| 1 | /* zlib.h -- interface of the 'zlib' general purpose compression library | 
 
 
 
 
 | 2 | version 1.2.8, April 28th, 2013 | 
 
 
 
 
 | 3 |  | 
 
 
 
 
 | 4 | Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler | 
 
 
 
 
 | 5 |  | 
 
 
 
 
 | 6 | This software is provided 'as-is', without any express or implied | 
 
 
 
 
 | 7 | warranty.  In no event will the authors be held liable for any damages | 
 
 
 
 
 | 8 | arising from the use of this software. | 
 
 
 
 
 | 9 |  | 
 
 
 
 
 | 10 | Permission is granted to anyone to use this software for any purpose, | 
 
 
 
 
 | 11 | including commercial applications, and to alter it and redistribute it | 
 
 
 
 
 | 12 | freely, subject to the following restrictions: | 
 
 
 
 
 | 13 |  | 
 
 
 
 
 | 14 | 1. The origin of this software must not be misrepresented; you must not | 
 
 
 
 
 | 15 | claim that you wrote the original software. If you use this software | 
 
 
 
 
 | 16 | in a product, an acknowledgment in the product documentation would be | 
 
 
 
 
 | 17 | appreciated but is not required. | 
 
 
 
 
 | 18 | 2. Altered source versions must be plainly marked as such, and must not be | 
 
 
 
 
 | 19 | misrepresented as being the original software. | 
 
 
 
 
 | 20 | 3. This notice may not be removed or altered from any source distribution. | 
 
 
 
 
 | 21 |  | 
 
 
 
 
 | 22 | Jean-loup Gailly        Mark Adler | 
 
 
 
 
 | 23 | jloup@gzip.org          madler@alumni.caltech.edu | 
 
 
 
 
 | 24 |  | 
 
 
 
 
 | 25 |  | 
 
 
 
 
 | 26 | The data format used by the zlib library is described by RFCs (Request for | 
 
 
 
 
 | 27 | Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 | 
 
 
 
 
 | 28 | (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). | 
 
 
 
 
 | 29 | */ | 
 
 
 
 
 | 30 |  | 
 
 
 
 
 | 31 | #ifndef ZLIB_H | 
 
 
 
 
 | 32 | #define ZLIB_H | 
 
 
 
 
 | 33 |  | 
 
 
 
 
 | 34 | #include "zconf.h" | 
 
 
 
 
 | 35 |  | 
 
 
 
 
 | 36 | #ifdef __cplusplus | 
 
 
 
 
 | 37 | extern "C" { | 
 
 
 
 
 | 38 | #endif | 
 
 
 
 
 | 39 |  | 
 
 
 
 
 | 40 | #define ZLIB_VERSION "1.2.8" | 
 
 
 
 
 | 41 | #define ZLIB_VERNUM 0x1280 | 
 
 
 
 
 | 42 | #define ZLIB_VER_MAJOR 1 | 
 
 
 
 
 | 43 | #define ZLIB_VER_MINOR 2 | 
 
 
 
 
 | 44 | #define ZLIB_VER_REVISION 8 | 
 
 
 
 
 | 45 | #define ZLIB_VER_SUBREVISION 0 | 
 
 
 
 
 | 46 |  | 
 
 
 
 
 | 47 | /* | 
 
 
 
 
 | 48 | The 'zlib' compression library provides in-memory compression and | 
 
 
 
 
 | 49 | decompression functions, including integrity checks of the uncompressed data. | 
 
 
 
 
 | 50 | This version of the library supports only one compression method (deflation) | 
 
 
 
 
 | 51 | but other algorithms will be added later and will have the same stream | 
 
 
 
 
 | 52 | interface. | 
 
 
 
 
 | 53 |  | 
 
 
 
 
 | 54 | Compression can be done in a single step if the buffers are large enough, | 
 
 
 
 
 | 55 | or can be done by repeated calls of the compression function.  In the latter | 
 
 
 
 
 | 56 | case, the application must provide more input and/or consume the output | 
 
 
 
 
 | 57 | (providing more output space) before each call. | 
 
 
 
 
 | 58 |  | 
 
 
 
 
 | 59 | The compressed data format used by default by the in-memory functions is | 
 
 
 
 
 | 60 | the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped | 
 
 
 
 
 | 61 | around a deflate stream, which is itself documented in RFC 1951. | 
 
 
 
 
 | 62 |  | 
 
 
 
 
 | 63 | The library also supports reading and writing files in gzip (.gz) format | 
 
 
 
 
 | 64 | with an interface similar to that of stdio using the functions that start | 
 
 
 
 
 | 65 | with "gz".  The gzip format is different from the zlib format.  gzip is a | 
 
 
 
 
 | 66 | gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. | 
 
 
 
 
 | 67 |  | 
 
 
 
 
 | 68 | This library can optionally read and write gzip streams in memory as well. | 
 
 
 
 
 | 69 |  | 
 
 
 
 
 | 70 | The zlib format was designed to be compact and fast for use in memory | 
 
 
 
 
 | 71 | and on communications channels.  The gzip format was designed for single- | 
 
 
 
 
 | 72 | file compression on file systems, has a larger header than zlib to maintain | 
 
 
 
 
 | 73 | directory information, and uses a different, slower check method than zlib. | 
 
 
 
 
 | 74 |  | 
 
 
 
 
 | 75 | The library does not install any signal handler.  The decoder checks | 
 
 
 
 
 | 76 | the consistency of the compressed data, so the library should never crash | 
 
 
 
 
 | 77 | even in case of corrupted input. | 
 
 
 
 
 | 78 | */ | 
 
 
 
 
 | 79 |  | 
 
 
 
 
 | 80 | typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); | 
 
 
 
 
 | 81 | typedef void   (*free_func)  OF((voidpf opaque, voidpf address)); | 
 
 
 
 
 | 82 |  | 
 
 
 
 
 | 83 | struct internal_state; | 
 
 
 
 
 | 84 |  | 
 
 
 
 
 | 85 | typedef struct z_stream_s { | 
 
 
 
 
 | 86 | z_const Bytef *next_in;     /* next input byte */ | 
 
 
 
 
 | 87 | uInt     avail_in;  /* number of bytes available at next_in */ | 
 
 
 
 
 | 88 | uLong    total_in;  /* total number of input bytes read so far */ | 
 
 
 
 
 | 89 |  | 
 
 
 
 
 | 90 | Bytef    *next_out; /* next output byte should be put there */ | 
 
 
 
 
 | 91 | uInt     avail_out; /* remaining free space at next_out */ | 
 
 
 
 
 | 92 | uLong    total_out; /* total number of bytes output so far */ | 
 
 
 
 
 | 93 |  | 
 
 
 
 
 | 94 | z_const char *msg;  /* last error message, NULL if no error */ | 
 
 
 
 
 | 95 | struct internal_state FAR *state; /* not visible by applications */ | 
 
 
 
 
 | 96 |  | 
 
 
 
 
 | 97 | alloc_func zalloc;  /* used to allocate the internal state */ | 
 
 
 
 
 | 98 | free_func  zfree;   /* used to free the internal state */ | 
 
 
 
 
 | 99 | voidpf     opaque;  /* private data object passed to zalloc and zfree */ | 
 
