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      1 /*
      2  * Copyright (C) 2009 Apple Inc. All rights reserved.
      3  * Copyright (C) 2013 Google Inc. All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #ifndef ArrayBufferContents_h
     28 #define ArrayBufferContents_h
     29 
     30 #include "wtf/ArrayBufferDeallocationObserver.h"
     31 #include "wtf/Noncopyable.h"
     32 #include "wtf/WTFExport.h"
     33 
     34 namespace WTF {
     35 
     36 class WTF_EXPORT ArrayBufferContents {
     37     WTF_MAKE_NONCOPYABLE(ArrayBufferContents);
     38 public:
     39     enum InitializationPolicy {
     40         ZeroInitialize,
     41         DontInitialize
     42     };
     43 
     44     ArrayBufferContents();
     45     ArrayBufferContents(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy);
     46 
     47     // Use with care. data must be allocated with allocateMemory.
     48     // ArrayBufferContents will take ownership of the data and free it (using freeMemorY)
     49     // upon destruction.
     50     // This constructor will not call observer->StartObserving(), so it is a responsibility
     51     // of the caller to make sure JS knows about external memory.
     52     ArrayBufferContents(void* data, unsigned sizeInBytes, ArrayBufferDeallocationObserver*);
     53 
     54     ~ArrayBufferContents();
     55 
     56     void clear();
     57 
     58     void* data() const { return m_data; }
     59     unsigned sizeInBytes() const { return m_sizeInBytes; }
     60 
     61     void setDeallocationObserver(ArrayBufferDeallocationObserver* observer)
     62     {
     63         if (!m_deallocationObserver) {
     64             m_deallocationObserver = observer;
     65             m_deallocationObserver->blinkAllocatedMemory(m_sizeInBytes);
     66         }
     67     }
     68 
     69     void transfer(ArrayBufferContents& other);
     70     void copyTo(ArrayBufferContents& other);
     71 
     72     static void allocateMemory(size_t, InitializationPolicy, void*&);
     73     static void freeMemory(void*, size_t);
     74 
     75 private:
     76     void* m_data;
     77     unsigned m_sizeInBytes;
     78     ArrayBufferDeallocationObserver* m_deallocationObserver;
     79 };
     80 
     81 } // namespace WTF
     82 
     83 #endif // ArrayBufferContents_h
     84