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1 /* zlib.h -- interface of the 'zlib' general purpose compression library
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2 version 1.2.5, April 19th, 2010
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3
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4 Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
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5
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6 This software is provided 'as-is', without any express or implied
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7 warranty. In no event will the authors be held liable for any damages
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8 arising from the use of this software.
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9
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10 Permission is granted to anyone to use this software for any purpose,
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11 including commercial applications, and to alter it and redistribute it
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12 freely, subject to the following restrictions:
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13
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14 1. The origin of this software must not be misrepresented; you must not
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15 claim that you wrote the original software. If you use this software
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16 in a product, an acknowledgment in the product documentation would be
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17 appreciated but is not required.
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18 2. Altered source versions must be plainly marked as such, and must not be
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19 misrepresented as being the original software.
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20 3. This notice may not be removed or altered from any source distribution.
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21
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22 Jean-loup Gailly Mark Adler
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23 jloup@gzip.org madler@alumni.caltech.edu
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24
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25
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26 The data format used by the zlib library is described by RFCs (Request for
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27 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
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28 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
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29 */
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30
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31 #ifndef ZLIB_H
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32 #define ZLIB_H
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33
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34 #include "zconf.h"
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35
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36 #ifdef __cplusplus
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37 extern "C" {
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38 #endif
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39
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40 #define ZLIB_VERSION "1.2.5"
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41 #define ZLIB_VERNUM 0x1250
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42 #define ZLIB_VER_MAJOR 1
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43 #define ZLIB_VER_MINOR 2
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44 #define ZLIB_VER_REVISION 5
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45 #define ZLIB_VER_SUBREVISION 0
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46
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47 /*
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48 The 'zlib' compression library provides in-memory compression and
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49 decompression functions, including integrity checks of the uncompressed data.
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50 This version of the library supports only one compression method (deflation)
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51 but other algorithms will be added later and will have the same stream
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52 interface.
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53
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54 Compression can be done in a single step if the buffers are large enough,
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55 or can be done by repeated calls of the compression function. In the latter
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56 case, the application must provide more input and/or consume the output
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57 (providing more output space) before each call.
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58
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59 The compressed data format used by default by the in-memory functions is
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60 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
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61 around a deflate stream, which is itself documented in RFC 1951.
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62
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63 The library also supports reading and writing files in gzip (.gz) format
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64 with an interface similar to that of stdio using the functions that start
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65 with "gz". The gzip format is different from the zlib format. gzip is a
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66 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
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67
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68 This library can optionally read and write gzip streams in memory as well.
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69
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70 The zlib format was designed to be compact and fast for use in memory
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71 and on communications channels. The gzip format was designed for single-
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72 file compression on file systems, has a larger header than zlib to maintain
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73 directory information, and uses a different, slower check method than zlib.
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74
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75 The library does not install any signal handler. The decoder checks
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76 the consistency of the compressed data, so the library should never crash
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77 even in case of corrupted input.
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78 */
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79
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80 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
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81 typedef void (*free_func) OF((voidpf opaque, voidpf address));
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82
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83 struct internal_state;
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84
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85 typedef struct z_stream_s {
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86 Bytef *next_in; /* next input byte */
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87 uInt avail_in; /* number of bytes available at next_in */
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88 uLong total_in; /* total nb of input bytes read so far */
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89
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90 Bytef *next_out; /* next output byte should be put there */
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91 uInt avail_out; /* remaining free space at next_out */
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92 uLong total_out; /* total nb of bytes output so far */
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93
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94 char *msg; /* last error message, NULL if no error */
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95 struct internal_state FAR *state; /* not visible by applications */
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96
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97 alloc_func zalloc; /* used to allocate the internal state */
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98 free_func zfree; /* used to free the internal state */
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99 voidpf opaque; /* private data object passed to zalloc and zfree */
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100
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101 int data_type; /* best guess about the data type: binary or text */
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102 uLong adler; /* adler32 value of the uncompressed data */
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103 uLong reserved; /* reserved for future use */
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104 } z_stream;
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105
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106 typedef z_stream FAR *z_streamp;
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107
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108 /*
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109 gzip header information passed to and from zlib routines. See RFC 1952
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110 for more details on the meanings of these fields.
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111 */
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112 typedef struct gz_header_s {
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113 int text; /* true if compressed data believed to be text */
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114 uLong time; /* modification time */
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115 int xflags; /* extra flags (not used when writing a gzip file) */
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116 int os; /* operating system */
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117 Bytef *extra; /* pointer to extra field or Z_NULL if none */
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118 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
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119 uInt extra_max; /* space at extra (only when reading header) */
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120 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
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121 uInt name_max; /* space at name (only when reading header) */
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122 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
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123 uInt comm_max; /* space at comment (only when reading header) */
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124 int hcrc; /* true if there was or will be a header crc */
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125 int done; /* true when done reading gzip header (not used
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126 when writing a gzip file) */
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127 } gz_header;
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128
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129 typedef gz_header FAR *gz_headerp;
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130
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131 /*
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132 The application must update next_in and avail_in when avail_in has dropped
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133 to zero. It must update next_out and avail_out when avail_out has dropped
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134 to zero. The application must initialize zalloc, zfree and opaque before
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135 calling the init function. All other fields are set by the compression
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136 library and must not be updated by the application.
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137
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138 The opaque value provided by the application will be passed as the first
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139 parameter for calls of zalloc and zfree. This can be useful for custom
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140 memory management. The compression library attaches no meaning to the
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141 opaque value.
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142
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143 zalloc must return Z_NULL if there is not enough memory for the object.
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144 If zlib is used in a multi-threaded application, zalloc and zfree must be
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145 thread safe.
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146
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147 On 16-bit systems, the functions zalloc and zfree must be able to allocate
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148 exactly 65536 bytes, but will not be required to allocate more than this if
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149 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
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150 returned by zalloc for objects of exactly 65536 bytes *must* have their
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151 offset normalized to zero. The default allocation function provided by this
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152 library ensures this (see zutil.c). To reduce memory requirements and avoid
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153 any allocation of 64K objects, at the expense of compression ratio, compile
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154 the library with -DMAX_WBITS=14 (see zconf.h).
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155
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156 The fields total_in and total_out can be used for statistics or progress
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157 reports. After compression, total_in holds the total size of the
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158 uncompressed data and may be saved for use in the decompressor (particularly
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159 if the decompressor wants to decompress everything in a single step).
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160 */
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161
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162 /* constants */
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163
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164 #define Z_NO_FLUSH 0
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165 #define Z_PARTIAL_FLUSH 1
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166 #define Z_SYNC_FLUSH 2
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167 #define Z_FULL_FLUSH 3
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168 #define Z_FINISH 4
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169 #define Z_BLOCK 5
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170 #define Z_TREES 6
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171 /* Allowed flush values; see deflate() and inflate() below for details */
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172
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173 #define Z_OK 0
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174 #define Z_STREAM_END 1
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175 #define Z_NEED_DICT 2
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176 #define Z_ERRNO (-1)
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177 #define Z_STREAM_ERROR (-2)
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178 #define Z_DATA_ERROR (-3)
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179 #define Z_MEM_ERROR (-4)
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180 #define Z_BUF_ERROR (-5)
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181 #define Z_VERSION_ERROR (-6)
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182 /* Return codes for the compression/decompression functions. Negative values
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183 * are errors, positive values are used for special but normal events.
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184 */
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185
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186 #define Z_NO_COMPRESSION 0
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187 #define Z_BEST_SPEED 1
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188 #define Z_BEST_COMPRESSION 9
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189 #define Z_DEFAULT_COMPRESSION (-1)
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190 /* compression levels */
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191
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192 #define Z_FILTERED 1
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193 #define Z_HUFFMAN_ONLY 2
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194 #define Z_RLE 3
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195 #define Z_FIXED 4
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196 #define Z_DEFAULT_STRATEGY 0
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197 /* compression strategy; see deflateInit2() below for details */
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198
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199 #define Z_BINARY 0
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200 #define Z_TEXT 1
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201 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
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202 #define Z_UNKNOWN 2
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203 /* Possible values of the data_type field (though see inflate()) */
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204
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205 #define Z_DEFLATED 8
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206 /* The deflate compression method (the only one supported in this version) */
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207
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208 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
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209
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210 #define zlib_version zlibVersion()
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211 /* for compatibility with versions < 1.0.2 */
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212
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213
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214 /* basic functions */
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215
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216 ZEXTERN const char * ZEXPORT zlibVersion OF((void));
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217 /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
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218 If the first character differs, the library code actually used is not
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219 compatible with the zlib.h header file used by the application. This check
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220 is automatically made by deflateInit and inflateInit.
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221 */
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222
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223 /*
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224 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
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225
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226 Initializes the internal stream state for compression. The fields
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227 zalloc, zfree and opaque must be initialized before by the caller. If
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228 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
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229 allocation functions.
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230
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231 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
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232 1 gives best speed, 9 gives best compression, 0 gives no compression at all
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233 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
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234 requests a default compromise between speed and compression (currently
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235 equivalent to level 6).
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236
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237 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
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238 memory, Z_STREAM_ERROR if level is not a valid compression level, or
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239 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
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240 with the version assumed by the caller (ZLIB_VERSION). msg is set to null
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241 if there is no error message. deflateInit does not perform any compression:
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242 this will be done by deflate().
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243 */
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244
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245
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246 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
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247 /*
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248 deflate compresses as much data as possible, and stops when the input
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249 buffer becomes empty or the output buffer becomes full. It may introduce
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250 some output latency (reading input without producing any output) except when
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251 forced to flush.
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252
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253 The detailed semantics are as follows. deflate performs one or both of the
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254 following actions:
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255
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256 - Compress more input starting at next_in and update next_in and avail_in
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257 accordingly. If not all input can be processed (because there is not
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258 enough room in the output buffer), next_in and avail_in are updated and
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259 processing will resume at this point for the next call of deflate().
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260
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261 - Provide more output starting at next_out and update next_out and avail_out
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262 accordingly. This action is forced if the parameter flush is non zero.
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263 Forcing flush frequently degrades the compression ratio, so this parameter
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264 should be set only when necessary (in interactive applications). Some
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265 output may be provided even if flush is not set.
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266
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267 Before the call of deflate(), the application should ensure that at least
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268 one of the actions is possible, by providing more input and/or consuming more
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269 output, and updating avail_in or avail_out accordingly; avail_out should
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270 never be zero before the call. The application can consume the compressed
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271 output when it wants, for example when the output buffer is full (avail_out
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272 == 0), or after each call of deflate(). If deflate returns Z_OK and with
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273 zero avail_out, it must be called again after making room in the output
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274 buffer because there might be more output pending.
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275
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276 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
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277 decide how much data to accumulate before producing output, in order to
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278 maximize compression.
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279
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280 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
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281 flushed to the output buffer and the output is aligned on a byte boundary, so
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282 that the decompressor can get all input data available so far. (In
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283 particular avail_in is zero after the call if enough output space has been
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284 provided before the call.) Flushing may degrade compression for some
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285 compression algorithms and so it should be used only when necessary. This
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286 completes the current deflate block and follows it with an empty stored block
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287 that is three bits plus filler bits to the next byte, followed by four bytes
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288 (00 00 ff ff).
