs] object for the file.
7252** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7253** from the pager.
7254**
7255** ^If the second parameter (zDbName) does not match the name of any
7256** open database file, then SQLITE_ERROR is returned. ^This error
7257** code is not remembered and will not be recalled by [sqlite3_errcode()]
7258** or [sqlite3_errmsg()]. The underlying xFileControl method might
7259** also return SQLITE_ERROR. There is no way to distinguish between
7260** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7261** xFileControl method.
7262**
7263** See also: [file control opcodes]
7264*/
7265SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7266
7267/*
7268** CAPI3REF: Testing Interface
7269**
7270** ^The sqlite3_test_control() interface is used to read out internal
7271** state of SQLite and to inject faults into SQLite for testing
7272** purposes. ^The first parameter is an operation code that determines
7273** the number, meaning, and operation of all subsequent parameters.
7274**
7275** This interface is not for use by applications. It exists solely
7276** for verifying the correct operation of the SQLite library. Depending
7277** on how the SQLite library is compiled, this interface might not exist.
7278**
7279** The details of the operation codes, their meanings, the parameters
7280** they take, and what they do are all subject to change without notice.
7281** Unlike most of the SQLite API, this function is not guaranteed to
7282** operate consistently from one release to the next.
7283*/
7284SQLITE_API int sqlite3_test_control(int op, ...);
7285
7286/*
7287** CAPI3REF: Testing Interface Operation Codes
7288**
7289** These constants are the valid operation code parameters used
7290** as the first argument to [sqlite3_test_control()].
7291**
7292** These parameters and their meanings are subject to change
7293** without notice. These values are for testing purposes only.
7294** Applications should not use any of these parameters or the
7295** [sqlite3_test_control()] interface.
7296*/
7297#define SQLITE_TESTCTRL_FIRST 5
7298#define SQLITE_TESTCTRL_PRNG_SAVE 5
7299#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7300#define SQLITE_TESTCTRL_PRNG_RESET 7
7301#define SQLITE_TESTCTRL_BITVEC_TEST 8
7302#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7303#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7304#define SQLITE_TESTCTRL_PENDING_BYTE 11
7305#define SQLITE_TESTCTRL_ASSERT 12
7306#define SQLITE_TESTCTRL_ALWAYS 13
7307#define SQLITE_TESTCTRL_RESERVE 14
7308#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7309#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7310#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7311#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7312#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7313#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7314#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7315#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7316#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7317#define SQLITE_TESTCTRL_BYTEORDER 22
7318#define SQLITE_TESTCTRL_ISINIT 23
7319#define SQLITE_TESTCTRL_SORTER_MMAP 24
7320#define SQLITE_TESTCTRL_IMPOSTER 25
7321#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7322#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */
7323
7324/*
7325** CAPI3REF: SQL Keyword Checking
7326**
7327** These routines provide access to the set of SQL language keywords
7328** recognized by SQLite. Applications can uses these routines to determine
7329** whether or not a specific identifier needs to be escaped (for example,
7330** by enclosing in double-quotes) so as not to confuse the parser.
7331**
7332** The sqlite3_keyword_count() interface returns the number of distinct
7333** keywords understood by SQLite.
7334**
7335** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7336** makes *Z point to that keyword expressed as UTF8 and writes the number
7337** of bytes in the keyword into *L. The string that *Z points to is not
7338** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7339** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7340** or L are NULL or invalid pointers then calls to
7341** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7342**
7343** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7344** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7345** if it is and zero if not.
7346**
7347** The parser used by SQLite is forgiving. It is often possible to use
7348** a keyword as an identifier as long as such use does not result in a
7349** parsing ambiguity. For example, the statement
7350** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7351** creates a new table named "BEGIN" with three columns named
7352** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7353** using keywords as identifiers. Common techniques used to avoid keyword
7354** name collisions include:
7355** <ul>
7356** <li> Put all identifier names inside double-quotes. This is the official
7357** SQL way to escape identifier names.
7358** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
7359** but it is what SQL Server does and so lots of programmers use this
7360** technique.
7361** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7362** with "Z".
7363** <li> Include a digit somewhere in every identifier name.
7364** </ul>
7365**
7366** Note that the number of keywords understood by SQLite can depend on
7367** compile-time options. For example, "VACUUM" is not a keyword if
7368** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7369** new keywords may be added to future releases of SQLite.
7370*/
7371SQLITE_API int sqlite3_keyword_count(void);
7372SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7373SQLITE_API int sqlite3_keyword_check(const char*,int);
7374
7375/*
7376** CAPI3REF: Dynamic String Object
7377** KEYWORDS: {dynamic string}
7378**
7379** An instance of the sqlite3_str object contains a dynamically-sized
7380** string under construction.
7381**
7382** The lifecycle of an sqlite3_str object is as follows:
7383** <ol>
7384** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7385** <li> ^Text is appended to the sqlite3_str object using various
7386** methods, such as [sqlite3_str_appendf()].
7387** <li> ^The sqlite3_str object is destroyed and the string it created
7388** is returned using the [sqlite3_str_finish()] interface.
7389** </ol>
7390*/
7391typedef struct sqlite3_str sqlite3_str;
7392
7393/*
7394** CAPI3REF: Create A New Dynamic String Object
7395** CONSTRUCTOR: sqlite3_str
7396**
7397** ^The [sqlite3_str_new(D)] interface allocates and initializes
7398** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7399** [sqlite3_str_new()] must be freed by a subsequent call to
7400** [sqlite3_str_finish(X)].
7401**
7402** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7403** valid [sqlite3_str] object, though in the event of an out-of-memory
7404** error the returned object might be a special singleton that will
7405** silently reject new text, always return SQLITE_NOMEM from
7406** [sqlite3_str_errcode()], always return 0 for
7407** [sqlite3_str_length()], and always return NULL from
7408** [sqlite3_str_finish(X)]. It is always safe to use the value
7409** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7410** to any of the other [sqlite3_str] methods.
7411**
7412** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7413** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7414** length of the string contained in the [sqlite3_str] object will be
7415** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7416** of [SQLITE_MAX_LENGTH].
7417*/
7418SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7419
7420/*
7421** CAPI3REF: Finalize A Dynamic String
7422** DESTRUCTOR: sqlite3_str
7423**
7424** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7425** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7426** that contains the constructed string. The calling application should
7427** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7428** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7429** errors were encountered during construction of the string. ^The
7430** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7431** string in [sqlite3_str] object X is zero bytes long.
7432*/
7433SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7434
7435/*
7436** CAPI3REF: Add Content To A Dynamic String
7437** METHOD: sqlite3_str
7438**
7439** These interfaces add content to an sqlite3_str object previously obtained
7440** from [sqlite3_str_new()].
7441**
7442** ^The [sqlite3_str_appendf(X,F,...)] and
7443** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7444** functionality of SQLite to append formatted text onto the end of
7445** [sqlite3_str] object X.
7446**
7447** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7448** onto the end of the [sqlite3_str] object X. N must be non-negative.
7449** S must contain at least N non-zero bytes of content. To append a
7450** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7451** method instead.
7452**
7453** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7454** zero-terminated string S onto the end of [sqlite3_str] object X.
7455**
7456** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7457** single-byte character C onto the end of [sqlite3_str] object X.
7458** ^This method can be used, for example, to add whitespace indentation.
7459**
7460** ^The [sqlite3_str_reset(X)] method resets the string under construction
7461** inside [sqlite3_str] object X back to zero bytes in length.
7462**
7463** These methods do not return a result code. ^If an error occurs, that fact
7464** is recorded in the [sqlite3_str] object and can be recovered by a
7465** subsequent call to [sqlite3_str_errcode(X)].
7466*/
7467SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7468SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7469SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7470SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7471SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7472SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7473
7474/*
7475** CAPI3REF: Status Of A Dynamic String
7476** METHOD: sqlite3_str
7477**
7478** These interfaces return the current status of an [sqlite3_str] object.
7479**
7480** ^If any prior errors have occurred while constructing the dynamic string
7481** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7482** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7483** [SQLITE_NOMEM] following any out-of-memory error, or
7484** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7485** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7486**
7487** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7488** of the dynamic string under construction in [sqlite3_str] object X.
7489** ^The length returned by [sqlite3_str_length(X)] does not include the
7490** zero-termination byte.
7491**
7492** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7493** content of the dynamic string under construction in X. The value
7494** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7495** and might be freed or altered by any subsequent method on the same
7496** [sqlite3_str] object. Applications must not used the pointer returned
7497** [sqlite3_str_value(X)] after any subsequent method call on the same
7498** object. ^Applications may change the content of the string returned
7499** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7500** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7501** write any byte after any subsequent sqlite3_str method call.
7502*/
7503SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7504SQLITE_API int sqlite3_str_length(sqlite3_str*);
7505SQLITE_API char *sqlite3_str_value(sqlite3_str*);
7506
7507/*
7508** CAPI3REF: SQLite Runtime Status
7509**
7510** ^These interfaces are used to retrieve runtime status information
7511** about the performance of SQLite, and optionally to reset various
7512** highwater marks. ^The first argument is an integer code for
7513** the specific parameter to measure. ^(Recognized integer codes
7514** are of the form [status parameters | SQLITE_STATUS_...].)^
7515** ^The current value of the parameter is returned into *pCurrent.
7516** ^The highest recorded value is returned in *pHighwater. ^If the
7517** resetFlag is true, then the highest record value is reset after
7518** *pHighwater is written. ^(Some parameters do not record the highest
7519** value. For those parameters
7520** nothing is written into *pHighwater and the resetFlag is ignored.)^
7521** ^(Other parameters record only the highwater mark and not the current
7522** value. For these latter parameters nothing is written into *pCurrent.)^
7523**
7524** ^The sqlite3_status() and sqlite3_status64() routines return
7525** SQLITE_OK on success and a non-zero [error code] on failure.
7526**
7527** If either the current value or the highwater mark is too large to
7528** be represented by a 32-bit integer, then the values returned by
7529** sqlite3_status() are undefined.
7530**
7531** See also: [sqlite3_db_status()]
7532*/
7533SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7534SQLITE_API int sqlite3_status64(
7535 int op,
7536 sqlite3_int64 *pCurrent,
7537 sqlite3_int64 *pHighwater,
7538 int resetFlag
7539);
7540
7541
7542/*
7543** CAPI3REF: Status Parameters
7544** KEYWORDS: {status parameters}
7545**
7546** These integer constants designate various run-time status parameters
7547** that can be returned by [sqlite3_status()].
7548**
7549** <dl>
7550** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7551** <dd>This parameter is the current amount of memory checked out
7552** using [sqlite3_malloc()], either directly or indirectly. The
7553** figure includes calls made to [sqlite3_malloc()] by the application
7554** and internal memory usage by the SQLite library. Auxiliary page-cache
7555** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
7556** this parameter. The amount returned is the sum of the allocation
7557** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
7558**
7559** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
7560** <dd>This parameter records the largest memory allocation request
7561** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
7562** internal equivalents). Only the value returned in the
7563** *pHighwater parameter to [sqlite3_status()] is of interest.
7564** The value written into the *pCurrent parameter is undefined.</dd>)^
7565**
7566** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
7567** <dd>This parameter records the number of separate memory allocations
7568** currently checked out.</dd>)^
7569**
7570** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
7571** <dd>This parameter returns the number of pages used out of the
7572** [pagecache memory allocator] that was configured using
7573** [SQLITE_CONFIG_PAGECACHE]. The
7574** value returned is in pages, not in bytes.</dd>)^
7575**
7576** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
7577** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
7578** <dd>This parameter returns the number of bytes of page cache
7579** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
7580** buffer and where forced to overflow to [sqlite3_malloc()]. The
7581** returned value includes allocations that overflowed because they
7582** where too large (they were larger than the "sz" parameter to
7583** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
7584** no space was left in the page cache.</dd>)^
7585**
7586** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
7587** <dd>This parameter records the largest memory allocation request
7588** handed to [pagecache memory allocator]. Only the value returned in the
7589** *pHighwater parameter to [sqlite3_status()] is of interest.
7590** The value written into the *pCurrent parameter is undefined.</dd>)^
7591**
7592** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
7593** <dd>No longer used.</dd>
7594**
7595** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
7596** <dd>No longer used.</dd>
7597**
7598** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
7599** <dd>No longer used.</dd>
7600**
7601** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
7602** <dd>The *pHighwater parameter records the deepest parser stack.
7603** The *pCurrent value is undefined. The *pHighwater value is only
7604** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
7605** </dl>
7606**
7607** New status parameters may be added from time to time.
7608*/
7609#define SQLITE_STATUS_MEMORY_USED 0
7610#define SQLITE_STATUS_PAGECACHE_USED 1
7611#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
7612#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
7613#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
7614#define SQLITE_STATUS_MALLOC_SIZE 5
7615#define SQLITE_STATUS_PARSER_STACK 6
7616#define SQLITE_STATUS_PAGECACHE_SIZE 7
7617#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
7618#define SQLITE_STATUS_MALLOC_COUNT 9
7619
7620/*
7621** CAPI3REF: Database Connection Status
7622** METHOD: sqlite3
7623**
7624** ^This interface is used to retrieve runtime status information
7625** about a single [database connection]. ^The first argument is the
7626** database connection object to be interrogated. ^The second argument
7627** is an integer constant, taken from the set of
7628** [SQLITE_DBSTATUS options], that
7629** determines the parameter to interrogate. The set of
7630** [SQLITE_DBSTATUS options] is likely
7631** to grow in future releases of SQLite.
7632**
7633** ^The current value of the requested parameter is written into *pCur
7634** and the highest instantaneous value is written into *pHiwtr. ^If
7635** the resetFlg is true, then the highest instantaneous value is
7636** reset back down to the current value.
7637**
7638** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
7639** non-zero [error code] on failure.
7640**
7641** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
7642*/
7643SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
7644
7645/*
7646** CAPI3REF: Status Parameters for database connections
7647** KEYWORDS: {SQLITE_DBSTATUS options}
7648**
7649** These constants are the available integer "verbs" that can be passed as
7650** the second argument to the [sqlite3_db_status()] interface.
7651**
7652** New verbs may be added in future releases of SQLite. Existing verbs
7653** might be discontinued. Applications should check the return code from
7654** [sqlite3_db_status()] to make sure that the call worked.
7655** The [sqlite3_db_status()] interface will return a non-zero error code
7656** if a discontinued or unsupported verb is invoked.
7657**
7658** <dl>
7659** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
7660** <dd>This parameter returns the number of lookaside memory slots currently
7661** checked out.</dd>)^
7662**
7663** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
7664** <dd>This parameter returns the number malloc attempts that were
7665** satisfied using lookaside memory. Only the high-water value is meaningful;
7666** the current value is always zero.)^
7667**
7668** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
7669** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
7670** <dd>This parameter returns the number malloc attempts that might have
7671** been satisfied using lookaside memory but failed due to the amount of
7672** memory requested being larger than the lookaside slot size.
7673** Only the high-water value is meaningful;
7674** the current value is always zero.)^
7675**
7676** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
7677** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
7678** <dd>This parameter returns the number malloc attempts that might have
7679** been satisfied using lookaside memory but failed due to all lookaside
7680** memory already being in use.
7681** Only the high-water value is meaningful;
7682** the current value is always zero.)^
7683**
7684** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
7685** <dd>This parameter returns the approximate number of bytes of heap
7686** memory used by all pager caches associated with the database connection.)^
7687** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
7688**
7689** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
7690** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
7691** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
7692** pager cache is shared between two or more connections the bytes of heap
7693** memory used by that pager cache is divided evenly between the attached
7694** connections.)^ In other words, if none of the pager caches associated
7695** with the database connection are shared, this request returns the same
7696** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
7697** shared, the value returned by this call will be smaller than that returned
7698** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
7699** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
7700**
7701** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
7702** <dd>This parameter returns the approximate number of bytes of heap
7703** memory used to store the schema for all databases associated
7704** with the connection - main, temp, and any [ATTACH]-ed databases.)^
7705** ^The full amount of memory used by the schemas is reported, even if the
7706** schema memory is shared with other database connections due to
7707** [shared cache mode] being enabled.
7708** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
7709**
7710** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
7711** <dd>This parameter returns the approximate number of bytes of heap
7712** and lookaside memory used by all prepared statements associated with
7713** the database connection.)^
7714** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7715** </dd>
7716**
7717** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7718** <dd>This parameter returns the number of pager cache hits that have
7719** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7720** is always 0.
7721** </dd>
7722**
7723** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7724** <dd>This parameter returns the number of pager cache misses that have
7725** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7726** is always 0.
7727** </dd>
7728**
7729** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7730** <dd>This parameter returns the number of dirty cache entries that have
7731** been written to disk. Specifically, the number of pages written to the
7732** wal file in wal mode databases, or the number of pages written to the
7733** database file in rollback mode databases. Any pages written as part of
7734** transaction rollback or database recovery operations are not included.
7735** If an IO or other error occurs while writing a page to disk, the effect
7736** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7737** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7738** </dd>
7739**
7740** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
7741** <dd>This parameter returns the number of dirty cache entries that have
7742** been written to disk in the middle of a transaction due to the page
7743** cache overflowing. Transactions are more efficient if they are written
7744** to disk all at once. When pages spill mid-transaction, that introduces
7745** additional overhead. This parameter can be used help identify
7746** inefficiencies that can be resolve by increasing the cache size.
7747** </dd>
7748**
7749** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7750** <dd>This parameter returns zero for the current value if and only if
7751** all foreign key constraints (deferred or immediate) have been
7752** resolved.)^ ^The highwater mark is always 0.
7753** </dd>
7754** </dl>
7755*/
7756#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7757#define SQLITE_DBSTATUS_CACHE_USED 1
7758#define SQLITE_DBSTATUS_SCHEMA_USED 2
7759#define SQLITE_DBSTATUS_STMT_USED 3
7760#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7761#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7762#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7763#define SQLITE_DBSTATUS_CACHE_HIT 7
7764#define SQLITE_DBSTATUS_CACHE_MISS 8
7765#define SQLITE_DBSTATUS_CACHE_WRITE 9
7766#define SQLITE_DBSTATUS_DEFERRED_FKS 10
7767#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7768#define SQLITE_DBSTATUS_CACHE_SPILL 12
7769#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
7770
7771
7772/*
7773** CAPI3REF: Prepared Statement Status
7774** METHOD: sqlite3_stmt
7775**
7776** ^(Each prepared statement maintains various
7777** [SQLITE_STMTSTATUS counters] that measure the number
7778** of times it has performed specific operations.)^ These counters can
7779** be used to monitor the performance characteristics of the prepared
7780** statements. For example, if the number of table steps greatly exceeds
7781** the number of table searches or result rows, that would tend to indicate
7782** that the prepared statement is using a full table scan rather than
7783** an index.
7784**
7785** ^(This interface is used to retrieve and reset counter values from
7786** a [prepared statement]. The first argument is the prepared statement
7787** object to be interrogated. The second argument
7788** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7789** to be interrogated.)^
7790** ^The current value of the requested counter is returned.
7791** ^If the resetFlg is true, then the counter is reset to zero after this
7792** interface call returns.
7793**
7794** See also: [sqlite3_status()] and [sqlite3_db_status()].
7795*/
7796SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7797
7798/*
7799** CAPI3REF: Status Parameters for prepared statements
7800** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7801**
7802** These preprocessor macros define integer codes that name counter
7803** values associated with the [sqlite3_stmt_status()] interface.
7804** The meanings of the various counters are as follows:
7805**
7806** <dl>
7807** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7808** <dd>^This is the number of times that SQLite has stepped forward in
7809** a table as part of a full table scan. Large numbers for this counter
7810** may indicate opportunities for performance improvement through
7811** careful use of indices.</dd>
7812**
7813** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7814** <dd>^This is the number of sort operations that have occurred.
7815** A non-zero value in this counter may indicate an opportunity to
7816** improvement performance through careful use of indices.</dd>
7817**
7818** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7819** <dd>^This is the number of rows inserted into transient indices that
7820** were created automatically in order to help joins run faster.
7821** A non-zero value in this counter may indicate an opportunity to
7822** improvement performance by adding permanent indices that do not
7823** need to be reinitialized each time the statement is run.</dd>
7824**
7825** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7826** <dd>^This is the number of virtual machine operations executed
7827** by the prepared statement if that number is less than or equal
7828** to 2147483647. The number of virtual machine operations can be
7829** used as a proxy for the total work done by the prepared statement.
7830** If the number of virtual machine operations exceeds 2147483647
7831** then the value returned by this statement status code is undefined.
