third_party/WebKit/Source/wtf/text/StringUTF8Adaptor.h

   1 /*
   2  * Copyright (C) 2013 Google 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 are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef StringUTF8Adaptor_h
  32 #define StringUTF8Adaptor_h
  33
  34 #include "wtf/text/CString.h"
  35 #include "wtf/text/TextEncoding.h"
  36 #include "wtf/text/WTFString.h"
  37
  38 namespace WTF {
  39
  40 // This class lets you get UTF-8 data out of a String without mallocing a
  41 // separate buffer to hold the data if the String happens to be 8 bit and
  42 // contain only ASCII characters.
  43 class StringUTF8Adaptor {
  44 public:
  45     enum ShouldNormalize {
  46         DoNotNormalize,
  47         Normalize
  48     };
  49
  50     explicit StringUTF8Adaptor(const String& string, ShouldNormalize normalize = DoNotNormalize, UnencodableHandling handling = EntitiesForUnencodables)
  51         : m_data(0)
  52         , m_length(0)
  53     {
  54         if (string.isEmpty())
  55             return;
  56         // Unfortunately, 8 bit WTFStrings are encoded in Latin-1 and GURL uses UTF-8
  57         // when processing 8 bit strings. If |relative| is entirely ASCII, we luck out
  58         // and can avoid mallocing a new buffer to hold the UTF-8 data because UTF-8
  59         // and Latin-1 use the same code units for ASCII code points.
  60         if (string.is8Bit() && string.containsOnlyASCII()) {
  61             m_data = reinterpret_cast<const char*>(string.characters8());
  62             m_length = string.length();
  63         } else {
  64             if (normalize == Normalize)
  65                 m_utf8Buffer = UTF8Encoding().normalizeAndEncode(string, handling);
  66             else
  67                 m_utf8Buffer = string.utf8();
  68             m_data = m_utf8Buffer.data();
  69             m_length = m_utf8Buffer.length();
  70         }
  71     }
  72
  73     const char* data() const { return m_data; }
  74     size_t length() const { return m_length; }
  75
  76 private:
  77     CString m_utf8Buffer;
  78     const char* m_data;
  79     size_t m_length;
  80 };
  81
  82 } // namespace WTF
  83
  84 using WTF::StringUTF8Adaptor;
  85
  86 #endif // StringUTF8Adaptor_h