 
 
 
 | 100 |  | 
 
 
 
 
 | 101 | int     data_type;  /* best guess about the data type: binary or text */ | 
 
 
 
 
 | 102 | uLong   adler;      /* adler32 value of the uncompressed data */ | 
 
 
 
 
 | 103 | uLong   reserved;   /* reserved for future use */ | 
 
 
 
 
 | 104 | } z_stream; | 
 
 
 
 
 | 105 |  | 
 
 
 
 
 | 106 | typedef z_stream FAR *z_streamp; | 
 
 
 
 
 | 107 |  | 
 
 
 
 
 | 108 | /* | 
 
 
 
 
 | 109 | gzip header information passed to and from zlib routines.  See RFC 1952 | 
 
 
 
 
 | 110 | for more details on the meanings of these fields. | 
 
 
 
 
 | 111 | */ | 
 
 
 
 
 | 112 | typedef struct gz_header_s { | 
 
 
 
 
 | 113 | int     text;       /* true if compressed data believed to be text */ | 
 
 
 
 
 | 114 | uLong   time;       /* modification time */ | 
 
 
 
 
 | 115 | int     xflags;     /* extra flags (not used when writing a gzip file) */ | 
 
 
 
 
 | 116 | int     os;         /* operating system */ | 
 
 
 
 
 | 117 | Bytef   *extra;     /* pointer to extra field or Z_NULL if none */ | 
 
 
 
 
 | 118 | uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */ | 
 
 
 
 
 | 119 | uInt    extra_max;  /* space at extra (only when reading header) */ | 
 
 
 
 
 | 120 | Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */ | 
 
 
 
 
 | 121 | uInt    name_max;   /* space at name (only when reading header) */ | 
 
 
 
 
 | 122 | Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */ | 
 
 
 
 
 | 123 | uInt    comm_max;   /* space at comment (only when reading header) */ | 
 
 
 
 
 | 124 | int     hcrc;       /* true if there was or will be a header crc */ | 
 
 
 
 
 | 125 | int     done;       /* true when done reading gzip header (not used | 
 
 
 
 
 | 126 | when writing a gzip file) */ | 
 
 
 
 
 | 127 | } gz_header; | 
 
 
 
 
 | 128 |  | 
 
 
 
 
 | 129 | typedef gz_header FAR *gz_headerp; | 
 
 
 
 
 | 130 |  | 
 
 
 
 
 | 131 | /* | 
 
 
 
 
 | 132 | The application must update next_in and avail_in when avail_in has dropped | 
 
 
 
 
 | 133 | to zero.  It must update next_out and avail_out when avail_out has dropped | 
 
 
 
 
 | 134 | to zero.  The application must initialize zalloc, zfree and opaque before | 
 
 
 
 
 | 135 | calling the init function.  All other fields are set by the compression | 
 
 
 
 
 | 136 | library and must not be updated by the application. | 
 
 
 
 
 | 137 |  | 
 
 
 
 
 | 138 | The opaque value provided by the application will be passed as the first | 
 
 
 
 
 | 139 | parameter for calls of zalloc and zfree.  This can be useful for custom | 
 
 
 
 
 | 140 | memory management.  The compression library attaches no meaning to the | 
 
 
 
 
 | 141 | opaque value. | 
 
 
 
 
 | 142 |  | 
 
 
 
 
 | 143 | zalloc must return Z_NULL if there is not enough memory for the object. | 
 
 
 
 
 | 144 | If zlib is used in a multi-threaded application, zalloc and zfree must be | 
 
 
 
 
 | 145 | thread safe. | 
 
 
 
 
 | 146 |  | 
 
 
 
 
 | 147 | On 16-bit systems, the functions zalloc and zfree must be able to allocate | 
 
 
 
 
 | 148 | exactly 65536 bytes, but will not be required to allocate more than this if | 
 
 
 
 
 | 149 | the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers | 
 
 
 
 
 | 150 | returned by zalloc for objects of exactly 65536 bytes *must* have their | 
 
 
 
 
 | 151 | offset normalized to zero.  The default allocation function provided by this | 
 
 
 
 
 | 152 | library ensures this (see zutil.c).  To reduce memory requirements and avoid | 
 
 
 
 
 | 153 | any allocation of 64K objects, at the expense of compression ratio, compile | 
 
 
 
 
 | 154 | the library with -DMAX_WBITS=14 (see zconf.h). | 
 
 
 
 
 | 155 |  | 
 
 
 
 
 | 156 | The fields total_in and total_out can be used for statistics or progress | 
 
 
 
 
 | 157 | reports.  After compression, total_in holds the total size of the | 
 
 
 
 
 | 158 | uncompressed data and may be saved for use in the decompressor (particularly | 
 
 
 
 
 | 159 | if the decompressor wants to decompress everything in a single step). | 
 
 
 
 
 | 160 | */ | 
 
 
 
 
 | 161 |  | 
 
 
 
 
 | 162 | /* constants */ | 
 
 
 
 
 | 163 |  | 
 
 
 
 
 | 164 | #define Z_NO_FLUSH      0 | 
 
 
 
 
 | 165 | #define Z_PARTIAL_FLUSH 1 | 
 
 
 
 
 | 166 | #define Z_SYNC_FLUSH    2 | 
 
 
 
 
 | 167 | #define Z_FULL_FLUSH    3 | 
 
 
 
 
 | 168 | #define Z_FINISH        4 | 
 
 
 
 
 | 169 | #define Z_BLOCK         5 | 
 
 
 
 
 | 170 | #define Z_TREES         6 | 
 
 
 
 
 | 171 | /* Allowed flush values; see deflate() and inflate() below for details */ | 
 
 
 
 
 | 172 |  | 
 
 
 
 
 | 173 | #define Z_OK            0 | 
 
 
 
 
 | 174 | #define Z_STREAM_END    1 | 
 
 
 
 
 | 175 | #define Z_NEED_DICT     2 | 
 
 
 
 
 | 176 | #define Z_ERRNO        (-1) | 
 
 
 
 
 | 177 | #define Z_STREAM_ERROR (-2) | 
 
 
 
 
 | 178 | #define Z_DATA_ERROR   (-3) | 
 
 
 
 
 | 179 | #define Z_MEM_ERROR    (-4) | 
 
 
 
 
 | 180 | #define Z_BUF_ERROR    (-5) | 
 
 
 
 
 | 181 | #define Z_VERSION_ERROR (-6) | 
 
 
 
 
 | 182 | /* Return codes for the compression/decompression functions. Negative values | 
 
