wtf/text/StringBuffer.h

   1 /*
   2  * Copyright (C) 2008, 2010 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  *
   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  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of its
  14  *     contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef StringBuffer_h
  30 #define StringBuffer_h
  31
  32 #include <wtf/Assertions.h>
  33 #include <wtf/Noncopyable.h>
  34 #include <wtf/unicode/Unicode.h>
  35 #include <limits>
  36
  37 namespace WebCore {
  38
  39 class StringBuffer : public Noncopyable {
  40 public:
  41     explicit StringBuffer(unsigned length)
  42         : m_length(length)
  43     {
  44         if (m_length > std::numeric_limits<unsigned>::max() / sizeof(UChar))
  45             CRASH();
  46         m_data = static_cast<UChar*>(fastMalloc(m_length * sizeof(UChar)));
  47     }
  48
  49     ~StringBuffer()
  50     {
  51         fastFree(m_data);
  52     }
  53
  54     void shrink(unsigned newLength)
  55     {
  56         ASSERT(newLength <= m_length);
  57         m_length = newLength;
  58     }
  59
  60     void resize(unsigned newLength)
  61     {
  62         if (newLength > m_length) {
  63             if (newLength > std::numeric_limits<unsigned>::max() / sizeof(UChar))
  64                 CRASH();
  65             m_data = static_cast<UChar*>(fastRealloc(m_data, newLength * sizeof(UChar)));
  66         }
  67         m_length = newLength;
  68     }
  69
  70     unsigned length() const { return m_length; }
  71     UChar* characters() { return m_data; }
  72
  73     UChar& operator[](unsigned i) { ASSERT(i < m_length); return m_data[i]; }
  74
  75     UChar* release() { UChar* data = m_data; m_data = 0; return data; }
  76
  77 private:
  78     unsigned m_length;
  79     UChar* m_data;
  80 };
  81
  82 } // namespace WTF
  83
  84 #endif // StringBuffer_h