1/*
2 * Copyright (C) 2013 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#ifndef WeakMapData_h
27#define WeakMapData_h
28
29#include "JSCell.h"
30#include "Structure.h"
31#include <wtf/HashFunctions.h>
32#include <wtf/HashMap.h>
33#include <wtf/MathExtras.h>
34
35namespace JSC {
36
37class WeakMapData : public JSCell {
38public:
39    typedef JSCell Base;
40
41    static WeakMapData* create(VM& vm)
42    {
43        WeakMapData* weakMapData = new (NotNull, allocateCell<WeakMapData>(vm.heap)) WeakMapData(vm);
44        weakMapData->finishCreation(vm);
45        return weakMapData;
46    }
47
48    static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
49    {
50        return Structure::create(vm, globalObject, prototype, TypeInfo(CompoundType, StructureFlags), info());
51    }
52
53    static const bool needsDestruction = true;
54    static const bool hasImmortalStructure = true;
55
56    void set(VM&, JSObject*, JSValue);
57    JSValue get(JSObject*);
58    bool remove(JSObject*);
59    bool contains(JSObject*);
60    void clear();
61
62    DECLARE_INFO;
63
64    static const unsigned StructureFlags = OverridesVisitChildren | StructureIsImmortal | Base::StructureFlags;
65
66private:
67    WeakMapData(VM&);
68    static void destroy(JSCell*);
69    static void visitChildren(JSCell*, SlotVisitor&);
70    void finishCreation(VM&);
71
72    class DeadKeyCleaner : public UnconditionalFinalizer, public WeakReferenceHarvester {
73    public:
74        DeadKeyCleaner(WeakMapData* target)
75            : m_target(target)
76        {
77        }
78    private:
79        virtual void visitWeakReferences(SlotVisitor&) override;
80        virtual void finalizeUnconditionally() override;
81        int m_liveKeyCount;
82        WeakMapData* m_target;
83    };
84    DeadKeyCleaner m_deadKeyCleaner;
85    typedef HashMap<JSObject*, WriteBarrier<Unknown>> MapType;
86    MapType m_map;
87};
88
89}
90
91#endif /* !defined(WeakMapData_h) */
92