7832**
7833** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
7834** <dd>^This is the number of times that the prepare statement has been
7835** automatically regenerated due to schema changes or change to
7836** [bound parameters] that might affect the query plan.
7837**
7838** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
7839** <dd>^This is the number of times that the prepared statement has
7840** been run. A single "run" for the purposes of this counter is one
7841** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
7842** The counter is incremented on the first [sqlite3_step()] call of each
7843** cycle.
7844**
7845** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
7846** <dd>^This is the approximate number of bytes of heap memory
7847** used to store the prepared statement. ^This value is not actually
7848** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
7849** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
7850** </dd>
7851** </dl>
7852*/
7853#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7854#define SQLITE_STMTSTATUS_SORT 2
7855#define SQLITE_STMTSTATUS_AUTOINDEX 3
7856#define SQLITE_STMTSTATUS_VM_STEP 4
7857#define SQLITE_STMTSTATUS_REPREPARE 5
7858#define SQLITE_STMTSTATUS_RUN 6
7859#define SQLITE_STMTSTATUS_MEMUSED 99
7860
7861/*
7862** CAPI3REF: Custom Page Cache Object
7863**
7864** The sqlite3_pcache type is opaque. It is implemented by
7865** the pluggable module. The SQLite core has no knowledge of
7866** its size or internal structure and never deals with the
7867** sqlite3_pcache object except by holding and passing pointers
7868** to the object.
7869**
7870** See [sqlite3_pcache_methods2] for additional information.
7871*/
7872typedef struct sqlite3_pcache sqlite3_pcache;
7873
7874/*
7875** CAPI3REF: Custom Page Cache Object
7876**
7877** The sqlite3_pcache_page object represents a single page in the
7878** page cache. The page cache will allocate instances of this
7879** object. Various methods of the page cache use pointers to instances
7880** of this object as parameters or as their return value.
7881**
7882** See [sqlite3_pcache_methods2] for additional information.
7883*/
7884typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7885struct sqlite3_pcache_page {
7886 void *pBuf; /* The content of the page */
7887 void *pExtra; /* Extra information associated with the page */
7888};
7889
7890/*
7891** CAPI3REF: Application Defined Page Cache.
7892** KEYWORDS: {page cache}
7893**
7894** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7895** register an alternative page cache implementation by passing in an
7896** instance of the sqlite3_pcache_methods2 structure.)^
7897** In many applications, most of the heap memory allocated by
7898** SQLite is used for the page cache.
7899** By implementing a
7900** custom page cache using this API, an application can better control
7901** the amount of memory consumed by SQLite, the way in which
7902** that memory is allocated and released, and the policies used to
7903** determine exactly which parts of a database file are cached and for
7904** how long.
7905**
7906** The alternative page cache mechanism is an
7907** extreme measure that is only needed by the most demanding applications.
7908** The built-in page cache is recommended for most uses.
7909**
7910** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7911** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7912** the application may discard the parameter after the call to
7913** [sqlite3_config()] returns.)^
7914**
7915** [[the xInit() page cache method]]
7916** ^(The xInit() method is called once for each effective
7917** call to [sqlite3_initialize()])^
7918** (usually only once during the lifetime of the process). ^(The xInit()
7919** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7920** The intent of the xInit() method is to set up global data structures
7921** required by the custom page cache implementation.
7922** ^(If the xInit() method is NULL, then the
7923** built-in default page cache is used instead of the application defined
7924** page cache.)^
7925**
7926** [[the xShutdown() page cache method]]
7927** ^The xShutdown() method is called by [sqlite3_shutdown()].
7928** It can be used to clean up
7929** any outstanding resources before process shutdown, if required.
7930** ^The xShutdown() method may be NULL.
7931**
7932** ^SQLite automatically serializes calls to the xInit method,
7933** so the xInit method need not be threadsafe. ^The
7934** xShutdown method is only called from [sqlite3_shutdown()] so it does
7935** not need to be threadsafe either. All other methods must be threadsafe
7936** in multithreaded applications.
7937**
7938** ^SQLite will never invoke xInit() more than once without an intervening
7939** call to xShutdown().
7940**
7941** [[the xCreate() page cache methods]]
7942** ^SQLite invokes the xCreate() method to construct a new cache instance.
7943** SQLite will typically create one cache instance for each open database file,
7944** though this is not guaranteed. ^The
7945** first parameter, szPage, is the size in bytes of the pages that must
7946** be allocated by the cache. ^szPage will always a power of two. ^The
7947** second parameter szExtra is a number of bytes of extra storage
7948** associated with each page cache entry. ^The szExtra parameter will
7949** a number less than 250. SQLite will use the
7950** extra szExtra bytes on each page to store metadata about the underlying
7951** database page on disk. The value passed into szExtra depends
7952** on the SQLite version, the target platform, and how SQLite was compiled.
7953** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7954** created will be used to cache database pages of a file stored on disk, or
7955** false if it is used for an in-memory database. The cache implementation
7956** does not have to do anything special based with the value of bPurgeable;
7957** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7958** never invoke xUnpin() except to deliberately delete a page.
7959** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7960** false will always have the "discard" flag set to true.
7961** ^Hence, a cache created with bPurgeable false will
7962** never contain any unpinned pages.
7963**
7964** [[the xCachesize() page cache method]]
7965** ^(The xCachesize() method may be called at any time by SQLite to set the
7966** suggested maximum cache-size (number of pages stored by) the cache
7967** instance passed as the first argument. This is the value configured using
7968** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7969** parameter, the implementation is not required to do anything with this
7970** value; it is advisory only.
7971**
7972** [[the xPagecount() page cache methods]]
7973** The xPagecount() method must return the number of pages currently
7974** stored in the cache, both pinned and unpinned.
7975**
7976** [[the xFetch() page cache methods]]
7977** The xFetch() method locates a page in the cache and returns a pointer to
7978** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7979** The pBuf element of the returned sqlite3_pcache_page object will be a
7980** pointer to a buffer of szPage bytes used to store the content of a
7981** single database page. The pExtra element of sqlite3_pcache_page will be
7982** a pointer to the szExtra bytes of extra storage that SQLite has requested
7983** for each entry in the page cache.
7984**
7985** The page to be fetched is determined by the key. ^The minimum key value
7986** is 1. After it has been retrieved using xFetch, the page is considered
7987** to be "pinned".
7988**
7989** If the requested page is already in the page cache, then the page cache
7990** implementation must return a pointer to the page buffer with its content
7991** intact. If the requested page is not already in the cache, then the
7992** cache implementation should use the value of the createFlag
7993** parameter to help it determined what action to take:
7994**
7995** <table border=1 width=85% align=center>
7996** <tr><th> createFlag <th> Behavior when page is not already in cache
7997** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7998** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7999** Otherwise return NULL.
8000** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8001** NULL if allocating a new page is effectively impossible.
8002** </table>
8003**
8004** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8005** will only use a createFlag of 2 after a prior call with a createFlag of 1
8006** failed.)^ In between the to xFetch() calls, SQLite may
8007** attempt to unpin one or more cache pages by spilling the content of
8008** pinned pages to disk and synching the operating system disk cache.
8009**
8010** [[the xUnpin() page cache method]]
8011** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8012** as its second argument. If the third parameter, discard, is non-zero,
8013** then the page must be evicted from the cache.
8014** ^If the discard parameter is
8015** zero, then the page may be discarded or retained at the discretion of
8016** page cache implementation. ^The page cache implementation
8017** may choose to evict unpinned pages at any time.
8018**
8019** The cache must not perform any reference counting. A single
8020** call to xUnpin() unpins the page regardless of the number of prior calls
8021** to xFetch().
8022**
8023** [[the xRekey() page cache methods]]
8024** The xRekey() method is used to change the key value associated with the
8025** page passed as the second argument. If the cache
8026** previously contains an entry associated with newKey, it must be
8027** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8028** to be pinned.
8029**
8030** When SQLite calls the xTruncate() method, the cache must discard all
8031** existing cache entries with page numbers (keys) greater than or equal
8032** to the value of the iLimit parameter passed to xTruncate(). If any
8033** of these pages are pinned, they are implicitly unpinned, meaning that
8034** they can be safely discarded.
8035**
8036** [[the xDestroy() page cache method]]
8037** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8038** All resources associated with the specified cache should be freed. ^After
8039** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8040** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8041** functions.
8042**
8043** [[the xShrink() page cache method]]
8044** ^SQLite invokes the xShrink() method when it wants the page cache to
8045** free up as much of heap memory as possible. The page cache implementation
8046** is not obligated to free any memory, but well-behaved implementations should
8047** do their best.
8048*/
8049typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8050struct sqlite3_pcache_methods2 {
8051 int iVersion;
8052 void *pArg;
8053 int (*xInit)(void*);
8054 void (*xShutdown)(void*);
8055 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8056 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8057 int (*xPagecount)(sqlite3_pcache*);
8058 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8059 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8060 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8061 unsigned oldKey, unsigned newKey);
8062 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8063 void (*xDestroy)(sqlite3_pcache*);
8064 void (*xShrink)(sqlite3_pcache*);
8065};
8066
8067/*
8068** This is the obsolete pcache_methods object that has now been replaced
8069** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8070** retained in the header file for backwards compatibility only.
8071*/
8072typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8073struct sqlite3_pcache_methods {
8074 void *pArg;
8075 int (*xInit)(void*);
8076 void (*xShutdown)(void*);
8077 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8078 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8079 int (*xPagecount)(sqlite3_pcache*);
8080 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8081 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8082 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8083 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8084 void (*xDestroy)(sqlite3_pcache*);
8085};
8086
8087
8088/*
8089** CAPI3REF: Online Backup Object
8090**
8091** The sqlite3_backup object records state information about an ongoing
8092** online backup operation. ^The sqlite3_backup object is created by
8093** a call to [sqlite3_backup_init()] and is destroyed by a call to
8094** [sqlite3_backup_finish()].
8095**
8096** See Also: [Using the SQLite Online Backup API]
8097*/
8098typedef struct sqlite3_backup sqlite3_backup;
8099
8100/*
8101** CAPI3REF: Online Backup API.
8102**
8103** The backup API copies the content of one database into another.
8104** It is useful either for creating backups of databases or
8105** for copying in-memory databases to or from persistent files.
8106**
8107** See Also: [Using the SQLite Online Backup API]
8108**
8109** ^SQLite holds a write transaction open on the destination database file
8110** for the duration of the backup operation.
8111** ^The source database is read-locked only while it is being read;
8112** it is not locked continuously for the entire backup operation.
8113** ^Thus, the backup may be performed on a live source database without
8114** preventing other database connections from
8115** reading or writing to the source database while the backup is underway.
8116**
8117** ^(To perform a backup operation:
8118** <ol>
8119** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8120** backup,
8121** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8122** the data between the two databases, and finally
8123** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8124** associated with the backup operation.
8125** </ol>)^
8126** There should be exactly one call to sqlite3_backup_finish() for each
8127** successful call to sqlite3_backup_init().
8128**
8129** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8130**
8131** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8132** [database connection] associated with the destination database
8133** and the database name, respectively.
8134** ^The database name is "main" for the main database, "temp" for the
8135** temporary database, or the name specified after the AS keyword in
8136** an [ATTACH] statement for an attached database.
8137** ^The S and M arguments passed to
8138** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8139** and database name of the source database, respectively.
8140** ^The source and destination [database connections] (parameters S and D)
8141** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8142** an error.
8143**
8144** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8145** there is already a read or read-write transaction open on the
8146** destination database.
8147**
8148** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8149** returned and an error code and error message are stored in the
8150** destination [database connection] D.
8151** ^The error code and message for the failed call to sqlite3_backup_init()
8152** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8153** [sqlite3_errmsg16()] functions.
8154** ^A successful call to sqlite3_backup_init() returns a pointer to an
8155** [sqlite3_backup] object.
8156** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8157** sqlite3_backup_finish() functions to perform the specified backup
8158** operation.
8159**
8160** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8161**
8162** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8163** the source and destination databases specified by [sqlite3_backup] object B.
8164** ^If N is negative, all remaining source pages are copied.
8165** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8166** are still more pages to be copied, then the function returns [SQLITE_OK].
8167** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8168** from source to destination, then it returns [SQLITE_DONE].
8169** ^If an error occurs while running sqlite3_backup_step(B,N),
8170** then an [error code] is returned. ^As well as [SQLITE_OK] and
8171** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8172** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8173** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8174**
8175** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8176** <ol>
8177** <li> the destination database was opened read-only, or
8178** <li> the destination database is using write-ahead-log journaling
8179** and the destination and source page sizes differ, or
8180** <li> the destination database is an in-memory database and the
8181** destination and source page sizes differ.
8182** </ol>)^
8183**
8184** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8185** the [sqlite3_busy_handler | busy-handler function]
8186** is invoked (if one is specified). ^If the
8187** busy-handler returns non-zero before the lock is available, then
8188** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8189** sqlite3_backup_step() can be retried later. ^If the source
8190** [database connection]
8191** is being used to write to the source database when sqlite3_backup_step()
8192** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8193** case the call to sqlite3_backup_step() can be retried later on. ^(If
8194** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8195** [SQLITE_READONLY] is returned, then
8196** there is no point in retrying the call to sqlite3_backup_step(). These
8197** errors are considered fatal.)^ The application must accept
8198** that the backup operation has failed and pass the backup operation handle
8199** to the sqlite3_backup_finish() to release associated resources.
8200**
8201** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8202** on the destination file. ^The exclusive lock is not released until either
8203** sqlite3_backup_finish() is called or the backup operation is complete
8204** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8205** sqlite3_backup_step() obtains a [shared lock] on the source database that
8206** lasts for the duration of the sqlite3_backup_step() call.
8207** ^Because the source database is not locked between calls to
8208** sqlite3_backup_step(), the source database may be modified mid-way
8209** through the backup process. ^If the source database is modified by an
8210** external process or via a database connection other than the one being
8211** used by the backup operation, then the backup will be automatically
8212** restarted by the next call to sqlite3_backup_step(). ^If the source
8213** database is modified by the using the same database connection as is used
8214** by the backup operation, then the backup database is automatically
8215** updated at the same time.
8216**
8217** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8218**
8219** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8220** application wishes to abandon the backup operation, the application
8221** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8222** ^The sqlite3_backup_finish() interfaces releases all
8223** resources associated with the [sqlite3_backup] object.
8224** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8225** active write-transaction on the destination database is rolled back.
8226** The [sqlite3_backup] object is invalid
8227** and may not be used following a call to sqlite3_backup_finish().
8228**
8229** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8230** sqlite3_backup_step() errors occurred, regardless or whether or not
8231** sqlite3_backup_step() completed.
8232** ^If an out-of-memory condition or IO error occurred during any prior
8233** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8234** sqlite3_backup_finish() returns the corresponding [error code].
8235**
8236** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8237** is not a permanent error and does not affect the return value of
8238** sqlite3_backup_finish().
8239**
8240** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8241** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8242**
8243** ^The sqlite3_backup_remaining() routine returns the number of pages still
8244** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8245** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8246** in the source database at the conclusion of the most recent
8247** sqlite3_backup_step().
8248** ^(The values returned by these functions are only updated by
8249** sqlite3_backup_step(). If the source database is modified in a way that
8250** changes the size of the source database or the number of pages remaining,
8251** those changes are not reflected in the output of sqlite3_backup_pagecount()
8252** and sqlite3_backup_remaining() until after the next
8253** sqlite3_backup_step().)^
8254**
8255** <b>Concurrent Usage of Database Handles</b>
8256**
8257** ^The source [database connection] may be used by the application for other
8258** purposes while a backup operation is underway or being initialized.
8259** ^If SQLite is compiled and configured to support threadsafe database
8260** connections, then the source database connection may be used concurrently
8261** from within other threads.
8262**
8263** However, the application must guarantee that the destination
8264** [database connection] is not passed to any other API (by any thread) after
8265** sqlite3_backup_init() is called and before the corresponding call to
8266** sqlite3_backup_finish(). SQLite does not currently check to see
8267** if the application incorrectly accesses the destination [database connection]
8268** and so no error code is reported, but the operations may malfunction
8269** nevertheless. Use of the destination database connection while a
8270** backup is in progress might also also cause a mutex deadlock.
8271**
8272** If running in [shared cache mode], the application must
8273** guarantee that the shared cache used by the destination database
8274** is not accessed while the backup is running. In practice this means
8275** that the application must guarantee that the disk file being
8276** backed up to is not accessed by any connection within the process,
8277** not just the specific connection that was passed to sqlite3_backup_init().
8278**
8279** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8280** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8281** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8282** APIs are not strictly speaking threadsafe. If they are invoked at the
8283** same time as another thread is invoking sqlite3_backup_step() it is
8284** possible that they return invalid values.
8285*/
8286SQLITE_API sqlite3_backup *sqlite3_backup_init(
8287 sqlite3 *pDest, /* Destination database handle */
8288 const char *zDestName, /* Destination database name */
8289 sqlite3 *pSource, /* Source database handle */
8290 const char *zSourceName /* Source database name */
8291);
8292SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8293SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8294SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8295SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8296
8297/*
8298** CAPI3REF: Unlock Notification
8299** METHOD: sqlite3
8300**
8301** ^When running in shared-cache mode, a database operation may fail with
8302** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8303** individual tables within the shared-cache cannot be obtained. See
8304** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8305** ^This API may be used to register a callback that SQLite will invoke
8306** when the connection currently holding the required lock relinquishes it.
8307** ^This API is only available if the library was compiled with the
8308** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8309**
8310** See Also: [Using the SQLite Unlock Notification Feature].
8311**
8312** ^Shared-cache locks are released when a database connection concludes
8313** its current transaction, either by committing it or rolling it back.
8314**
8315** ^When a connection (known as the blocked connection) fails to obtain a
8316** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8317** identity of the database connection (the blocking connection) that
8318** has locked the required resource is stored internally. ^After an
8319** application receives an SQLITE_LOCKED error, it may call the
8320** sqlite3_unlock_notify() method with the blocked connection handle as
8321** the first argument to register for a callback that will be invoked
8322** when the blocking connections current transaction is concluded. ^The
8323** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8324** call that concludes the blocking connections transaction.
8325**
8326** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8327** there is a chance that the blocking connection will have already
8328** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8329** If this happens, then the specified callback is invoked immediately,
8330** from within the call to sqlite3_unlock_notify().)^
8331**
8332** ^If the blocked connection is attempting to obtain a write-lock on a
8333** shared-cache table, and more than one other connection currently holds
8334** a read-lock on the same table, then SQLite arbitrarily selects one of
8335** the other connections to use as the blocking connection.
8336**
8337** ^(There may be at most one unlock-notify callback registered by a
8338** blocked connection. If sqlite3_unlock_notify() is called when the
8339** blocked connection already has a registered unlock-notify callback,
8340** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8341** called with a NULL pointer as its second argument, then any existing
8342** unlock-notify callback is canceled. ^The blocked connections
8343** unlock-notify callback may also be canceled by closing the blocked
8344** connection using [sqlite3_close()].
8345**
8346** The unlock-notify callback is not reentrant. If an application invokes
8347** any sqlite3_xxx API functions from within an unlock-notify callback, a
8348** crash or deadlock may be the result.
8349**
8350** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8351** returns SQLITE_OK.
8352**
8353** <b>Callback Invocation Details</b>
8354**
8355** When an unlock-notify callback is registered, the application provides a
8356** single void* pointer that is passed to the callback when it is invoked.
8357** However, the signature of the callback function allows SQLite to pass
8358** it an array of void* context pointers. The first argument passed to
8359** an unlock-notify callback is a pointer to an array of void* pointers,
8360** and the second is the number of entries in the array.
8361**
8362** When a blocking connections transaction is concluded, there may be
8363** more than one blocked connection that has registered for an unlock-notify
8364** callback. ^If two or more such blocked connections have specified the
8365** same callback function, then instead of invoking the callback function
8366** multiple times, it is invoked once with the set of void* context pointers
8367** specified by the blocked connections bundled together into an array.
8368** This gives the application an opportunity to prioritize any actions
8369** related to the set of unblocked database connections.
8370**
8371** <b>Deadlock Detection</b>
8372**
8373** Assuming that after registering for an unlock-notify callback a
8374** database waits for the callback to be issued before taking any further
8375** action (a reasonable assumption), then using this API may cause the
8376** application to deadlock. For example, if connection X is waiting for
8377** connection Y's transaction to be concluded, and similarly connection
8378** Y is waiting on connection X's transaction, then neither connection
8379** will proceed and the system may remain deadlocked indefinitely.
