runtime/JSByteArray.h

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