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 "wtf/PassRefPtr.h"
  30 #include "wtf/RefCounted.h"
  31
  32 namespace WTF {
  33     class ByteArray : public RefCountedBase {
  34     public:
  35         unsigned length() const { return m_size; }
  36
  37         void set(unsigned index, double value)
  38         {
  39             if (index >= m_size)
  40                 return;
  41             if (!(value > 0)) // Clamp NaN to 0
  42                 value = 0;
  43             else if (value > 255)
  44                 value = 255;
  45             m_data[index] = static_cast<unsigned char>(value + 0.5);
  46         }
  47
  48         bool get(unsigned index, unsigned char& result) const
  49         {
  50             if (index >= m_size)
  51                 return false;
  52             result = m_data[index];
  53             return true;
  54         }
  55
  56         unsigned char* data() { return m_data; }
  57
  58         void deref()
  59         {
  60             if (derefBase()) {
  61                 // We allocated with new unsigned char[] in create(),
  62                 // and then used placement new to construct the object.
  63                 this->~ByteArray();
  64                 delete[] reinterpret_cast<unsigned char*>(this);
  65             }
  66         }
  67
  68         static PassRefPtr<ByteArray> create(size_t size);
  69
  70     private:
  71         ByteArray(size_t size)
  72             : RefCountedBase(1)
  73             , m_size(size)
  74         {
  75         }
  76         size_t m_size;
  77         unsigned char m_data[sizeof(size_t)];
  78     };
  79 }
  80
  81 #endif