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289
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290 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
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291 output buffer, but the output is not aligned to a byte boundary. All of the
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292 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
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293 This completes the current deflate block and follows it with an empty fixed
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294 codes block that is 10 bits long. This assures that enough bytes are output
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295 in order for the decompressor to finish the block before the empty fixed code
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296 block.
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297
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298 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
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299 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
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300 seven bits of the current block are held to be written as the next byte after
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301 the next deflate block is completed. In this case, the decompressor may not
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302 be provided enough bits at this point in order to complete decompression of
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303 the data provided so far to the compressor. It may need to wait for the next
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304 block to be emitted. This is for advanced applications that need to control
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305 the emission of deflate blocks.
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306
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307 If flush is set to Z_FULL_FLUSH, all output is flushed as with
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308 Z_SYNC_FLUSH, and the compression state is reset so that decompression can
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309 restart from this point if previous compressed data has been damaged or if
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310 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
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311 compression.
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312
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313 If deflate returns with avail_out == 0, this function must be called again
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314 with the same value of the flush parameter and more output space (updated
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315 avail_out), until the flush is complete (deflate returns with non-zero
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316 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
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317 avail_out is greater than six to avoid repeated flush markers due to
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318 avail_out == 0 on return.
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319
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320 If the parameter flush is set to Z_FINISH, pending input is processed,
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321 pending output is flushed and deflate returns with Z_STREAM_END if there was
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322 enough output space; if deflate returns with Z_OK, this function must be
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323 called again with Z_FINISH and more output space (updated avail_out) but no
|
alpar@9
|
324 more input data, until it returns with Z_STREAM_END or an error. After
|
alpar@9
|
325 deflate has returned Z_STREAM_END, the only possible operations on the stream
|
alpar@9
|
326 are deflateReset or deflateEnd.
|
alpar@9
|
327
|
alpar@9
|
328 Z_FINISH can be used immediately after deflateInit if all the compression
|
alpar@9
|
329 is to be done in a single step. In this case, avail_out must be at least the
|
alpar@9
|
330 value returned by deflateBound (see below). If deflate does not return
|
alpar@9
|
331 Z_STREAM_END, then it must be called again as described above.
|
alpar@9
|
332
|
alpar@9
|
333 deflate() sets strm->adler to the adler32 checksum of all input read
|
alpar@9
|
334 so far (that is, total_in bytes).
|
alpar@9
|
335
|
alpar@9
|
336 deflate() may update strm->data_type if it can make a good guess about
|
alpar@9
|
337 the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
|
alpar@9
|
338 binary. This field is only for information purposes and does not affect the
|
alpar@9
|
339 compression algorithm in any manner.
|
alpar@9
|
340
|
alpar@9
|
341 deflate() returns Z_OK if some progress has been made (more input
|
alpar@9
|
342 processed or more output produced), Z_STREAM_END if all input has been
|
alpar@9
|
343 consumed and all output has been produced (only when flush is set to
|
alpar@9
|
344 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
|
alpar@9
|
345 if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
|
alpar@9
|
346 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
|
alpar@9
|
347 fatal, and deflate() can be called again with more input and more output
|
alpar@9
|
348 space to continue compressing.
|
alpar@9
|
349 */
|
alpar@9
|
350
|
alpar@9
|
351
|
alpar@9
|
352 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
|
alpar@9
|
353 /*
|
alpar@9
|
354 All dynamically allocated data structures for this stream are freed.
|
alpar@9
|
355 This function discards any unprocessed input and does not flush any pending
|
alpar@9
|
356 output.
|
alpar@9
|
357
|
alpar@9
|
358 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
|
alpar@9
|
359 stream state was inconsistent, Z_DATA_ERROR if the stream was freed
|
alpar@9
|
360 prematurely (some input or output was discarded). In the error case, msg
|
alpar@9
|
361 may be set but then points to a static string (which must not be
|
alpar@9
|
362 deallocated).
|
alpar@9
|
363 */
|
alpar@9
|
364
|
alpar@9
|
365
|
alpar@9
|
366 /*
|
alpar@9
|
367 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
|
alpar@9
|
368
|
alpar@9
|
369 Initializes the internal stream state for decompression. The fields
|
alpar@9
|
370 next_in, avail_in, zalloc, zfree and opaque must be initialized before by
|
alpar@9
|
371 the caller. If next_in is not Z_NULL and avail_in is large enough (the
|
alpar@9
|
372 exact value depends on the compression method), inflateInit determines the
|
alpar@9
|
373 compression method from the zlib header and allocates all data structures
|
alpar@9
|
374 accordingly; otherwise the allocation will be deferred to the first call of
|
alpar@9
|
375 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
|
alpar@9
|
376 use default allocation functions.
|
alpar@9
|
377
|
alpar@9
|
378 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
alpar@9
|
379 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
|
alpar@9
|
380 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
|
alpar@9
|
381 invalid, such as a null pointer to the structure. msg is set to null if
|
alpar@9
|
382 there is no error message. inflateInit does not perform any decompression
|
alpar@9
|
383 apart from possibly reading the zlib header if present: actual decompression
|
alpar@9
|
384 will be done by inflate(). (So next_in and avail_in may be modified, but
|
alpar@9
|
385 next_out and avail_out are unused and unchanged.) The current implementation
|
alpar@9
|
386 of inflateInit() does not process any header information -- that is deferred
|
alpar@9
|
387 until inflate() is called.
|
alpar@9
|
388 */
|
alpar@9
|
389
|
alpar@9
|
390
|
alpar@9
|
391 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
|
alpar@9
|
392 /*
|
alpar@9
|
393 inflate decompresses as much data as possible, and stops when the input
|
alpar@9
|
394 buffer becomes empty or the output buffer becomes full. It may introduce
|
alpar@9
|
395 some output latency (reading input without producing any output) except when
|
alpar@9
|
396 forced to flush.
|
alpar@9
|
397
|
alpar@9
|
398 The detailed semantics are as follows. inflate performs one or both of the
|
alpar@9
|
399 following actions:
|
alpar@9
|
400
|
alpar@9
|
401 - Decompress more input starting at next_in and update next_in and avail_in
|
alpar@9
|
402 accordingly. If not all input can be processed (because there is not
|
alpar@9
|
403 enough room in the output buffer), next_in is updated and processing will
|
alpar@9
|
404 resume at this point for the next call of inflate().
|
alpar@9
|
405
|
alpar@9
|
406 - Provide more output starting at next_out and update next_out and avail_out
|
alpar@9
|
407 accordingly. inflate() provides as much output as possible, until there is
|
alpar@9
|
408 no more input data or no more space in the output buffer (see below about
|
alpar@9
|
409 the flush parameter).
|
alpar@9
|
410
|
alpar@9
|
411 Before the call of inflate(), the application should ensure that at least
|
alpar@9
|
412 one of the actions is possible, by providing more input and/or consuming more
|
alpar@9
|
413 output, and updating the next_* and avail_* values accordingly. The
|
alpar@9
|
414 application can consume the uncompressed output when it wants, for example
|
alpar@9
|
415 when the output buffer is full (avail_out == 0), or after each call of
|
alpar@9
|
416 inflate(). If inflate returns Z_OK and with zero avail_out, it must be
|
alpar@9
|
417 called again after making room in the output buffer because there might be
|
alpar@9
|
418 more output pending.
|
alpar@9
|
419
|
alpar@9
|
420 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
|
alpar@9
|
421 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
|
alpar@9
|
422 output as possible to the output buffer. Z_BLOCK requests that inflate()
|
alpar@9
|
423 stop if and when it gets to the next deflate block boundary. When decoding
|
alpar@9
|
424 the zlib or gzip format, this will cause inflate() to return immediately
|
alpar@9
|
425 after the header and before the first block. When doing a raw inflate,
|
alpar@9
|
426 inflate() will go ahead and process the first block, and will return when it
|
alpar@9
|
427 gets to the end of that block, or when it runs out of data.
|
alpar@9
|
428
|
alpar@9
|
429 The Z_BLOCK option assists in appending to or combining deflate streams.
|
alpar@9
|
430 Also to assist in this, on return inflate() will set strm->data_type to the
|
alpar@9
|
431 number of unused bits in the last byte taken from strm->next_in, plus 64 if
|
alpar@9
|
432 inflate() is currently decoding the last block in the deflate stream, plus
|
alpar@9
|
433 128 if inflate() returned immediately after decoding an end-of-block code or
|
alpar@9
|
434 decoding the complete header up to just before the first byte of the deflate
|
alpar@9
|
435 stream. The end-of-block will not be indicated until all of the uncompressed
|
alpar@9
|
436 data from that block has been written to strm->next_out. The number of
|
alpar@9
|
437 unused bits may in general be greater than seven, except when bit 7 of
|
alpar@9
|
438 data_type is set, in which case the number of unused bits will be less than
|
alpar@9
|
439 eight. data_type is set as noted here every time inflate() returns for all
|
alpar@9
|
440 flush options, and so can be used to determine the amount of currently
|
alpar@9
|
441 consumed input in bits.
|
alpar@9
|
442
|
alpar@9
|
443 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
|
alpar@9
|
444 end of each deflate block header is reached, before any actual data in that
|
alpar@9
|
445 block is decoded. This allows the caller to determine the length of the
|
alpar@9
|
446 deflate block header for later use in random access within a deflate block.
|
alpar@9
|
447 256 is added to the value of strm->data_type when inflate() returns
|
alpar@9
|
448 immediately after reaching the end of the deflate block header.
|
alpar@9
|
449
|
alpar@9
|
450 inflate() should normally be called until it returns Z_STREAM_END or an
|
alpar@9
|
451 error. However if all decompression is to be performed in a single step (a
|
alpar@9
|
452 single call of inflate), the parameter flush should be set to Z_FINISH. In
|
alpar@9
|
453 this case all pending input is processed and all pending output is flushed;
|
alpar@9
|
454 avail_out must be large enough to hold all the uncompressed data. (The size
|
alpar@9
|
455 of the uncompressed data may have been saved by the compressor for this
|
alpar@9
|
456 purpose.) The next operation on this stream must be inflateEnd to deallocate
|
alpar@9
|
457 the decompression state. The use of Z_FINISH is never required, but can be
|
alpar@9
|
458 used to inform inflate that a faster approach may be used for the single
|
alpar@9
|
459 inflate() call.
|
alpar@9
|
460
|
alpar@9
|
461 In this implementation, inflate() always flushes as much output as
|
alpar@9
|
462 possible to the output buffer, and always uses the faster approach on the
|
alpar@9
|
463 first call. So the only effect of the flush parameter in this implementation
|
alpar@9
|
464 is on the return value of inflate(), as noted below, or when it returns early
|
alpar@9
|
465 because Z_BLOCK or Z_TREES is used.
|
alpar@9
|
466
|
alpar@9
|
467 If a preset dictionary is needed after this call (see inflateSetDictionary
|
alpar@9
|
468 below), inflate sets strm->adler to the adler32 checksum of the dictionary
|
alpar@9
|
469 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
|
alpar@9
|
470 strm->adler to the adler32 checksum of all output produced so far (that is,
|
alpar@9
|
471 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
|
alpar@9
|
472 below. At the end of the stream, inflate() checks that its computed adler32
|
alpar@9
|
473 checksum is equal to that saved by the compressor and returns Z_STREAM_END
|
alpar@9
|
474 only if the checksum is correct.