8380**
8381** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8382** detection. ^If a given call to sqlite3_unlock_notify() would put the
8383** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8384** unlock-notify callback is registered. The system is said to be in
8385** a deadlocked state if connection A has registered for an unlock-notify
8386** callback on the conclusion of connection B's transaction, and connection
8387** B has itself registered for an unlock-notify callback when connection
8388** A's transaction is concluded. ^Indirect deadlock is also detected, so
8389** the system is also considered to be deadlocked if connection B has
8390** registered for an unlock-notify callback on the conclusion of connection
8391** C's transaction, where connection C is waiting on connection A. ^Any
8392** number of levels of indirection are allowed.
8393**
8394** <b>The "DROP TABLE" Exception</b>
8395**
8396** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
8397** always appropriate to call sqlite3_unlock_notify(). There is however,
8398** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8399** SQLite checks if there are any currently executing SELECT statements
8400** that belong to the same connection. If there are, SQLITE_LOCKED is
8401** returned. In this case there is no "blocking connection", so invoking
8402** sqlite3_unlock_notify() results in the unlock-notify callback being
8403** invoked immediately. If the application then re-attempts the "DROP TABLE"
8404** or "DROP INDEX" query, an infinite loop might be the result.
8405**
8406** One way around this problem is to check the extended error code returned
8407** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8408** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
8409** the special "DROP TABLE/INDEX" case, the extended error code is just
8410** SQLITE_LOCKED.)^
8411*/
8412SQLITE_API int sqlite3_unlock_notify(
8413 sqlite3 *pBlocked, /* Waiting connection */
8414 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8415 void *pNotifyArg /* Argument to pass to xNotify */
8416);
8417
8418
8419/*
8420** CAPI3REF: String Comparison
8421**
8422** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8423** and extensions to compare the contents of two buffers containing UTF-8
8424** strings in a case-independent fashion, using the same definition of "case
8425** independence" that SQLite uses internally when comparing identifiers.
8426*/
8427SQLITE_API int sqlite3_stricmp(const char *, const char *);
8428SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8429
8430/*
8431** CAPI3REF: String Globbing
8432*
8433** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8434** string X matches the [GLOB] pattern P.
8435** ^The definition of [GLOB] pattern matching used in
8436** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8437** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8438** is case sensitive.
8439**
8440** Note that this routine returns zero on a match and non-zero if the strings
8441** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8442**
8443** See also: [sqlite3_strlike()].
8444*/
8445SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8446
8447/*
8448** CAPI3REF: String LIKE Matching
8449*
8450** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8451** string X matches the [LIKE] pattern P with escape character E.
8452** ^The definition of [LIKE] pattern matching used in
8453** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8454** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8455** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8456** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8457** insensitive - equivalent upper and lower case ASCII characters match
8458** one another.
8459**
8460** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8461** only ASCII characters are case folded.
8462**
8463** Note that this routine returns zero on a match and non-zero if the strings
8464** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8465**
8466** See also: [sqlite3_strglob()].
8467*/
8468SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8469
8470/*
8471** CAPI3REF: Error Logging Interface
8472**
8473** ^The [sqlite3_log()] interface writes a message into the [error log]
8474** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8475** ^If logging is enabled, the zFormat string and subsequent arguments are
8476** used with [sqlite3_snprintf()] to generate the final output string.
8477**
8478** The sqlite3_log() interface is intended for use by extensions such as
8479** virtual tables, collating functions, and SQL functions. While there is
8480** nothing to prevent an application from calling sqlite3_log(), doing so
8481** is considered bad form.
8482**
8483** The zFormat string must not be NULL.
8484**
8485** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8486** will not use dynamically allocated memory. The log message is stored in
8487** a fixed-length buffer on the stack. If the log message is longer than
8488** a few hundred characters, it will be truncated to the length of the
8489** buffer.
8490*/
8491SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8492
8493/*
8494** CAPI3REF: Write-Ahead Log Commit Hook
8495** METHOD: sqlite3
8496**
8497** ^The [sqlite3_wal_hook()] function is used to register a callback that
8498** is invoked each time data is committed to a database in wal mode.
8499**
8500** ^(The callback is invoked by SQLite after the commit has taken place and
8501** the associated write-lock on the database released)^, so the implementation
8502** may read, write or [checkpoint] the database as required.
8503**
8504** ^The first parameter passed to the callback function when it is invoked
8505** is a copy of the third parameter passed to sqlite3_wal_hook() when
8506** registering the callback. ^The second is a copy of the database handle.
8507** ^The third parameter is the name of the database that was written to -
8508** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8509** is the number of pages currently in the write-ahead log file,
8510** including those that were just committed.
8511**
8512** The callback function should normally return [SQLITE_OK]. ^If an error
8513** code is returned, that error will propagate back up through the
8514** SQLite code base to cause the statement that provoked the callback
8515** to report an error, though the commit will have still occurred. If the
8516** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8517** that does not correspond to any valid SQLite error code, the results
8518** are undefined.
8519**
8520** A single database handle may have at most a single write-ahead log callback
8521** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8522** previously registered write-ahead log callback. ^Note that the
8523** [sqlite3_wal_autocheckpoint()] interface and the
8524** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8525** overwrite any prior [sqlite3_wal_hook()] settings.
8526*/
8527SQLITE_API void *sqlite3_wal_hook(
8528 sqlite3*,
8529 int(*)(void *,sqlite3*,const char*,int),
8530 void*
8531);
8532
8533/*
8534** CAPI3REF: Configure an auto-checkpoint
8535** METHOD: sqlite3
8536**
8537** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8538** [sqlite3_wal_hook()] that causes any database on [database connection] D
8539** to automatically [checkpoint]
8540** after committing a transaction if there are N or
8541** more frames in the [write-ahead log] file. ^Passing zero or
8542** a negative value as the nFrame parameter disables automatic
8543** checkpoints entirely.
8544**
8545** ^The callback registered by this function replaces any existing callback
8546** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8547** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8548** configured by this function.
8549**
8550** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8551** from SQL.
8552**
8553** ^Checkpoints initiated by this mechanism are
8554** [sqlite3_wal_checkpoint_v2|PASSIVE].
8555**
8556** ^Every new [database connection] defaults to having the auto-checkpoint
8557** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
8558** pages. The use of this interface
8559** is only necessary if the default setting is found to be suboptimal
8560** for a particular application.
8561*/
8562SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
8563
8564/*
8565** CAPI3REF: Checkpoint a database
8566** METHOD: sqlite3
8567**
8568** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
8569** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
8570**
8571** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
8572** [write-ahead log] for database X on [database connection] D to be
8573** transferred into the database file and for the write-ahead log to
8574** be reset. See the [checkpointing] documentation for addition
8575** information.
8576**
8577** This interface used to be the only way to cause a checkpoint to
8578** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
8579** interface was added. This interface is retained for backwards
8580** compatibility and as a convenience for applications that need to manually
8581** start a callback but which do not need the full power (and corresponding
8582** complication) of [sqlite3_wal_checkpoint_v2()].
8583*/
8584SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
8585
8586/*
8587** CAPI3REF: Checkpoint a database
8588** METHOD: sqlite3
8589**
8590** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
8591** operation on database X of [database connection] D in mode M. Status
8592** information is written back into integers pointed to by L and C.)^
8593** ^(The M parameter must be a valid [checkpoint mode]:)^
8594**
8595** <dl>
8596** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
8597** ^Checkpoint as many frames as possible without waiting for any database
8598** readers or writers to finish, then sync the database file if all frames
8599** in the log were checkpointed. ^The [busy-handler callback]
8600** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
8601** ^On the other hand, passive mode might leave the checkpoint unfinished
8602** if there are concurrent readers or writers.
8603**
8604** <dt>SQLITE_CHECKPOINT_FULL<dd>
8605** ^This mode blocks (it invokes the
8606** [sqlite3_busy_handler|busy-handler callback]) until there is no
8607** database writer and all readers are reading from the most recent database
8608** snapshot. ^It then checkpoints all frames in the log file and syncs the
8609** database file. ^This mode blocks new database writers while it is pending,
8610** but new database readers are allowed to continue unimpeded.
8611**
8612** <dt>SQLITE_CHECKPOINT_RESTART<dd>
8613** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
8614** that after checkpointing the log file it blocks (calls the
8615** [busy-handler callback])
8616** until all readers are reading from the database file only. ^This ensures
8617** that the next writer will restart the log file from the beginning.
8618** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
8619** database writer attempts while it is pending, but does not impede readers.
8620**
8621** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
8622** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
8623** addition that it also truncates the log file to zero bytes just prior
8624** to a successful return.
8625** </dl>
8626**
8627** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
8628** the log file or to -1 if the checkpoint could not run because
8629** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
8630** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
8631** log file (including any that were already checkpointed before the function
8632** was called) or to -1 if the checkpoint could not run due to an error or
8633** because the database is not in WAL mode. ^Note that upon successful
8634** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
8635** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
8636**
8637** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
8638** any other process is running a checkpoint operation at the same time, the
8639** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
8640** busy-handler configured, it will not be invoked in this case.
8641**
8642** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
8643** exclusive "writer" lock on the database file. ^If the writer lock cannot be
8644** obtained immediately, and a busy-handler is configured, it is invoked and
8645** the writer lock retried until either the busy-handler returns 0 or the lock
8646** is successfully obtained. ^The busy-handler is also invoked while waiting for
8647** database readers as described above. ^If the busy-handler returns 0 before
8648** the writer lock is obtained or while waiting for database readers, the
8649** checkpoint operation proceeds from that point in the same way as
8650** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
8651** without blocking any further. ^SQLITE_BUSY is returned in this case.
8652**
8653** ^If parameter zDb is NULL or points to a zero length string, then the
8654** specified operation is attempted on all WAL databases [attached] to
8655** [database connection] db. In this case the
8656** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
8657** an SQLITE_BUSY error is encountered when processing one or more of the
8658** attached WAL databases, the operation is still attempted on any remaining
8659** attached databases and SQLITE_BUSY is returned at the end. ^If any other
8660** error occurs while processing an attached database, processing is abandoned
8661** and the error code is returned to the caller immediately. ^If no error
8662** (SQLITE_BUSY or otherwise) is encountered while processing the attached
8663** databases, SQLITE_OK is returned.
8664**
8665** ^If database zDb is the name of an attached database that is not in WAL
8666** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
8667** zDb is not NULL (or a zero length string) and is not the name of any
8668** attached database, SQLITE_ERROR is returned to the caller.
8669**
8670** ^Unless it returns SQLITE_MISUSE,
8671** the sqlite3_wal_checkpoint_v2() interface
8672** sets the error information that is queried by
8673** [sqlite3_errcode()] and [sqlite3_errmsg()].
8674**
8675** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
8676** from SQL.
8677*/
8678SQLITE_API int sqlite3_wal_checkpoint_v2(
8679 sqlite3 *db, /* Database handle */
8680 const char *zDb, /* Name of attached database (or NULL) */
8681 int eMode, /* SQLITE_CHECKPOINT_* value */
8682 int *pnLog, /* OUT: Size of WAL log in frames */
8683 int *pnCkpt /* OUT: Total number of frames checkpointed */
8684);
8685
8686/*
8687** CAPI3REF: Checkpoint Mode Values
8688** KEYWORDS: {checkpoint mode}
8689**
8690** These constants define all valid values for the "checkpoint mode" passed
8691** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
8692** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
8693** meaning of each of these checkpoint modes.
8694*/
8695#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
8696#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
8697#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
8698#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
8699
8700/*
8701** CAPI3REF: Virtual Table Interface Configuration
8702**
8703** This function may be called by either the [xConnect] or [xCreate] method
8704** of a [virtual table] implementation to configure
8705** various facets of the virtual table interface.
8706**
8707** If this interface is invoked outside the context of an xConnect or
8708** xCreate virtual table method then the behavior is undefined.
8709**
8710** At present, there is only one option that may be configured using
8711** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
8712** may be added in the future.
8713*/
8714SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
8715
8716/*
8717** CAPI3REF: Virtual Table Configuration Options
8718**
8719** These macros define the various options to the
8720** [sqlite3_vtab_config()] interface that [virtual table] implementations
8721** can use to customize and optimize their behavior.
8722**
8723** <dl>
8724** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
8725** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
8726** <dd>Calls of the form
8727** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
8728** where X is an integer. If X is zero, then the [virtual table] whose
8729** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
8730** support constraints. In this configuration (which is the default) if
8731** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
8732** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
8733** specified as part of the users SQL statement, regardless of the actual
8734** ON CONFLICT mode specified.
8735**
8736** If X is non-zero, then the virtual table implementation guarantees
8737** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
8738** any modifications to internal or persistent data structures have been made.
8739** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
8740** is able to roll back a statement or database transaction, and abandon
8741** or continue processing the current SQL statement as appropriate.
8742** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
8743** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
8744** had been ABORT.
8745**
8746** Virtual table implementations that are required to handle OR REPLACE
8747** must do so within the [xUpdate] method. If a call to the
8748** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8749** CONFLICT policy is REPLACE, the virtual table implementation should
8750** silently replace the appropriate rows within the xUpdate callback and
8751** return SQLITE_OK. Or, if this is not possible, it may return
8752** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8753** constraint handling.
8754** </dl>
8755*/
8756#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8757
8758/*
8759** CAPI3REF: Determine The Virtual Table Conflict Policy
8760**
8761** This function may only be called from within a call to the [xUpdate] method
8762** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8763** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8764** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8765** of the SQL statement that triggered the call to the [xUpdate] method of the
8766** [virtual table].
8767*/
8768SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8769
8770/*
8771** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
8772**
8773** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
8774** method of a [virtual table], then it returns true if and only if the
8775** column is being fetched as part of an UPDATE operation during which the
8776** column value will not change. Applications might use this to substitute
8777** a return value that is less expensive to compute and that the corresponding
8778** [xUpdate] method understands as a "no-change" value.
8779**
8780** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
8781** the column is not changed by the UPDATE statement, then the xColumn
8782** method can optionally return without setting a result, without calling
8783** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
8784** In that case, [sqlite3_value_nochange(X)] will return true for the
8785** same column in the [xUpdate] method.
8786*/
8787SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
8788
8789/*
8790** CAPI3REF: Determine The Collation For a Virtual Table Constraint
8791**
8792** This function may only be called from within a call to the [xBestIndex]
8793** method of a [virtual table].
8794**
8795** The first argument must be the sqlite3_index_info object that is the
8796** first parameter to the xBestIndex() method. The second argument must be
8797** an index into the aConstraint[] array belonging to the sqlite3_index_info
8798** structure passed to xBestIndex. This function returns a pointer to a buffer
8799** containing the name of the collation sequence for the corresponding
8800** constraint.
8801*/
8802SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
8803
8804/*
8805** CAPI3REF: Conflict resolution modes
8806** KEYWORDS: {conflict resolution mode}
8807**
8808** These constants are returned by [sqlite3_vtab_on_conflict()] to
8809** inform a [virtual table] implementation what the [ON CONFLICT] mode
8810** is for the SQL statement being evaluated.
8811**
8812** Note that the [SQLITE_IGNORE] constant is also used as a potential
8813** return value from the [sqlite3_set_authorizer()] callback and that
8814** [SQLITE_ABORT] is also a [result code].
8815*/
8816#define SQLITE_ROLLBACK 1
8817/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8818#define SQLITE_FAIL 3
8819/* #define SQLITE_ABORT 4 // Also an error code */
8820#define SQLITE_REPLACE 5
8821
8822/*
8823** CAPI3REF: Prepared Statement Scan Status Opcodes
8824** KEYWORDS: {scanstatus options}
8825**
8826** The following constants can be used for the T parameter to the
8827** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8828** different metric for sqlite3_stmt_scanstatus() to return.
8829**
8830** When the value returned to V is a string, space to hold that string is
8831** managed by the prepared statement S and will be automatically freed when
8832** S is finalized.
8833**
8834** <dl>
8835** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8836** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8837** set to the total number of times that the X-th loop has run.</dd>
8838**
8839** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8840** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8841** to the total number of rows examined by all iterations of the X-th loop.</dd>
8842**
8843** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8844** <dd>^The "double" variable pointed to by the T parameter will be set to the
8845** query planner's estimate for the average number of rows output from each
8846** iteration of the X-th loop. If the query planner's estimates was accurate,
8847** then this value will approximate the quotient NVISIT/NLOOP and the
8848** product of this value for all prior loops with the same SELECTID will
8849** be the NLOOP value for the current loop.
8850**
8851** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8852** <dd>^The "const char *" variable pointed to by the T parameter will be set
8853** to a zero-terminated UTF-8 string containing the name of the index or table
8854** used for the X-th loop.
8855**
8856** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8857** <dd>^The "const char *" variable pointed to by the T parameter will be set
8858** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8859** description for the X-th loop.
8860**
8861** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8862** <dd>^The "int" variable pointed to by the T parameter will be set to the
8863** "select-id" for the X-th loop. The select-id identifies which query or
8864** subquery the loop is part of. The main query has a select-id of zero.
8865** The select-id is the same value as is output in the first column
8866** of an [EXPLAIN QUERY PLAN] query.
8867** </dl>
8868*/
8869#define SQLITE_SCANSTAT_NLOOP 0
8870#define SQLITE_SCANSTAT_NVISIT 1
8871#define SQLITE_SCANSTAT_EST 2
8872#define SQLITE_SCANSTAT_NAME 3
8873#define SQLITE_SCANSTAT_EXPLAIN 4
8874#define SQLITE_SCANSTAT_SELECTID 5
8875
8876/*
8877** CAPI3REF: Prepared Statement Scan Status
8878** METHOD: sqlite3_stmt
8879**
8880** This interface returns information about the predicted and measured
8881** performance for pStmt. Advanced applications can use this
8882** interface to compare the predicted and the measured performance and
8883** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8884**
8885** Since this interface is expected to be rarely used, it is only
8886** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8887** compile-time option.
8888**
8889** The "iScanStatusOp" parameter determines which status information to return.
8890** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8891** of this interface is undefined.
8892** ^The requested measurement is written into a variable pointed to by
8893** the "pOut" parameter.
8894** Parameter "idx" identifies the specific loop to retrieve statistics for.
8895** Loops are numbered starting from zero. ^If idx is out of range - less than
8896** zero or greater than or equal to the total number of loops used to implement
8897** the statement - a non-zero value is returned and the variable that pOut
8898** points to is unchanged.
8899**
8900** ^Statistics might not be available for all loops in all statements. ^In cases
8901** where there exist loops with no available statistics, this function behaves
8902** as if the loop did not exist - it returns non-zero and leave the variable
8903** that pOut points to unchanged.
8904**
8905** See also: [sqlite3_stmt_scanstatus_reset()]
8906*/
8907SQLITE_API int sqlite3_stmt_scanstatus(
8908 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8909 int idx, /* Index of loop to report on */
8910 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8911 void *pOut /* Result written here */
8912);
8913
8914/*
8915** CAPI3REF: Zero Scan-Status Counters
8916** METHOD: sqlite3_stmt
8917**
8918** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8919**
8920** This API is only available if the library is built with pre-processor
8921** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8922*/
8923SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8924
8925/*
8926** CAPI3REF: Flush caches to disk mid-transaction
8927**
8928** ^If a write-transaction is open on [database connection] D when the
8929** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8930** pages in the pager-cache that are not currently in use are written out
8931** to disk. A dirty page may be in use if a database cursor created by an
8932** active SQL statement is reading from it, or if it is page 1 of a database
8933** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8934** interface flushes caches for all schemas - "main", "temp", and
8935** any [attached] databases.
8936**
8937** ^If this function needs to obtain extra database locks before dirty pages
8938** can be flushed to disk, it does so. ^If those locks cannot be obtained
8939** immediately and there is a busy-handler callback configured, it is invoked
8940** in the usual manner. ^If the required lock still cannot be obtained, then
8941** the database is skipped and an attempt made to flush any dirty pages
8942** belonging to the next (if any) database. ^If any databases are skipped
8943** because locks cannot be obtained, but no other error occurs, this
8944** function returns SQLITE_BUSY.
8945**
8946** ^If any other error occurs while flushing dirty pages to disk (for
8947** example an IO error or out-of-memory condition), then processing is
8948** abandoned and an SQLite [error code] is returned to the caller immediately.
8949**
8950** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8951**
8952** ^This function does not set the database handle error code or message
8953** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8954*/
8955SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8956
8957/*
8958** CAPI3REF: The pre-update hook.
8959**
8960** ^These interfaces are only available if SQLite is compiled using the
8961** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8962**
8963** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8964** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8965** on a database table.
8966** ^At most one preupdate hook may be registered at a time on a single
8967** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8968** the previous setting.
