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 "JSObject.h"
30#include "JSSet.h"
31
32namespace JSC {
33
34// Now, it is only used for serialization.
35class JSSetIterator final : public JSCell {
36 typedef HashMapBucket<HashMapBucketDataKey> 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 JSSetIterator* create(VM& vm, Structure* structure, JSSet* iteratedObject, IterationKind kind)
48 {
49 JSSetIterator* instance = new (NotNull, allocateCell<JSSetIterator>(vm.heap)) JSSetIterator(vm, structure, iteratedObject, kind);
50 instance->finishCreation(vm, iteratedObject);
51 return instance;
52 }
53
54 ALWAYS_INLINE HashMapBucketType* advanceIter(ExecState* exec)
55 {
56 HashMapBucketType* prev = m_iter.get();
57 if (!prev)
58 return nullptr;
59 VM& vm = exec->vm();
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
71 bool next(ExecState* exec, JSValue& value)
72 {
73 HashMapBucketType* bucket = advanceIter(exec);
74 if (!bucket)
75 return false;
76
77 if (m_kind == IterateValue || m_kind == IterateKey)
78 value = bucket->key();
79 else
80 value = createPair(exec, bucket->key(), bucket->key());
81 return true;
82 }
83
84 IterationKind kind() const { return m_kind; }
85 JSValue iteratedValue() const { return m_set.get(); }
86
87private:
88 JSSetIterator(VM& vm, Structure* structure, JSSet*, IterationKind kind)
89 : Base(vm, structure)
90 , m_kind(kind)
91 {
92 }
93
94 void setIterator(VM& vm, HashMapBucketType* bucket)
95 {
96 m_iter.setMayBeNull(vm, this, bucket);
97 }
98
99 JS_EXPORT_PRIVATE void finishCreation(VM&, JSSet*);
100 JS_EXPORT_PRIVATE JSValue createPair(CallFrame*, JSValue, JSValue);
101 static void visitChildren(JSCell*, SlotVisitor&);
102
103 WriteBarrier<JSSet> m_set;
104 WriteBarrier<HashMapBucketType> m_iter;
105 IterationKind m_kind;
106};
107STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(JSSetIterator);
108
109} // namespace JSC
110