1/*
2 * Copyright (C) 2014 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include <wtf/text/icu/UTextProviderUTF16.h>
28
29#include <algorithm>
30#include <wtf/text/icu/UTextProvider.h>
31
32namespace WTF {
33
34// UTF16ContextAware provider
35
36static UText* uTextUTF16ContextAwareClone(UText*, const UText*, UBool, UErrorCode*);
37static int64_t uTextUTF16ContextAwareNativeLength(UText*);
38static UBool uTextUTF16ContextAwareAccess(UText*, int64_t, UBool);
39static int32_t uTextUTF16ContextAwareExtract(UText*, int64_t, int64_t, UChar*, int32_t, UErrorCode*);
40static void uTextUTF16ContextAwareClose(UText*);
41
42static const struct UTextFuncs textUTF16ContextAwareFuncs = {
43 sizeof(UTextFuncs),
44 0,
45 0,
46 0,
47 uTextUTF16ContextAwareClone,
48 uTextUTF16ContextAwareNativeLength,
49 uTextUTF16ContextAwareAccess,
50 uTextUTF16ContextAwareExtract,
51 nullptr,
52 nullptr,
53 nullptr,
54 nullptr,
55 uTextUTF16ContextAwareClose,
56 nullptr,
57 nullptr,
58 nullptr
59};
60
61static inline UTextProviderContext textUTF16ContextAwareGetCurrentContext(const UText* text)
62{
63 if (!text->chunkContents)
64 return UTextProviderContext::NoContext;
65 return text->chunkContents == text->p ? UTextProviderContext::PrimaryContext : UTextProviderContext::PriorContext;
66}
67
68static void textUTF16ContextAwareMoveInPrimaryContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward)
69{
70 ASSERT(text->chunkContents == text->p);
71 ASSERT_UNUSED(forward, forward ? nativeIndex >= text->b : nativeIndex > text->b);
72 ASSERT_UNUSED(forward, forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength);
73 text->chunkNativeStart = text->b;
74 text->chunkNativeLimit = nativeLength;
75 int64_t length = text->chunkNativeLimit - text->chunkNativeStart;
76 // Ensure chunk length is well defined if computed length exceeds int32_t range.
77 ASSERT(length < std::numeric_limits<int32_t>::max());
78 text->chunkLength = length < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(length) : 0;
79 text->nativeIndexingLimit = text->chunkLength;
80 int64_t offset = nativeIndex - text->chunkNativeStart;
81 // Ensure chunk offset is well defined if computed offset exceeds int32_t range or chunk length.
82 ASSERT(offset < std::numeric_limits<int32_t>::max());
83 text->chunkOffset = std::min(offset < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(offset) : 0, text->chunkLength);
84}
85
86static void textUTF16ContextAwareSwitchToPrimaryContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward)
87{
88 ASSERT(!text->chunkContents || text->chunkContents == text->q);
89 text->chunkContents = static_cast<const UChar*>(text->p);
90 textUTF16ContextAwareMoveInPrimaryContext(text, nativeIndex, nativeLength, forward);
91}
92
93static void textUTF16ContextAwareMoveInPriorContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward)
94{
95 ASSERT(text->chunkContents == text->q);
96 ASSERT(forward ? nativeIndex < text->b : nativeIndex <= text->b);
97 ASSERT_UNUSED(nativeLength, forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength);
98 ASSERT_UNUSED(forward, forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength);
99 text->chunkNativeStart = 0;
100 text->chunkNativeLimit = text->b;
101 text->chunkLength = text->b;
102 text->nativeIndexingLimit = text->chunkLength;
103 int64_t offset = nativeIndex - text->chunkNativeStart;
104 // Ensure chunk offset is well defined if computed offset exceeds int32_t range or chunk length.
105 ASSERT(offset < std::numeric_limits<int32_t>::max());
106 text->chunkOffset = std::min(offset < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(offset) : 0, text->chunkLength);
107}
108
109static void textUTF16ContextAwareSwitchToPriorContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward)
110{
111 ASSERT(!text->chunkContents || text->chunkContents == text->p);
112 text->chunkContents = static_cast<const UChar*>(text->q);
113 textUTF16ContextAwareMoveInPriorContext(text, nativeIndex, nativeLength, forward);
114}
115
116static UText* uTextUTF16ContextAwareClone(UText* destination, const UText* source, UBool deep, UErrorCode* status)
117{
118 return uTextCloneImpl(destination, source, deep, status);
119}
120
121static inline int64_t uTextUTF16ContextAwareNativeLength(UText* text)
122{
123 return text->a + text->b;
124}
125
126static UBool uTextUTF16ContextAwareAccess(UText* text, int64_t nativeIndex, UBool forward)
127{
128 if (!text->context)
129 return FALSE;
130 int64_t nativeLength = uTextUTF16ContextAwareNativeLength(text);
131 UBool isAccessible;
132 if (uTextAccessInChunkOrOutOfRange(text, nativeIndex, nativeLength, forward, isAccessible))
133 return isAccessible;
134 nativeIndex = uTextAccessPinIndex(nativeIndex, nativeLength);
135 UTextProviderContext currentContext = textUTF16ContextAwareGetCurrentContext(text);
136 UTextProviderContext newContext = uTextProviderContext(text, nativeIndex, forward);
137 ASSERT(newContext != UTextProviderContext::NoContext);
138 if (newContext == currentContext) {
139 if (currentContext == UTextProviderContext::PrimaryContext)
140 textUTF16ContextAwareMoveInPrimaryContext(text, nativeIndex, nativeLength, forward);
141 else
142 textUTF16ContextAwareMoveInPriorContext(text, nativeIndex, nativeLength, forward);
143 } else if (newContext == UTextProviderContext::PrimaryContext)
144 textUTF16ContextAwareSwitchToPrimaryContext(text, nativeIndex, nativeLength, forward);
145 else {
146 ASSERT(newContext == UTextProviderContext::PriorContext);
147 textUTF16ContextAwareSwitchToPriorContext(text, nativeIndex, nativeLength, forward);
148 }
149 return TRUE;
150}
151
152static int32_t uTextUTF16ContextAwareExtract(UText*, int64_t, int64_t, UChar*, int32_t, UErrorCode* errorCode)
153{
154 // In the present context, this text provider is used only with ICU functions
155 // that do not perform an extract operation.
156 ASSERT_NOT_REACHED();
157 *errorCode = U_UNSUPPORTED_ERROR;
158 return 0;
159}
160
161static void uTextUTF16ContextAwareClose(UText* text)
162{
163 text->context = nullptr;
164}
165
166UText* openUTF16ContextAwareUTextProvider(UText* text, const UChar* string, unsigned length, const UChar* priorContext, int priorContextLength, UErrorCode* status)
167{
168 if (U_FAILURE(*status))
169 return 0;
170 if (!string || length > static_cast<unsigned>(std::numeric_limits<int32_t>::max())) {
171 *status = U_ILLEGAL_ARGUMENT_ERROR;
172 return 0;
173 }
174 text = utext_setup(text, 0, status);
175 if (U_FAILURE(*status)) {
176 ASSERT(!text);
177 return 0;
178 }
179
180 initializeContextAwareUTextProvider(text, &textUTF16ContextAwareFuncs, string, length, priorContext, priorContextLength);
181 return text;
182}
183
184} // namespace WTF
185