8969** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8970** with a NULL pointer as the second parameter.
8971** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8972** the first parameter to callbacks.
8973**
8974** ^The preupdate hook only fires for changes to real database tables; the
8975** preupdate hook is not invoked for changes to [virtual tables] or to
8976** system tables like sqlite_master or sqlite_stat1.
8977**
8978** ^The second parameter to the preupdate callback is a pointer to
8979** the [database connection] that registered the preupdate hook.
8980** ^The third parameter to the preupdate callback is one of the constants
8981** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8982** kind of update operation that is about to occur.
8983** ^(The fourth parameter to the preupdate callback is the name of the
8984** database within the database connection that is being modified. This
8985** will be "main" for the main database or "temp" for TEMP tables or
8986** the name given after the AS keyword in the [ATTACH] statement for attached
8987** databases.)^
8988** ^The fifth parameter to the preupdate callback is the name of the
8989** table that is being modified.
8990**
8991** For an UPDATE or DELETE operation on a [rowid table], the sixth
8992** parameter passed to the preupdate callback is the initial [rowid] of the
8993** row being modified or deleted. For an INSERT operation on a rowid table,
8994** or any operation on a WITHOUT ROWID table, the value of the sixth
8995** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8996** seventh parameter is the final rowid value of the row being inserted
8997** or updated. The value of the seventh parameter passed to the callback
8998** function is not defined for operations on WITHOUT ROWID tables, or for
8999** INSERT operations on rowid tables.
9000**
9001** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
9002** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
9003** provide additional information about a preupdate event. These routines
9004** may only be called from within a preupdate callback. Invoking any of
9005** these routines from outside of a preupdate callback or with a
9006** [database connection] pointer that is different from the one supplied
9007** to the preupdate callback results in undefined and probably undesirable
9008** behavior.
9009**
9010** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
9011** in the row that is being inserted, updated, or deleted.
9012**
9013** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
9014** a [protected sqlite3_value] that contains the value of the Nth column of
9015** the table row before it is updated. The N parameter must be between 0
9016** and one less than the number of columns or the behavior will be
9017** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
9018** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
9019** behavior is undefined. The [sqlite3_value] that P points to
9020** will be destroyed when the preupdate callback returns.
9021**
9022** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
9023** a [protected sqlite3_value] that contains the value of the Nth column of
9024** the table row after it is updated. The N parameter must be between 0
9025** and one less than the number of columns or the behavior will be
9026** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
9027** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
9028** behavior is undefined. The [sqlite3_value] that P points to
9029** will be destroyed when the preupdate callback returns.
9030**
9031** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
9032** callback was invoked as a result of a direct insert, update, or delete
9033** operation; or 1 for inserts, updates, or deletes invoked by top-level
9034** triggers; or 2 for changes resulting from triggers called by top-level
9035** triggers; and so forth.
9036**
9037** See also: [sqlite3_update_hook()]
9038*/
9039#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9040SQLITE_API void *sqlite3_preupdate_hook(
9041 sqlite3 *db,
9042 void(*xPreUpdate)(
9043 void *pCtx, /* Copy of third arg to preupdate_hook() */
9044 sqlite3 *db, /* Database handle */
9045 int op, /* SQLITE_UPDATE, DELETE or INSERT */
9046 char const *zDb, /* Database name */
9047 char const *zName, /* Table name */
9048 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9049 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9050 ),
9051 void*
9052);
9053SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9054SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9055SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9056SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9057#endif
9058
9059/*
9060** CAPI3REF: Low-level system error code
9061**
9062** ^Attempt to return the underlying operating system error code or error
9063** number that caused the most recent I/O error or failure to open a file.
9064** The return value is OS-dependent. For example, on unix systems, after
9065** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9066** called to get back the underlying "errno" that caused the problem, such
9067** as ENOSPC, EAUTH, EISDIR, and so forth.
9068*/
9069SQLITE_API int sqlite3_system_errno(sqlite3*);
9070
9071/*
9072** CAPI3REF: Database Snapshot
9073** KEYWORDS: {snapshot} {sqlite3_snapshot}
9074**
9075** An instance of the snapshot object records the state of a [WAL mode]
9076** database for some specific point in history.
9077**
9078** In [WAL mode], multiple [database connections] that are open on the
9079** same database file can each be reading a different historical version
9080** of the database file. When a [database connection] begins a read
9081** transaction, that connection sees an unchanging copy of the database
9082** as it existed for the point in time when the transaction first started.
9083** Subsequent changes to the database from other connections are not seen
9084** by the reader until a new read transaction is started.
9085**
9086** The sqlite3_snapshot object records state information about an historical
9087** version of the database file so that it is possible to later open a new read
9088** transaction that sees that historical version of the database rather than
9089** the most recent version.
9090*/
9091typedef struct sqlite3_snapshot {
9092 unsigned char hidden[48];
9093} sqlite3_snapshot;
9094
9095/*
9096** CAPI3REF: Record A Database Snapshot
9097** CONSTRUCTOR: sqlite3_snapshot
9098**
9099** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9100** new [sqlite3_snapshot] object that records the current state of
9101** schema S in database connection D. ^On success, the
9102** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9103** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9104** If there is not already a read-transaction open on schema S when
9105** this function is called, one is opened automatically.
9106**
9107** The following must be true for this function to succeed. If any of
9108** the following statements are false when sqlite3_snapshot_get() is
9109** called, SQLITE_ERROR is returned. The final value of *P is undefined
9110** in this case.
9111**
9112** <ul>
9113** <li> The database handle must not be in [autocommit mode].
9114**
9115** <li> Schema S of [database connection] D must be a [WAL mode] database.
9116**
9117** <li> There must not be a write transaction open on schema S of database
9118** connection D.
9119**
9120** <li> One or more transactions must have been written to the current wal
9121** file since it was created on disk (by any connection). This means
9122** that a snapshot cannot be taken on a wal mode database with no wal
9123** file immediately after it is first opened. At least one transaction
9124** must be written to it first.
9125** </ul>
9126**
9127** This function may also return SQLITE_NOMEM. If it is called with the
9128** database handle in autocommit mode but fails for some other reason,
9129** whether or not a read transaction is opened on schema S is undefined.
9130**
9131** The [sqlite3_snapshot] object returned from a successful call to
9132** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9133** to avoid a memory leak.
9134**
9135** The [sqlite3_snapshot_get()] interface is only available when the
9136** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9137*/
9138SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9139 sqlite3 *db,
9140 const char *zSchema,
9141 sqlite3_snapshot **ppSnapshot
9142);
9143
9144/*
9145** CAPI3REF: Start a read transaction on an historical snapshot
9146** METHOD: sqlite3_snapshot
9147**
9148** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9149** transaction or upgrades an existing one for schema S of
9150** [database connection] D such that the read transaction refers to
9151** historical [snapshot] P, rather than the most recent change to the
9152** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9153** on success or an appropriate [error code] if it fails.
9154**
9155** ^In order to succeed, the database connection must not be in
9156** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9157** is already a read transaction open on schema S, then the database handle
9158** must have no active statements (SELECT statements that have been passed
9159** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9160** SQLITE_ERROR is returned if either of these conditions is violated, or
9161** if schema S does not exist, or if the snapshot object is invalid.
9162**
9163** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9164** snapshot has been overwritten by a [checkpoint]. In this case
9165** SQLITE_ERROR_SNAPSHOT is returned.
9166**
9167** If there is already a read transaction open when this function is
9168** invoked, then the same read transaction remains open (on the same
9169** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9170** is returned. If another error code - for example SQLITE_PROTOCOL or an
9171** SQLITE_IOERR error code - is returned, then the final state of the
9172** read transaction is undefined. If SQLITE_OK is returned, then the
9173** read transaction is now open on database snapshot P.
9174**
9175** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9176** database connection D does not know that the database file for
9177** schema S is in [WAL mode]. A database connection might not know
9178** that the database file is in [WAL mode] if there has been no prior
9179** I/O on that database connection, or if the database entered [WAL mode]
9180** after the most recent I/O on the database connection.)^
9181** (Hint: Run "[PRAGMA application_id]" against a newly opened
9182** database connection in order to make it ready to use snapshots.)
9183**
9184** The [sqlite3_snapshot_open()] interface is only available when the
9185** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9186*/
9187SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9188 sqlite3 *db,
9189 const char *zSchema,
9190 sqlite3_snapshot *pSnapshot
9191);
9192
9193/*
9194** CAPI3REF: Destroy a snapshot
9195** DESTRUCTOR: sqlite3_snapshot
9196**
9197** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9198** The application must eventually free every [sqlite3_snapshot] object
9199** using this routine to avoid a memory leak.
9200**
9201** The [sqlite3_snapshot_free()] interface is only available when the
9202** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9203*/
9204SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9205
9206/*
9207** CAPI3REF: Compare the ages of two snapshot handles.
9208** METHOD: sqlite3_snapshot
9209**
9210** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9211** of two valid snapshot handles.
9212**
9213** If the two snapshot handles are not associated with the same database
9214** file, the result of the comparison is undefined.
9215**
9216** Additionally, the result of the comparison is only valid if both of the
9217** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9218** last time the wal file was deleted. The wal file is deleted when the
9219** database is changed back to rollback mode or when the number of database
9220** clients drops to zero. If either snapshot handle was obtained before the
9221** wal file was last deleted, the value returned by this function
9222** is undefined.
9223**
9224** Otherwise, this API returns a negative value if P1 refers to an older
9225** snapshot than P2, zero if the two handles refer to the same database
9226** snapshot, and a positive value if P1 is a newer snapshot than P2.
9227**
9228** This interface is only available if SQLite is compiled with the
9229** [SQLITE_ENABLE_SNAPSHOT] option.
9230*/
9231SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9232 sqlite3_snapshot *p1,
9233 sqlite3_snapshot *p2
9234);
9235
9236/*
9237** CAPI3REF: Recover snapshots from a wal file
9238** METHOD: sqlite3_snapshot
9239**
9240** If a [WAL file] remains on disk after all database connections close
9241** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9242** or because the last process to have the database opened exited without
9243** calling [sqlite3_close()]) and a new connection is subsequently opened
9244** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9245** will only be able to open the last transaction added to the WAL file
9246** even though the WAL file contains other valid transactions.
9247**
9248** This function attempts to scan the WAL file associated with database zDb
9249** of database handle db and make all valid snapshots available to
9250** sqlite3_snapshot_open(). It is an error if there is already a read
9251** transaction open on the database, or if the database is not a WAL mode
9252** database.
9253**
9254** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9255**
9256** This interface is only available if SQLite is compiled with the
9257** [SQLITE_ENABLE_SNAPSHOT] option.
9258*/
9259SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9260
9261/*
9262** CAPI3REF: Serialize a database
9263**
9264** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9265** that is a serialization of the S database on [database connection] D.
9266** If P is not a NULL pointer, then the size of the database in bytes
9267** is written into *P.
9268**
9269** For an ordinary on-disk database file, the serialization is just a
9270** copy of the disk file. For an in-memory database or a "TEMP" database,
9271** the serialization is the same sequence of bytes which would be written
9272** to disk if that database where backed up to disk.
9273**
9274** The usual case is that sqlite3_serialize() copies the serialization of
9275** the database into memory obtained from [sqlite3_malloc64()] and returns
9276** a pointer to that memory. The caller is responsible for freeing the
9277** returned value to avoid a memory leak. However, if the F argument
9278** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9279** are made, and the sqlite3_serialize() function will return a pointer
9280** to the contiguous memory representation of the database that SQLite
9281** is currently using for that database, or NULL if the no such contiguous
9282** memory representation of the database exists. A contiguous memory
9283** representation of the database will usually only exist if there has
9284** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9285** values of D and S.
9286** The size of the database is written into *P even if the
9287** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9288** of the database exists.
9289**
9290** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9291** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9292** allocation error occurs.
9293**
9294** This interface is only available if SQLite is compiled with the
9295** [SQLITE_ENABLE_DESERIALIZE] option.
9296*/
9297SQLITE_API unsigned char *sqlite3_serialize(
9298 sqlite3 *db, /* The database connection */
9299 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9300 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9301 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9302);
9303
9304/*
9305** CAPI3REF: Flags for sqlite3_serialize
9306**
9307** Zero or more of the following constants can be OR-ed together for
9308** the F argument to [sqlite3_serialize(D,S,P,F)].
9309**
9310** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9311** a pointer to contiguous in-memory database that it is currently using,
9312** without making a copy of the database. If SQLite is not currently using
9313** a contiguous in-memory database, then this option causes
9314** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9315** using a contiguous in-memory database if it has been initialized by a
9316** prior call to [sqlite3_deserialize()].
9317*/
9318#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9319
9320/*
9321** CAPI3REF: Deserialize a database
9322**
9323** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9324** [database connection] D to disconnect from database S and then
9325** reopen S as an in-memory database based on the serialization contained
9326** in P. The serialized database P is N bytes in size. M is the size of
9327** the buffer P, which might be larger than N. If M is larger than N, and
9328** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9329** permitted to add content to the in-memory database as long as the total
9330** size does not exceed M bytes.
9331**
9332** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9333** invoke sqlite3_free() on the serialization buffer when the database
9334** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9335** SQLite will try to increase the buffer size using sqlite3_realloc64()
9336** if writes on the database cause it to grow larger than M bytes.
9337**
9338** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9339** database is currently in a read transaction or is involved in a backup
9340** operation.
9341**
9342** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9343** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9344** [sqlite3_free()] is invoked on argument P prior to returning.
9345**
9346** This interface is only available if SQLite is compiled with the
9347** [SQLITE_ENABLE_DESERIALIZE] option.
9348*/
9349SQLITE_API int sqlite3_deserialize(
9350 sqlite3 *db, /* The database connection */
9351 const char *zSchema, /* Which DB to reopen with the deserialization */
9352 unsigned char *pData, /* The serialized database content */
9353 sqlite3_int64 szDb, /* Number bytes in the deserialization */
9354 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9355 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9356);
9357
9358/*
9359** CAPI3REF: Flags for sqlite3_deserialize()
9360**
9361** The following are allowed values for 6th argument (the F argument) to
9362** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9363**
9364** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9365** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9366** and that SQLite should take ownership of this memory and automatically
9367** free it when it has finished using it. Without this flag, the caller
9368** is responsible for freeing any dynamically allocated memory.
9369**
9370** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9371** grow the size of the database using calls to [sqlite3_realloc64()]. This
9372** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9373** Without this flag, the deserialized database cannot increase in size beyond
9374** the number of bytes specified by the M parameter.
9375**
9376** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9377** should be treated as read-only.
9378*/
9379#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9380#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9381#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9382
9383/*
9384** Undo the hack that converts floating point types to integer for
9385** builds on processors without floating point support.
9386*/
9387#ifdef SQLITE_OMIT_FLOATING_POINT
9388# undef double
9389#endif
9390
9391#ifdef __cplusplus
9392} /* End of the 'extern "C"' block */
9393#endif
9394#endif /* SQLITE3_H */
9395
9396/******** Begin file sqlite3rtree.h *********/
9397/*
9398** 2010 August 30
9399**
9400** The author disclaims copyright to this source code. In place of
9401** a legal notice, here is a blessing:
9402**
9403** May you do good and not evil.
9404** May you find forgiveness for yourself and forgive others.
9405** May you share freely, never taking more than you give.
9406**
9407*************************************************************************
9408*/
9409
9410#ifndef _SQLITE3RTREE_H_
9411#define _SQLITE3RTREE_H_
9412
9413
9414#ifdef __cplusplus
9415extern "C" {
9416#endif
9417
9418typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
9419typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9420
9421/* The double-precision datatype used by RTree depends on the
9422** SQLITE_RTREE_INT_ONLY compile-time option.
9423*/
9424#ifdef SQLITE_RTREE_INT_ONLY
9425 typedef sqlite3_int64 sqlite3_rtree_dbl;
9426#else
9427 typedef double sqlite3_rtree_dbl;
9428#endif
9429
9430/*
9431** Register a geometry callback named zGeom that can be used as part of an
9432** R-Tree geometry query as follows:
9433**
9434** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9435*/
9436SQLITE_API int sqlite3_rtree_geometry_callback(
9437 sqlite3 *db,
9438 const char *zGeom,
9439 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
9440 void *pContext
9441);
9442
9443
9444/*
9445** A pointer to a structure of the following type is passed as the first
9446** argument to callbacks registered using rtree_geometry_callback().
9447*/
9448struct sqlite3_rtree_geometry {
9449 void *pContext; /* Copy of pContext passed to s_r_g_c() */
9450 int nParam; /* Size of array aParam[] */
9451 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
9452 void *pUser; /* Callback implementation user data */
9453 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9454};
9455
9456/*
9457** Register a 2nd-generation geometry callback named zScore that can be
9458** used as part of an R-Tree geometry query as follows:
9459**
9460** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9461*/
9462SQLITE_API int sqlite3_rtree_query_callback(
9463 sqlite3 *db,
9464 const char *zQueryFunc,
9465 int (*xQueryFunc)(sqlite3_rtree_query_info*),
9466 void *pContext,
9467 void (*xDestructor)(void*)
9468);
9469
9470
9471/*
9472** A pointer to a structure of the following type is passed as the
9473** argument to scored geometry callback registered using
9474** sqlite3_rtree_query_callback().
9475**
9476** Note that the first 5 fields of this structure are identical to
9477** sqlite3_rtree_geometry. This structure is a subclass of
9478** sqlite3_rtree_geometry.
9479*/
9480struct sqlite3_rtree_query_info {
9481 void *pContext; /* pContext from when function registered */
9482 int nParam; /* Number of function parameters */
9483 sqlite3_rtree_dbl *aParam; /* value of function parameters */
9484 void *pUser; /* callback can use this, if desired */
9485 void (*xDelUser)(void*); /* function to free pUser */
9486 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9487 unsigned int *anQueue; /* Number of pending entries in the queue */
9488 int nCoord; /* Number of coordinates */
9489 int iLevel; /* Level of current node or entry */
9490 int mxLevel; /* The largest iLevel value in the tree */
9491 sqlite3_int64 iRowid; /* Rowid for current entry */
9492 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9493 int eParentWithin; /* Visibility of parent node */
9494 int eWithin; /* OUT: Visibility */
9495 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9496 /* The following fields are only available in 3.8.11 and later */
9497 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9498};
9499
9500/*
9501** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9502*/
9503#define NOT_WITHIN 0 /* Object completely outside of query region */
9504#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9505#define FULLY_WITHIN 2 /* Object fully contained within query region */
9506
9507
9508#ifdef __cplusplus
9509} /* end of the 'extern "C"' block */
9510#endif
9511
9512#endif /* ifndef _SQLITE3RTREE_H_ */
9513
9514/******** End of sqlite3rtree.h *********/
9515/******** Begin file sqlite3session.h *********/
9516
9517#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
9518#define __SQLITESESSION_H_ 1
9519
9520/*
9521** Make sure we can call this stuff from C++.
9522*/
9523#ifdef __cplusplus
9524extern "C" {
9525#endif
9526
9527
9528/*
9529** CAPI3REF: Session Object Handle
9530**
9531** An instance of this object is a [session] that can be used to
9532** record changes to a database.
9533*/
9534typedef struct sqlite3_session sqlite3_session;
9535
9536/*
9537** CAPI3REF: Changeset Iterator Handle
9538**
9539** An instance of this object acts as a cursor for iterating
9540** over the elements of a [changeset] or [patchset].
9541*/
9542typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
9543
9544/*
9545** CAPI3REF: Create A New Session Object
9546** CONSTRUCTOR: sqlite3_session
9547**
9548** Create a new session object attached to database handle db. If successful,
9549** a pointer to the new object is written to *ppSession and SQLITE_OK is
9550** returned. If an error occurs, *ppSession is set to NULL and an SQLite
9551** error code (e.g. SQLITE_NOMEM) is returned.
9552**
9553** It is possible to create multiple session objects attached to a single
9554** database handle.
9555**
9556** Session objects created using this function should be deleted using the
9557** [sqlite3session_delete()] function before the database handle that they
9558** are attached to is itself closed. If the database handle is closed before
9559** the session object is deleted, then the results of calling any session
9560** module function, including [sqlite3session_delete()] on the session object
9561** are undefined.
9562**
9563** Because the session module uses the [sqlite3_preupdate_hook()] API, it
9564** is not possible for an application to register a pre-update hook on a
9565** database handle that has one or more session objects attached. Nor is
9566** it possible to create a session object attached to a database handle for
9567** which a pre-update hook is already defined. The results of attempting
9568** either of these things are undefined.