|
alpar@9
|
475
|
alpar@9
|
476 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
|
alpar@9
|
477 deflate data. The header type is detected automatically, if requested when
|
alpar@9
|
478 initializing with inflateInit2(). Any information contained in the gzip
|
alpar@9
|
479 header is not retained, so applications that need that information should
|
alpar@9
|
480 instead use raw inflate, see inflateInit2() below, or inflateBack() and
|
alpar@9
|
481 perform their own processing of the gzip header and trailer.
|
alpar@9
|
482
|
alpar@9
|
483 inflate() returns Z_OK if some progress has been made (more input processed
|
alpar@9
|
484 or more output produced), Z_STREAM_END if the end of the compressed data has
|
alpar@9
|
485 been reached and all uncompressed output has been produced, Z_NEED_DICT if a
|
alpar@9
|
486 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
|
alpar@9
|
487 corrupted (input stream not conforming to the zlib format or incorrect check
|
alpar@9
|
488 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
|
alpar@9
|
489 next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
|
alpar@9
|
490 Z_BUF_ERROR if no progress is possible or if there was not enough room in the
|
alpar@9
|
491 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
|
alpar@9
|
492 inflate() can be called again with more input and more output space to
|
alpar@9
|
493 continue decompressing. If Z_DATA_ERROR is returned, the application may
|
alpar@9
|
494 then call inflateSync() to look for a good compression block if a partial
|
alpar@9
|
495 recovery of the data is desired.
|
alpar@9
|
496 */
|
alpar@9
|
497
|
alpar@9
|
498
|
alpar@9
|
499 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
|
alpar@9
|
500 /*
|
alpar@9
|
501 All dynamically allocated data structures for this stream are freed.
|
alpar@9
|
502 This function discards any unprocessed input and does not flush any pending
|
alpar@9
|
503 output.
|
alpar@9
|
504
|
alpar@9
|
505 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
|
alpar@9
|
506 was inconsistent. In the error case, msg may be set but then points to a
|
alpar@9
|
507 static string (which must not be deallocated).
|
alpar@9
|
508 */
|
alpar@9
|
509
|
alpar@9
|
510
|
alpar@9
|
511 /* Advanced functions */
|
alpar@9
|
512
|
alpar@9
|
513 /*
|
alpar@9
|
514 The following functions are needed only in some special applications.
|
alpar@9
|
515 */
|
alpar@9
|
516
|
alpar@9
|
517 /*
|
alpar@9
|
518 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
|
alpar@9
|
519 int level,
|
alpar@9
|
520 int method,
|
alpar@9
|
521 int windowBits,
|
alpar@9
|
522 int memLevel,
|
alpar@9
|
523 int strategy));
|
alpar@9
|
524
|
alpar@9
|
525 This is another version of deflateInit with more compression options. The
|
alpar@9
|
526 fields next_in, zalloc, zfree and opaque must be initialized before by the
|
alpar@9
|
527 caller.
|
alpar@9
|
528
|
alpar@9
|
529 The method parameter is the compression method. It must be Z_DEFLATED in
|
alpar@9
|
530 this version of the library.
|
alpar@9
|
531
|
alpar@9
|
532 The windowBits parameter is the base two logarithm of the window size
|
alpar@9
|
533 (the size of the history buffer). It should be in the range 8..15 for this
|
alpar@9
|
534 version of the library. Larger values of this parameter result in better
|
alpar@9
|
535 compression at the expense of memory usage. The default value is 15 if
|
alpar@9
|
536 deflateInit is used instead.
|
alpar@9
|
537
|
alpar@9
|
538 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
|
alpar@9
|
539 determines the window size. deflate() will then generate raw deflate data
|
alpar@9
|
540 with no zlib header or trailer, and will not compute an adler32 check value.
|
alpar@9
|
541
|
alpar@9
|
542 windowBits can also be greater than 15 for optional gzip encoding. Add
|
alpar@9
|
543 16 to windowBits to write a simple gzip header and trailer around the
|
alpar@9
|
544 compressed data instead of a zlib wrapper. The gzip header will have no
|
alpar@9
|
545 file name, no extra data, no comment, no modification time (set to zero), no
|
alpar@9
|
546 header crc, and the operating system will be set to 255 (unknown). If a
|
alpar@9
|
547 gzip stream is being written, strm->adler is a crc32 instead of an adler32.
|
alpar@9
|
548
|
alpar@9
|
549 The memLevel parameter specifies how much memory should be allocated
|
alpar@9
|
550 for the internal compression state. memLevel=1 uses minimum memory but is
|
alpar@9
|
551 slow and reduces compression ratio; memLevel=9 uses maximum memory for
|
alpar@9
|
552 optimal speed. The default value is 8. See zconf.h for total memory usage
|
alpar@9
|
553 as a function of windowBits and memLevel.
|
alpar@9
|
554
|
alpar@9
|
555 The strategy parameter is used to tune the compression algorithm. Use the
|
alpar@9
|
556 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
|
alpar@9
|
557 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
|
alpar@9
|
558 string match), or Z_RLE to limit match distances to one (run-length
|
alpar@9
|
559 encoding). Filtered data consists mostly of small values with a somewhat
|
alpar@9
|
560 random distribution. In this case, the compression algorithm is tuned to
|
alpar@9
|
561 compress them better. The effect of Z_FILTERED is to force more Huffman
|
alpar@9
|
562 coding and less string matching; it is somewhat intermediate between
|
alpar@9
|
563 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
|
alpar@9
|
564 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
|
alpar@9
|
565 strategy parameter only affects the compression ratio but not the
|
alpar@9
|
566 correctness of the compressed output even if it is not set appropriately.
|
alpar@9
|
567 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
|
alpar@9
|
568 decoder for special applications.
|
alpar@9
|
569
|
alpar@9
|
570 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
alpar@9
|
571 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
|
alpar@9
|
572 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
|
alpar@9
|
573 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
|
alpar@9
|
574 set to null if there is no error message. deflateInit2 does not perform any
|
alpar@9
|
575 compression: this will be done by deflate().
|
alpar@9
|
576 */
|
alpar@9
|
577
|
alpar@9
|
578 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
|
alpar@9
|
579 const Bytef *dictionary,
|
alpar@9
|
580 uInt dictLength));
|
alpar@9
|
581 /*
|
alpar@9
|
582 Initializes the compression dictionary from the given byte sequence
|
alpar@9
|
583 without producing any compressed output. This function must be called
|
alpar@9
|
584 immediately after deflateInit, deflateInit2 or deflateReset, before any call
|
alpar@9
|
585 of deflate. The compressor and decompressor must use exactly the same
|
alpar@9
|
586 dictionary (see inflateSetDictionary).
|
alpar@9
|
587
|
alpar@9
|
588 The dictionary should consist of strings (byte sequences) that are likely
|
alpar@9
|
589 to be encountered later in the data to be compressed, with the most commonly
|
alpar@9
|
590 used strings preferably put towards the end of the dictionary. Using a
|
alpar@9
|
591 dictionary is most useful when the data to be compressed is short and can be
|
alpar@9
|
592 predicted with good accuracy; the data can then be compressed better than
|
alpar@9
|
593 with the default empty dictionary.
|
alpar@9
|
594
|
alpar@9
|
595 Depending on the size of the compression data structures selected by
|
alpar@9
|
596 deflateInit or deflateInit2, a part of the dictionary may in effect be
|
alpar@9
|
597 discarded, for example if the dictionary is larger than the window size
|
alpar@9
|
598 provided in deflateInit or deflateInit2. Thus the strings most likely to be
|
alpar@9
|
599 useful should be put at the end of the dictionary, not at the front. In
|
alpar@9
|
600 addition, the current implementation of deflate will use at most the window
|
alpar@9
|
601 size minus 262 bytes of the provided dictionary.
|
alpar@9
|
602
|
alpar@9
|
603 Upon return of this function, strm->adler is set to the adler32 value
|
alpar@9
|
604 of the dictionary; the decompressor may later use this value to determine
|
alpar@9
|
605 which dictionary has been used by the compressor. (The adler32 value
|
alpar@9
|
606 applies to the whole dictionary even if only a subset of the dictionary is
|
alpar@9
|
607 actually used by the compressor.) If a raw deflate was requested, then the
|
alpar@9
|
608 adler32 value is not computed and strm->adler is not set.
|
alpar@9
|
609
|
alpar@9
|
610 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
|
alpar@9
|
611 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
|
alpar@9
|
612 inconsistent (for example if deflate has already been called for this stream
|
alpar@9
|
613 or if the compression method is bsort). deflateSetDictionary does not
|
alpar@9
|
614 perform any compression: this will be done by deflate().
|
alpar@9
|
615 */
|
alpar@9
|
616
|
alpar@9
|
617 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
|
alpar@9
|
618 z_streamp source));
|
alpar@9
|
619 /*
|
alpar@9
|
620 Sets the destination stream as a complete copy of the source stream.
|
alpar@9
|
621
|
alpar@9
|
622 This function can be useful when several compression strategies will be
|
alpar@9
|
623 tried, for example when there are several ways of pre-processing the input
|
alpar@9
|
624 data with a filter. The streams that will be discarded should then be freed
|
alpar@9
|
625 by calling deflateEnd. Note that deflateCopy duplicates the internal
|
alpar@9
|
626 compression state which can be quite large, so this strategy is slow and can
|
alpar@9
|
627 consume lots of memory.
|
alpar@9
|
628
|
alpar@9
|
629 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
|
alpar@9
|
630 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
|
alpar@9
|
631 (such as zalloc being Z_NULL). msg is left unchanged in both source and
|
alpar@9
|
632 destination.
|
alpar@9
|
633 */
|
alpar@9
|
634
|
alpar@9
|
635 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
|
alpar@9
|
636 /*
|
alpar@9
|
637 This function is equivalent to deflateEnd followed by deflateInit,
|
alpar@9
|
638 but does not free and reallocate all the internal compression state. The
|
alpar@9
|
639 stream will keep the same compression level and any other attributes that
|
alpar@9
|
640 may have been set by deflateInit2.
|
alpar@9
|
641
|
alpar@9
|
642 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
643 stream state was inconsistent (such as zalloc or state being Z_NULL).
|
alpar@9
|
644 */
|
alpar@9
|
645
|
alpar@9
|
646 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
|
alpar@9
|
647 int level,
|
alpar@9
|
648 int strategy));
|
alpar@9
|
649 /*
|
alpar@9
|
650 Dynamically update the compression level and compression strategy. The
|
alpar@9
|
651 interpretation of level and strategy is as in deflateInit2. This can be
|
alpar@9
|
652 used to switch between compression and straight copy of the input data, or
|
alpar@9
|
653 to switch to a different kind of input data requiring a different strategy.
|
alpar@9
|
654 If the compression level is changed, the input available so far is
|
alpar@9
|
655 compressed with the old level (and may be flushed); the new level will take
|
alpar@9
|
656 effect only at the next call of deflate().
|
alpar@9
|
657
|
alpar@9
|
658 Before the call of deflateParams, the stream state must be set as for
|
alpar@9
|
659 a call of deflate(), since the currently available input may have to be
|
alpar@9
|
660 compressed and flushed. In particular, strm->avail_out must be non-zero.
|
alpar@9
|
661
|
alpar@9
|
662 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
|
alpar@9
|
663 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
|
alpar@9
|
664 strm->avail_out was zero.