 
 
 
 | 183 | * are errors, positive values are used for special but normal events. | 
 
 
 
 
 | 184 | */ | 
 
 
 
 
 | 185 |  | 
 
 
 
 
 | 186 | #define Z_NO_COMPRESSION         0 | 
 
 
 
 
 | 187 | #define Z_BEST_SPEED             1 | 
 
 
 
 
 | 188 | #define Z_BEST_COMPRESSION       9 | 
 
 
 
 
 | 189 | #define Z_DEFAULT_COMPRESSION  (-1) | 
 
 
 
 
 | 190 | /* compression levels */ | 
 
 
 
 
 | 191 |  | 
 
 
 
 
 | 192 | #define Z_FILTERED            1 | 
 
 
 
 
 | 193 | #define Z_HUFFMAN_ONLY        2 | 
 
 
 
 
 | 194 | #define Z_RLE                 3 | 
 
 
 
 
 | 195 | #define Z_FIXED               4 | 
 
 
 
 
 | 196 | #define Z_DEFAULT_STRATEGY    0 | 
 
 
 
 
 | 197 | /* compression strategy; see deflateInit2() below for details */ | 
 
 
 
 
 | 198 |  | 
 
 
 
 
 | 199 | #define Z_BINARY   0 | 
 
 
 
 
 | 200 | #define Z_TEXT     1 | 
 
 
 
 
 | 201 | #define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */ | 
 
 
 
 
 | 202 | #define Z_UNKNOWN  2 | 
 
 
 
 
 | 203 | /* Possible values of the data_type field (though see inflate()) */ | 
 
 
 
 
 | 204 |  | 
 
 
 
 
 | 205 | #define Z_DEFLATED   8 | 
 
 
 
 
 | 206 | /* The deflate compression method (the only one supported in this version) */ | 
 
 
 
 
 | 207 |  | 
 
 
 
 
 | 208 | #define Z_NULL  0  /* for initializing zalloc, zfree, opaque */ | 
 
 
 
 
 | 209 |  | 
 
 
 
 
 | 210 | #define zlib_version zlibVersion() | 
 
 
 
 
 | 211 | /* for compatibility with versions < 1.0.2 */ | 
 
 
 
 
 | 212 |  | 
 
 
 
 
 | 213 |  | 
 
 
 
 
 | 214 | /* basic functions */ | 
 
 
 
 
 | 215 |  | 
 
 
 
 
 | 216 | ZEXTERN const char * ZEXPORT zlibVersion OF((void)); | 
 
 
 
 
 | 217 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency. | 
 
 
 
 
 | 218 | If the first character differs, the library code actually used is not | 
 
 
 
 
 | 219 | compatible with the zlib.h header file used by the application.  This check | 
 
 
 
 
 | 220 | is automatically made by deflateInit and inflateInit. | 
 
 
 
 
 | 221 | */ | 
 
 
 
 
 | 222 |  | 
 
 
 
 
 | 223 | /* | 
 
 
 
 
 | 224 | ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); | 
 
 
 
 
 | 225 |  | 
 
 
 
 
 | 226 | Initializes the internal stream state for compression.  The fields | 
 
 
 
 
 | 227 | zalloc, zfree and opaque must be initialized before by the caller.  If | 
 
 
 
 
 | 228 | zalloc and zfree are set to Z_NULL, deflateInit updates them to use default | 
 
 
 
 
 | 229 | allocation functions. | 
 
 
 
 
 | 230 |  | 
 
 
 
 
 | 231 | The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: | 
 
 
 
 
 | 232 | 1 gives best speed, 9 gives best compression, 0 gives no compression at all | 
 
 
 
 
 | 233 | (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION | 
 
 
 
 
 | 234 | requests a default compromise between speed and compression (currently | 
 
 
 
 
 | 235 | equivalent to level 6). | 
 
 
 
 
 | 236 |  | 
 
 
 
 
 | 237 | deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 
 
 
 
 | 238 | memory, Z_STREAM_ERROR if level is not a valid compression level, or | 
 
 
 
 
 | 239 | Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible | 
 
 
 
 
 | 240 | with the version assumed by the caller (ZLIB_VERSION).  msg is set to null | 
 
 
 
 
 | 241 | if there is no error message.  deflateInit does not perform any compression: | 
 
 
 
 
 | 242 | this will be done by deflate(). | 
 
 
 
 
 | 243 | */ | 
 
 
 
 
 | 244 |  | 
 
 
 
 
 | 245 |  | 
 
 
 
 
 | 246 | ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); | 
 
 
 
 
 | 247 | /* | 
 
 
 
 
 | 248 | deflate compresses as much data as possible, and stops when the input | 
 
 
 
 
 | 249 | buffer becomes empty or the output buffer becomes full.  It may introduce | 
 
 
 
 
 | 250 | some output latency (reading input without producing any output) except when | 
 
 
 
 
 | 251 | forced to flush. | 
 
 
 
 
 | 252 |  | 
 
 
 
 
 | 253 | The detailed semantics are as follows.  deflate performs one or both of the | 
 
 
 
 
 | 254 | following actions: | 
 
 
 
 
 | 255 |  | 
 
 
 
 
 | 256 | - Compress more input starting at next_in and update next_in and avail_in | 
 
 
 
 
 | 257 | accordingly.  If not all input can be processed (because there is not | 
 
 
 
 
 | 258 | enough room in the output buffer), next_in and avail_in are updated and | 
 
 
 
 
 | 259 | processing will resume at this point for the next call of deflate(). | 
 
 
 
 
 | 260 |  | 
 
 
 
 
 | 261 | - Provide more output starting at next_out and update next_out and avail_out | 
 
 
 
 
 | 262 | accordingly.  This action is forced if the parameter flush is non zero. | 
 
 
 
 
 | 263 | Forcing flush frequently degrades the compression ratio, so this parameter | 
 
 
 
 
 | 264 | should be set only when necessary (in interactive applications).  Some | 
 
 
 
 
 | 265 | output may be provided even if flush is not set. | 
 
 
 
 
 | 266 |  | 
 
 
 
 
 | 267 | Before the call of deflate(), the application should ensure that at least | 
 
 
 
 
 | 268 | one of the actions is possible, by providing more input and/or consuming more | 
 
 
 
 
 | 269 | output, and updating avail_in or avail_out accordingly; avail_out should | 
 
 
 
 
 | 270 | never be zero before the call.  The application can consume the compressed | 
 
 
 
 
 | 271 | output when it wants, for example when the output buffer is full (avail_out | 
 
 
 
 
 | 272 | == 0), or after each call of deflate().  If deflate returns Z_OK and with | 
 
 
 
 
 | 273 | zero avail_out, it must be called again after making room in the output | 
 
 
 
 
 | 274 | buffer because there might be more output pending. | 
 
 
 
 
 | 275 |  | 
 
 
 
 
 | 276 | Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to | 
 
 
 
 
 | 277 | decide how much data to accumulate before producing output, in order to | 
 
 
 
 
 | 278 | maximize compression. | 
 
 
 
 
 | 279 |  | 
 
 
 
 
 | 280 | If the parameter flush is set to Z_SYNC_FLUSH, all pending output is | 
 
 
 
 
 | 281 | flushed to the output buffer and the output is aligned on a byte boundary, so | 
 
 
 
 
 | 282 | that the decompressor can get all input data available so far.  (In | 
 
 
 
 
 | 283 | particular avail_in is zero after the call if enough output space has been | 
 
 
 
 
 | 284 | provided before the call.) Flushing may degrade compression for some | 
 
 
 
 
 | 285 | compression algorithms and so it should be used only when necessary.  This | 
 