9569**
9570** The session object will be used to create changesets for tables in
9571** database zDb, where zDb is either "main", or "temp", or the name of an
9572** attached database. It is not an error if database zDb is not attached
9573** to the database when the session object is created.
9574*/
9575SQLITE_API int sqlite3session_create(
9576 sqlite3 *db, /* Database handle */
9577 const char *zDb, /* Name of db (e.g. "main") */
9578 sqlite3_session **ppSession /* OUT: New session object */
9579);
9580
9581/*
9582** CAPI3REF: Delete A Session Object
9583** DESTRUCTOR: sqlite3_session
9584**
9585** Delete a session object previously allocated using
9586** [sqlite3session_create()]. Once a session object has been deleted, the
9587** results of attempting to use pSession with any other session module
9588** function are undefined.
9589**
9590** Session objects must be deleted before the database handle to which they
9591** are attached is closed. Refer to the documentation for
9592** [sqlite3session_create()] for details.
9593*/
9594SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
9595
9596
9597/*
9598** CAPI3REF: Enable Or Disable A Session Object
9599** METHOD: sqlite3_session
9600**
9601** Enable or disable the recording of changes by a session object. When
9602** enabled, a session object records changes made to the database. When
9603** disabled - it does not. A newly created session object is enabled.
9604** Refer to the documentation for [sqlite3session_changeset()] for further
9605** details regarding how enabling and disabling a session object affects
9606** the eventual changesets.
9607**
9608** Passing zero to this function disables the session. Passing a value
9609** greater than zero enables it. Passing a value less than zero is a
9610** no-op, and may be used to query the current state of the session.
9611**
9612** The return value indicates the final state of the session object: 0 if
9613** the session is disabled, or 1 if it is enabled.
9614*/
9615SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
9616
9617/*
9618** CAPI3REF: Set Or Clear the Indirect Change Flag
9619** METHOD: sqlite3_session
9620**
9621** Each change recorded by a session object is marked as either direct or
9622** indirect. A change is marked as indirect if either:
9623**
9624** <ul>
9625** <li> The session object "indirect" flag is set when the change is
9626** made, or
9627** <li> The change is made by an SQL trigger or foreign key action
9628** instead of directly as a result of a users SQL statement.
9629** </ul>
9630**
9631** If a single row is affected by more than one operation within a session,
9632** then the change is considered indirect if all operations meet the criteria
9633** for an indirect change above, or direct otherwise.
9634**
9635** This function is used to set, clear or query the session object indirect
9636** flag. If the second argument passed to this function is zero, then the
9637** indirect flag is cleared. If it is greater than zero, the indirect flag
9638** is set. Passing a value less than zero does not modify the current value
9639** of the indirect flag, and may be used to query the current state of the
9640** indirect flag for the specified session object.
9641**
9642** The return value indicates the final state of the indirect flag: 0 if
9643** it is clear, or 1 if it is set.
9644*/
9645SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
9646
9647/*
9648** CAPI3REF: Attach A Table To A Session Object
9649** METHOD: sqlite3_session
9650**
9651** If argument zTab is not NULL, then it is the name of a table to attach
9652** to the session object passed as the first argument. All subsequent changes
9653** made to the table while the session object is enabled will be recorded. See
9654** documentation for [sqlite3session_changeset()] for further details.
9655**
9656** Or, if argument zTab is NULL, then changes are recorded for all tables
9657** in the database. If additional tables are added to the database (by
9658** executing "CREATE TABLE" statements) after this call is made, changes for
9659** the new tables are also recorded.
9660**
9661** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
9662** defined as part of their CREATE TABLE statement. It does not matter if the
9663** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
9664** KEY may consist of a single column, or may be a composite key.
9665**
9666** It is not an error if the named table does not exist in the database. Nor
9667** is it an error if the named table does not have a PRIMARY KEY. However,
9668** no changes will be recorded in either of these scenarios.
9669**
9670** Changes are not recorded for individual rows that have NULL values stored
9671** in one or more of their PRIMARY KEY columns.
9672**
9673** SQLITE_OK is returned if the call completes without error. Or, if an error
9674** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
9675**
9676** <h3>Special sqlite_stat1 Handling</h3>
9677**
9678** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
9679** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
9680** <pre>
9681** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
9682** </pre>
9683**
9684** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
9685** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
9686** are recorded for rows for which (idx IS NULL) is true. However, for such
9687** rows a zero-length blob (SQL value X'') is stored in the changeset or
9688** patchset instead of a NULL value. This allows such changesets to be
9689** manipulated by legacy implementations of sqlite3changeset_invert(),
9690** concat() and similar.
9691**
9692** The sqlite3changeset_apply() function automatically converts the
9693** zero-length blob back to a NULL value when updating the sqlite_stat1
9694** table. However, if the application calls sqlite3changeset_new(),
9695** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
9696** iterator directly (including on a changeset iterator passed to a
9697** conflict-handler callback) then the X'' value is returned. The application
9698** must translate X'' to NULL itself if required.
9699**
9700** Legacy (older than 3.22.0) versions of the sessions module cannot capture
9701** changes made to the sqlite_stat1 table. Legacy versions of the
9702** sqlite3changeset_apply() function silently ignore any modifications to the
9703** sqlite_stat1 table that are part of a changeset or patchset.
9704*/
9705SQLITE_API int sqlite3session_attach(
9706 sqlite3_session *pSession, /* Session object */
9707 const char *zTab /* Table name */
9708);
9709
9710/*
9711** CAPI3REF: Set a table filter on a Session Object.
9712** METHOD: sqlite3_session
9713**
9714** The second argument (xFilter) is the "filter callback". For changes to rows
9715** in tables that are not attached to the Session object, the filter is called
9716** to determine whether changes to the table's rows should be tracked or not.
9717** If xFilter returns 0, changes is not tracked. Note that once a table is
9718** attached, xFilter will not be called again.
9719*/
9720SQLITE_API void sqlite3session_table_filter(
9721 sqlite3_session *pSession, /* Session object */
9722 int(*xFilter)(
9723 void *pCtx, /* Copy of third arg to _filter_table() */
9724 const char *zTab /* Table name */
9725 ),
9726 void *pCtx /* First argument passed to xFilter */
9727);
9728
9729/*
9730** CAPI3REF: Generate A Changeset From A Session Object
9731** METHOD: sqlite3_session
9732**
9733** Obtain a changeset containing changes to the tables attached to the
9734** session object passed as the first argument. If successful,
9735** set *ppChangeset to point to a buffer containing the changeset
9736** and *pnChangeset to the size of the changeset in bytes before returning
9737** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
9738** zero and return an SQLite error code.
9739**
9740** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
9741** each representing a change to a single row of an attached table. An INSERT
9742** change contains the values of each field of a new database row. A DELETE
9743** contains the original values of each field of a deleted database row. An
9744** UPDATE change contains the original values of each field of an updated
9745** database row along with the updated values for each updated non-primary-key
9746** column. It is not possible for an UPDATE change to represent a change that
9747** modifies the values of primary key columns. If such a change is made, it
9748** is represented in a changeset as a DELETE followed by an INSERT.
9749**
9750** Changes are not recorded for rows that have NULL values stored in one or
9751** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
9752** no corresponding change is present in the changesets returned by this
9753** function. If an existing row with one or more NULL values stored in
9754** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
9755** only an INSERT is appears in the changeset. Similarly, if an existing row
9756** with non-NULL PRIMARY KEY values is updated so that one or more of its
9757** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
9758** DELETE change only.
9759**
9760** The contents of a changeset may be traversed using an iterator created
9761** using the [sqlite3changeset_start()] API. A changeset may be applied to
9762** a database with a compatible schema using the [sqlite3changeset_apply()]
9763** API.
9764**
9765** Within a changeset generated by this function, all changes related to a
9766** single table are grouped together. In other words, when iterating through
9767** a changeset or when applying a changeset to a database, all changes related
9768** to a single table are processed before moving on to the next table. Tables
9769** are sorted in the same order in which they were attached (or auto-attached)
9770** to the sqlite3_session object. The order in which the changes related to
9771** a single table are stored is undefined.
9772**
9773** Following a successful call to this function, it is the responsibility of
9774** the caller to eventually free the buffer that *ppChangeset points to using
9775** [sqlite3_free()].
9776**
9777** <h3>Changeset Generation</h3>
9778**
9779** Once a table has been attached to a session object, the session object
9780** records the primary key values of all new rows inserted into the table.
9781** It also records the original primary key and other column values of any
9782** deleted or updated rows. For each unique primary key value, data is only
9783** recorded once - the first time a row with said primary key is inserted,
9784** updated or deleted in the lifetime of the session.
9785**
9786** There is one exception to the previous paragraph: when a row is inserted,
9787** updated or deleted, if one or more of its primary key columns contain a
9788** NULL value, no record of the change is made.
9789**
9790** The session object therefore accumulates two types of records - those
9791** that consist of primary key values only (created when the user inserts
9792** a new record) and those that consist of the primary key values and the
9793** original values of other table columns (created when the users deletes
9794** or updates a record).
9795**
9796** When this function is called, the requested changeset is created using
9797** both the accumulated records and the current contents of the database
9798** file. Specifically:
9799**
9800** <ul>
9801** <li> For each record generated by an insert, the database is queried
9802** for a row with a matching primary key. If one is found, an INSERT
9803** change is added to the changeset. If no such row is found, no change
9804** is added to the changeset.
9805**
9806** <li> For each record generated by an update or delete, the database is
9807** queried for a row with a matching primary key. If such a row is
9808** found and one or more of the non-primary key fields have been
9809** modified from their original values, an UPDATE change is added to
9810** the changeset. Or, if no such row is found in the table, a DELETE
9811** change is added to the changeset. If there is a row with a matching
9812** primary key in the database, but all fields contain their original
9813** values, no change is added to the changeset.
9814** </ul>
9815**
9816** This means, amongst other things, that if a row is inserted and then later
9817** deleted while a session object is active, neither the insert nor the delete
9818** will be present in the changeset. Or if a row is deleted and then later a
9819** row with the same primary key values inserted while a session object is
9820** active, the resulting changeset will contain an UPDATE change instead of
9821** a DELETE and an INSERT.
9822**
9823** When a session object is disabled (see the [sqlite3session_enable()] API),
9824** it does not accumulate records when rows are inserted, updated or deleted.
9825** This may appear to have some counter-intuitive effects if a single row
9826** is written to more than once during a session. For example, if a row
9827** is inserted while a session object is enabled, then later deleted while
9828** the same session object is disabled, no INSERT record will appear in the
9829** changeset, even though the delete took place while the session was disabled.
9830** Or, if one field of a row is updated while a session is disabled, and
9831** another field of the same row is updated while the session is enabled, the
9832** resulting changeset will contain an UPDATE change that updates both fields.
9833*/
9834SQLITE_API int sqlite3session_changeset(
9835 sqlite3_session *pSession, /* Session object */
9836 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
9837 void **ppChangeset /* OUT: Buffer containing changeset */
9838);
9839
9840/*
9841** CAPI3REF: Load The Difference Between Tables Into A Session
9842** METHOD: sqlite3_session
9843**
9844** If it is not already attached to the session object passed as the first
9845** argument, this function attaches table zTbl in the same manner as the
9846** [sqlite3session_attach()] function. If zTbl does not exist, or if it
9847** does not have a primary key, this function is a no-op (but does not return
9848** an error).
9849**
9850** Argument zFromDb must be the name of a database ("main", "temp" etc.)
9851** attached to the same database handle as the session object that contains
9852** a table compatible with the table attached to the session by this function.
9853** A table is considered compatible if it:
9854**
9855** <ul>
9856** <li> Has the same name,
9857** <li> Has the same set of columns declared in the same order, and
9858** <li> Has the same PRIMARY KEY definition.
9859** </ul>
9860**
9861** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
9862** are compatible but do not have any PRIMARY KEY columns, it is not an error
9863** but no changes are added to the session object. As with other session
9864** APIs, tables without PRIMARY KEYs are simply ignored.
9865**
9866** This function adds a set of changes to the session object that could be
9867** used to update the table in database zFrom (call this the "from-table")
9868** so that its content is the same as the table attached to the session
9869** object (call this the "to-table"). Specifically:
9870**
9871** <ul>
9872** <li> For each row (primary key) that exists in the to-table but not in
9873** the from-table, an INSERT record is added to the session object.
9874**
9875** <li> For each row (primary key) that exists in the to-table but not in
9876** the from-table, a DELETE record is added to the session object.
9877**
9878** <li> For each row (primary key) that exists in both tables, but features
9879** different non-PK values in each, an UPDATE record is added to the
9880** session.
9881** </ul>
9882**
9883** To clarify, if this function is called and then a changeset constructed
9884** using [sqlite3session_changeset()], then after applying that changeset to
9885** database zFrom the contents of the two compatible tables would be
9886** identical.
9887**
9888** It an error if database zFrom does not exist or does not contain the
9889** required compatible table.
9890**
9891** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
9892** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
9893** may be set to point to a buffer containing an English language error
9894** message. It is the responsibility of the caller to free this buffer using
9895** sqlite3_free().
9896*/
9897SQLITE_API int sqlite3session_diff(
9898 sqlite3_session *pSession,
9899 const char *zFromDb,
9900 const char *zTbl,
9901 char **pzErrMsg
9902);
9903
9904
9905/*
9906** CAPI3REF: Generate A Patchset From A Session Object
9907** METHOD: sqlite3_session
9908**
9909** The differences between a patchset and a changeset are that:
9910**
9911** <ul>
9912** <li> DELETE records consist of the primary key fields only. The
9913** original values of other fields are omitted.
9914** <li> The original values of any modified fields are omitted from
9915** UPDATE records.
9916** </ul>
9917**
9918** A patchset blob may be used with up to date versions of all
9919** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
9920** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
9921** attempting to use a patchset blob with old versions of the
9922** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
9923**
9924** Because the non-primary key "old.*" fields are omitted, no
9925** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
9926** is passed to the sqlite3changeset_apply() API. Other conflict types work
9927** in the same way as for changesets.
9928**
9929** Changes within a patchset are ordered in the same way as for changesets
9930** generated by the sqlite3session_changeset() function (i.e. all changes for
9931** a single table are grouped together, tables appear in the order in which
9932** they were attached to the session object).
9933*/
9934SQLITE_API int sqlite3session_patchset(
9935 sqlite3_session *pSession, /* Session object */
9936 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
9937 void **ppPatchset /* OUT: Buffer containing patchset */
9938);
9939
9940/*
9941** CAPI3REF: Test if a changeset has recorded any changes.
9942**
9943** Return non-zero if no changes to attached tables have been recorded by
9944** the session object passed as the first argument. Otherwise, if one or
9945** more changes have been recorded, return zero.
9946**
9947** Even if this function returns zero, it is possible that calling
9948** [sqlite3session_changeset()] on the session handle may still return a
9949** changeset that contains no changes. This can happen when a row in
9950** an attached table is modified and then later on the original values
9951** are restored. However, if this function returns non-zero, then it is
9952** guaranteed that a call to sqlite3session_changeset() will return a
9953** changeset containing zero changes.
9954*/
9955SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
9956
9957/*
9958** CAPI3REF: Create An Iterator To Traverse A Changeset
9959** CONSTRUCTOR: sqlite3_changeset_iter
9960**
9961** Create an iterator used to iterate through the contents of a changeset.
9962** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9963** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9964** SQLite error code is returned.
9965**
9966** The following functions can be used to advance and query a changeset
9967** iterator created by this function:
9968**
9969** <ul>
9970** <li> [sqlite3changeset_next()]
9971** <li> [sqlite3changeset_op()]
9972** <li> [sqlite3changeset_new()]
9973** <li> [sqlite3changeset_old()]
9974** </ul>
9975**
9976** It is the responsibility of the caller to eventually destroy the iterator
9977** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9978** changeset (pChangeset) must remain valid until after the iterator is
9979** destroyed.
9980**
9981** Assuming the changeset blob was created by one of the
9982** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9983** [sqlite3changeset_invert()] functions, all changes within the changeset
9984** that apply to a single table are grouped together. This means that when
9985** an application iterates through a changeset using an iterator created by
9986** this function, all changes that relate to a single table are visited
9987** consecutively. There is no chance that the iterator will visit a change
9988** the applies to table X, then one for table Y, and then later on visit
9989** another change for table X.
9990**
9991** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
9992** may be modified by passing a combination of
9993** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
9994**
9995** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
9996** and therefore subject to change.
9997*/
9998SQLITE_API int sqlite3changeset_start(
9999 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10000 int nChangeset, /* Size of changeset blob in bytes */
10001 void *pChangeset /* Pointer to blob containing changeset */
10002);
10003SQLITE_API int sqlite3changeset_start_v2(
10004 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10005 int nChangeset, /* Size of changeset blob in bytes */
10006 void *pChangeset, /* Pointer to blob containing changeset */
10007 int flags /* SESSION_CHANGESETSTART_* flags */
10008);
10009
10010/*
10011** CAPI3REF: Flags for sqlite3changeset_start_v2
10012**
10013** The following flags may passed via the 4th parameter to
10014** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
10015**
10016** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10017** Invert the changeset while iterating through it. This is equivalent to
10018** inverting a changeset using sqlite3changeset_invert() before applying it.
10019** It is an error to specify this flag with a patchset.
10020*/
10021#define SQLITE_CHANGESETSTART_INVERT 0x0002
10022
10023
10024/*
10025** CAPI3REF: Advance A Changeset Iterator
10026** METHOD: sqlite3_changeset_iter
10027**
10028** This function may only be used with iterators created by function
10029** [sqlite3changeset_start()]. If it is called on an iterator passed to
10030** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
10031** is returned and the call has no effect.
10032**
10033** Immediately after an iterator is created by sqlite3changeset_start(), it
10034** does not point to any change in the changeset. Assuming the changeset
10035** is not empty, the first call to this function advances the iterator to
10036** point to the first change in the changeset. Each subsequent call advances
10037** the iterator to point to the next change in the changeset (if any). If
10038** no error occurs and the iterator points to a valid change after a call
10039** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
10040** Otherwise, if all changes in the changeset have already been visited,
10041** SQLITE_DONE is returned.
10042**
10043** If an error occurs, an SQLite error code is returned. Possible error
10044** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
10045** SQLITE_NOMEM.
10046*/
10047SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
10048
10049/*
10050** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
10051** METHOD: sqlite3_changeset_iter
10052**
10053** The pIter argument passed to this function may either be an iterator
10054** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10055** created by [sqlite3changeset_start()]. In the latter case, the most recent
10056** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10057** is not the case, this function returns [SQLITE_MISUSE].
10058**
10059** If argument pzTab is not NULL, then *pzTab is set to point to a
10060** nul-terminated utf-8 encoded string containing the name of the table
10061** affected by the current change. The buffer remains valid until either
10062** sqlite3changeset_next() is called on the iterator or until the
10063** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
10064** set to the number of columns in the table affected by the change. If
10065** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
10066** is an indirect change, or false (0) otherwise. See the documentation for
10067** [sqlite3session_indirect()] for a description of direct and indirect
10068** changes. Finally, if pOp is not NULL, then *pOp is set to one of
10069** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
10070** type of change that the iterator currently points to.
10071**
10072** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10073** SQLite error code is returned. The values of the output variables may not
10074** be trusted in this case.
10075*/
10076SQLITE_API int sqlite3changeset_op(
10077 sqlite3_changeset_iter *pIter, /* Iterator object */
10078 const char **pzTab, /* OUT: Pointer to table name */
10079 int *pnCol, /* OUT: Number of columns in table */
10080 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10081 int *pbIndirect /* OUT: True for an 'indirect' change */
10082);
10083
10084/*
10085** CAPI3REF: Obtain The Primary Key Definition Of A Table
10086** METHOD: sqlite3_changeset_iter
10087**
10088** For each modified table, a changeset includes the following:
10089**
10090** <ul>
10091** <li> The number of columns in the table, and
10092** <li> Which of those columns make up the tables PRIMARY KEY.
10093** </ul>
10094**
10095** This function is used to find which columns comprise the PRIMARY KEY of
10096** the table modified by the change that iterator pIter currently points to.
10097** If successful, *pabPK is set to point to an array of nCol entries, where
10098** nCol is the number of columns in the table. Elements of *pabPK are set to
10099** 0x01 if the corresponding column is part of the tables primary key, or
10100** 0x00 if it is not.
10101**
10102** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10103** in the table.
10104**
10105** If this function is called when the iterator does not point to a valid
10106** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10107** SQLITE_OK is returned and the output variables populated as described
10108** above.