|
alpar@9
|
665 */
|
alpar@9
|
666
|
alpar@9
|
667 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
|
alpar@9
|
668 int good_length,
|
alpar@9
|
669 int max_lazy,
|
alpar@9
|
670 int nice_length,
|
alpar@9
|
671 int max_chain));
|
alpar@9
|
672 /*
|
alpar@9
|
673 Fine tune deflate's internal compression parameters. This should only be
|
alpar@9
|
674 used by someone who understands the algorithm used by zlib's deflate for
|
alpar@9
|
675 searching for the best matching string, and even then only by the most
|
alpar@9
|
676 fanatic optimizer trying to squeeze out the last compressed bit for their
|
alpar@9
|
677 specific input data. Read the deflate.c source code for the meaning of the
|
alpar@9
|
678 max_lazy, good_length, nice_length, and max_chain parameters.
|
alpar@9
|
679
|
alpar@9
|
680 deflateTune() can be called after deflateInit() or deflateInit2(), and
|
alpar@9
|
681 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
|
alpar@9
|
682 */
|
alpar@9
|
683
|
alpar@9
|
684 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
|
alpar@9
|
685 uLong sourceLen));
|
alpar@9
|
686 /*
|
alpar@9
|
687 deflateBound() returns an upper bound on the compressed size after
|
alpar@9
|
688 deflation of sourceLen bytes. It must be called after deflateInit() or
|
alpar@9
|
689 deflateInit2(), and after deflateSetHeader(), if used. This would be used
|
alpar@9
|
690 to allocate an output buffer for deflation in a single pass, and so would be
|
alpar@9
|
691 called before deflate().
|
alpar@9
|
692 */
|
alpar@9
|
693
|
alpar@9
|
694 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
|
alpar@9
|
695 int bits,
|
alpar@9
|
696 int value));
|
alpar@9
|
697 /*
|
alpar@9
|
698 deflatePrime() inserts bits in the deflate output stream. The intent
|
alpar@9
|
699 is that this function is used to start off the deflate output with the bits
|
alpar@9
|
700 leftover from a previous deflate stream when appending to it. As such, this
|
alpar@9
|
701 function can only be used for raw deflate, and must be used before the first
|
alpar@9
|
702 deflate() call after a deflateInit2() or deflateReset(). bits must be less
|
alpar@9
|
703 than or equal to 16, and that many of the least significant bits of value
|
alpar@9
|
704 will be inserted in the output.
|
alpar@9
|
705
|
alpar@9
|
706 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
707 stream state was inconsistent.
|
alpar@9
|
708 */
|
alpar@9
|
709
|
alpar@9
|
710 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
|
alpar@9
|
711 gz_headerp head));
|
alpar@9
|
712 /*
|
alpar@9
|
713 deflateSetHeader() provides gzip header information for when a gzip
|
alpar@9
|
714 stream is requested by deflateInit2(). deflateSetHeader() may be called
|
alpar@9
|
715 after deflateInit2() or deflateReset() and before the first call of
|
alpar@9
|
716 deflate(). The text, time, os, extra field, name, and comment information
|
alpar@9
|
717 in the provided gz_header structure are written to the gzip header (xflag is
|
alpar@9
|
718 ignored -- the extra flags are set according to the compression level). The
|
alpar@9
|
719 caller must assure that, if not Z_NULL, name and comment are terminated with
|
alpar@9
|
720 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
|
alpar@9
|
721 available there. If hcrc is true, a gzip header crc is included. Note that
|
alpar@9
|
722 the current versions of the command-line version of gzip (up through version
|
alpar@9
|
723 1.3.x) do not support header crc's, and will report that it is a "multi-part
|
alpar@9
|
724 gzip file" and give up.
|
alpar@9
|
725
|
alpar@9
|
726 If deflateSetHeader is not used, the default gzip header has text false,
|
alpar@9
|
727 the time set to zero, and os set to 255, with no extra, name, or comment
|
alpar@9
|
728 fields. The gzip header is returned to the default state by deflateReset().
|
alpar@9
|
729
|
alpar@9
|
730 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
731 stream state was inconsistent.
|
alpar@9
|
732 */
|
alpar@9
|
733
|
alpar@9
|
734 /*
|
alpar@9
|
735 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
|
alpar@9
|
736 int windowBits));
|
alpar@9
|
737
|
alpar@9
|
738 This is another version of inflateInit with an extra parameter. The
|
alpar@9
|
739 fields next_in, avail_in, zalloc, zfree and opaque must be initialized
|
alpar@9
|
740 before by the caller.
|
alpar@9
|
741
|
alpar@9
|
742 The windowBits parameter is the base two logarithm of the maximum window
|
alpar@9
|
743 size (the size of the history buffer). It should be in the range 8..15 for
|
alpar@9
|
744 this version of the library. The default value is 15 if inflateInit is used
|
alpar@9
|
745 instead. windowBits must be greater than or equal to the windowBits value
|
alpar@9
|
746 provided to deflateInit2() while compressing, or it must be equal to 15 if
|
alpar@9
|
747 deflateInit2() was not used. If a compressed stream with a larger window
|
alpar@9
|
748 size is given as input, inflate() will return with the error code
|
alpar@9
|
749 Z_DATA_ERROR instead of trying to allocate a larger window.
|
alpar@9
|
750
|
alpar@9
|
751 windowBits can also be zero to request that inflate use the window size in
|
alpar@9
|
752 the zlib header of the compressed stream.
|
alpar@9
|
753
|
alpar@9
|
754 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
|
alpar@9
|
755 determines the window size. inflate() will then process raw deflate data,
|
alpar@9
|
756 not looking for a zlib or gzip header, not generating a check value, and not
|
alpar@9
|
757 looking for any check values for comparison at the end of the stream. This
|
alpar@9
|
758 is for use with other formats that use the deflate compressed data format
|
alpar@9
|
759 such as zip. Those formats provide their own check values. If a custom
|
alpar@9
|
760 format is developed using the raw deflate format for compressed data, it is
|
alpar@9
|
761 recommended that a check value such as an adler32 or a crc32 be applied to
|
alpar@9
|
762 the uncompressed data as is done in the zlib, gzip, and zip formats. For
|
alpar@9
|
763 most applications, the zlib format should be used as is. Note that comments
|
alpar@9
|
764 above on the use in deflateInit2() applies to the magnitude of windowBits.
|
alpar@9
|
765
|
alpar@9
|
766 windowBits can also be greater than 15 for optional gzip decoding. Add
|
alpar@9
|
767 32 to windowBits to enable zlib and gzip decoding with automatic header
|
alpar@9
|
768 detection, or add 16 to decode only the gzip format (the zlib format will
|
alpar@9
|
769 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
|
alpar@9
|
770 crc32 instead of an adler32.
|
alpar@9
|
771
|
alpar@9
|
772 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
alpar@9
|
773 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
|
alpar@9
|
774 version assumed by the caller, or Z_STREAM_ERROR if the parameters are
|
alpar@9
|
775 invalid, such as a null pointer to the structure. msg is set to null if
|
alpar@9
|
776 there is no error message. inflateInit2 does not perform any decompression
|
alpar@9
|
777 apart from possibly reading the zlib header if present: actual decompression
|
alpar@9
|
778 will be done by inflate(). (So next_in and avail_in may be modified, but
|
alpar@9
|
779 next_out and avail_out are unused and unchanged.) The current implementation
|
alpar@9
|
780 of inflateInit2() does not process any header information -- that is
|
alpar@9
|
781 deferred until inflate() is called.
|
alpar@9
|
782 */
|
alpar@9
|
783
|
alpar@9
|
784 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
|
alpar@9
|
785 const Bytef *dictionary,
|
alpar@9
|
786 uInt dictLength));
|
alpar@9
|
787 /*
|
alpar@9
|
788 Initializes the decompression dictionary from the given uncompressed byte
|
alpar@9
|
789 sequence. This function must be called immediately after a call of inflate,
|
alpar@9
|
790 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
|
alpar@9
|
791 can be determined from the adler32 value returned by that call of inflate.
|
alpar@9
|
792 The compressor and decompressor must use exactly the same dictionary (see
|
alpar@9
|
793 deflateSetDictionary). For raw inflate, this function can be called
|
alpar@9
|
794 immediately after inflateInit2() or inflateReset() and before any call of
|
alpar@9
|
795 inflate() to set the dictionary. The application must insure that the
|
alpar@9
|
796 dictionary that was used for compression is provided.
|
alpar@9
|
797
|
alpar@9
|
798 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
|
alpar@9
|
799 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
|
alpar@9
|
800 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
|
alpar@9
|
801 expected one (incorrect adler32 value). inflateSetDictionary does not
|
alpar@9
|
802 perform any decompression: this will be done by subsequent calls of
|
alpar@9
|
803 inflate().
|
alpar@9
|
804 */
|
alpar@9
|
805
|
alpar@9
|
806 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
|
alpar@9
|
807 /*
|
alpar@9
|
808 Skips invalid compressed data until a full flush point (see above the
|
alpar@9
|
809 description of deflate with Z_FULL_FLUSH) can be found, or until all
|
alpar@9
|
810 available input is skipped. No output is provided.
|
alpar@9
|
811
|
alpar@9
|
812 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
|
alpar@9
|
813 if no more input was provided, Z_DATA_ERROR if no flush point has been
|
alpar@9
|
814 found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the
|
alpar@9
|
815 success case, the application may save the current current value of total_in
|
alpar@9
|
816 which indicates where valid compressed data was found. In the error case,
|
alpar@9
|
817 the application may repeatedly call inflateSync, providing more input each
|
alpar@9
|
818 time, until success or end of the input data.
|
alpar@9
|
819 */
|
alpar@9
|
820
|
alpar@9
|
821 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
|
alpar@9
|
822 z_streamp source));
|
alpar@9
|
823 /*
|
alpar@9
|
824 Sets the destination stream as a complete copy of the source stream.
|
alpar@9
|
825
|
alpar@9
|
826 This function can be useful when randomly accessing a large stream. The
|
alpar@9
|
827 first pass through the stream can periodically record the inflate state,
|
alpar@9
|
828 allowing restarting inflate at those points when randomly accessing the
|
alpar@9
|
829 stream.
|
alpar@9
|
830
|
alpar@9
|
831 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
|
alpar@9
|
832 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
|
alpar@9
|
833 (such as zalloc being Z_NULL). msg is left unchanged in both source and
|
alpar@9
|
834 destination.
|
alpar@9
|
835 */
|
alpar@9
|
836
|
alpar@9
|
837 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
|
alpar@9
|
838 /*
|
alpar@9
|
839 This function is equivalent to inflateEnd followed by inflateInit,
|
alpar@9
|
840 but does not free and reallocate all the internal decompression state. The
|
alpar@9
|
841 stream will keep attributes that may have been set by inflateInit2.
|
alpar@9
|
842
|
alpar@9
|
843 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
844 stream state was inconsistent (such as zalloc or state being Z_NULL).
|
alpar@9
|
845 */
|
alpar@9
|
846
|
alpar@9
|
847 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
|
alpar@9
|
848 int windowBits));
|
alpar@9
|
849 /*
|
alpar@9
|
850 This function is the same as inflateReset, but it also permits changing
|
alpar@9
|
851 the wrap and window size requests. The windowBits parameter is interpreted
|
alpar@9
|
852 the same as it is for inflateInit2.
|
alpar@9
|
853
|
alpar@9
|
854 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
855 stream state was inconsistent (such as zalloc or state being Z_NULL), or if
|
alpar@9
|
856 the windowBits parameter is invalid.