 
 
 
 | 286 | completes the current deflate block and follows it with an empty stored block | 
 
 
 
 
 | 287 | that is three bits plus filler bits to the next byte, followed by four bytes | 
 
 
 
 
 | 288 | (00 00 ff ff). | 
 
 
 
 
 | 289 |  | 
 
 
 
 
 | 290 | If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the | 
 
 
 
 
 | 291 | output buffer, but the output is not aligned to a byte boundary.  All of the | 
 
 
 
 
 | 292 | input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. | 
 
 
 
 
 | 293 | This completes the current deflate block and follows it with an empty fixed | 
 
 
 
 
 | 294 | codes block that is 10 bits long.  This assures that enough bytes are output | 
 
 
 
 
 | 295 | in order for the decompressor to finish the block before the empty fixed code | 
 
 
 
 
 | 296 | block. | 
 
 
 
 
 | 297 |  | 
 
 
 
 
 | 298 | If flush is set to Z_BLOCK, a deflate block is completed and emitted, as | 
 
 
 
 
 | 299 | for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to | 
 
 
 
 
 | 300 | seven bits of the current block are held to be written as the next byte after | 
 
 
 
 
 | 301 | the next deflate block is completed.  In this case, the decompressor may not | 
 
 
 
 
 | 302 | be provided enough bits at this point in order to complete decompression of | 
 
 
 
 
 | 303 | the data provided so far to the compressor.  It may need to wait for the next | 
 
 
 
 
 | 304 | block to be emitted.  This is for advanced applications that need to control | 
 
 
 
 
 | 305 | the emission of deflate blocks. | 
 
 
 
 
 | 306 |  | 
 
 
 
 
 | 307 | If flush is set to Z_FULL_FLUSH, all output is flushed as with | 
 
 
 
 
 | 308 | Z_SYNC_FLUSH, and the compression state is reset so that decompression can | 
 
 
 
 
 | 309 | restart from this point if previous compressed data has been damaged or if | 
 
 
 
 
 | 310 | random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade | 
 
 
 
 
 | 311 | compression. | 
 
 
 
 
 | 312 |  | 
 
 
 
 
 | 313 | If deflate returns with avail_out == 0, this function must be called again | 
 
 
 
 
 | 314 | with the same value of the flush parameter and more output space (updated | 
 
 
 
 
 | 315 | avail_out), until the flush is complete (deflate returns with non-zero | 
 
 
 
 
 | 316 | avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that | 
 
 
 
 
 | 317 | avail_out is greater than six to avoid repeated flush markers due to | 
 
 
 
 
 | 318 | avail_out == 0 on return. | 
 
 
 
 
 | 319 |  | 
 
 
 
 
 | 320 | If the parameter flush is set to Z_FINISH, pending input is processed, | 
 
 
 
 
 | 321 | pending output is flushed and deflate returns with Z_STREAM_END if there was | 
 
 
 
 
 | 322 | enough output space; if deflate returns with Z_OK, this function must be | 
 
 
 
 
 | 323 | called again with Z_FINISH and more output space (updated avail_out) but no | 
 
 
 
 
 | 324 | more input data, until it returns with Z_STREAM_END or an error.  After | 
 
 
 
 
 | 325 | deflate has returned Z_STREAM_END, the only possible operations on the stream | 
 
 
 
 
 | 326 | are deflateReset or deflateEnd. | 
 
 
 
 
 | 327 |  | 
 
 
 
 
 | 328 | Z_FINISH can be used immediately after deflateInit if all the compression | 
 
 
 
 
 | 329 | is to be done in a single step.  In this case, avail_out must be at least the | 
 
 
 
 
 | 330 | value returned by deflateBound (see below).  Then deflate is guaranteed to | 
 
 
 
 
 | 331 | return Z_STREAM_END.  If not enough output space is provided, deflate will | 
 
 
 
 
 | 332 | not return Z_STREAM_END, and it must be called again as described above. | 
 
 
 
 
 | 333 |  | 
 
 
 
 
 | 334 | deflate() sets strm->adler to the adler32 checksum of all input read | 
 
 
 
 
 | 335 | so far (that is, total_in bytes). | 
 
 
 
 
 | 336 |  | 
 
 
 
 
 | 337 | deflate() may update strm->data_type if it can make a good guess about | 
 
 
 
 
 | 338 | the input data type (Z_BINARY or Z_TEXT).  In doubt, the data is considered | 
 
 
 
 
 | 339 | binary.  This field is only for information purposes and does not affect the | 
 
 
 
 
 | 340 | compression algorithm in any manner. | 
 
 
 
 
 | 341 |  | 
 
 
 
 
 | 342 | deflate() returns Z_OK if some progress has been made (more input | 
 
 
 
 
 | 343 | processed or more output produced), Z_STREAM_END if all input has been | 
 
 
 
 
 | 344 | consumed and all output has been produced (only when flush is set to | 
 
 
 
 
 | 345 | Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example | 
 
 
 
 
 | 346 | if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible | 
 
 
 
 
 | 347 | (for example avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not | 
 
 
 
 
 | 348 | fatal, and deflate() can be called again with more input and more output | 
 
 
 
 
 | 349 | space to continue compressing. | 
 
 
 
 
 | 350 | */ | 
 
 
 
 
 | 351 |  | 
 
 
 
 
 | 352 |  | 
 
 
 
 
 | 353 | ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); | 
 
 
 
 
 | 354 | /* | 
 
 
 
 
 | 355 | All dynamically allocated data structures for this stream are freed. | 
 
 
 
 
 | 356 | This function discards any unprocessed input and does not flush any pending | 
 
 
 
 
 | 357 | output. | 
 
 
 
 
 | 358 |  | 
 
 
 
 
 | 359 | deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the | 
 
 
 
 
 | 360 | stream state was inconsistent, Z_DATA_ERROR if the stream was freed | 
 
 
 
 
 | 361 | prematurely (some input or output was discarded).  In the error case, msg | 
 
 
 
 
 | 362 | may be set but then points to a static string (which must not be | 
 
 
 
 
 | 363 | deallocated). | 
 
 
 
 
 | 364 | */ | 
 
 
 
 
 | 365 |  | 
 
 
 
 
 | 366 |  | 
 
 
 
 
 | 367 | /* | 
 
 
 
 
 | 368 | ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); | 
 
 
 
 
 | 369 |  | 
 
 
 
 
 | 370 | Initializes the internal stream state for decompression.  The fields | 
 
 
 
 
 | 371 | next_in, avail_in, zalloc, zfree and opaque must be initialized before by | 
 
 
 
 
 | 372 | the caller.  If next_in is not Z_NULL and avail_in is large enough (the | 
 
 
 
 
 | 373 | exact value depends on the compression method), inflateInit determines the | 
 
 
 
 
 | 374 | compression method from the zlib header and allocates all data structures | 
 
 
 
 
 | 375 | accordingly; otherwise the allocation will be deferred to the first call of | 
 
