source: trunk/libtransmission/ConvertUTF.h @ 5810

Last change on this file since 5810 was 5810, checked in by charles, 14 years ago

add json-to-benc parser

File size: 5.9 KB
Line 
1#ifndef CONVERT_UNICODE_H
2#define CONVERT_UNICODE_H
3
4/*
5 * Copyright 2001-2004 Unicode, Inc.
6 *
7 * Disclaimer
8 *
9 * This source code is provided as is by Unicode, Inc. No claims are
10 * made as to fitness for any particular purpose. No warranties of any
11 * kind are expressed or implied. The recipient agrees to determine
12 * applicability of information provided. If this file has been
13 * purchased on magnetic or optical media from Unicode, Inc., the
14 * sole remedy for any claim will be exchange of defective media
15 * within 90 days of receipt.
16 *
17 * Limitations on Rights to Redistribute This Code
18 *
19 * Unicode, Inc. hereby grants the right to freely use the information
20 * supplied in this file in the creation of products supporting the
21 * Unicode Standard, and to make copies of this file in any form
22 * for internal or external distribution as long as this notice
23 * remains attached.
24 */
25
26/* ---------------------------------------------------------------------
27
28    Conversions between UTF32, UTF-16, and UTF-8.  Header file.
29
30    Several funtions are included here, forming a complete set of
31    conversions between the three formats.  UTF-7 is not included
32    here, but is handled in a separate source file.
33
34    Each of these routines takes pointers to input buffers and output
35    buffers.  The input buffers are const.
36
37    Each routine converts the text between *sourceStart and sourceEnd,
38    putting the result into the buffer between *targetStart and
39    targetEnd. Note: the end pointers are *after* the last item: e.g.
40    *(sourceEnd - 1) is the last item.
41
42    The return result indicates whether the conversion was successful,
43    and if not, whether the problem was in the source or target buffers.
44    (Only the first encountered problem is indicated.)
45
46    After the conversion, *sourceStart and *targetStart are both
47    updated to point to the end of last text successfully converted in
48    the respective buffers.
49
50    Input parameters:
51        sourceStart - pointer to a pointer to the source buffer.
52                The contents of this are modified on return so that
53                it points at the next thing to be converted.
54        targetStart - similarly, pointer to pointer to the target buffer.
55        sourceEnd, targetEnd - respectively pointers to the ends of the
56                two buffers, for overflow checking only.
57
58    These conversion functions take a ConversionFlags argument. When this
59    flag is set to strict, both irregular sequences and isolated surrogates
60    will cause an error.  When the flag is set to lenient, both irregular
61    sequences and isolated surrogates are converted.
62
63    Whether the flag is strict or lenient, all illegal sequences will cause
64    an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>,
65    or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code
66    must check for illegal sequences.
67
68    When the flag is set to lenient, characters over 0x10FFFF are converted
69    to the replacement character; otherwise (when the flag is set to strict)
70    they constitute an error.
71
72    Output parameters:
73        The value "sourceIllegal" is returned from some routines if the input
74        sequence is malformed.  When "sourceIllegal" is returned, the source
75        value will point to the illegal value that caused the problem. E.g.,
76        in UTF-8 when a sequence is malformed, it points to the start of the
77        malformed sequence. 
78
79    Author: Mark E. Davis, 1994.
80    Rev History: Rick McGowan, fixes & updates May 2001.
81                 Fixes & updates, Sept 2001.
82
83------------------------------------------------------------------------ */
84
85/* ---------------------------------------------------------------------
86    The following 4 definitions are compiler-specific.
87    The C standard does not guarantee that wchar_t has at least
88    16 bits, so wchar_t is no less portable than unsigned short!
89    All should be unsigned values to avoid sign extension during
90    bit mask & shift operations.
91------------------------------------------------------------------------ */
92
93
94typedef unsigned int    UTF32;  /* at least 32 bits */
95typedef unsigned short  UTF16;  /* at least 16 bits */
96typedef unsigned char   UTF8;   /* typically 8 bits */
97typedef unsigned char   Boolean; /* 0 or 1 */
98
99/* Some fundamental constants */
100#define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD
101#define UNI_MAX_BMP (UTF32)0x0000FFFF
102#define UNI_MAX_UTF16 (UTF32)0x0010FFFF
103#define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF
104#define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF
105
106typedef enum {
107        conversionOK,           /* conversion successful */
108        sourceExhausted,        /* partial character in source, but hit end */
109        targetExhausted,        /* insuff. room in target for conversion */
110        sourceIllegal           /* source sequence is illegal/malformed */
111} ConversionResult;
112
113typedef enum {
114        strictConversion = 0,
115        lenientConversion
116} ConversionFlags;
117
118/* This is for C++ and does no harm in C */
119#ifdef __cplusplus
120extern "C" {
121#endif
122
123ConversionResult ConvertUTF8toUTF16 (
124                const UTF8** sourceStart, const UTF8* sourceEnd, 
125                UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
126
127ConversionResult ConvertUTF16toUTF8 (
128                const UTF16** sourceStart, const UTF16* sourceEnd, 
129                UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
130               
131ConversionResult ConvertUTF8toUTF32 (
132                const UTF8** sourceStart, const UTF8* sourceEnd, 
133                UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
134
135ConversionResult ConvertUTF32toUTF8 (
136                const UTF32** sourceStart, const UTF32* sourceEnd, 
137                UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags);
138               
139ConversionResult ConvertUTF16toUTF32 (
140                const UTF16** sourceStart, const UTF16* sourceEnd, 
141                UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags);
142
143ConversionResult ConvertUTF32toUTF16 (
144                const UTF32** sourceStart, const UTF32* sourceEnd, 
145                UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags);
146
147Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd);
148
149#ifdef __cplusplus
150}
151#endif
152
153/* --------------------------------------------------------------------- */
154
155#endif // CONVERT_UNICODE_H
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