|
alpar@9
|
857 */
|
alpar@9
|
858
|
alpar@9
|
859 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
|
alpar@9
|
860 int bits,
|
alpar@9
|
861 int value));
|
alpar@9
|
862 /*
|
alpar@9
|
863 This function inserts bits in the inflate input stream. The intent is
|
alpar@9
|
864 that this function is used to start inflating at a bit position in the
|
alpar@9
|
865 middle of a byte. The provided bits will be used before any bytes are used
|
alpar@9
|
866 from next_in. This function should only be used with raw inflate, and
|
alpar@9
|
867 should be used before the first inflate() call after inflateInit2() or
|
alpar@9
|
868 inflateReset(). bits must be less than or equal to 16, and that many of the
|
alpar@9
|
869 least significant bits of value will be inserted in the input.
|
alpar@9
|
870
|
alpar@9
|
871 If bits is negative, then the input stream bit buffer is emptied. Then
|
alpar@9
|
872 inflatePrime() can be called again to put bits in the buffer. This is used
|
alpar@9
|
873 to clear out bits leftover after feeding inflate a block description prior
|
alpar@9
|
874 to feeding inflate codes.
|
alpar@9
|
875
|
alpar@9
|
876 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
877 stream state was inconsistent.
|
alpar@9
|
878 */
|
alpar@9
|
879
|
alpar@9
|
880 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
|
alpar@9
|
881 /*
|
alpar@9
|
882 This function returns two values, one in the lower 16 bits of the return
|
alpar@9
|
883 value, and the other in the remaining upper bits, obtained by shifting the
|
alpar@9
|
884 return value down 16 bits. If the upper value is -1 and the lower value is
|
alpar@9
|
885 zero, then inflate() is currently decoding information outside of a block.
|
alpar@9
|
886 If the upper value is -1 and the lower value is non-zero, then inflate is in
|
alpar@9
|
887 the middle of a stored block, with the lower value equaling the number of
|
alpar@9
|
888 bytes from the input remaining to copy. If the upper value is not -1, then
|
alpar@9
|
889 it is the number of bits back from the current bit position in the input of
|
alpar@9
|
890 the code (literal or length/distance pair) currently being processed. In
|
alpar@9
|
891 that case the lower value is the number of bytes already emitted for that
|
alpar@9
|
892 code.
|
alpar@9
|
893
|
alpar@9
|
894 A code is being processed if inflate is waiting for more input to complete
|
alpar@9
|
895 decoding of the code, or if it has completed decoding but is waiting for
|
alpar@9
|
896 more output space to write the literal or match data.
|
alpar@9
|
897
|
alpar@9
|
898 inflateMark() is used to mark locations in the input data for random
|
alpar@9
|
899 access, which may be at bit positions, and to note those cases where the
|
alpar@9
|
900 output of a code may span boundaries of random access blocks. The current
|
alpar@9
|
901 location in the input stream can be determined from avail_in and data_type
|
alpar@9
|
902 as noted in the description for the Z_BLOCK flush parameter for inflate.
|
alpar@9
|
903
|
alpar@9
|
904 inflateMark returns the value noted above or -1 << 16 if the provided
|
alpar@9
|
905 source stream state was inconsistent.
|
alpar@9
|
906 */
|
alpar@9
|
907
|
alpar@9
|
908 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
|
alpar@9
|
909 gz_headerp head));
|
alpar@9
|
910 /*
|
alpar@9
|
911 inflateGetHeader() requests that gzip header information be stored in the
|
alpar@9
|
912 provided gz_header structure. inflateGetHeader() may be called after
|
alpar@9
|
913 inflateInit2() or inflateReset(), and before the first call of inflate().
|
alpar@9
|
914 As inflate() processes the gzip stream, head->done is zero until the header
|
alpar@9
|
915 is completed, at which time head->done is set to one. If a zlib stream is
|
alpar@9
|
916 being decoded, then head->done is set to -1 to indicate that there will be
|
alpar@9
|
917 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
|
alpar@9
|
918 used to force inflate() to return immediately after header processing is
|
alpar@9
|
919 complete and before any actual data is decompressed.
|
alpar@9
|
920
|
alpar@9
|
921 The text, time, xflags, and os fields are filled in with the gzip header
|
alpar@9
|
922 contents. hcrc is set to true if there is a header CRC. (The header CRC
|
alpar@9
|
923 was valid if done is set to one.) If extra is not Z_NULL, then extra_max
|
alpar@9
|
924 contains the maximum number of bytes to write to extra. Once done is true,
|
alpar@9
|
925 extra_len contains the actual extra field length, and extra contains the
|
alpar@9
|
926 extra field, or that field truncated if extra_max is less than extra_len.
|
alpar@9
|
927 If name is not Z_NULL, then up to name_max characters are written there,
|
alpar@9
|
928 terminated with a zero unless the length is greater than name_max. If
|
alpar@9
|
929 comment is not Z_NULL, then up to comm_max characters are written there,
|
alpar@9
|
930 terminated with a zero unless the length is greater than comm_max. When any
|
alpar@9
|
931 of extra, name, or comment are not Z_NULL and the respective field is not
|
alpar@9
|
932 present in the header, then that field is set to Z_NULL to signal its
|
alpar@9
|
933 absence. This allows the use of deflateSetHeader() with the returned
|
alpar@9
|
934 structure to duplicate the header. However if those fields are set to
|
alpar@9
|
935 allocated memory, then the application will need to save those pointers
|
alpar@9
|
936 elsewhere so that they can be eventually freed.
|
alpar@9
|
937
|
alpar@9
|
938 If inflateGetHeader is not used, then the header information is simply
|
alpar@9
|
939 discarded. The header is always checked for validity, including the header
|
alpar@9
|
940 CRC if present. inflateReset() will reset the process to discard the header
|
alpar@9
|
941 information. The application would need to call inflateGetHeader() again to
|
alpar@9
|
942 retrieve the header from the next gzip stream.
|
alpar@9
|
943
|
alpar@9
|
944 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
|
alpar@9
|
945 stream state was inconsistent.
|
alpar@9
|
946 */
|
alpar@9
|
947
|
alpar@9
|
948 /*
|
alpar@9
|
949 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
|
alpar@9
|
950 unsigned char FAR *window));
|
alpar@9
|
951
|
alpar@9
|
952 Initialize the internal stream state for decompression using inflateBack()
|
alpar@9
|
953 calls. The fields zalloc, zfree and opaque in strm must be initialized
|
alpar@9
|
954 before the call. If zalloc and zfree are Z_NULL, then the default library-
|
alpar@9
|
955 derived memory allocation routines are used. windowBits is the base two
|
alpar@9
|
956 logarithm of the window size, in the range 8..15. window is a caller
|
alpar@9
|
957 supplied buffer of that size. Except for special applications where it is
|
alpar@9
|
958 assured that deflate was used with small window sizes, windowBits must be 15
|
alpar@9
|
959 and a 32K byte window must be supplied to be able to decompress general
|
alpar@9
|
960 deflate streams.
|
alpar@9
|
961
|
alpar@9
|
962 See inflateBack() for the usage of these routines.
|
alpar@9
|
963
|
alpar@9
|
964 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
|
alpar@9
|
965 the paramaters are invalid, Z_MEM_ERROR if the internal state could not be
|
alpar@9
|
966 allocated, or Z_VERSION_ERROR if the version of the library does not match
|
alpar@9
|
967 the version of the header file.
|
alpar@9
|
968 */
|
alpar@9
|
969
|
alpar@9
|
970 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
|
alpar@9
|
971 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
|
alpar@9
|
972
|
alpar@9
|
973 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
|
alpar@9
|
974 in_func in, void FAR *in_desc,
|
alpar@9
|
975 out_func out, void FAR *out_desc));
|
alpar@9
|
976 /*
|
alpar@9
|
977 inflateBack() does a raw inflate with a single call using a call-back
|
alpar@9
|
978 interface for input and output. This is more efficient than inflate() for
|
alpar@9
|
979 file i/o applications in that it avoids copying between the output and the
|
alpar@9
|
980 sliding window by simply making the window itself the output buffer. This
|
alpar@9
|
981 function trusts the application to not change the output buffer passed by
|
alpar@9
|
982 the output function, at least until inflateBack() returns.
|
alpar@9
|
983
|
alpar@9
|
984 inflateBackInit() must be called first to allocate the internal state
|
alpar@9
|
985 and to initialize the state with the user-provided window buffer.
|
alpar@9
|
986 inflateBack() may then be used multiple times to inflate a complete, raw
|
alpar@9
|
987 deflate stream with each call. inflateBackEnd() is then called to free the
|
alpar@9
|
988 allocated state.
|
alpar@9
|
989
|
alpar@9
|
990 A raw deflate stream is one with no zlib or gzip header or trailer.
|
alpar@9
|
991 This routine would normally be used in a utility that reads zip or gzip
|
alpar@9
|
992 files and writes out uncompressed files. The utility would decode the
|
alpar@9
|
993 header and process the trailer on its own, hence this routine expects only
|
alpar@9
|
994 the raw deflate stream to decompress. This is different from the normal
|
alpar@9
|
995 behavior of inflate(), which expects either a zlib or gzip header and
|
alpar@9
|
996 trailer around the deflate stream.
|
alpar@9
|
997
|
alpar@9
|
998 inflateBack() uses two subroutines supplied by the caller that are then
|
alpar@9
|
999 called by inflateBack() for input and output. inflateBack() calls those
|
alpar@9
|
1000 routines until it reads a complete deflate stream and writes out all of the
|
alpar@9
|
1001 uncompressed data, or until it encounters an error. The function's
|
alpar@9
|
1002 parameters and return types are defined above in the in_func and out_func
|
alpar@9
|
1003 typedefs. inflateBack() will call in(in_desc, &buf) which should return the
|
alpar@9
|
1004 number of bytes of provided input, and a pointer to that input in buf. If
|
alpar@9
|
1005 there is no input available, in() must return zero--buf is ignored in that
|
alpar@9
|
1006 case--and inflateBack() will return a buffer error. inflateBack() will call
|
alpar@9
|
1007 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
|
alpar@9
|
1008 should return zero on success, or non-zero on failure. If out() returns
|
alpar@9
|
1009 non-zero, inflateBack() will return with an error. Neither in() nor out()
|
alpar@9
|
1010 are permitted to change the contents of the window provided to
|
alpar@9
|
1011 inflateBackInit(), which is also the buffer that out() uses to write from.
|
alpar@9
|
1012 The length written by out() will be at most the window size. Any non-zero
|
alpar@9
|
1013 amount of input may be provided by in().
|
alpar@9
|
1014
|
alpar@9
|
1015 For convenience, inflateBack() can be provided input on the first call by
|
alpar@9
|
1016 setting strm->next_in and strm->avail_in. If that input is exhausted, then
|
alpar@9
|
1017 in() will be called. Therefore strm->next_in must be initialized before
|
alpar@9
|
1018 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
|
alpar@9
|
1019 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
|
alpar@9
|
1020 must also be initialized, and then if strm->avail_in is not zero, input will
|
alpar@9
|
1021 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
|
alpar@9
|
1022
|
alpar@9
|
1023 The in_desc and out_desc parameters of inflateBack() is passed as the
|
alpar@9
|
1024 first parameter of in() and out() respectively when they are called. These
|
alpar@9
|
1025 descriptors can be optionally used to pass any information that the caller-
|
alpar@9
|
1026 supplied in() and out() functions need to do their job.