 
 
 
 | 376 | inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to | 
 
 
 
 
 | 377 | use default allocation functions. | 
 
 
 
 
 | 378 |  | 
 
 
 
 
 | 379 | inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 
 
 
 
 | 380 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | 
 
 
 
 
 | 381 | version assumed by the caller, or Z_STREAM_ERROR if the parameters are | 
 
 
 
 
 | 382 | invalid, such as a null pointer to the structure.  msg is set to null if | 
 
 
 
 
 | 383 | there is no error message.  inflateInit does not perform any decompression | 
 
 
 
 
 | 384 | apart from possibly reading the zlib header if present: actual decompression | 
 
 
 
 
 | 385 | will be done by inflate().  (So next_in and avail_in may be modified, but | 
 
 
 
 
 | 386 | next_out and avail_out are unused and unchanged.) The current implementation | 
 
 
 
 
 | 387 | of inflateInit() does not process any header information -- that is deferred | 
 
 
 
 
 | 388 | until inflate() is called. | 
 
 
 
 
 | 389 | */ | 
 
 
 
 
 | 390 |  | 
 
 
 
 
 | 391 |  | 
 
 
 
 
 | 392 | ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); | 
 
 
 
 
 | 393 | /* | 
 
 
 
 
 | 394 | inflate decompresses as much data as possible, and stops when the input | 
 
 
 
 
 | 395 | buffer becomes empty or the output buffer becomes full.  It may introduce | 
 
 
 
 
 | 396 | some output latency (reading input without producing any output) except when | 
 
 
 
 
 | 397 | forced to flush. | 
 
 
 
 
 | 398 |  | 
 
 
 
 
 | 399 | The detailed semantics are as follows.  inflate performs one or both of the | 
 
 
 
 
 | 400 | following actions: | 
 
 
 
 
 | 401 |  | 
 
 
 
 
 | 402 | - Decompress more input starting at next_in and update next_in and avail_in | 
 
 
 
 
 | 403 | accordingly.  If not all input can be processed (because there is not | 
 
 
 
 
 | 404 | enough room in the output buffer), next_in is updated and processing will | 
 
 
 
 
 | 405 | resume at this point for the next call of inflate(). | 
 
 
 
 
 | 406 |  | 
 
 
 
 
 | 407 | - Provide more output starting at next_out and update next_out and avail_out | 
 
 
 
 
 | 408 | accordingly.  inflate() provides as much output as possible, until there is | 
 
 
 
 
 | 409 | no more input data or no more space in the output buffer (see below about | 
 
 
 
 
 | 410 | the flush parameter). | 
 
 
 
 
 | 411 |  | 
 
 
 
 
 | 412 | Before the call of inflate(), the application should ensure that at least | 
 
 
 
 
 | 413 | one of the actions is possible, by providing more input and/or consuming more | 
 
 
 
 
 | 414 | output, and updating the next_* and avail_* values accordingly.  The | 
 
 
 
 
 | 415 | application can consume the uncompressed output when it wants, for example | 
 
 
 
 
 | 416 | when the output buffer is full (avail_out == 0), or after each call of | 
 
 
 
 
 | 417 | inflate().  If inflate returns Z_OK and with zero avail_out, it must be | 
 
 
 
 
 | 418 | called again after making room in the output buffer because there might be | 
 
 
 
 
 | 419 | more output pending. | 
 
 
 
 
 | 420 |  | 
 
 
 
 
 | 421 | The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, | 
 
 
 
 
 | 422 | Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much | 
 
 
 
 
 | 423 | output as possible to the output buffer.  Z_BLOCK requests that inflate() | 
 
 
 
 
 | 424 | stop if and when it gets to the next deflate block boundary.  When decoding | 
 
 
 
 
 | 425 | the zlib or gzip format, this will cause inflate() to return immediately | 
 
 
 
 
 | 426 | after the header and before the first block.  When doing a raw inflate, | 
 
 
 
 
 | 427 | inflate() will go ahead and process the first block, and will return when it | 
 
 
 
 
 | 428 | gets to the end of that block, or when it runs out of data. | 
 
 
 
 
 | 429 |  | 
 
 
 
 
 | 430 | The Z_BLOCK option assists in appending to or combining deflate streams. | 
 
 
 
 
 | 431 | Also to assist in this, on return inflate() will set strm->data_type to the | 
 
 
 
 
 | 432 | number of unused bits in the last byte taken from strm->next_in, plus 64 if | 
 
 
 
 
 | 433 | inflate() is currently decoding the last block in the deflate stream, plus | 
 
 
 
 
 | 434 | 128 if inflate() returned immediately after decoding an end-of-block code or | 
 
 
 
 
 | 435 | decoding the complete header up to just before the first byte of the deflate | 
 
 
 
 
 | 436 | stream.  The end-of-block will not be indicated until all of the uncompressed | 
 
 
 
 
 | 437 | data from that block has been written to strm->next_out.  The number of | 
 
 
 
 
 | 438 | unused bits may in general be greater than seven, except when bit 7 of | 
 
 
 
 
 | 439 | data_type is set, in which case the number of unused bits will be less than | 
 
 
 
 
 | 440 | eight.  data_type is set as noted here every time inflate() returns for all | 
 
 
 
 
 | 441 | flush options, and so can be used to determine the amount of currently | 
 
 
 
 
 | 442 | consumed input in bits. | 
 
 
 
 
 | 443 |  | 
 
 
 
 
 | 444 | The Z_TREES option behaves as Z_BLOCK does, but it also returns when the | 
 
 
 
 
 | 445 | end of each deflate block header is reached, before any actual data in that | 
 
 
 
 
 | 446 | block is decoded.  This allows the caller to determine the length of the | 
 
 
 
 
 | 447 | deflate block header for later use in random access within a deflate block. | 
 
 
 
 
 | 448 | 256 is added to the value of strm->data_type when inflate() returns | 
 
 
 
 
 | 449 | immediately after reaching the end of the deflate block header. | 
 
 
 
 
 | 450 |  | 
 
 
 
 
 | 451 | inflate() should normally be called until it returns Z_STREAM_END or an | 
 
 
 
 
 | 452 | error.  However if all decompression is to be performed in a single step (a | 
 
 
 
 
 | 453 | single call of inflate), the parameter flush should be set to Z_FINISH.  In | 
 
 
 
 
 | 454 | this case all pending input is processed and all pending output is flushed; | 
 
 
 
 
 | 455 | avail_out must be large enough to hold all of the uncompressed data for the | 
 
 
 
 
 | 456 | operation to complete.  (The size of the uncompressed data may have been | 
 
 
 
 
 | 457 | saved by the compressor for this purpose.) The use of Z_FINISH is not | 
 
 
 
 
 | 458 | required to perform an inflation in one step.  However it may be used to | 
 
 
 
 
 | 459 | inform inflate that a faster approach can be used for the single inflate() | 
 
 
 
 
 | 460 | call.  Z_FINISH also informs inflate to not maintain a sliding window if the | 
 
 
 
 
 | 461 | stream completes, which reduces inflate's memory footprint.  If the stream | 
 
 
 
 
 | 462 | does not complete, either because not all of the stream is provided or not | 
 
 
 
 
 | 463 | enough output space is provided, then a sliding window will be allocated and | 
 
 
 
 
 | 464 | inflate() can be called again to continue the operation as if Z_NO_FLUSH had | 
 
