third_party/WebKit/Source/wtf/text/CString.cpp

   1 /*
   2  * Copyright (C) 2003, 2006, 2008, 2009, 2010, 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 COMPUTER, 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 COMPUTER, 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
  27 #include "config.h"
  28 #include "CString.h"
  29
  30 #include "wtf/PartitionAlloc.h"
  31 #include "wtf/Partitions.h"
  32 #include <string.h>
  33
  34 using namespace std;
  35
  36 namespace WTF {
  37
  38 PassRefPtr<CStringBuffer> CStringBuffer::createUninitialized(size_t length)
  39 {
  40     RELEASE_ASSERT(length < (numeric_limits<unsigned>::max() - sizeof(CStringBuffer)));
  41
  42     // The +1 is for the terminating NUL character.
  43     size_t size = sizeof(CStringBuffer) + length + 1;
  44     CStringBuffer* stringBuffer = static_cast<CStringBuffer*>(Partitions::bufferMalloc(size));
  45     return adoptRef(new (stringBuffer) CStringBuffer(length));
  46 }
  47
  48 void CStringBuffer::operator delete(void* ptr)
  49 {
  50     Partitions::bufferFree(ptr);
  51 }
  52
  53 CString::CString(const char* str)
  54 {
  55     if (!str)
  56         return;
  57
  58     init(str, strlen(str));
  59 }
  60
  61 CString::CString(const char* str, size_t length)
  62 {
  63     if (!str) {
  64         ASSERT(!length);
  65         return;
  66     }
  67
  68     init(str, length);
  69 }
  70
  71 void CString::init(const char* str, size_t length)
  72 {
  73     ASSERT(str);
  74
  75     m_buffer = CStringBuffer::createUninitialized(length);
  76     memcpy(m_buffer->mutableData(), str, length);
  77     m_buffer->mutableData()[length] = '\0';
  78 }
  79
  80 char* CString::mutableData()
  81 {
  82     copyBufferIfNeeded();
  83     if (!m_buffer)
  84         return 0;
  85     return m_buffer->mutableData();
  86 }
  87
  88 CString CString::newUninitialized(size_t length, char*& characterBuffer)
  89 {
  90     CString result;
  91     result.m_buffer = CStringBuffer::createUninitialized(length);
  92     char* bytes = result.m_buffer->mutableData();
  93     bytes[length] = '\0';
  94     characterBuffer = bytes;
  95     return result;
  96 }
  97
  98 void CString::copyBufferIfNeeded()
  99 {
 100     if (!m_buffer || m_buffer->hasOneRef())
 101         return;
 102
 103     RefPtr<CStringBuffer> buffer = m_buffer.release();
 104     size_t length = buffer->length();
 105     m_buffer = CStringBuffer::createUninitialized(length);
 106     memcpy(m_buffer->mutableData(), buffer->data(), length + 1);
 107 }
 108
 109 bool CString::isSafeToSendToAnotherThread() const
 110 {
 111     return !m_buffer || m_buffer->hasOneRef();
 112 }
 113
 114 bool operator==(const CString& a, const CString& b)
 115 {
 116     if (a.isNull() != b.isNull())
 117         return false;
 118     if (a.length() != b.length())
 119         return false;
 120     return !memcmp(a.data(), b.data(), a.length());
 121 }
 122
 123 bool operator==(const CString& a, const char* b)
 124 {
 125     if (a.isNull() != !b)
 126         return false;
 127     if (!b)
 128         return true;
 129     return !strcmp(a.data(), b);
 130 }
 131
 132 } // namespace WTF