third_party/WebKit/Source/wtf/BitArray.h

   1 /*
   2  * Copyright (C) 2012 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 BitArray_h
  27 #define BitArray_h
  28
  29 #include <string.h>
  30 #include "wtf/Assertions.h"
  31
  32 namespace WTF {
  33
  34 template<unsigned arraySize>
  35 class BitArray {
  36 public:
  37     BitArray(bool value = false)
  38     {
  39         memset(m_data, value ? 0xFF : 0, sizeof(m_data));
  40     }
  41
  42     void set(unsigned index)
  43     {
  44         ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
  45         m_data[index / 8] |= 1 << (index & 7);
  46     }
  47
  48     void clear(unsigned index)
  49     {
  50         ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
  51         m_data[index / 8] &= ~(1 << (index & 7));
  52     }
  53
  54     bool get(unsigned index) const
  55     {
  56         ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
  57         return !!(m_data[index / 8] & (1 << (index & 7)));
  58     }
  59
  60 private:
  61     unsigned char m_data[arraySize / 8 + 1];
  62 };
  63
  64 } // namespace WTF
  65
  66 using WTF::BitArray;
  67
  68 #endif // BitArray_h