 
 
 
 | 465 | been used. | 
 
 
 
 
 | 466 |  | 
 
 
 
 
 | 467 | In this implementation, inflate() always flushes as much output as | 
 
 
 
 
 | 468 | possible to the output buffer, and always uses the faster approach on the | 
 
 
 
 
 | 469 | first call.  So the effects of the flush parameter in this implementation are | 
 
 
 
 
 | 470 | on the return value of inflate() as noted below, when inflate() returns early | 
 
 
 
 
 | 471 | when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of | 
 
 
 
 
 | 472 | memory for a sliding window when Z_FINISH is used. | 
 
 
 
 
 | 473 |  | 
 
 
 
 
 | 474 | If a preset dictionary is needed after this call (see inflateSetDictionary | 
 
 
 
 
 | 475 | below), inflate sets strm->adler to the Adler-32 checksum of the dictionary | 
 
 
 
 
 | 476 | chosen by the compressor and returns Z_NEED_DICT; otherwise it sets | 
 
 
 
 
 | 477 | strm->adler to the Adler-32 checksum of all output produced so far (that is, | 
 
 
 
 
 | 478 | total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described | 
 
 
 
 
 | 479 | below.  At the end of the stream, inflate() checks that its computed adler32 | 
 
 
 
 
 | 480 | checksum is equal to that saved by the compressor and returns Z_STREAM_END | 
 
 
 
 
 | 481 | only if the checksum is correct. | 
 
 
 
 
 | 482 |  | 
 
 
 
 
 | 483 | inflate() can decompress and check either zlib-wrapped or gzip-wrapped | 
 
 
 
 
 | 484 | deflate data.  The header type is detected automatically, if requested when | 
 
 
 
 
 | 485 | initializing with inflateInit2().  Any information contained in the gzip | 
 
 
 
 
 | 486 | header is not retained, so applications that need that information should | 
 
 
 
 
 | 487 | instead use raw inflate, see inflateInit2() below, or inflateBack() and | 
 
 
 
 
 | 488 | perform their own processing of the gzip header and trailer.  When processing | 
 
 
 
 
 | 489 | gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output | 
 
 
 
 
 | 490 | producted so far.  The CRC-32 is checked against the gzip trailer. | 
 
 
 
 
 | 491 |  | 
 
 
 
 
 | 492 | inflate() returns Z_OK if some progress has been made (more input processed | 
 
 
 
 
 | 493 | or more output produced), Z_STREAM_END if the end of the compressed data has | 
 
 
 
 
 | 494 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a | 
 
 
 
 
 | 495 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was | 
 
 
 
 
 | 496 | corrupted (input stream not conforming to the zlib format or incorrect check | 
 
 
 
 
 | 497 | value), Z_STREAM_ERROR if the stream structure was inconsistent (for example | 
 
 
 
 
 | 498 | next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, | 
 
 
 
 
 | 499 | Z_BUF_ERROR if no progress is possible or if there was not enough room in the | 
 
 
 
 
 | 500 | output buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and | 
 
 
 
 
 | 501 | inflate() can be called again with more input and more output space to | 
 
 
 
 
 | 502 | continue decompressing.  If Z_DATA_ERROR is returned, the application may | 
 
 
 
 
 | 503 | then call inflateSync() to look for a good compression block if a partial | 
 
 
 
 
 | 504 | recovery of the data is desired. | 
 
 
 
 
 | 505 | */ | 
 
 
 
 
 | 506 |  | 
 
 
 
 
 | 507 |  | 
 
 
 
 
 | 508 | ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); | 
 
 
 
 
 | 509 | /* | 
 
 
 
 
 | 510 | All dynamically allocated data structures for this stream are freed. | 
 
 
 
 
 | 511 | This function discards any unprocessed input and does not flush any pending | 
 
 
 
 
 | 512 | output. | 
 
 
 
 
 | 513 |  | 
 
 
 
 
 | 514 | inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state | 
 
 
 
 
 | 515 | was inconsistent.  In the error case, msg may be set but then points to a | 
 
 
 
 
 | 516 | static string (which must not be deallocated). | 
 
 
 
 
 | 517 | */ | 
 
 
 
 
 | 518 |  | 
 
 
 
 
 | 519 |  | 
 
 
 
 
 | 520 | /* Advanced functions */ | 
 
 
 
 
 | 521 |  | 
 
 
 
 
 | 522 | /* | 
 
 
 
 
 | 523 | The following functions are needed only in some special applications. | 
 
 
 
 
 | 524 | */ | 
 
 
 
 
 | 525 |  | 
 
 
 
 
 | 526 | /* | 
 
 
 
 
 | 527 | ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, | 
 
 
 
 
 | 528 | int  level, | 
 
 
 
 
 | 529 | int  method, | 
 
 
 
 
 | 530 | int  windowBits, | 
 
 
 
 
 | 531 | int  memLevel, | 
 
 
 
 
 | 532 | int  strategy)); | 
 
 
 
 
 | 533 |  | 
 
 
 
 
 | 534 | This is another version of deflateInit with more compression options.  The | 
 
 
 
 
 | 535 | fields next_in, zalloc, zfree and opaque must be initialized before by the | 
 
 
 
 
 | 536 | caller. | 
 
 
 
 
 | 537 |  | 
 
 
 
 
 | 538 | The method parameter is the compression method.  It must be Z_DEFLATED in | 
 
 
 
 
 | 539 | this version of the library. | 
 
 
 
 
 | 540 |  | 
 
 
 
 
 | 541 | The windowBits parameter is the base two logarithm of the window size | 
 
 
 
 
 | 542 | (the size of the history buffer).  It should be in the range 8..15 for this | 
 
 
 
 
 | 543 | version of the library.  Larger values of this parameter result in better | 
 
 
 
 
 | 544 | compression at the expense of memory usage.  The default value is 15 if | 
 
 
 
 
 | 545 | deflateInit is used instead. | 
 
 
 
 
 | 546 |  | 
 
 
 
 
 | 547 | windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits | 
 
 
 
 
 | 548 | determines the window size.  deflate() will then generate raw deflate data | 
 
 
 
 
 | 549 | with no zlib header or trailer, and will not compute an adler32 check value. | 
 
 
 
 
 | 550 |  | 
 
 
 
 
 | 551 | windowBits can also be greater than 15 for optional gzip encoding.  Add | 
 
 
 
 
 | 552 | 16 to windowBits to write a simple gzip header and trailer around the | 
 
 
 
 
 | 553 | compressed data instead of a zlib wrapper.  The gzip header will have no | 
 
 
 
 
 | 554 | file name, no extra data, no comment, no modification time (set to zero), no | 
 
 
 
 
 | 555 | header crc, and the operating system will be set to 255 (unknown).  If a | 
 
 
 
 
 | 556 | gzip stream is being written, strm->adler is a crc32 instead of an adler32. | 
 
 
 
 
 | 557 |  | 
 
 
 
 
 | 558 | The memLevel parameter specifies how much memory should be allocated | 
 
 
 
 
 | 559 | for the internal compression state.  memLevel=1 uses minimum memory but is | 
 