|
alpar@9
|
1027
|
alpar@9
|
1028 On return, inflateBack() will set strm->next_in and strm->avail_in to
|
alpar@9
|
1029 pass back any unused input that was provided by the last in() call. The
|
alpar@9
|
1030 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
|
alpar@9
|
1031 if in() or out() returned an error, Z_DATA_ERROR if there was a format error
|
alpar@9
|
1032 in the deflate stream (in which case strm->msg is set to indicate the nature
|
alpar@9
|
1033 of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
|
alpar@9
|
1034 In the case of Z_BUF_ERROR, an input or output error can be distinguished
|
alpar@9
|
1035 using strm->next_in which will be Z_NULL only if in() returned an error. If
|
alpar@9
|
1036 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
|
alpar@9
|
1037 non-zero. (in() will always be called before out(), so strm->next_in is
|
alpar@9
|
1038 assured to be defined if out() returns non-zero.) Note that inflateBack()
|
alpar@9
|
1039 cannot return Z_OK.
|
alpar@9
|
1040 */
|
alpar@9
|
1041
|
alpar@9
|
1042 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
|
alpar@9
|
1043 /*
|
alpar@9
|
1044 All memory allocated by inflateBackInit() is freed.
|
alpar@9
|
1045
|
alpar@9
|
1046 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
|
alpar@9
|
1047 state was inconsistent.
|
alpar@9
|
1048 */
|
alpar@9
|
1049
|
alpar@9
|
1050 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
|
alpar@9
|
1051 /* Return flags indicating compile-time options.
|
alpar@9
|
1052
|
alpar@9
|
1053 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
|
alpar@9
|
1054 1.0: size of uInt
|
alpar@9
|
1055 3.2: size of uLong
|
alpar@9
|
1056 5.4: size of voidpf (pointer)
|
alpar@9
|
1057 7.6: size of z_off_t
|
alpar@9
|
1058
|
alpar@9
|
1059 Compiler, assembler, and debug options:
|
alpar@9
|
1060 8: DEBUG
|
alpar@9
|
1061 9: ASMV or ASMINF -- use ASM code
|
alpar@9
|
1062 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
|
alpar@9
|
1063 11: 0 (reserved)
|
alpar@9
|
1064
|
alpar@9
|
1065 One-time table building (smaller code, but not thread-safe if true):
|
alpar@9
|
1066 12: BUILDFIXED -- build static block decoding tables when needed
|
alpar@9
|
1067 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
|
alpar@9
|
1068 14,15: 0 (reserved)
|
alpar@9
|
1069
|
alpar@9
|
1070 Library content (indicates missing functionality):
|
alpar@9
|
1071 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
|
alpar@9
|
1072 deflate code when not needed)
|
alpar@9
|
1073 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
|
alpar@9
|
1074 and decode gzip streams (to avoid linking crc code)
|
alpar@9
|
1075 18-19: 0 (reserved)
|
alpar@9
|
1076
|
alpar@9
|
1077 Operation variations (changes in library functionality):
|
alpar@9
|
1078 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
|
alpar@9
|
1079 21: FASTEST -- deflate algorithm with only one, lowest compression level
|
alpar@9
|
1080 22,23: 0 (reserved)
|
alpar@9
|
1081
|
alpar@9
|
1082 The sprintf variant used by gzprintf (zero is best):
|
alpar@9
|
1083 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
|
alpar@9
|
1084 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
|
alpar@9
|
1085 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
|
alpar@9
|
1086
|
alpar@9
|
1087 Remainder:
|
alpar@9
|
1088 27-31: 0 (reserved)
|
alpar@9
|
1089 */
|
alpar@9
|
1090
|
alpar@9
|
1091
|
alpar@9
|
1092 /* utility functions */
|
alpar@9
|
1093
|
alpar@9
|
1094 /*
|
alpar@9
|
1095 The following utility functions are implemented on top of the basic
|
alpar@9
|
1096 stream-oriented functions. To simplify the interface, some default options
|
alpar@9
|
1097 are assumed (compression level and memory usage, standard memory allocation
|
alpar@9
|
1098 functions). The source code of these utility functions can be modified if
|
alpar@9
|
1099 you need special options.
|
alpar@9
|
1100 */
|
alpar@9
|
1101
|
alpar@9
|
1102 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
|
alpar@9
|
1103 const Bytef *source, uLong sourceLen));
|
alpar@9
|
1104 /*
|
alpar@9
|
1105 Compresses the source buffer into the destination buffer. sourceLen is
|
alpar@9
|
1106 the byte length of the source buffer. Upon entry, destLen is the total size
|
alpar@9
|
1107 of the destination buffer, which must be at least the value returned by
|
alpar@9
|
1108 compressBound(sourceLen). Upon exit, destLen is the actual size of the
|
alpar@9
|
1109 compressed buffer.
|
alpar@9
|
1110
|
alpar@9
|
1111 compress returns Z_OK if success, Z_MEM_ERROR if there was not
|
alpar@9
|
1112 enough memory, Z_BUF_ERROR if there was not enough room in the output
|
alpar@9
|
1113 buffer.
|
alpar@9
|
1114 */
|
alpar@9
|
1115
|
alpar@9
|
1116 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
|
alpar@9
|
1117 const Bytef *source, uLong sourceLen,
|
alpar@9
|
1118 int level));
|
alpar@9
|
1119 /*
|
alpar@9
|
1120 Compresses the source buffer into the destination buffer. The level
|
alpar@9
|
1121 parameter has the same meaning as in deflateInit. sourceLen is the byte
|
alpar@9
|
1122 length of the source buffer. Upon entry, destLen is the total size of the
|
alpar@9
|
1123 destination buffer, which must be at least the value returned by
|
alpar@9
|
1124 compressBound(sourceLen). Upon exit, destLen is the actual size of the
|
alpar@9
|
1125 compressed buffer.
|
alpar@9
|
1126
|
alpar@9
|
1127 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
|
alpar@9
|
1128 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
|
alpar@9
|
1129 Z_STREAM_ERROR if the level parameter is invalid.
|
alpar@9
|
1130 */
|
alpar@9
|
1131
|
alpar@9
|
1132 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
|
alpar@9
|
1133 /*
|
alpar@9
|
1134 compressBound() returns an upper bound on the compressed size after
|
alpar@9
|
1135 compress() or compress2() on sourceLen bytes. It would be used before a
|
alpar@9
|
1136 compress() or compress2() call to allocate the destination buffer.
|
alpar@9
|
1137 */
|
alpar@9
|
1138
|
alpar@9
|
1139 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
|
alpar@9
|
1140 const Bytef *source, uLong sourceLen));
|
alpar@9
|
1141 /*
|
alpar@9
|
1142 Decompresses the source buffer into the destination buffer. sourceLen is
|
alpar@9
|
1143 the byte length of the source buffer. Upon entry, destLen is the total size
|
alpar@9
|
1144 of the destination buffer, which must be large enough to hold the entire
|
alpar@9
|
1145 uncompressed data. (The size of the uncompressed data must have been saved
|
alpar@9
|
1146 previously by the compressor and transmitted to the decompressor by some
|
alpar@9
|
1147 mechanism outside the scope of this compression library.) Upon exit, destLen
|
alpar@9
|
1148 is the actual size of the uncompressed buffer.
|
alpar@9
|
1149
|
alpar@9
|
1150 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
|
alpar@9
|
1151 enough memory, Z_BUF_ERROR if there was not enough room in the output
|
alpar@9
|
1152 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
|
alpar@9
|
1153 */
|
alpar@9
|
1154
|
alpar@9
|
1155
|
alpar@9
|
1156 /* gzip file access functions */
|
alpar@9
|
1157
|
alpar@9
|
1158 /*
|
alpar@9
|
1159 This library supports reading and writing files in gzip (.gz) format with
|
alpar@9
|
1160 an interface similar to that of stdio, using the functions that start with
|
alpar@9
|
1161 "gz". The gzip format is different from the zlib format. gzip is a gzip
|
alpar@9
|
1162 wrapper, documented in RFC 1952, wrapped around a deflate stream.
|
alpar@9
|
1163 */
|
alpar@9
|
1164
|
alpar@9
|
1165 typedef voidp gzFile; /* opaque gzip file descriptor */
|
alpar@9
|
1166
|
alpar@9
|
1167 /*
|
alpar@9
|
1168 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
|
alpar@9
|
1169
|
alpar@9
|
1170 Opens a gzip (.gz) file for reading or writing. The mode parameter is as
|
alpar@9
|
1171 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
|
alpar@9
|
1172 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
|
alpar@9
|
1173 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
|
alpar@9
|
1174 for fixed code compression as in "wb9F". (See the description of
|
alpar@9
|
1175 deflateInit2 for more information about the strategy parameter.) Also "a"
|
alpar@9
|
1176 can be used instead of "w" to request that the gzip stream that will be
|
alpar@9
|
1177 written be appended to the file. "+" will result in an error, since reading
|
alpar@9
|
1178 and writing to the same gzip file is not supported.
|
alpar@9
|
1179
|
alpar@9
|
1180 gzopen can be used to read a file which is not in gzip format; in this
|
alpar@9
|
1181 case gzread will directly read from the file without decompression.
|
alpar@9
|
1182
|
alpar@9
|
1183 gzopen returns NULL if the file could not be opened, if there was
|
alpar@9
|
1184 insufficient memory to allocate the gzFile state, or if an invalid mode was
|
alpar@9
|
1185 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
|
alpar@9
|
1186 errno can be checked to determine if the reason gzopen failed was that the
|
alpar@9
|
1187 file could not be opened.
|
alpar@9
|
1188 */
|
alpar@9
|
1189
|
alpar@9
|
1190 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
|
alpar@9
|
1191 /*
|
alpar@9
|
1192 gzdopen associates a gzFile with the file descriptor fd. File descriptors
|
alpar@9
|
1193 are obtained from calls like open, dup, creat, pipe or fileno (if the file
|
alpar@9
|
1194 has been previously opened with fopen). The mode parameter is as in gzopen.
|
alpar@9
|
1195
|
alpar@9
|
1196 The next call of gzclose on the returned gzFile will also close the file
|
alpar@9
|
1197 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
|
alpar@9
|
1198 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
|
alpar@9
|
1199 mode);. The duplicated descriptor should be saved to avoid a leak, since
|
alpar@9
|
1200 gzdopen does not close fd if it fails.
|
alpar@9
|
1201
|
alpar@9
|
1202 gzdopen returns NULL if there was insufficient memory to allocate the
|
alpar@9
|
1203 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
|
alpar@9
|
1204 provided, or '+' was provided), or if fd is -1. The file descriptor is not
|
alpar@9
|
1205 used until the next gz* read, write, seek, or close operation, so gzdopen
|
alpar@9
|
1206 will not detect if fd is invalid (unless fd is -1).
