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

   1 /*
   2  * Copyright (C) 2004, 2006 Apple Computer, Inc.  All rights reserved.
   3  * Copyright (C) 2006 Alexey Proskuryakov <ap@nypop.com>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   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  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef TextCodec_h
  28 #define TextCodec_h
  29
  30 #include "wtf/Forward.h"
  31 #include "wtf/Noncopyable.h"
  32 #include "wtf/PassOwnPtr.h"
  33 #include "wtf/text/Unicode.h"
  34 #include "wtf/text/WTFString.h"
  35
  36 namespace WTF {
  37
  38 class TextEncoding;
  39
  40 // Specifies what will happen when a character is encountered that is
  41 // not encodable in the character set.
  42 enum UnencodableHandling {
  43     // Substitutes the replacement character "?".
  44     QuestionMarksForUnencodables,
  45
  46     // Encodes the character as an XML entity. For example, U+06DE
  47     // would be "&#1758;" (0x6DE = 1758 in octal).
  48     EntitiesForUnencodables,
  49
  50     // Encodes the character as en entity as above, but escaped
  51     // non-alphanumeric characters. This is used in URLs.
  52     // For example, U+6DE would be "%26%231758%3B".
  53     URLEncodedEntitiesForUnencodables
  54 };
  55
  56 typedef char UnencodableReplacementArray[32];
  57
  58 enum FlushBehavior {
  59     // More bytes are coming, don't flush the codec.
  60     DoNotFlush = 0,
  61
  62     // A fetch has hit EOF. Some codecs handle fetches differently, for compat reasons.
  63     FetchEOF,
  64
  65     // Do a full flush of the codec.
  66     DataEOF
  67 };
  68
  69 static_assert(!DoNotFlush, "DoNotFlush should be falsy");
  70 static_assert(FetchEOF, "FetchEOF should be truthy");
  71 static_assert(DataEOF, "DataEOF should be truthy");
  72
  73
  74 class TextCodec {
  75     WTF_MAKE_NONCOPYABLE(TextCodec); WTF_MAKE_FAST_ALLOCATED(TextCodec);
  76 public:
  77     TextCodec() { }
  78     virtual ~TextCodec();
  79
  80     String decode(const char* str, size_t length, FlushBehavior flush = DoNotFlush)
  81     {
  82         bool ignored;
  83         return decode(str, length, flush, false, ignored);
  84     }
  85
  86     virtual String decode(const char*, size_t length, FlushBehavior, bool stopOnError, bool& sawError) = 0;
  87     virtual CString encode(const UChar*, size_t length, UnencodableHandling) = 0;
  88     virtual CString encode(const LChar*, size_t length, UnencodableHandling) = 0;
  89
  90     // Fills a null-terminated string representation of the given
  91     // unencodable character into the given replacement buffer.
  92     // The length of the string (not including the null) will be returned.
  93     static int getUnencodableReplacement(unsigned codePoint, UnencodableHandling, UnencodableReplacementArray);
  94 };
  95
  96 typedef void (*EncodingNameRegistrar)(const char* alias, const char* name);
  97
  98 typedef PassOwnPtr<TextCodec> (*NewTextCodecFunction)(const TextEncoding&, const void* additionalData);
  99 typedef void (*TextCodecRegistrar)(const char* name, NewTextCodecFunction, const void* additionalData);
 100
 101 } // namespace WTF
 102
 103 using WTF::TextCodec;
 104
 105 #endif // TextCodec_h