 
 
 
 | 560 | slow and reduces compression ratio; memLevel=9 uses maximum memory for | 
 
 
 
 
 | 561 | optimal speed.  The default value is 8.  See zconf.h for total memory usage | 
 
 
 
 
 | 562 | as a function of windowBits and memLevel. | 
 
 
 
 
 | 563 |  | 
 
 
 
 
 | 564 | The strategy parameter is used to tune the compression algorithm.  Use the | 
 
 
 
 
 | 565 | value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a | 
 
 
 
 
 | 566 | filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no | 
 
 
 
 
 | 567 | string match), or Z_RLE to limit match distances to one (run-length | 
 
 
 
 
 | 568 | encoding).  Filtered data consists mostly of small values with a somewhat | 
 
 
 
 
 | 569 | random distribution.  In this case, the compression algorithm is tuned to | 
 
 
 
 
 | 570 | compress them better.  The effect of Z_FILTERED is to force more Huffman | 
 
 
 
 
 | 571 | coding and less string matching; it is somewhat intermediate between | 
 
 
 
 
 | 572 | Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as | 
 
 
 
 
 | 573 | fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The | 
 
 
 
 
 | 574 | strategy parameter only affects the compression ratio but not the | 
 
 
 
 
 | 575 | correctness of the compressed output even if it is not set appropriately. | 
 
 
 
 
 | 576 | Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler | 
 
 
 
 
 | 577 | decoder for special applications. | 
 
 
 
 
 | 578 |  | 
 
 
 
 
 | 579 | deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 
 
 
 
 | 580 | memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid | 
 
 
 
 
 | 581 | method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is | 
 
 
 
 
 | 582 | incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is | 
 
 
 
 
 | 583 | set to null if there is no error message.  deflateInit2 does not perform any | 
 
 
 
 
 | 584 | compression: this will be done by deflate(). | 
 
 
 
 
 | 585 | */ | 
 
 
 
 
 | 586 |  | 
 
 
 
 
 | 587 | ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, | 
 
 
 
 
 | 588 | const Bytef *dictionary, | 
 
 
 
 
 | 589 | uInt  dictLength)); | 
 
 
 
 
 | 590 | /* | 
 
 
 
 
 | 591 | Initializes the compression dictionary from the given byte sequence | 
 
 
 
 
 | 592 | without producing any compressed output.  When using the zlib format, this | 
 
 
 
 
 | 593 | function must be called immediately after deflateInit, deflateInit2 or | 
 
 
 
 
 | 594 | deflateReset, and before any call of deflate.  When doing raw deflate, this | 
 
 
 
 
 | 595 | function must be called either before any call of deflate, or immediately | 
 
 
 
 
 | 596 | after the completion of a deflate block, i.e. after all input has been | 
 
 
 
 
 | 597 | consumed and all output has been delivered when using any of the flush | 
 
 
 
 
 | 598 | options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The | 
 
 
 
 
 | 599 | compressor and decompressor must use exactly the same dictionary (see | 
 
 
 
 
 | 600 | inflateSetDictionary). | 
 
 
 
 
 | 601 |  | 
 
 
 
 
 | 602 | The dictionary should consist of strings (byte sequences) that are likely | 
 
 
 
 
 | 603 | to be encountered later in the data to be compressed, with the most commonly | 
 
 
 
 
 | 604 | used strings preferably put towards the end of the dictionary.  Using a | 
 
 
 
 
 | 605 | dictionary is most useful when the data to be compressed is short and can be | 
 
 
 
 
 | 606 | predicted with good accuracy; the data can then be compressed better than | 
 
 
 
 
 | 607 | with the default empty dictionary. | 
 
 
 
 
 | 608 |  | 
 
 
 
 
 | 609 | Depending on the size of the compression data structures selected by | 
 
 
 
 
 | 610 | deflateInit or deflateInit2, a part of the dictionary may in effect be | 
 
 
 
 
 | 611 | discarded, for example if the dictionary is larger than the window size | 
 
 
 
 
 | 612 | provided in deflateInit or deflateInit2.  Thus the strings most likely to be | 
 
 
 
 
 | 613 | useful should be put at the end of the dictionary, not at the front.  In | 
 
 
 
 
 | 614 | addition, the current implementation of deflate will use at most the window | 
 
 
 
 
 | 615 | size minus 262 bytes of the provided dictionary. | 
 
 
 
 
 | 616 |  | 
 
 
 
 
 | 617 | Upon return of this function, strm->adler is set to the adler32 value | 
 
 
 
 
 | 618 | of the dictionary; the decompressor may later use this value to determine | 
 
 
 
 
 | 619 | which dictionary has been used by the compressor.  (The adler32 value | 
 
 
 
 
 | 620 | applies to the whole dictionary even if only a subset of the dictionary is | 
 
 
 
 
 | 621 | actually used by the compressor.) If a raw deflate was requested, then the | 
 
 
 
 
 | 622 | adler32 value is not computed and strm->adler is not set. | 
 
 
 
 
 | 623 |  | 
 
 
 
 
 | 624 | deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a | 
 
 
 
 
 | 625 | parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is | 
 
 
 
 
 | 626 | inconsistent (for example if deflate has already been called for this stream | 
 
 
 
 
 | 627 | or if not at a block boundary for raw deflate).  deflateSetDictionary does | 
 
 
 
 
 | 628 | not perform any compression: this will be done by deflate(). | 
 
 
 
 
 | 629 | */ | 
 
 
 
 
 | 630 |  | 
 
 
 
 
 | 631 | ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, | 
 
 
 
 
 | 632 | z_streamp source)); | 
 
 
 
 
 | 633 | /* | 
 
 
 
 
 | 634 | Sets the destination stream as a complete copy of the source stream. | 
 
 
 
 
 | 635 |  | 
 
 
 
 
 | 636 | This function can be useful when several compression strategies will be | 
 
 
 
 
 | 637 | tried, for example when there are several ways of pre-processing the input | 
 
 
 
 
 | 638 | data with a filter.  The streams that will be discarded should then be freed | 
 
 
 
 
 | 639 | by calling deflateEnd.  Note that deflateCopy duplicates the internal | 
 
 
 
 
 | 640 | compression state which can be quite large, so this strategy is slow and can | 
 
 
 
 
 | 641 | consume lots of memory. | 
 
 
 
 
 | 642 |  | 
 
 
 
 
 | 643 | deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | 
 
 
 
 
 | 644 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | 
 
 
 
 
 | 645 | (such as zalloc being Z_NULL).  msg is left unchanged in both source and | 
 
 
 
 
 | 646 | destination. | 
 
 
 
 
 | 647 | */ | 
 
 
 
 
 | 648 |  | 
 
 
 
 
 | 649 | ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); | 
 
 
 
 
 | 650 | /* | 
 
 
 
 
 | 651 | This function is equivalent to deflateEnd followed by deflateInit, | 
 
 
 
 
 | 652 | but does not free and reallocate all the internal compression state.  The | 
 
 
 
 
 | 653 | stream will keep the same compression level and any other attributes that | 
 