|
alpar@9
|
1207 */
|
alpar@9
|
1208
|
alpar@9
|
1209 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
|
alpar@9
|
1210 /*
|
alpar@9
|
1211 Set the internal buffer size used by this library's functions. The
|
alpar@9
|
1212 default buffer size is 8192 bytes. This function must be called after
|
alpar@9
|
1213 gzopen() or gzdopen(), and before any other calls that read or write the
|
alpar@9
|
1214 file. The buffer memory allocation is always deferred to the first read or
|
alpar@9
|
1215 write. Two buffers are allocated, either both of the specified size when
|
alpar@9
|
1216 writing, or one of the specified size and the other twice that size when
|
alpar@9
|
1217 reading. A larger buffer size of, for example, 64K or 128K bytes will
|
alpar@9
|
1218 noticeably increase the speed of decompression (reading).
|
alpar@9
|
1219
|
alpar@9
|
1220 The new buffer size also affects the maximum length for gzprintf().
|
alpar@9
|
1221
|
alpar@9
|
1222 gzbuffer() returns 0 on success, or -1 on failure, such as being called
|
alpar@9
|
1223 too late.
|
alpar@9
|
1224 */
|
alpar@9
|
1225
|
alpar@9
|
1226 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
|
alpar@9
|
1227 /*
|
alpar@9
|
1228 Dynamically update the compression level or strategy. See the description
|
alpar@9
|
1229 of deflateInit2 for the meaning of these parameters.
|
alpar@9
|
1230
|
alpar@9
|
1231 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
|
alpar@9
|
1232 opened for writing.
|
alpar@9
|
1233 */
|
alpar@9
|
1234
|
alpar@9
|
1235 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
|
alpar@9
|
1236 /*
|
alpar@9
|
1237 Reads the given number of uncompressed bytes from the compressed file. If
|
alpar@9
|
1238 the input file was not in gzip format, gzread copies the given number of
|
alpar@9
|
1239 bytes into the buffer.
|
alpar@9
|
1240
|
alpar@9
|
1241 After reaching the end of a gzip stream in the input, gzread will continue
|
alpar@9
|
1242 to read, looking for another gzip stream, or failing that, reading the rest
|
alpar@9
|
1243 of the input file directly without decompression. The entire input file
|
alpar@9
|
1244 will be read if gzread is called until it returns less than the requested
|
alpar@9
|
1245 len.
|
alpar@9
|
1246
|
alpar@9
|
1247 gzread returns the number of uncompressed bytes actually read, less than
|
alpar@9
|
1248 len for end of file, or -1 for error.
|
alpar@9
|
1249 */
|
alpar@9
|
1250
|
alpar@9
|
1251 ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
|
alpar@9
|
1252 voidpc buf, unsigned len));
|
alpar@9
|
1253 /*
|
alpar@9
|
1254 Writes the given number of uncompressed bytes into the compressed file.
|
alpar@9
|
1255 gzwrite returns the number of uncompressed bytes written or 0 in case of
|
alpar@9
|
1256 error.
|
alpar@9
|
1257 */
|
alpar@9
|
1258
|
alpar@9
|
1259 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
|
alpar@9
|
1260 /*
|
alpar@9
|
1261 Converts, formats, and writes the arguments to the compressed file under
|
alpar@9
|
1262 control of the format string, as in fprintf. gzprintf returns the number of
|
alpar@9
|
1263 uncompressed bytes actually written, or 0 in case of error. The number of
|
alpar@9
|
1264 uncompressed bytes written is limited to 8191, or one less than the buffer
|
alpar@9
|
1265 size given to gzbuffer(). The caller should assure that this limit is not
|
alpar@9
|
1266 exceeded. If it is exceeded, then gzprintf() will return an error (0) with
|
alpar@9
|
1267 nothing written. In this case, there may also be a buffer overflow with
|
alpar@9
|
1268 unpredictable consequences, which is possible only if zlib was compiled with
|
alpar@9
|
1269 the insecure functions sprintf() or vsprintf() because the secure snprintf()
|
alpar@9
|
1270 or vsnprintf() functions were not available. This can be determined using
|
alpar@9
|
1271 zlibCompileFlags().
|
alpar@9
|
1272 */
|
alpar@9
|
1273
|
alpar@9
|
1274 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
|
alpar@9
|
1275 /*
|
alpar@9
|
1276 Writes the given null-terminated string to the compressed file, excluding
|
alpar@9
|
1277 the terminating null character.
|
alpar@9
|
1278
|
alpar@9
|
1279 gzputs returns the number of characters written, or -1 in case of error.
|
alpar@9
|
1280 */
|
alpar@9
|
1281
|
alpar@9
|
1282 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
|
alpar@9
|
1283 /*
|
alpar@9
|
1284 Reads bytes from the compressed file until len-1 characters are read, or a
|
alpar@9
|
1285 newline character is read and transferred to buf, or an end-of-file
|
alpar@9
|
1286 condition is encountered. If any characters are read or if len == 1, the
|
alpar@9
|
1287 string is terminated with a null character. If no characters are read due
|
alpar@9
|
1288 to an end-of-file or len < 1, then the buffer is left untouched.
|
alpar@9
|
1289
|
alpar@9
|
1290 gzgets returns buf which is a null-terminated string, or it returns NULL
|
alpar@9
|
1291 for end-of-file or in case of error. If there was an error, the contents at
|
alpar@9
|
1292 buf are indeterminate.
|
alpar@9
|
1293 */
|
alpar@9
|
1294
|
alpar@9
|
1295 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
|
alpar@9
|
1296 /*
|
alpar@9
|
1297 Writes c, converted to an unsigned char, into the compressed file. gzputc
|
alpar@9
|
1298 returns the value that was written, or -1 in case of error.
|
alpar@9
|
1299 */
|
alpar@9
|
1300
|
alpar@9
|
1301 ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
|
alpar@9
|
1302 /*
|
alpar@9
|
1303 Reads one byte from the compressed file. gzgetc returns this byte or -1
|
alpar@9
|
1304 in case of end of file or error.
|
alpar@9
|
1305 */
|
alpar@9
|
1306
|
alpar@9
|
1307 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
|
alpar@9
|
1308 /*
|
alpar@9
|
1309 Push one character back onto the stream to be read as the first character
|
alpar@9
|
1310 on the next read. At least one character of push-back is allowed.
|
alpar@9
|
1311 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
|
alpar@9
|
1312 fail if c is -1, and may fail if a character has been pushed but not read
|
alpar@9
|
1313 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
|
alpar@9
|
1314 output buffer size of pushed characters is allowed. (See gzbuffer above.)
|
alpar@9
|
1315 The pushed character will be discarded if the stream is repositioned with
|
alpar@9
|
1316 gzseek() or gzrewind().
|
alpar@9
|
1317 */
|
alpar@9
|
1318
|
alpar@9
|
1319 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
|
alpar@9
|
1320 /*
|
alpar@9
|
1321 Flushes all pending output into the compressed file. The parameter flush
|
alpar@9
|
1322 is as in the deflate() function. The return value is the zlib error number
|
alpar@9
|
1323 (see function gzerror below). gzflush is only permitted when writing.
|
alpar@9
|
1324
|
alpar@9
|
1325 If the flush parameter is Z_FINISH, the remaining data is written and the
|
alpar@9
|
1326 gzip stream is completed in the output. If gzwrite() is called again, a new
|
alpar@9
|
1327 gzip stream will be started in the output. gzread() is able to read such
|
alpar@9
|
1328 concatented gzip streams.
|
alpar@9
|
1329
|
alpar@9
|
1330 gzflush should be called only when strictly necessary because it will
|
alpar@9
|
1331 degrade compression if called too often.
|
alpar@9
|
1332 */
|
alpar@9
|
1333
|
alpar@9
|
1334 /*
|
alpar@9
|
1335 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
|
alpar@9
|
1336 z_off_t offset, int whence));
|
alpar@9
|
1337
|
alpar@9
|
1338 Sets the starting position for the next gzread or gzwrite on the given
|
alpar@9
|
1339 compressed file. The offset represents a number of bytes in the
|
alpar@9
|
1340 uncompressed data stream. The whence parameter is defined as in lseek(2);
|
alpar@9
|
1341 the value SEEK_END is not supported.
|
alpar@9
|
1342
|
alpar@9
|
1343 If the file is opened for reading, this function is emulated but can be
|
alpar@9
|
1344 extremely slow. If the file is opened for writing, only forward seeks are
|
alpar@9
|
1345 supported; gzseek then compresses a sequence of zeroes up to the new
|
alpar@9
|
1346 starting position.
|
alpar@9
|
1347
|
alpar@9
|
1348 gzseek returns the resulting offset location as measured in bytes from
|
alpar@9
|
1349 the beginning of the uncompressed stream, or -1 in case of error, in
|
alpar@9
|
1350 particular if the file is opened for writing and the new starting position
|
alpar@9
|
1351 would be before the current position.
|
alpar@9
|
1352 */
|
alpar@9
|
1353
|
alpar@9
|
1354 ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
|
alpar@9
|
1355 /*
|
alpar@9
|
1356 Rewinds the given file. This function is supported only for reading.
|
alpar@9
|
1357
|
alpar@9
|
1358 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
|
alpar@9
|
1359 */
|
alpar@9
|
1360
|
alpar@9
|
1361 /*
|
alpar@9
|
1362 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
|
alpar@9
|
1363
|
alpar@9
|
1364 Returns the starting position for the next gzread or gzwrite on the given
|
alpar@9
|
1365 compressed file. This position represents a number of bytes in the
|
alpar@9
|
1366 uncompressed data stream, and is zero when starting, even if appending or
|
alpar@9
|
1367 reading a gzip stream from the middle of a file using gzdopen().
|
alpar@9
|
1368
|
alpar@9
|
1369 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
|
alpar@9
|
1370 */
|
alpar@9
|
1371
|
alpar@9
|
1372 /*
|
alpar@9
|
1373 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
|
alpar@9
|
1374
|
alpar@9
|
1375 Returns the current offset in the file being read or written. This offset
|
alpar@9
|
1376 includes the count of bytes that precede the gzip stream, for example when
|
alpar@9
|
1377 appending or when using gzdopen() for reading. When reading, the offset
|
alpar@9
|
1378 does not include as yet unused buffered input. This information can be used
|
alpar@9
|
1379 for a progress indicator. On error, gzoffset() returns -1.
|
alpar@9
|
1380 */
|
alpar@9
|
1381
|
alpar@9
|
1382 ZEXTERN int ZEXPORT gzeof OF((gzFile file));
|
alpar@9
|
1383 /*
|
alpar@9
|
1384 Returns true (1) if the end-of-file indicator has been set while reading,
|
alpar@9
|
1385 false (0) otherwise. Note that the end-of-file indicator is set only if the
|
alpar@9
|
1386 read tried to go past the end of the input, but came up short. Therefore,
|
alpar@9
|
1387 just like feof(), gzeof() may return false even if there is no more data to
|
alpar@9
|
1388 read, in the event that the last read request was for the exact number of
|
alpar@9
|
1389 bytes remaining in the input file. This will happen if the input file size
|
alpar@9
|
1390 is an exact multiple of the buffer size.
|
alpar@9
|
1391
|
alpar@9
|
1392 If gzeof() returns true, then the read functions will return no more data,
|
alpar@9
|
1393 unless the end-of-file indicator is reset by gzclearerr() and the input file
|
alpar@9
|
1394 has grown since the previous end of file was detected.
|
alpar@9
|
1395 */
|
alpar@9
|
1396
|
alpar@9
|
1397 ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
|
alpar@9
|
1398 /*
|
alpar@9
|
1399 Returns true (1) if file is being copied directly while reading, or false
|
alpar@9
|
1400 (0) if file is a gzip stream being decompressed. This state can change from
|
alpar@9
|
1401 false to true while reading the input file if the end of a gzip stream is
|
alpar@9
|
1402 reached, but is followed by data that is not another gzip stream.
