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      1 /*
      2  * Copyright (C) 2007 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 #ifndef WTF_UTF8_h
     27 #define WTF_UTF8_h
     28 
     29 #include "wtf/unicode/Unicode.h"
     30 #include "wtf/WTFExport.h"
     31 
     32 namespace WTF {
     33 namespace Unicode {
     34 
     35     // Given a first byte, gives the length of the UTF-8 sequence it begins.
     36     // Returns 0 for bytes that are not legal starts of UTF-8 sequences.
     37     // Only allows sequences of up to 4 bytes, since that works for all Unicode characters (U-00000000 to U-0010FFFF).
     38     WTF_EXPORT int UTF8SequenceLength(char);
     39 
     40     // Takes a null-terminated C-style string with a UTF-8 sequence in it and converts it to a character.
     41     // Only allows Unicode characters (U-00000000 to U-0010FFFF).
     42     // Returns -1 if the sequence is not valid (including presence of extra bytes).
     43     WTF_EXPORT int decodeUTF8Sequence(const char*);
     44 
     45     typedef enum {
     46             conversionOK,       // conversion successful
     47             sourceExhausted,    // partial character in source, but hit end
     48             targetExhausted,    // insuff. room in target for conversion
     49             sourceIllegal       // source sequence is illegal/malformed
     50     } ConversionResult;
     51 
     52     // These conversion functions take a "strict" argument. When this
     53     // flag is set to strict, both irregular sequences and isolated surrogates
     54     // will cause an error.  When the flag is set to lenient, both irregular
     55     // sequences and isolated surrogates are converted.
     56     //
     57     // Whether the flag is strict or lenient, all illegal sequences will cause
     58     // an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
     59     // or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
     60     // must check for illegal sequences.
     61     //
     62     // When the flag is set to lenient, characters over 0x10FFFF are converted
     63     // to the replacement character; otherwise (when the flag is set to strict)
     64     // they constitute an error.
     65 
     66     WTF_EXPORT ConversionResult convertUTF8ToUTF16(
     67                     const char** sourceStart, const char* sourceEnd,
     68                     UChar** targetStart, UChar* targetEnd, bool* isSourceAllASCII = 0, bool strict = true);
     69 
     70     WTF_EXPORT ConversionResult convertLatin1ToUTF8(
     71                     const LChar** sourceStart, const LChar* sourceEnd,
     72                     char** targetStart, char* targetEnd);
     73 
     74     WTF_EXPORT ConversionResult convertUTF16ToUTF8(
     75                     const UChar** sourceStart, const UChar* sourceEnd,
     76                     char** targetStart, char* targetEnd, bool strict = true);
     77 
     78     WTF_EXPORT unsigned calculateStringHashAndLengthFromUTF8MaskingTop8Bits(const char* data, const char* dataEnd, unsigned& dataLength, unsigned& utf16Length);
     79 
     80     WTF_EXPORT bool equalUTF16WithUTF8(const UChar* a, const UChar* aEnd, const char* b, const char* bEnd);
     81     WTF_EXPORT bool equalLatin1WithUTF8(const LChar* a, const LChar* aEnd, const char* b, const char* bEnd);
     82 
     83 } // namespace Unicode
     84 } // namespace WTF
     85 
     86 #endif // WTF_UTF8_h
     87