10109*/
10110SQLITE_API int sqlite3changeset_pk(
10111 sqlite3_changeset_iter *pIter, /* Iterator object */
10112 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10113 int *pnCol /* OUT: Number of entries in output array */
10114);
10115
10116/*
10117** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10118** METHOD: sqlite3_changeset_iter
10119**
10120** The pIter argument passed to this function may either be an iterator
10121** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10122** created by [sqlite3changeset_start()]. In the latter case, the most recent
10123** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10124** Furthermore, it may only be called if the type of change that the iterator
10125** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10126** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10127**
10128** Argument iVal must be greater than or equal to 0, and less than the number
10129** of columns in the table affected by the current change. Otherwise,
10130** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10131**
10132** If successful, this function sets *ppValue to point to a protected
10133** sqlite3_value object containing the iVal'th value from the vector of
10134** original row values stored as part of the UPDATE or DELETE change and
10135** returns SQLITE_OK. The name of the function comes from the fact that this
10136** is similar to the "old.*" columns available to update or delete triggers.
10137**
10138** If some other error occurs (e.g. an OOM condition), an SQLite error code
10139** is returned and *ppValue is set to NULL.
10140*/
10141SQLITE_API int sqlite3changeset_old(
10142 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10143 int iVal, /* Column number */
10144 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10145);
10146
10147/*
10148** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10149** METHOD: sqlite3_changeset_iter
10150**
10151** The pIter argument passed to this function may either be an iterator
10152** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10153** created by [sqlite3changeset_start()]. In the latter case, the most recent
10154** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10155** Furthermore, it may only be called if the type of change that the iterator
10156** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10157** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10158**
10159** Argument iVal must be greater than or equal to 0, and less than the number
10160** of columns in the table affected by the current change. Otherwise,
10161** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10162**
10163** If successful, this function sets *ppValue to point to a protected
10164** sqlite3_value object containing the iVal'th value from the vector of
10165** new row values stored as part of the UPDATE or INSERT change and
10166** returns SQLITE_OK. If the change is an UPDATE and does not include
10167** a new value for the requested column, *ppValue is set to NULL and
10168** SQLITE_OK returned. The name of the function comes from the fact that
10169** this is similar to the "new.*" columns available to update or delete
10170** triggers.
10171**
10172** If some other error occurs (e.g. an OOM condition), an SQLite error code
10173** is returned and *ppValue is set to NULL.
10174*/
10175SQLITE_API int sqlite3changeset_new(
10176 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10177 int iVal, /* Column number */
10178 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10179);
10180
10181/*
10182** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10183** METHOD: sqlite3_changeset_iter
10184**
10185** This function should only be used with iterator objects passed to a
10186** conflict-handler callback by [sqlite3changeset_apply()] with either
10187** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10188** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10189** is set to NULL.
10190**
10191** Argument iVal must be greater than or equal to 0, and less than the number
10192** of columns in the table affected by the current change. Otherwise,
10193** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10194**
10195** If successful, this function sets *ppValue to point to a protected
10196** sqlite3_value object containing the iVal'th value from the
10197** "conflicting row" associated with the current conflict-handler callback
10198** and returns SQLITE_OK.
10199**
10200** If some other error occurs (e.g. an OOM condition), an SQLite error code
10201** is returned and *ppValue is set to NULL.
10202*/
10203SQLITE_API int sqlite3changeset_conflict(
10204 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10205 int iVal, /* Column number */
10206 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10207);
10208
10209/*
10210** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10211** METHOD: sqlite3_changeset_iter
10212**
10213** This function may only be called with an iterator passed to an
10214** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10215** it sets the output variable to the total number of known foreign key
10216** violations in the destination database and returns SQLITE_OK.
10217**
10218** In all other cases this function returns SQLITE_MISUSE.
10219*/
10220SQLITE_API int sqlite3changeset_fk_conflicts(
10221 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10222 int *pnOut /* OUT: Number of FK violations */
10223);
10224
10225
10226/*
10227** CAPI3REF: Finalize A Changeset Iterator
10228** METHOD: sqlite3_changeset_iter
10229**
10230** This function is used to finalize an iterator allocated with
10231** [sqlite3changeset_start()].
10232**
10233** This function should only be called on iterators created using the
10234** [sqlite3changeset_start()] function. If an application calls this
10235** function with an iterator passed to a conflict-handler by
10236** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10237** call has no effect.
10238**
10239** If an error was encountered within a call to an sqlite3changeset_xxx()
10240** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10241** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10242** to that error is returned by this function. Otherwise, SQLITE_OK is
10243** returned. This is to allow the following pattern (pseudo-code):
10244**
10245** <pre>
10246** sqlite3changeset_start();
10247** while( SQLITE_ROW==sqlite3changeset_next() ){
10248** // Do something with change.
10249** }
10250** rc = sqlite3changeset_finalize();
10251** if( rc!=SQLITE_OK ){
10252** // An error has occurred
10253** }
10254** </pre>
10255*/
10256SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10257
10258/*
10259** CAPI3REF: Invert A Changeset
10260**
10261** This function is used to "invert" a changeset object. Applying an inverted
10262** changeset to a database reverses the effects of applying the uninverted
10263** changeset. Specifically:
10264**
10265** <ul>
10266** <li> Each DELETE change is changed to an INSERT, and
10267** <li> Each INSERT change is changed to a DELETE, and
10268** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10269** </ul>
10270**
10271** This function does not change the order in which changes appear within
10272** the changeset. It merely reverses the sense of each individual change.
10273**
10274** If successful, a pointer to a buffer containing the inverted changeset
10275** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10276** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10277** zeroed and an SQLite error code returned.
10278**
10279** It is the responsibility of the caller to eventually call sqlite3_free()
10280** on the *ppOut pointer to free the buffer allocation following a successful
10281** call to this function.
10282**
10283** WARNING/TODO: This function currently assumes that the input is a valid
10284** changeset. If it is not, the results are undefined.
10285*/
10286SQLITE_API int sqlite3changeset_invert(
10287 int nIn, const void *pIn, /* Input changeset */
10288 int *pnOut, void **ppOut /* OUT: Inverse of input */
10289);
10290
10291/*
10292** CAPI3REF: Concatenate Two Changeset Objects
10293**
10294** This function is used to concatenate two changesets, A and B, into a
10295** single changeset. The result is a changeset equivalent to applying
10296** changeset A followed by changeset B.
10297**
10298** This function combines the two input changesets using an
10299** sqlite3_changegroup object. Calling it produces similar results as the
10300** following code fragment:
10301**
10302** <pre>
10303** sqlite3_changegroup *pGrp;
10304** rc = sqlite3_changegroup_new(&pGrp);
10305** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10306** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10307** if( rc==SQLITE_OK ){
10308** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10309** }else{
10310** *ppOut = 0;
10311** *pnOut = 0;
10312** }
10313** </pre>
10314**
10315** Refer to the sqlite3_changegroup documentation below for details.
10316*/
10317SQLITE_API int sqlite3changeset_concat(
10318 int nA, /* Number of bytes in buffer pA */
10319 void *pA, /* Pointer to buffer containing changeset A */
10320 int nB, /* Number of bytes in buffer pB */
10321 void *pB, /* Pointer to buffer containing changeset B */
10322 int *pnOut, /* OUT: Number of bytes in output changeset */
10323 void **ppOut /* OUT: Buffer containing output changeset */
10324);
10325
10326
10327/*
10328** CAPI3REF: Changegroup Handle
10329**
10330** A changegroup is an object used to combine two or more
10331** [changesets] or [patchsets]
10332*/
10333typedef struct sqlite3_changegroup sqlite3_changegroup;
10334
10335/*
10336** CAPI3REF: Create A New Changegroup Object
10337** CONSTRUCTOR: sqlite3_changegroup
10338**
10339** An sqlite3_changegroup object is used to combine two or more changesets
10340** (or patchsets) into a single changeset (or patchset). A single changegroup
10341** object may combine changesets or patchsets, but not both. The output is
10342** always in the same format as the input.
10343**
10344** If successful, this function returns SQLITE_OK and populates (*pp) with
10345** a pointer to a new sqlite3_changegroup object before returning. The caller
10346** should eventually free the returned object using a call to
10347** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10348** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10349**
10350** The usual usage pattern for an sqlite3_changegroup object is as follows:
10351**
10352** <ul>
10353** <li> It is created using a call to sqlite3changegroup_new().
10354**
10355** <li> Zero or more changesets (or patchsets) are added to the object
10356** by calling sqlite3changegroup_add().
10357**
10358** <li> The result of combining all input changesets together is obtained
10359** by the application via a call to sqlite3changegroup_output().
10360**
10361** <li> The object is deleted using a call to sqlite3changegroup_delete().
10362** </ul>
10363**
10364** Any number of calls to add() and output() may be made between the calls to
10365** new() and delete(), and in any order.
10366**
10367** As well as the regular sqlite3changegroup_add() and
10368** sqlite3changegroup_output() functions, also available are the streaming
10369** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10370*/
10371SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
10372
10373/*
10374** CAPI3REF: Add A Changeset To A Changegroup
10375** METHOD: sqlite3_changegroup
10376**
10377** Add all changes within the changeset (or patchset) in buffer pData (size
10378** nData bytes) to the changegroup.
10379**
10380** If the buffer contains a patchset, then all prior calls to this function
10381** on the same changegroup object must also have specified patchsets. Or, if
10382** the buffer contains a changeset, so must have the earlier calls to this
10383** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10384** to the changegroup.
10385**
10386** Rows within the changeset and changegroup are identified by the values in
10387** their PRIMARY KEY columns. A change in the changeset is considered to
10388** apply to the same row as a change already present in the changegroup if
10389** the two rows have the same primary key.
10390**
10391** Changes to rows that do not already appear in the changegroup are
10392** simply copied into it. Or, if both the new changeset and the changegroup
10393** contain changes that apply to a single row, the final contents of the
10394** changegroup depends on the type of each change, as follows:
10395**
10396** <table border=1 style="margin-left:8ex;margin-right:8ex">
10397** <tr><th style="white-space:pre">Existing Change </th>
10398** <th style="white-space:pre">New Change </th>
10399** <th>Output Change
10400** <tr><td>INSERT <td>INSERT <td>
10401** The new change is ignored. This case does not occur if the new
10402** changeset was recorded immediately after the changesets already
10403** added to the changegroup.
10404** <tr><td>INSERT <td>UPDATE <td>
10405** The INSERT change remains in the changegroup. The values in the
10406** INSERT change are modified as if the row was inserted by the
10407** existing change and then updated according to the new change.
10408** <tr><td>INSERT <td>DELETE <td>
10409** The existing INSERT is removed from the changegroup. The DELETE is
10410** not added.
10411** <tr><td>UPDATE <td>INSERT <td>
10412** The new change is ignored. This case does not occur if the new
10413** changeset was recorded immediately after the changesets already
10414** added to the changegroup.
10415** <tr><td>UPDATE <td>UPDATE <td>
10416** The existing UPDATE remains within the changegroup. It is amended
10417** so that the accompanying values are as if the row was updated once
10418** by the existing change and then again by the new change.
10419** <tr><td>UPDATE <td>DELETE <td>
10420** The existing UPDATE is replaced by the new DELETE within the
10421** changegroup.
10422** <tr><td>DELETE <td>INSERT <td>
10423** If one or more of the column values in the row inserted by the
10424** new change differ from those in the row deleted by the existing
10425** change, the existing DELETE is replaced by an UPDATE within the
10426** changegroup. Otherwise, if the inserted row is exactly the same
10427** as the deleted row, the existing DELETE is simply discarded.
10428** <tr><td>DELETE <td>UPDATE <td>
10429** The new change is ignored. This case does not occur if the new
10430** changeset was recorded immediately after the changesets already
10431** added to the changegroup.
10432** <tr><td>DELETE <td>DELETE <td>
10433** The new change is ignored. This case does not occur if the new
10434** changeset was recorded immediately after the changesets already
10435** added to the changegroup.
10436** </table>
10437**
10438** If the new changeset contains changes to a table that is already present
10439** in the changegroup, then the number of columns and the position of the
10440** primary key columns for the table must be consistent. If this is not the
10441** case, this function fails with SQLITE_SCHEMA. If the input changeset
10442** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10443** returned. Or, if an out-of-memory condition occurs during processing, this
10444** function returns SQLITE_NOMEM. In all cases, if an error occurs the
10445** final contents of the changegroup is undefined.
10446**
10447** If no error occurs, SQLITE_OK is returned.
10448*/
10449SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
10450
10451/*
10452** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10453** METHOD: sqlite3_changegroup
10454**
10455** Obtain a buffer containing a changeset (or patchset) representing the
10456** current contents of the changegroup. If the inputs to the changegroup
10457** were themselves changesets, the output is a changeset. Or, if the
10458** inputs were patchsets, the output is also a patchset.
10459**
10460** As with the output of the sqlite3session_changeset() and
10461** sqlite3session_patchset() functions, all changes related to a single
10462** table are grouped together in the output of this function. Tables appear
10463** in the same order as for the very first changeset added to the changegroup.
10464** If the second or subsequent changesets added to the changegroup contain
10465** changes for tables that do not appear in the first changeset, they are
10466** appended onto the end of the output changeset, again in the order in
10467** which they are first encountered.
10468**
10469** If an error occurs, an SQLite error code is returned and the output
10470** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
10471** is returned and the output variables are set to the size of and a
10472** pointer to the output buffer, respectively. In this case it is the
10473** responsibility of the caller to eventually free the buffer using a
10474** call to sqlite3_free().
10475*/
10476SQLITE_API int sqlite3changegroup_output(
10477 sqlite3_changegroup*,
10478 int *pnData, /* OUT: Size of output buffer in bytes */
10479 void **ppData /* OUT: Pointer to output buffer */
10480);
10481
10482/*
10483** CAPI3REF: Delete A Changegroup Object
10484** DESTRUCTOR: sqlite3_changegroup
10485*/
10486SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
10487
10488/*
10489** CAPI3REF: Apply A Changeset To A Database
10490**
10491** Apply a changeset or patchset to a database. These functions attempt to
10492** update the "main" database attached to handle db with the changes found in
10493** the changeset passed via the second and third arguments.
10494**
10495** The fourth argument (xFilter) passed to these functions is the "filter
10496** callback". If it is not NULL, then for each table affected by at least one
10497** change in the changeset, the filter callback is invoked with
10498** the table name as the second argument, and a copy of the context pointer
10499** passed as the sixth argument as the first. If the "filter callback"
10500** returns zero, then no attempt is made to apply any changes to the table.
10501** Otherwise, if the return value is non-zero or the xFilter argument to
10502** is NULL, all changes related to the table are attempted.
10503**
10504** For each table that is not excluded by the filter callback, this function
10505** tests that the target database contains a compatible table. A table is
10506** considered compatible if all of the following are true:
10507**
10508** <ul>
10509** <li> The table has the same name as the name recorded in the
10510** changeset, and
10511** <li> The table has at least as many columns as recorded in the
10512** changeset, and
10513** <li> The table has primary key columns in the same position as
10514** recorded in the changeset.
10515** </ul>
10516**
10517** If there is no compatible table, it is not an error, but none of the
10518** changes associated with the table are applied. A warning message is issued
10519** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
10520** one such warning is issued for each table in the changeset.
10521**
10522** For each change for which there is a compatible table, an attempt is made
10523** to modify the table contents according to the UPDATE, INSERT or DELETE
10524** change. If a change cannot be applied cleanly, the conflict handler
10525** function passed as the fifth argument to sqlite3changeset_apply() may be
10526** invoked. A description of exactly when the conflict handler is invoked for
10527** each type of change is below.
10528**
10529** Unlike the xFilter argument, xConflict may not be passed NULL. The results
10530** of passing anything other than a valid function pointer as the xConflict
10531** argument are undefined.
10532**
10533** Each time the conflict handler function is invoked, it must return one
10534** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
10535** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
10536** if the second argument passed to the conflict handler is either
10537** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
10538** returns an illegal value, any changes already made are rolled back and
10539** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
10540** actions are taken by sqlite3changeset_apply() depending on the value
10541** returned by each invocation of the conflict-handler function. Refer to
10542** the documentation for the three
10543** [SQLITE_CHANGESET_OMIT|available return values] for details.
10544**
10545** <dl>
10546** <dt>DELETE Changes<dd>
10547** For each DELETE change, the function checks if the target database
10548** contains a row with the same primary key value (or values) as the
10549** original row values stored in the changeset. If it does, and the values
10550** stored in all non-primary key columns also match the values stored in
10551** the changeset the row is deleted from the target database.
10552**
10553** If a row with matching primary key values is found, but one or more of
10554** the non-primary key fields contains a value different from the original
10555** row value stored in the changeset, the conflict-handler function is
10556** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
10557** database table has more columns than are recorded in the changeset,
10558** only the values of those non-primary key fields are compared against
10559** the current database contents - any trailing database table columns
10560** are ignored.
10561**
10562** If no row with matching primary key values is found in the database,
10563** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10564** passed as the second argument.
10565**
10566** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
10567** (which can only happen if a foreign key constraint is violated), the
10568** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
10569** passed as the second argument. This includes the case where the DELETE
10570** operation is attempted because an earlier call to the conflict handler
10571** function returned [SQLITE_CHANGESET_REPLACE].
10572**
10573** <dt>INSERT Changes<dd>
10574** For each INSERT change, an attempt is made to insert the new row into
10575** the database. If the changeset row contains fewer fields than the
10576** database table, the trailing fields are populated with their default
10577** values.
10578**
10579** If the attempt to insert the row fails because the database already
10580** contains a row with the same primary key values, the conflict handler
10581** function is invoked with the second argument set to
10582** [SQLITE_CHANGESET_CONFLICT].
10583**
10584** If the attempt to insert the row fails because of some other constraint
10585** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
10586** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
10587** This includes the case where the INSERT operation is re-attempted because
10588** an earlier call to the conflict handler function returned
10589** [SQLITE_CHANGESET_REPLACE].
10590**
10591** <dt>UPDATE Changes<dd>
10592** For each UPDATE change, the function checks if the target database
10593** contains a row with the same primary key value (or values) as the
10594** original row values stored in the changeset. If it does, and the values
10595** stored in all modified non-primary key columns also match the values
10596** stored in the changeset the row is updated within the target database.
10597**
10598** If a row with matching primary key values is found, but one or more of
10599** the modified non-primary key fields contains a value different from an
10600** original row value stored in the changeset, the conflict-handler function
10601** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
10602** UPDATE changes only contain values for non-primary key fields that are
10603** to be modified, only those fields need to match the original values to
10604** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
10605**
10606** If no row with matching primary key values is found in the database,
10607** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10608** passed as the second argument.
10609**
10610** If the UPDATE operation is attempted, but SQLite returns
10611** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
10612** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
10613** This includes the case where the UPDATE operation is attempted after
10614** an earlier call to the conflict handler function returned
10615** [SQLITE_CHANGESET_REPLACE].
10616** </dl>
10617**
10618** It is safe to execute SQL statements, including those that write to the
10619** table that the callback related to, from within the xConflict callback.
10620** This can be used to further customize the applications conflict
10621** resolution strategy.
10622**
10623** All changes made by these functions are enclosed in a savepoint transaction.
10624** If any other error (aside from a constraint failure when attempting to
10625** write to the target database) occurs, then the savepoint transaction is
10626** rolled back, restoring the target database to its original state, and an
10627** SQLite error code returned.
10628**
10629** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
10630** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
10631** may set (*ppRebase) to point to a "rebase" that may be used with the
10632** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
10633** is set to the size of the buffer in bytes. It is the responsibility of the
10634** caller to eventually free any such buffer using sqlite3_free(). The buffer
10635** is only allocated and populated if one or more conflicts were encountered
10636** while applying the patchset. See comments surrounding the sqlite3_rebaser
10637** APIs for further details.
10638**
10639** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
10640** may be modified by passing a combination of
10641** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
10642**
10643** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
10644** and therefore subject to change.