|
alpar@9
|
1403
|
alpar@9
|
1404 If the input file is empty, gzdirect() will return true, since the input
|
alpar@9
|
1405 does not contain a gzip stream.
|
alpar@9
|
1406
|
alpar@9
|
1407 If gzdirect() is used immediately after gzopen() or gzdopen() it will
|
alpar@9
|
1408 cause buffers to be allocated to allow reading the file to determine if it
|
alpar@9
|
1409 is a gzip file. Therefore if gzbuffer() is used, it should be called before
|
alpar@9
|
1410 gzdirect().
|
alpar@9
|
1411 */
|
alpar@9
|
1412
|
alpar@9
|
1413 ZEXTERN int ZEXPORT gzclose OF((gzFile file));
|
alpar@9
|
1414 /*
|
alpar@9
|
1415 Flushes all pending output if necessary, closes the compressed file and
|
alpar@9
|
1416 deallocates the (de)compression state. Note that once file is closed, you
|
alpar@9
|
1417 cannot call gzerror with file, since its structures have been deallocated.
|
alpar@9
|
1418 gzclose must not be called more than once on the same file, just as free
|
alpar@9
|
1419 must not be called more than once on the same allocation.
|
alpar@9
|
1420
|
alpar@9
|
1421 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
|
alpar@9
|
1422 file operation error, or Z_OK on success.
|
alpar@9
|
1423 */
|
alpar@9
|
1424
|
alpar@9
|
1425 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
|
alpar@9
|
1426 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
|
alpar@9
|
1427 /*
|
alpar@9
|
1428 Same as gzclose(), but gzclose_r() is only for use when reading, and
|
alpar@9
|
1429 gzclose_w() is only for use when writing or appending. The advantage to
|
alpar@9
|
1430 using these instead of gzclose() is that they avoid linking in zlib
|
alpar@9
|
1431 compression or decompression code that is not used when only reading or only
|
alpar@9
|
1432 writing respectively. If gzclose() is used, then both compression and
|
alpar@9
|
1433 decompression code will be included the application when linking to a static
|
alpar@9
|
1434 zlib library.
|
alpar@9
|
1435 */
|
alpar@9
|
1436
|
alpar@9
|
1437 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
|
alpar@9
|
1438 /*
|
alpar@9
|
1439 Returns the error message for the last error which occurred on the given
|
alpar@9
|
1440 compressed file. errnum is set to zlib error number. If an error occurred
|
alpar@9
|
1441 in the file system and not in the compression library, errnum is set to
|
alpar@9
|
1442 Z_ERRNO and the application may consult errno to get the exact error code.
|
alpar@9
|
1443
|
alpar@9
|
1444 The application must not modify the returned string. Future calls to
|
alpar@9
|
1445 this function may invalidate the previously returned string. If file is
|
alpar@9
|
1446 closed, then the string previously returned by gzerror will no longer be
|
alpar@9
|
1447 available.
|
alpar@9
|
1448
|
alpar@9
|
1449 gzerror() should be used to distinguish errors from end-of-file for those
|
alpar@9
|
1450 functions above that do not distinguish those cases in their return values.
|
alpar@9
|
1451 */
|
alpar@9
|
1452
|
alpar@9
|
1453 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
|
alpar@9
|
1454 /*
|
alpar@9
|
1455 Clears the error and end-of-file flags for file. This is analogous to the
|
alpar@9
|
1456 clearerr() function in stdio. This is useful for continuing to read a gzip
|
alpar@9
|
1457 file that is being written concurrently.
|
alpar@9
|
1458 */
|
alpar@9
|
1459
|
alpar@9
|
1460
|
alpar@9
|
1461 /* checksum functions */
|
alpar@9
|
1462
|
alpar@9
|
1463 /*
|
alpar@9
|
1464 These functions are not related to compression but are exported
|
alpar@9
|
1465 anyway because they might be useful in applications using the compression
|
alpar@9
|
1466 library.
|
alpar@9
|
1467 */
|
alpar@9
|
1468
|
alpar@9
|
1469 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
|
alpar@9
|
1470 /*
|
alpar@9
|
1471 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
|
alpar@9
|
1472 return the updated checksum. If buf is Z_NULL, this function returns the
|
alpar@9
|
1473 required initial value for the checksum.
|
alpar@9
|
1474
|
alpar@9
|
1475 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
|
alpar@9
|
1476 much faster.
|
alpar@9
|
1477
|
alpar@9
|
1478 Usage example:
|
alpar@9
|
1479
|
alpar@9
|
1480 uLong adler = adler32(0L, Z_NULL, 0);
|
alpar@9
|
1481
|
alpar@9
|
1482 while (read_buffer(buffer, length) != EOF) {
|
alpar@9
|
1483 adler = adler32(adler, buffer, length);
|
alpar@9
|
1484 }
|
alpar@9
|
1485 if (adler != original_adler) error();
|
alpar@9
|
1486 */
|
alpar@9
|
1487
|
alpar@9
|
1488 /*
|
alpar@9
|
1489 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
|
alpar@9
|
1490 z_off_t len2));
|
alpar@9
|
1491
|
alpar@9
|
1492 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
|
alpar@9
|
1493 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
|
alpar@9
|
1494 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
|
alpar@9
|
1495 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
|
alpar@9
|
1496 */
|
alpar@9
|
1497
|
alpar@9
|
1498 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
|
alpar@9
|
1499 /*
|
alpar@9
|
1500 Update a running CRC-32 with the bytes buf[0..len-1] and return the
|
alpar@9
|
1501 updated CRC-32. If buf is Z_NULL, this function returns the required
|
alpar@9
|
1502 initial value for the for the crc. Pre- and post-conditioning (one's
|
alpar@9
|
1503 complement) is performed within this function so it shouldn't be done by the
|
alpar@9
|
1504 application.
|
alpar@9
|
1505
|
alpar@9
|
1506 Usage example:
|
alpar@9
|
1507
|
alpar@9
|
1508 uLong crc = crc32(0L, Z_NULL, 0);
|
alpar@9
|
1509
|
alpar@9
|
1510 while (read_buffer(buffer, length) != EOF) {
|
alpar@9
|
1511 crc = crc32(crc, buffer, length);
|
alpar@9
|
1512 }
|
alpar@9
|
1513 if (crc != original_crc) error();
|
alpar@9
|
1514 */
|
alpar@9
|
1515
|
alpar@9
|
1516 /*
|
alpar@9
|
1517 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
|
alpar@9
|
1518
|
alpar@9
|
1519 Combine two CRC-32 check values into one. For two sequences of bytes,
|
alpar@9
|
1520 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
|
alpar@9
|
1521 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
|
alpar@9
|
1522 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
|
alpar@9
|
1523 len2.
|
alpar@9
|
1524 */
|
alpar@9
|
1525
|
alpar@9
|
1526
|
alpar@9
|
1527 /* various hacks, don't look :) */
|
alpar@9
|
1528
|
alpar@9
|
1529 /* deflateInit and inflateInit are macros to allow checking the zlib version
|
alpar@9
|
1530 * and the compiler's view of z_stream:
|
alpar@9
|
1531 */
|
alpar@9
|
1532 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
|
alpar@9
|
1533 const char *version, int stream_size));
|
alpar@9
|
1534 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
|
alpar@9
|
1535 const char *version, int stream_size));
|
alpar@9
|
1536 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
|
alpar@9
|
1537 int windowBits, int memLevel,
|
alpar@9
|
1538 int strategy, const char *version,
|
alpar@9
|
1539 int stream_size));
|
alpar@9
|
1540 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
|
alpar@9
|
1541 const char *version, int stream_size));
|
alpar@9
|
1542 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
|
alpar@9
|
1543 unsigned char FAR *window,
|
alpar@9
|
1544 const char *version,
|
alpar@9
|
1545 int stream_size));
|
alpar@9
|
1546 #define deflateInit(strm, level) \
|
alpar@9
|
1547 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
|
alpar@9
|
1548 #define inflateInit(strm) \
|
alpar@9
|
1549 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
|
alpar@9
|
1550 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
|
alpar@9
|
1551 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
|
alpar@9
|
1552 (strategy), ZLIB_VERSION, sizeof(z_stream))
|
alpar@9
|
1553 #define inflateInit2(strm, windowBits) \
|
alpar@9
|
1554 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
|
alpar@9
|
1555 #define inflateBackInit(strm, windowBits, window) \
|
alpar@9
|
1556 inflateBackInit_((strm), (windowBits), (window), \
|
alpar@9
|
1557 ZLIB_VERSION, sizeof(z_stream))
|
alpar@9
|
1558
|
alpar@9
|
1559 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
|
alpar@9
|
1560 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
|
alpar@9
|
1561 * both are true, the application gets the *64 functions, and the regular
|
alpar@9
|
1562 * functions are changed to 64 bits) -- in case these are set on systems
|
alpar@9
|
1563 * without large file support, _LFS64_LARGEFILE must also be true
|
alpar@9
|
1564 */
|
alpar@9
|
1565 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
|
alpar@9
|
1566 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
|
alpar@9
|
1567 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
|
alpar@9
|
1568 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
|
alpar@9
|
1569 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
|
alpar@9
|
1570 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
|
alpar@9
|
1571 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
|
alpar@9
|
1572 #endif
|
alpar@9
|
1573
|
alpar@9
|
1574 #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
|
alpar@9
|
1575 # define gzopen gzopen64
|
alpar@9
|
1576 # define gzseek gzseek64
|
alpar@9
|
1577 # define gztell gztell64
|
alpar@9
|
1578 # define gzoffset gzoffset64
|
alpar@9
|
1579 # define adler32_combine adler32_combine64
|
alpar@9
|
1580 # define crc32_combine crc32_combine64
|
alpar@9
|
1581 # ifdef _LARGEFILE64_SOURCE
|
alpar@9
|
1582 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
|
alpar@9
|
1583 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
|
alpar@9
|
1584 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
|
alpar@9
|
1585 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
|
alpar@9
|
1586 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
|
alpar@9
|
1587 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
|
alpar@9
|
1588 # endif
|
alpar@9
|
1589 #else
|
alpar@9
|
1590 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
|
alpar@9
|
1591 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
|
alpar@9
|
1592 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
|
alpar@9
|
1593 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
|
alpar@9
|
1594 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
|
alpar@9
|
1595 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
|
alpar@9
|
1596 #endif
|
alpar@9
|
1597
|
alpar@9
|
1598 /* hack for buggy compilers */
|
alpar@9
|
1599 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
|
alpar@9
|
1600 struct internal_state {int dummy;};
|
alpar@9
|
1601 #endif
|
alpar@9
|
1602
|
alpar@9
|
1603 /* undocumented functions */
|
alpar@9
|
1604 ZEXTERN const char * ZEXPORT zError OF((int));
|
alpar@9
|
1605 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
|
alpar@9
|
1606 ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
|
alpar@9
|
1607 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
|
alpar@9
|
1608
|
alpar@9
|
1609 #ifdef __cplusplus
|
alpar@9
|
1610 }
|
alpar@9
|
1611 #endif
|
alpar@9
|
1612
|
alpar@9
|
1613 #endif /* ZLIB_H */
|