1/*
2 * Copyright (C) 2013, 2016 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. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include "IterationKind.h"
29#include "JSMap.h"
30#include "JSObject.h"
31
32namespace JSC {
33
34// Now, it is only used for serialization.
35class JSMapIterator final : public JSCell {
36 typedef HashMapBucket<HashMapBucketDataKeyValue> HashMapBucketType;
37public:
38 using Base = JSCell;
39
40 DECLARE_EXPORT_INFO;
41
42 static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
43 {
44 return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
45 }
46
47 static JSMapIterator* create(VM& vm, Structure* structure, JSMap* iteratedObject, IterationKind kind)
48 {
49 JSMapIterator* instance = new (NotNull, allocateCell<JSMapIterator>(vm.heap)) JSMapIterator(vm, structure, iteratedObject, kind);
50 instance->finishCreation(vm, iteratedObject);
51 return instance;
52 }
53
54 ALWAYS_INLINE HashMapBucketType* advanceIter(JSGlobalObject* globalObject)
55 {
56 HashMapBucketType* prev = m_iter.get();
57 if (!prev)
58 return nullptr;
59 VM& vm = getVM(globalObject);
60 HashMapBucketType* bucket = m_iter->next();
61 while (bucket && bucket->deleted())
62 bucket = bucket->next();
63 if (!bucket) {
64 setIterator(vm, nullptr);
65 return nullptr;
66 }
67 setIterator(vm, bucket); // We keep m_iter on the last value since the first thing we do in this function is call next().
68 return bucket;
69 }
70 bool next(JSGlobalObject* globalObject, JSValue& value)
71 {
72 HashMapBucketType* bucket = advanceIter(globalObject);
73 if (!bucket)
74 return false;
75
76 if (m_kind == IterateValue)
77 value = bucket->value();
78 else if (m_kind == IterateKey)
79 value = bucket->key();
80 else
81 value = createPair(globalObject, bucket->key(), bucket->value());
82 return true;
83 }
84
85 bool nextKeyValue(JSGlobalObject* globalObject, JSValue& key, JSValue& value)
86 {
87 HashMapBucketType* bucket = advanceIter(globalObject);
88 if (!bucket)
89 return false;
90
91 key = bucket->key();
92 value = bucket->value();
93 return true;
94 }
95
96 IterationKind kind() const { return m_kind; }
97 JSValue iteratedValue() const { return m_map.get(); }
98
99private:
100 JSMapIterator(VM& vm, Structure* structure, JSMap*, IterationKind kind)
101 : Base(vm, structure)
102 , m_kind(kind)
103 { }
104
105 void setIterator(VM& vm, HashMapBucketType* bucket)
106 {
107 m_iter.setMayBeNull(vm, this, bucket);
108 }
109
110 JS_EXPORT_PRIVATE void finishCreation(VM&, JSMap*);
111 JSValue createPair(JSGlobalObject*, JSValue, JSValue);
112 static void visitChildren(JSCell*, SlotVisitor&);
113
114 WriteBarrier<JSMap> m_map;
115 WriteBarrier<HashMapBucketType> m_iter;
116 IterationKind m_kind;
117};
118STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(JSMapIterator);
119
120} // namespace JSC
121