10645*/
10646SQLITE_API int sqlite3changeset_apply(
10647 sqlite3 *db, /* Apply change to "main" db of this handle */
10648 int nChangeset, /* Size of changeset in bytes */
10649 void *pChangeset, /* Changeset blob */
10650 int(*xFilter)(
10651 void *pCtx, /* Copy of sixth arg to _apply() */
10652 const char *zTab /* Table name */
10653 ),
10654 int(*xConflict)(
10655 void *pCtx, /* Copy of sixth arg to _apply() */
10656 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10657 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10658 ),
10659 void *pCtx /* First argument passed to xConflict */
10660);
10661SQLITE_API int sqlite3changeset_apply_v2(
10662 sqlite3 *db, /* Apply change to "main" db of this handle */
10663 int nChangeset, /* Size of changeset in bytes */
10664 void *pChangeset, /* Changeset blob */
10665 int(*xFilter)(
10666 void *pCtx, /* Copy of sixth arg to _apply() */
10667 const char *zTab /* Table name */
10668 ),
10669 int(*xConflict)(
10670 void *pCtx, /* Copy of sixth arg to _apply() */
10671 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10672 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10673 ),
10674 void *pCtx, /* First argument passed to xConflict */
10675 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
10676 int flags /* SESSION_CHANGESETAPPLY_* flags */
10677);
10678
10679/*
10680** CAPI3REF: Flags for sqlite3changeset_apply_v2
10681**
10682** The following flags may passed via the 9th parameter to
10683** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
10684**
10685** <dl>
10686** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
10687** Usually, the sessions module encloses all operations performed by
10688** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
10689** SAVEPOINT is committed if the changeset or patchset is successfully
10690** applied, or rolled back if an error occurs. Specifying this flag
10691** causes the sessions module to omit this savepoint. In this case, if the
10692** caller has an open transaction or savepoint when apply_v2() is called,
10693** it may revert the partially applied changeset by rolling it back.
10694**
10695** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10696** Invert the changeset before applying it. This is equivalent to inverting
10697** a changeset using sqlite3changeset_invert() before applying it. It is
10698** an error to specify this flag with a patchset.
10699*/
10700#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
10701#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
10702
10703/*
10704** CAPI3REF: Constants Passed To The Conflict Handler
10705**
10706** Values that may be passed as the second argument to a conflict-handler.
10707**
10708** <dl>
10709** <dt>SQLITE_CHANGESET_DATA<dd>
10710** The conflict handler is invoked with CHANGESET_DATA as the second argument
10711** when processing a DELETE or UPDATE change if a row with the required
10712** PRIMARY KEY fields is present in the database, but one or more other
10713** (non primary-key) fields modified by the update do not contain the
10714** expected "before" values.
10715**
10716** The conflicting row, in this case, is the database row with the matching
10717** primary key.
10718**
10719** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
10720** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
10721** argument when processing a DELETE or UPDATE change if a row with the
10722** required PRIMARY KEY fields is not present in the database.
10723**
10724** There is no conflicting row in this case. The results of invoking the
10725** sqlite3changeset_conflict() API are undefined.
10726**
10727** <dt>SQLITE_CHANGESET_CONFLICT<dd>
10728** CHANGESET_CONFLICT is passed as the second argument to the conflict
10729** handler while processing an INSERT change if the operation would result
10730** in duplicate primary key values.
10731**
10732** The conflicting row in this case is the database row with the matching
10733** primary key.
10734**
10735** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
10736** If foreign key handling is enabled, and applying a changeset leaves the
10737** database in a state containing foreign key violations, the conflict
10738** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
10739** exactly once before the changeset is committed. If the conflict handler
10740** returns CHANGESET_OMIT, the changes, including those that caused the
10741** foreign key constraint violation, are committed. Or, if it returns
10742** CHANGESET_ABORT, the changeset is rolled back.
10743**
10744** No current or conflicting row information is provided. The only function
10745** it is possible to call on the supplied sqlite3_changeset_iter handle
10746** is sqlite3changeset_fk_conflicts().
10747**
10748** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
10749** If any other constraint violation occurs while applying a change (i.e.
10750** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
10751** invoked with CHANGESET_CONSTRAINT as the second argument.
10752**
10753** There is no conflicting row in this case. The results of invoking the
10754** sqlite3changeset_conflict() API are undefined.
10755**
10756** </dl>
10757*/
10758#define SQLITE_CHANGESET_DATA 1
10759#define SQLITE_CHANGESET_NOTFOUND 2
10760#define SQLITE_CHANGESET_CONFLICT 3
10761#define SQLITE_CHANGESET_CONSTRAINT 4
10762#define SQLITE_CHANGESET_FOREIGN_KEY 5
10763
10764/*
10765** CAPI3REF: Constants Returned By The Conflict Handler
10766**
10767** A conflict handler callback must return one of the following three values.
10768**
10769** <dl>
10770** <dt>SQLITE_CHANGESET_OMIT<dd>
10771** If a conflict handler returns this value no special action is taken. The
10772** change that caused the conflict is not applied. The session module
10773** continues to the next change in the changeset.
10774**
10775** <dt>SQLITE_CHANGESET_REPLACE<dd>
10776** This value may only be returned if the second argument to the conflict
10777** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
10778** is not the case, any changes applied so far are rolled back and the
10779** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
10780**
10781** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
10782** handler, then the conflicting row is either updated or deleted, depending
10783** on the type of change.
10784**
10785** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
10786** handler, then the conflicting row is removed from the database and a
10787** second attempt to apply the change is made. If this second attempt fails,
10788** the original row is restored to the database before continuing.
10789**
10790** <dt>SQLITE_CHANGESET_ABORT<dd>
10791** If this value is returned, any changes applied so far are rolled back
10792** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
10793** </dl>
10794*/
10795#define SQLITE_CHANGESET_OMIT 0
10796#define SQLITE_CHANGESET_REPLACE 1
10797#define SQLITE_CHANGESET_ABORT 2
10798
10799/*
10800** CAPI3REF: Rebasing changesets
10801** EXPERIMENTAL
10802**
10803** Suppose there is a site hosting a database in state S0. And that
10804** modifications are made that move that database to state S1 and a
10805** changeset recorded (the "local" changeset). Then, a changeset based
10806** on S0 is received from another site (the "remote" changeset) and
10807** applied to the database. The database is then in state
10808** (S1+"remote"), where the exact state depends on any conflict
10809** resolution decisions (OMIT or REPLACE) made while applying "remote".
10810** Rebasing a changeset is to update it to take those conflict
10811** resolution decisions into account, so that the same conflicts
10812** do not have to be resolved elsewhere in the network.
10813**
10814** For example, if both the local and remote changesets contain an
10815** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
10816**
10817** local: INSERT INTO t1 VALUES(1, 'v1');
10818** remote: INSERT INTO t1 VALUES(1, 'v2');
10819**
10820** and the conflict resolution is REPLACE, then the INSERT change is
10821** removed from the local changeset (it was overridden). Or, if the
10822** conflict resolution was "OMIT", then the local changeset is modified
10823** to instead contain:
10824**
10825** UPDATE t1 SET b = 'v2' WHERE a=1;
10826**
10827** Changes within the local changeset are rebased as follows:
10828**
10829** <dl>
10830** <dt>Local INSERT<dd>
10831** This may only conflict with a remote INSERT. If the conflict
10832** resolution was OMIT, then add an UPDATE change to the rebased
10833** changeset. Or, if the conflict resolution was REPLACE, add
10834** nothing to the rebased changeset.
10835**
10836** <dt>Local DELETE<dd>
10837** This may conflict with a remote UPDATE or DELETE. In both cases the
10838** only possible resolution is OMIT. If the remote operation was a
10839** DELETE, then add no change to the rebased changeset. If the remote
10840** operation was an UPDATE, then the old.* fields of change are updated
10841** to reflect the new.* values in the UPDATE.
10842**
10843** <dt>Local UPDATE<dd>
10844** This may conflict with a remote UPDATE or DELETE. If it conflicts
10845** with a DELETE, and the conflict resolution was OMIT, then the update
10846** is changed into an INSERT. Any undefined values in the new.* record
10847** from the update change are filled in using the old.* values from
10848** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
10849** the UPDATE change is simply omitted from the rebased changeset.
10850**
10851** If conflict is with a remote UPDATE and the resolution is OMIT, then
10852** the old.* values are rebased using the new.* values in the remote
10853** change. Or, if the resolution is REPLACE, then the change is copied
10854** into the rebased changeset with updates to columns also updated by
10855** the conflicting remote UPDATE removed. If this means no columns would
10856** be updated, the change is omitted.
10857** </dl>
10858**
10859** A local change may be rebased against multiple remote changes
10860** simultaneously. If a single key is modified by multiple remote
10861** changesets, they are combined as follows before the local changeset
10862** is rebased:
10863**
10864** <ul>
10865** <li> If there has been one or more REPLACE resolutions on a
10866** key, it is rebased according to a REPLACE.
10867**
10868** <li> If there have been no REPLACE resolutions on a key, then
10869** the local changeset is rebased according to the most recent
10870** of the OMIT resolutions.
10871** </ul>
10872**
10873** Note that conflict resolutions from multiple remote changesets are
10874** combined on a per-field basis, not per-row. This means that in the
10875** case of multiple remote UPDATE operations, some fields of a single
10876** local change may be rebased for REPLACE while others are rebased for
10877** OMIT.
10878**
10879** In order to rebase a local changeset, the remote changeset must first
10880** be applied to the local database using sqlite3changeset_apply_v2() and
10881** the buffer of rebase information captured. Then:
10882**
10883** <ol>
10884** <li> An sqlite3_rebaser object is created by calling
10885** sqlite3rebaser_create().
10886** <li> The new object is configured with the rebase buffer obtained from
10887** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
10888** If the local changeset is to be rebased against multiple remote
10889** changesets, then sqlite3rebaser_configure() should be called
10890** multiple times, in the same order that the multiple
10891** sqlite3changeset_apply_v2() calls were made.
10892** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
10893** <li> The sqlite3_rebaser object is deleted by calling
10894** sqlite3rebaser_delete().
10895** </ol>
10896*/
10897typedef struct sqlite3_rebaser sqlite3_rebaser;
10898
10899/*
10900** CAPI3REF: Create a changeset rebaser object.
10901** EXPERIMENTAL
10902**
10903** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
10904** point to the new object and return SQLITE_OK. Otherwise, if an error
10905** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
10906** to NULL.
10907*/
10908SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
10909
10910/*
10911** CAPI3REF: Configure a changeset rebaser object.
10912** EXPERIMENTAL
10913**
10914** Configure the changeset rebaser object to rebase changesets according
10915** to the conflict resolutions described by buffer pRebase (size nRebase
10916** bytes), which must have been obtained from a previous call to
10917** sqlite3changeset_apply_v2().
10918*/
10919SQLITE_API int sqlite3rebaser_configure(
10920 sqlite3_rebaser*,
10921 int nRebase, const void *pRebase
10922);
10923
10924/*
10925** CAPI3REF: Rebase a changeset
10926** EXPERIMENTAL
10927**
10928** Argument pIn must point to a buffer containing a changeset nIn bytes
10929** in size. This function allocates and populates a buffer with a copy
10930** of the changeset rebased rebased according to the configuration of the
10931** rebaser object passed as the first argument. If successful, (*ppOut)
10932** is set to point to the new buffer containing the rebased changeset and
10933** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
10934** responsibility of the caller to eventually free the new buffer using
10935** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
10936** are set to zero and an SQLite error code returned.
10937*/
10938SQLITE_API int sqlite3rebaser_rebase(
10939 sqlite3_rebaser*,
10940 int nIn, const void *pIn,
10941 int *pnOut, void **ppOut
10942);
10943
10944/*
10945** CAPI3REF: Delete a changeset rebaser object.
10946** EXPERIMENTAL
10947**
10948** Delete the changeset rebaser object and all associated resources. There
10949** should be one call to this function for each successful invocation
10950** of sqlite3rebaser_create().
10951*/
10952SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
10953
10954/*
10955** CAPI3REF: Streaming Versions of API functions.
10956**
10957** The six streaming API xxx_strm() functions serve similar purposes to the
10958** corresponding non-streaming API functions:
10959**
10960** <table border=1 style="margin-left:8ex;margin-right:8ex">
10961** <tr><th>Streaming function<th>Non-streaming equivalent</th>
10962** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
10963** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
10964** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
10965** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
10966** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
10967** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
10968** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
10969** </table>
10970**
10971** Non-streaming functions that accept changesets (or patchsets) as input
10972** require that the entire changeset be stored in a single buffer in memory.
10973** Similarly, those that return a changeset or patchset do so by returning
10974** a pointer to a single large buffer allocated using sqlite3_malloc().
10975** Normally this is convenient. However, if an application running in a
10976** low-memory environment is required to handle very large changesets, the
10977** large contiguous memory allocations required can become onerous.
10978**
10979** In order to avoid this problem, instead of a single large buffer, input
10980** is passed to a streaming API functions by way of a callback function that
10981** the sessions module invokes to incrementally request input data as it is
10982** required. In all cases, a pair of API function parameters such as
10983**
10984** <pre>
10985** &nbsp; int nChangeset,
10986** &nbsp; void *pChangeset,
10987** </pre>
10988**
10989** Is replaced by:
10990**
10991** <pre>
10992** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
10993** &nbsp; void *pIn,
10994** </pre>
10995**
10996** Each time the xInput callback is invoked by the sessions module, the first
10997** argument passed is a copy of the supplied pIn context pointer. The second
10998** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
10999** error occurs the xInput method should copy up to (*pnData) bytes of data
11000** into the buffer and set (*pnData) to the actual number of bytes copied
11001** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
11002** should be set to zero to indicate this. Or, if an error occurs, an SQLite
11003** error code should be returned. In all cases, if an xInput callback returns
11004** an error, all processing is abandoned and the streaming API function
11005** returns a copy of the error code to the caller.
11006**
11007** In the case of sqlite3changeset_start_strm(), the xInput callback may be
11008** invoked by the sessions module at any point during the lifetime of the
11009** iterator. If such an xInput callback returns an error, the iterator enters
11010** an error state, whereby all subsequent calls to iterator functions
11011** immediately fail with the same error code as returned by xInput.
11012**
11013** Similarly, streaming API functions that return changesets (or patchsets)
11014** return them in chunks by way of a callback function instead of via a
11015** pointer to a single large buffer. In this case, a pair of parameters such
11016** as:
11017**
11018** <pre>
11019** &nbsp; int *pnChangeset,
11020** &nbsp; void **ppChangeset,
11021** </pre>
11022**
11023** Is replaced by:
11024**
11025** <pre>
11026** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
11027** &nbsp; void *pOut
11028** </pre>
11029**
11030** The xOutput callback is invoked zero or more times to return data to
11031** the application. The first parameter passed to each call is a copy of the
11032** pOut pointer supplied by the application. The second parameter, pData,
11033** points to a buffer nData bytes in size containing the chunk of output
11034** data being returned. If the xOutput callback successfully processes the
11035** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
11036** it should return some other SQLite error code. In this case processing
11037** is immediately abandoned and the streaming API function returns a copy
11038** of the xOutput error code to the application.
11039**
11040** The sessions module never invokes an xOutput callback with the third
11041** parameter set to a value less than or equal to zero. Other than this,
11042** no guarantees are made as to the size of the chunks of data returned.
11043*/
11044SQLITE_API int sqlite3changeset_apply_strm(
11045 sqlite3 *db, /* Apply change to "main" db of this handle */
11046 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11047 void *pIn, /* First arg for xInput */
11048 int(*xFilter)(
11049 void *pCtx, /* Copy of sixth arg to _apply() */
11050 const char *zTab /* Table name */
11051 ),
11052 int(*xConflict)(
11053 void *pCtx, /* Copy of sixth arg to _apply() */
11054 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11055 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11056 ),
11057 void *pCtx /* First argument passed to xConflict */
11058);
11059SQLITE_API int sqlite3changeset_apply_v2_strm(
11060 sqlite3 *db, /* Apply change to "main" db of this handle */
11061 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11062 void *pIn, /* First arg for xInput */
11063 int(*xFilter)(
11064 void *pCtx, /* Copy of sixth arg to _apply() */
11065 const char *zTab /* Table name */
11066 ),
11067 int(*xConflict)(
11068 void *pCtx, /* Copy of sixth arg to _apply() */
11069 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11070 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11071 ),
11072 void *pCtx, /* First argument passed to xConflict */
11073 void **ppRebase, int *pnRebase,
11074 int flags
11075);
11076SQLITE_API int sqlite3changeset_concat_strm(
11077 int (*xInputA)(void *pIn, void *pData, int *pnData),
11078 void *pInA,
11079 int (*xInputB)(void *pIn, void *pData, int *pnData),
11080 void *pInB,
11081 int (*xOutput)(void *pOut, const void *pData, int nData),
11082 void *pOut
11083);
11084SQLITE_API int sqlite3changeset_invert_strm(
11085 int (*xInput)(void *pIn, void *pData, int *pnData),
11086 void *pIn,
11087 int (*xOutput)(void *pOut, const void *pData, int nData),
11088 void *pOut
11089);
11090SQLITE_API int sqlite3changeset_start_strm(
11091 sqlite3_changeset_iter **pp,
11092 int (*xInput)(void *pIn, void *pData, int *pnData),
11093 void *pIn
11094);
11095SQLITE_API int sqlite3changeset_start_v2_strm(
11096 sqlite3_changeset_iter **pp,
11097 int (*xInput)(void *pIn, void *pData, int *pnData),
11098 void *pIn,
11099 int flags
11100);
11101SQLITE_API int sqlite3session_changeset_strm(
11102 sqlite3_session *pSession,
11103 int (*xOutput)(void *pOut, const void *pData, int nData),
11104 void *pOut
11105);
11106SQLITE_API int sqlite3session_patchset_strm(
11107 sqlite3_session *pSession,
11108 int (*xOutput)(void *pOut, const void *pData, int nData),
11109 void *pOut
11110);
11111SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11112 int (*xInput)(void *pIn, void *pData, int *pnData),
11113 void *pIn
11114);
11115SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11116 int (*xOutput)(void *pOut, const void *pData, int nData),
11117 void *pOut
11118);
11119SQLITE_API int sqlite3rebaser_rebase_strm(
11120 sqlite3_rebaser *pRebaser,
11121 int (*xInput)(void *pIn, void *pData, int *pnData),
11122 void *pIn,
11123 int (*xOutput)(void *pOut, const void *pData, int nData),
11124 void *pOut
11125);
11126
11127/*
11128** CAPI3REF: Configure global parameters
11129**
11130** The sqlite3session_config() interface is used to make global configuration
11131** changes to the sessions module in order to tune it to the specific needs
11132** of the application.
11133**
11134** The sqlite3session_config() interface is not threadsafe. If it is invoked
11135** while any other thread is inside any other sessions method then the
11136** results are undefined. Furthermore, if it is invoked after any sessions
11137** related objects have been created, the results are also undefined.
11138**
11139** The first argument to the sqlite3session_config() function must be one
11140** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11141** interpretation of the (void*) value passed as the second parameter and
11142** the effect of calling this function depends on the value of the first
11143** parameter.
11144**
11145** <dl>
11146** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11147** By default, the sessions module streaming interfaces attempt to input
11148** and output data in approximately 1 KiB chunks. This operand may be used
11149** to set and query the value of this configuration setting. The pointer
11150** passed as the second argument must point to a value of type (int).
11151** If this value is greater than 0, it is used as the new streaming data
11152** chunk size for both input and output. Before returning, the (int) value
11153** pointed to by pArg is set to the final value of the streaming interface
11154** chunk size.
11155** </dl>
11156**
11157** This function returns SQLITE_OK if successful, or an SQLite error code
11158** otherwise.
11159*/
11160SQLITE_API int sqlite3session_config(int op, void *pArg);
11161
11162/*
11163** CAPI3REF: Values for sqlite3session_config().
11164*/
11165#define SQLITE_SESSION_CONFIG_STRMSIZE 1
11166
11167/*
11168** Make sure we can call this stuff from C++.
11169*/
11170#ifdef __cplusplus
11171}
11172#endif
11173
11174#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11175
11176/******** End of sqlite3session.h *********/
11177/******** Begin file fts5.h *********/
11178/*
11179** 2014 May 31
11180**
11181** The author disclaims copyright to this source code. In place of
11182** a legal notice, here is a blessing:
11183**
11184** May you do good and not evil.
11185** May you find forgiveness for yourself and forgive others.
11186** May you share freely, never taking more than you give.
11187**
11188******************************************************************************
11189**
11190** Interfaces to extend FTS5. Using the interfaces defined in this file,
11191** FTS5 may be extended with:
11192**
11193** * custom tokenizers, and
11194** * custom auxiliary functions.
11195*/
11196
11197
11198#ifndef _FTS5_H
11199#define _FTS5_H
11200
11201
11202#ifdef __cplusplus
11203extern "C" {
11204#endif
11205
11206/*************************************************************************
11207** CUSTOM AUXILIARY FUNCTIONS
11208**
11209** Virtual table implementations may overload SQL functions by implementing
11210** the sqlite3_module.xFindFunction() method.
