wtf/ByteArray.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 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