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      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 ByteArray_h
     27 #define ByteArray_h
     28 
     29 #include <limits.h>
     30 #include <wtf/PassRefPtr.h>
     31 #include <wtf/Platform.h>
     32 #include <wtf/RefCounted.h>
     33 
     34 namespace WTF {
     35     class ByteArray : public RefCountedBase {
     36     public:
     37         unsigned length() const { return m_size; }
     38 
     39         void set(unsigned index, double value)
     40         {
     41             if (index >= m_size)
     42                 return;
     43             if (!(value > 0)) // Clamp NaN to 0
     44                 value = 0;
     45             else if (value > 255)
     46                 value = 255;
     47             m_data[index] = static_cast<unsigned char>(value + 0.5);
     48         }
     49 
     50         void set(unsigned index, unsigned char value)
     51         {
     52             if (index >= m_size)
     53                 return;
     54             m_data[index] = value;
     55         }
     56 
     57         bool get(unsigned index, unsigned char& result) const
     58         {
     59             if (index >= m_size)
     60                 return false;
     61             result = m_data[index];
     62             return true;
     63         }
     64 
     65         unsigned char get(unsigned index) const
     66         {
     67             ASSERT(index < m_size);
     68             return m_data[index];
     69         }
     70 
     71         unsigned char* data() { return m_data; }
     72 
     73         void deref()
     74         {
     75             if (derefBase()) {
     76                 // We allocated with new unsigned char[] in create(),
     77                 // and then used placement new to construct the object.
     78                 this->~ByteArray();
     79                 delete[] reinterpret_cast<unsigned char*>(this);
     80             }
     81         }
     82 
     83         static PassRefPtr<ByteArray> create(size_t size);
     84 
     85     private:
     86         ByteArray(size_t size)
     87             : m_size(size)
     88         {
     89         }
     90         size_t m_size;
     91 // MSVC can't handle correctly unsized array.
     92 // warning C4200: nonstandard extension used : zero-sized array in struct/union
     93 // Cannot generate copy-ctor or copy-assignment operator when UDT contains a zero-sized array
     94 #if COMPILER(MSVC)
     95         unsigned char m_data[INT_MAX];
     96 #else
     97         unsigned char m_data[];
     98 #endif
     99     };
    100 } // namespace WTF
    101 
    102 using WTF::ByteArray;
    103 
    104 #endif
    105