11211*/
11212
11213typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11214typedef struct Fts5Context Fts5Context;
11215typedef struct Fts5PhraseIter Fts5PhraseIter;
11216
11217typedef void (*fts5_extension_function)(
11218 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11219 Fts5Context *pFts, /* First arg to pass to pApi functions */
11220 sqlite3_context *pCtx, /* Context for returning result/error */
11221 int nVal, /* Number of values in apVal[] array */
11222 sqlite3_value **apVal /* Array of trailing arguments */
11223);
11224
11225struct Fts5PhraseIter {
11226 const unsigned char *a;
11227 const unsigned char *b;
11228};
11229
11230/*
11231** EXTENSION API FUNCTIONS
11232**
11233** xUserData(pFts):
11234** Return a copy of the context pointer the extension function was
11235** registered with.
11236**
11237** xColumnTotalSize(pFts, iCol, pnToken):
11238** If parameter iCol is less than zero, set output variable *pnToken
11239** to the total number of tokens in the FTS5 table. Or, if iCol is
11240** non-negative but less than the number of columns in the table, return
11241** the total number of tokens in column iCol, considering all rows in
11242** the FTS5 table.
11243**
11244** If parameter iCol is greater than or equal to the number of columns
11245** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11246** an OOM condition or IO error), an appropriate SQLite error code is
11247** returned.
11248**
11249** xColumnCount(pFts):
11250** Return the number of columns in the table.
11251**
11252** xColumnSize(pFts, iCol, pnToken):
11253** If parameter iCol is less than zero, set output variable *pnToken
11254** to the total number of tokens in the current row. Or, if iCol is
11255** non-negative but less than the number of columns in the table, set
11256** *pnToken to the number of tokens in column iCol of the current row.
11257**
11258** If parameter iCol is greater than or equal to the number of columns
11259** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11260** an OOM condition or IO error), an appropriate SQLite error code is
11261** returned.
11262**
11263** This function may be quite inefficient if used with an FTS5 table
11264** created with the "columnsize=0" option.
11265**
11266** xColumnText:
11267** This function attempts to retrieve the text of column iCol of the
11268** current document. If successful, (*pz) is set to point to a buffer
11269** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11270** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11271** if an error occurs, an SQLite error code is returned and the final values
11272** of (*pz) and (*pn) are undefined.
11273**
11274** xPhraseCount:
11275** Returns the number of phrases in the current query expression.
11276**
11277** xPhraseSize:
11278** Returns the number of tokens in phrase iPhrase of the query. Phrases
11279** are numbered starting from zero.
11280**
11281** xInstCount:
11282** Set *pnInst to the total number of occurrences of all phrases within
11283** the query within the current row. Return SQLITE_OK if successful, or
11284** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11285**
11286** This API can be quite slow if used with an FTS5 table created with the
11287** "detail=none" or "detail=column" option. If the FTS5 table is created
11288** with either "detail=none" or "detail=column" and "content=" option
11289** (i.e. if it is a contentless table), then this API always returns 0.
11290**
11291** xInst:
11292** Query for the details of phrase match iIdx within the current row.
11293** Phrase matches are numbered starting from zero, so the iIdx argument
11294** should be greater than or equal to zero and smaller than the value
11295** output by xInstCount().
11296**
11297** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11298** to the column in which it occurs and *piOff the token offset of the
11299** first token of the phrase. Returns SQLITE_OK if successful, or an error
11300** code (i.e. SQLITE_NOMEM) if an error occurs.
11301**
11302** This API can be quite slow if used with an FTS5 table created with the
11303** "detail=none" or "detail=column" option.
11304**
11305** xRowid:
11306** Returns the rowid of the current row.
11307**
11308** xTokenize:
11309** Tokenize text using the tokenizer belonging to the FTS5 table.
11310**
11311** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11312** This API function is used to query the FTS table for phrase iPhrase
11313** of the current query. Specifically, a query equivalent to:
11314**
11315** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11316**
11317** with $p set to a phrase equivalent to the phrase iPhrase of the
11318** current query is executed. Any column filter that applies to
11319** phrase iPhrase of the current query is included in $p. For each
11320** row visited, the callback function passed as the fourth argument
11321** is invoked. The context and API objects passed to the callback
11322** function may be used to access the properties of each matched row.
11323** Invoking Api.xUserData() returns a copy of the pointer passed as
11324** the third argument to pUserData.
11325**
11326** If the callback function returns any value other than SQLITE_OK, the
11327** query is abandoned and the xQueryPhrase function returns immediately.
11328** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11329** Otherwise, the error code is propagated upwards.
11330**
11331** If the query runs to completion without incident, SQLITE_OK is returned.
11332** Or, if some error occurs before the query completes or is aborted by
11333** the callback, an SQLite error code is returned.
11334**
11335**
11336** xSetAuxdata(pFts5, pAux, xDelete)
11337**
11338** Save the pointer passed as the second argument as the extension functions
11339** "auxiliary data". The pointer may then be retrieved by the current or any
11340** future invocation of the same fts5 extension function made as part of
11341** the same MATCH query using the xGetAuxdata() API.
11342**
11343** Each extension function is allocated a single auxiliary data slot for
11344** each FTS query (MATCH expression). If the extension function is invoked
11345** more than once for a single FTS query, then all invocations share a
11346** single auxiliary data context.
11347**
11348** If there is already an auxiliary data pointer when this function is
11349** invoked, then it is replaced by the new pointer. If an xDelete callback
11350** was specified along with the original pointer, it is invoked at this
11351** point.
11352**
11353** The xDelete callback, if one is specified, is also invoked on the
11354** auxiliary data pointer after the FTS5 query has finished.
11355**
11356** If an error (e.g. an OOM condition) occurs within this function,
11357** the auxiliary data is set to NULL and an error code returned. If the
11358** xDelete parameter was not NULL, it is invoked on the auxiliary data
11359** pointer before returning.
11360**
11361**
11362** xGetAuxdata(pFts5, bClear)
11363**
11364** Returns the current auxiliary data pointer for the fts5 extension
11365** function. See the xSetAuxdata() method for details.
11366**
11367** If the bClear argument is non-zero, then the auxiliary data is cleared
11368** (set to NULL) before this function returns. In this case the xDelete,
11369** if any, is not invoked.
11370**
11371**
11372** xRowCount(pFts5, pnRow)
11373**
11374** This function is used to retrieve the total number of rows in the table.
11375** In other words, the same value that would be returned by:
11376**
11377** SELECT count(*) FROM ftstable;
11378**
11379** xPhraseFirst()
11380** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11381** method, to iterate through all instances of a single query phrase within
11382** the current row. This is the same information as is accessible via the
11383** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
11384** to use, this API may be faster under some circumstances. To iterate
11385** through instances of phrase iPhrase, use the following code:
11386**
11387** Fts5PhraseIter iter;
11388** int iCol, iOff;
11389** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11390** iCol>=0;
11391** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11392** ){
11393** // An instance of phrase iPhrase at offset iOff of column iCol
11394** }
11395**
11396** The Fts5PhraseIter structure is defined above. Applications should not
11397** modify this structure directly - it should only be used as shown above
11398** with the xPhraseFirst() and xPhraseNext() API methods (and by
11399** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11400**
11401** This API can be quite slow if used with an FTS5 table created with the
11402** "detail=none" or "detail=column" option. If the FTS5 table is created
11403** with either "detail=none" or "detail=column" and "content=" option
11404** (i.e. if it is a contentless table), then this API always iterates
11405** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11406**
11407** xPhraseNext()
11408** See xPhraseFirst above.
11409**
11410** xPhraseFirstColumn()
11411** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11412** and xPhraseNext() APIs described above. The difference is that instead
11413** of iterating through all instances of a phrase in the current row, these
11414** APIs are used to iterate through the set of columns in the current row
11415** that contain one or more instances of a specified phrase. For example:
11416**
11417** Fts5PhraseIter iter;
11418** int iCol;
11419** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11420** iCol>=0;
11421** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11422** ){
11423** // Column iCol contains at least one instance of phrase iPhrase
11424** }
11425**
11426** This API can be quite slow if used with an FTS5 table created with the
11427** "detail=none" option. If the FTS5 table is created with either
11428** "detail=none" "content=" option (i.e. if it is a contentless table),
11429** then this API always iterates through an empty set (all calls to
11430** xPhraseFirstColumn() set iCol to -1).
11431**
11432** The information accessed using this API and its companion
11433** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11434** (or xInst/xInstCount). The chief advantage of this API is that it is
11435** significantly more efficient than those alternatives when used with
11436** "detail=column" tables.
11437**
11438** xPhraseNextColumn()
11439** See xPhraseFirstColumn above.
11440*/
11441struct Fts5ExtensionApi {
11442 int iVersion; /* Currently always set to 3 */
11443
11444 void *(*xUserData)(Fts5Context*);
11445
11446 int (*xColumnCount)(Fts5Context*);
11447 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11448 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11449
11450 int (*xTokenize)(Fts5Context*,
11451 const char *pText, int nText, /* Text to tokenize */
11452 void *pCtx, /* Context passed to xToken() */
11453 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11454 );
11455
11456 int (*xPhraseCount)(Fts5Context*);
11457 int (*xPhraseSize)(Fts5Context*, int iPhrase);
11458
11459 int (*xInstCount)(Fts5Context*, int *pnInst);
11460 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11461
11462 sqlite3_int64 (*xRowid)(Fts5Context*);
11463 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11464 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11465
11466 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11467 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11468 );
11469 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11470 void *(*xGetAuxdata)(Fts5Context*, int bClear);
11471
11472 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11473 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11474
11475 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11476 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11477};
11478
11479/*
11480** CUSTOM AUXILIARY FUNCTIONS
11481*************************************************************************/
11482
11483/*************************************************************************
11484** CUSTOM TOKENIZERS
11485**
11486** Applications may also register custom tokenizer types. A tokenizer
11487** is registered by providing fts5 with a populated instance of the
11488** following structure. All structure methods must be defined, setting
11489** any member of the fts5_tokenizer struct to NULL leads to undefined
11490** behaviour. The structure methods are expected to function as follows:
11491**
11492** xCreate:
11493** This function is used to allocate and initialize a tokenizer instance.
11494** A tokenizer instance is required to actually tokenize text.
11495**
11496** The first argument passed to this function is a copy of the (void*)
11497** pointer provided by the application when the fts5_tokenizer object
11498** was registered with FTS5 (the third argument to xCreateTokenizer()).
11499** The second and third arguments are an array of nul-terminated strings
11500** containing the tokenizer arguments, if any, specified following the
11501** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
11502** to create the FTS5 table.
11503**
11504** The final argument is an output variable. If successful, (*ppOut)
11505** should be set to point to the new tokenizer handle and SQLITE_OK
11506** returned. If an error occurs, some value other than SQLITE_OK should
11507** be returned. In this case, fts5 assumes that the final value of *ppOut
11508** is undefined.
11509**
11510** xDelete:
11511** This function is invoked to delete a tokenizer handle previously
11512** allocated using xCreate(). Fts5 guarantees that this function will
11513** be invoked exactly once for each successful call to xCreate().
11514**
11515** xTokenize:
11516** This function is expected to tokenize the nText byte string indicated
11517** by argument pText. pText may or may not be nul-terminated. The first
11518** argument passed to this function is a pointer to an Fts5Tokenizer object
11519** returned by an earlier call to xCreate().
11520**
11521** The second argument indicates the reason that FTS5 is requesting
11522** tokenization of the supplied text. This is always one of the following
11523** four values:
11524**
11525** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
11526** or removed from the FTS table. The tokenizer is being invoked to
11527** determine the set of tokens to add to (or delete from) the
11528** FTS index.
11529**
11530** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
11531** against the FTS index. The tokenizer is being called to tokenize
11532** a bareword or quoted string specified as part of the query.
11533**
11534** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
11535** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
11536** followed by a "*" character, indicating that the last token
11537** returned by the tokenizer will be treated as a token prefix.
11538**
11539** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
11540** satisfy an fts5_api.xTokenize() request made by an auxiliary
11541** function. Or an fts5_api.xColumnSize() request made by the same
11542** on a columnsize=0 database.
11543** </ul>
11544**
11545** For each token in the input string, the supplied callback xToken() must
11546** be invoked. The first argument to it should be a copy of the pointer
11547** passed as the second argument to xTokenize(). The third and fourth
11548** arguments are a pointer to a buffer containing the token text, and the
11549** size of the token in bytes. The 4th and 5th arguments are the byte offsets
11550** of the first byte of and first byte immediately following the text from
11551** which the token is derived within the input.
11552**
11553** The second argument passed to the xToken() callback ("tflags") should
11554** normally be set to 0. The exception is if the tokenizer supports
11555** synonyms. In this case see the discussion below for details.
11556**
11557** FTS5 assumes the xToken() callback is invoked for each token in the
11558** order that they occur within the input text.
11559**
11560** If an xToken() callback returns any value other than SQLITE_OK, then
11561** the tokenization should be abandoned and the xTokenize() method should
11562** immediately return a copy of the xToken() return value. Or, if the
11563** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
11564** if an error occurs with the xTokenize() implementation itself, it
11565** may abandon the tokenization and return any error code other than
11566** SQLITE_OK or SQLITE_DONE.
11567**
11568** SYNONYM SUPPORT
11569**
11570** Custom tokenizers may also support synonyms. Consider a case in which a
11571** user wishes to query for a phrase such as "first place". Using the
11572** built-in tokenizers, the FTS5 query 'first + place' will match instances
11573** of "first place" within the document set, but not alternative forms
11574** such as "1st place". In some applications, it would be better to match
11575** all instances of "first place" or "1st place" regardless of which form
11576** the user specified in the MATCH query text.
11577**
11578** There are several ways to approach this in FTS5:
11579**
11580** <ol><li> By mapping all synonyms to a single token. In this case, the
11581** In the above example, this means that the tokenizer returns the
11582** same token for inputs "first" and "1st". Say that token is in
11583** fact "first", so that when the user inserts the document "I won
11584** 1st place" entries are added to the index for tokens "i", "won",
11585** "first" and "place". If the user then queries for '1st + place',
11586** the tokenizer substitutes "first" for "1st" and the query works
11587** as expected.
11588**
11589** <li> By querying the index for all synonyms of each query term
11590** separately. In this case, when tokenizing query text, the
11591** tokenizer may provide multiple synonyms for a single term
11592** within the document. FTS5 then queries the index for each
11593** synonym individually. For example, faced with the query:
11594**
11595** <codeblock>
11596** ... MATCH 'first place'</codeblock>
11597**
11598** the tokenizer offers both "1st" and "first" as synonyms for the
11599** first token in the MATCH query and FTS5 effectively runs a query
11600** similar to:
11601**
11602** <codeblock>
11603** ... MATCH '(first OR 1st) place'</codeblock>
11604**
11605** except that, for the purposes of auxiliary functions, the query
11606** still appears to contain just two phrases - "(first OR 1st)"
11607** being treated as a single phrase.
11608**
11609** <li> By adding multiple synonyms for a single term to the FTS index.
11610** Using this method, when tokenizing document text, the tokenizer
11611** provides multiple synonyms for each token. So that when a
11612** document such as "I won first place" is tokenized, entries are
11613** added to the FTS index for "i", "won", "first", "1st" and
11614** "place".
11615**
11616** This way, even if the tokenizer does not provide synonyms
11617** when tokenizing query text (it should not - to do so would be
11618** inefficient), it doesn't matter if the user queries for
11619** 'first + place' or '1st + place', as there are entries in the
11620** FTS index corresponding to both forms of the first token.
11621** </ol>
11622**
11623** Whether it is parsing document or query text, any call to xToken that
11624** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
11625** is considered to supply a synonym for the previous token. For example,
11626** when parsing the document "I won first place", a tokenizer that supports
11627** synonyms would call xToken() 5 times, as follows:
11628**
11629** <codeblock>
11630** xToken(pCtx, 0, "i", 1, 0, 1);
11631** xToken(pCtx, 0, "won", 3, 2, 5);
11632** xToken(pCtx, 0, "first", 5, 6, 11);
11633** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
11634** xToken(pCtx, 0, "place", 5, 12, 17);
11635**</codeblock>
11636**
11637** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
11638** xToken() is called. Multiple synonyms may be specified for a single token
11639** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
11640** There is no limit to the number of synonyms that may be provided for a
11641** single token.
11642**
11643** In many cases, method (1) above is the best approach. It does not add
11644** extra data to the FTS index or require FTS5 to query for multiple terms,
11645** so it is efficient in terms of disk space and query speed. However, it
11646** does not support prefix queries very well. If, as suggested above, the
11647** token "first" is substituted for "1st" by the tokenizer, then the query:
11648**
11649** <codeblock>
11650** ... MATCH '1s*'</codeblock>
11651**
11652** will not match documents that contain the token "1st" (as the tokenizer
11653** will probably not map "1s" to any prefix of "first").
11654**
11655** For full prefix support, method (3) may be preferred. In this case,
11656** because the index contains entries for both "first" and "1st", prefix
11657** queries such as 'fi*' or '1s*' will match correctly. However, because
11658** extra entries are added to the FTS index, this method uses more space
11659** within the database.
11660**
11661** Method (2) offers a midpoint between (1) and (3). Using this method,
11662** a query such as '1s*' will match documents that contain the literal
11663** token "1st", but not "first" (assuming the tokenizer is not able to
11664** provide synonyms for prefixes). However, a non-prefix query like '1st'
11665** will match against "1st" and "first". This method does not require
11666** extra disk space, as no extra entries are added to the FTS index.
11667** On the other hand, it may require more CPU cycles to run MATCH queries,
11668** as separate queries of the FTS index are required for each synonym.
11669**
11670** When using methods (2) or (3), it is important that the tokenizer only
11671** provide synonyms when tokenizing document text (method (2)) or query
11672** text (method (3)), not both. Doing so will not cause any errors, but is
11673** inefficient.
11674*/
11675typedef struct Fts5Tokenizer Fts5Tokenizer;
11676typedef struct fts5_tokenizer fts5_tokenizer;
11677struct fts5_tokenizer {
11678 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
11679 void (*xDelete)(Fts5Tokenizer*);
11680 int (*xTokenize)(Fts5Tokenizer*,
11681 void *pCtx,
11682 int flags, /* Mask of FTS5_TOKENIZE_* flags */
11683 const char *pText, int nText,
11684 int (*xToken)(
11685 void *pCtx, /* Copy of 2nd argument to xTokenize() */
11686 int tflags, /* Mask of FTS5_TOKEN_* flags */
11687 const char *pToken, /* Pointer to buffer containing token */
11688 int nToken, /* Size of token in bytes */
11689 int iStart, /* Byte offset of token within input text */
11690 int iEnd /* Byte offset of end of token within input text */
11691 )
11692 );
11693};
11694
11695/* Flags that may be passed as the third argument to xTokenize() */
11696#define FTS5_TOKENIZE_QUERY 0x0001
11697#define FTS5_TOKENIZE_PREFIX 0x0002
11698#define FTS5_TOKENIZE_DOCUMENT 0x0004
11699#define FTS5_TOKENIZE_AUX 0x0008
11700
11701/* Flags that may be passed by the tokenizer implementation back to FTS5
11702** as the third argument to the supplied xToken callback. */
11703#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
11704
11705/*
11706** END OF CUSTOM TOKENIZERS
11707*************************************************************************/
11708
11709/*************************************************************************
11710** FTS5 EXTENSION REGISTRATION API
11711*/
11712typedef struct fts5_api fts5_api;
11713struct fts5_api {
11714 int iVersion; /* Currently always set to 2 */
11715
11716 /* Create a new tokenizer */
11717 int (*xCreateTokenizer)(
11718 fts5_api *pApi,
11719 const char *zName,
11720 void *pContext,
11721 fts5_tokenizer *pTokenizer,
11722 void (*xDestroy)(void*)
11723 );
11724
11725 /* Find an existing tokenizer */
11726 int (*xFindTokenizer)(
11727 fts5_api *pApi,
11728 const char *zName,
11729 void **ppContext,
11730 fts5_tokenizer *pTokenizer
11731 );
11732
11733 /* Create a new auxiliary function */
11734 int (*xCreateFunction)(
11735 fts5_api *pApi,
11736 const char *zName,
11737 void *pContext,
11738 fts5_extension_function xFunction,
11739 void (*xDestroy)(void*)
11740 );
11741};
11742
11743/*
11744** END OF REGISTRATION API
11745*************************************************************************/
11746
11747#ifdef __cplusplus
11748} /* end of the 'extern "C"' block */
11749#endif
11750
11751#endif /* _FTS5_H */
11752
11753/******** End of fts5.h *********/
11754