1/*
2 * Copyright (C) 2009 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#ifndef JSByteArray_h
27#define JSByteArray_h
28
29#include "JSObject.h"
30
31#include <wtf/ByteArray.h>
32
33namespace JSC {
34
35    class JSByteArray : public JSObject {
36        friend class JSGlobalData;
37    public:
38        bool canAccessIndex(unsigned i) { return i < m_storage->length(); }
39        JSValue getIndex(ExecState* exec, unsigned i)
40        {
41            ASSERT(canAccessIndex(i));
42            return jsNumber(exec, m_storage->data()[i]);
43        }
44
45        void setIndex(unsigned i, int value)
46        {
47            ASSERT(canAccessIndex(i));
48            if (value & ~0xFF) {
49                if (value < 0)
50                    value = 0;
51                else
52                    value = 255;
53            }
54            m_storage->data()[i] = static_cast<unsigned char>(value);
55        }
56
57        void setIndex(unsigned i, double value)
58        {
59            ASSERT(canAccessIndex(i));
60            if (!(value > 0)) // Clamp NaN to 0
61                value = 0;
62            else if (value > 255)
63                value = 255;
64            m_storage->data()[i] = static_cast<unsigned char>(value + 0.5);
65        }
66
67        void setIndex(ExecState* exec, unsigned i, JSValue value)
68        {
69            double byteValue = value.toNumber(exec);
70            if (exec->hadException())
71                return;
72            if (canAccessIndex(i))
73                setIndex(i, byteValue);
74        }
75
76        JSByteArray(ExecState* exec, NonNullPassRefPtr<Structure>, WTF::ByteArray* storage, const JSC::ClassInfo* = &s_defaultInfo);
77        static PassRefPtr<Structure> createStructure(JSValue prototype);
78
79        virtual bool getOwnPropertySlot(JSC::ExecState*, const JSC::Identifier& propertyName, JSC::PropertySlot&);
80        virtual bool getOwnPropertySlot(JSC::ExecState*, unsigned propertyName, JSC::PropertySlot&);
81        virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
82        virtual void put(JSC::ExecState*, const JSC::Identifier& propertyName, JSC::JSValue, JSC::PutPropertySlot&);
83        virtual void put(JSC::ExecState*, unsigned propertyName, JSC::JSValue);
84
85        virtual void getOwnPropertyNames(JSC::ExecState*, JSC::PropertyNameArray&, EnumerationMode mode = ExcludeDontEnumProperties);
86
87        virtual const ClassInfo* classInfo() const { return m_classInfo; }
88        static const ClassInfo s_defaultInfo;
89
90        size_t length() const { return m_storage->length(); }
91
92        WTF::ByteArray* storage() const { return m_storage.get(); }
93
94#if !ASSERT_DISABLED
95        virtual ~JSByteArray();
96#endif
97
98    protected:
99        static const unsigned StructureFlags = OverridesGetOwnPropertySlot | OverridesGetPropertyNames | JSObject::StructureFlags;
100
101    private:
102        enum VPtrStealingHackType { VPtrStealingHack };
103        JSByteArray(VPtrStealingHackType)
104            : JSObject(createStructure(jsNull()))
105            , m_classInfo(0)
106        {
107        }
108
109        RefPtr<WTF::ByteArray> m_storage;
110        const ClassInfo* m_classInfo;
111    };
112
113    JSByteArray* asByteArray(JSValue value);
114    inline JSByteArray* asByteArray(JSValue value)
115    {
116        return static_cast<JSByteArray*>(asCell(value));
117    }
118
119    inline bool isJSByteArray(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsByteArrayVPtr; }
120
121} // namespace JSC
122
123#endif // JSByteArray_h
124