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 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