 
 
 
 | 654 | may have been set by deflateInit2. | 
 
 
 
 
 | 655 |  | 
 
 
 
 
 | 656 | deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 657 | stream state was inconsistent (such as zalloc or state being Z_NULL). | 
 
 
 
 
 | 658 | */ | 
 
 
 
 
 | 659 |  | 
 
 
 
 
 | 660 | ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, | 
 
 
 
 
 | 661 | int level, | 
 
 
 
 
 | 662 | int strategy)); | 
 
 
 
 
 | 663 | /* | 
 
 
 
 
 | 664 | Dynamically update the compression level and compression strategy.  The | 
 
 
 
 
 | 665 | interpretation of level and strategy is as in deflateInit2.  This can be | 
 
 
 
 
 | 666 | used to switch between compression and straight copy of the input data, or | 
 
 
 
 
 | 667 | to switch to a different kind of input data requiring a different strategy. | 
 
 
 
 
 | 668 | If the compression level is changed, the input available so far is | 
 
 
 
 
 | 669 | compressed with the old level (and may be flushed); the new level will take | 
 
 
 
 
 | 670 | effect only at the next call of deflate(). | 
 
 
 
 
 | 671 |  | 
 
 
 
 
 | 672 | Before the call of deflateParams, the stream state must be set as for | 
 
 
 
 
 | 673 | a call of deflate(), since the currently available input may have to be | 
 
 
 
 
 | 674 | compressed and flushed.  In particular, strm->avail_out must be non-zero. | 
 
 
 
 
 | 675 |  | 
 
 
 
 
 | 676 | deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source | 
 
 
 
 
 | 677 | stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if | 
 
 
 
 
 | 678 | strm->avail_out was zero. | 
 
 
 
 
 | 679 | */ | 
 
 
 
 
 | 680 |  | 
 
 
 
 
 | 681 | ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, | 
 
 
 
 
 | 682 | int good_length, | 
 
 
 
 
 | 683 | int max_lazy, | 
 
 
 
 
 | 684 | int nice_length, | 
 
 
 
 
 | 685 | int max_chain)); | 
 
 
 
 
 | 686 | /* | 
 
 
 
 
 | 687 | Fine tune deflate's internal compression parameters.  This should only be | 
 
 
 
 
 | 688 | used by someone who understands the algorithm used by zlib's deflate for | 
 
 
 
 
 | 689 | searching for the best matching string, and even then only by the most | 
 
 
 
 
 | 690 | fanatic optimizer trying to squeeze out the last compressed bit for their | 
 
 
 
 
 | 691 | specific input data.  Read the deflate.c source code for the meaning of the | 
 
 
 
 
 | 692 | max_lazy, good_length, nice_length, and max_chain parameters. | 
 
 
 
 
 | 693 |  | 
 
 
 
 
 | 694 | deflateTune() can be called after deflateInit() or deflateInit2(), and | 
 
 
 
 
 | 695 | returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. | 
 
 
 
 
 | 696 | */ | 
 
 
 
 
 | 697 |  | 
 
 
 
 
 | 698 | ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, | 
 
 
 
 
 | 699 | uLong sourceLen)); | 
 
 
 
 
 | 700 | /* | 
 
 
 
 
 | 701 | deflateBound() returns an upper bound on the compressed size after | 
 
 
 
 
 | 702 | deflation of sourceLen bytes.  It must be called after deflateInit() or | 
 
 
 
 
 | 703 | deflateInit2(), and after deflateSetHeader(), if used.  This would be used | 
 
 
 
 
 | 704 | to allocate an output buffer for deflation in a single pass, and so would be | 
 
 
 
 
 | 705 | called before deflate().  If that first deflate() call is provided the | 
 
 
 
 
 | 706 | sourceLen input bytes, an output buffer allocated to the size returned by | 
 
 
 
 
 | 707 | deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed | 
 
 
 
 
 | 708 | to return Z_STREAM_END.  Note that it is possible for the compressed size to | 
 
 
 
 
 | 709 | be larger than the value returned by deflateBound() if flush options other | 
 
 
 
 
 | 710 | than Z_FINISH or Z_NO_FLUSH are used. | 
 
 
 
 
 | 711 | */ | 
 
 
 
 
 | 712 |  | 
 
 
 
 
 | 713 | ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, | 
 
 
 
 
 | 714 | unsigned *pending, | 
 
 
 
 
 | 715 | int *bits)); | 
 
 
 
 
 | 716 | /* | 
 
 
 
 
 | 717 | deflatePending() returns the number of bytes and bits of output that have | 
 
 
 
 
 | 718 | been generated, but not yet provided in the available output.  The bytes not | 
 
 
 
 
 | 719 | provided would be due to the available output space having being consumed. | 
 
 
 
 
 | 720 | The number of bits of output not provided are between 0 and 7, where they | 
 
 
 
 
 | 721 | await more bits to join them in order to fill out a full byte.  If pending | 
 
 
 
 
 | 722 | or bits are Z_NULL, then those values are not set. | 
 
 
 
 
 | 723 |  | 
 
 
 
 
 | 724 | deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 725 | stream state was inconsistent. | 
 
 
 
 
 | 726 | */ | 
 
 
 
 
 | 727 |  | 
 
 
 
 
 | 728 | ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, | 
 
 
 
 
 | 729 | int bits, | 
 
 
 
 
 | 730 | int value)); | 
 
 
 
 
 | 731 | /* | 
 
 
 
 
 | 732 | deflatePrime() inserts bits in the deflate output stream.  The intent | 
 
 
 
 
 | 733 | is that this function is used to start off the deflate output with the bits | 
 
 
 
 
 | 734 | leftover from a previous deflate stream when appending to it.  As such, this | 
 
 
 
 
 | 735 | function can only be used for raw deflate, and must be used before the first | 
 
 
 
 
 | 736 | deflate() call after a deflateInit2() or deflateReset().  bits must be less | 
 
 
 
 
 | 737 | than or equal to 16, and that many of the least significant bits of value | 
 
 
 
 
 | 738 | will be inserted in the output. | 
 
 
 
 
 | 739 |  | 
 
 
 
 
 | 740 | deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough | 
 
 
 
 
 | 741 | room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the | 
 
 
 
 
 | 742 | source stream state was inconsistent. | 
 
 
 
 
 | 743 | */ | 
 
 
 
 
 | 744 |  | 
 
 
 
 
 | 745 | ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, | 
 
 
 
 
 | 746 | gz_headerp head)); | 
 
 
 
 
 | 747 | /* | 
 
 
 
 
 | 748 | deflateSetHeader() provides gzip header information for when a gzip | 
 
 
 
 
 | 749 | stream is requested by deflateInit2().  deflateSetHeader() may be called | 
 
 
 
 
 | 750 | after deflateInit2() or deflateReset() and before the first call of | 
 
 
 
 
 | 751 | deflate().  The text, time, os, extra field, name, and comment information | 
 
 
 
 
 | 752 | in the provided gz_header structure are written to the gzip header (xflag is | 
 
 
 
 
 | 753 | ignored -- the extra flags are set according to the compression level).  The | 
 
 
 
 
 | 754 | caller must assure that, if not Z_NULL, name and comment are terminated with | 
 
 
 
 
 | 755 | a zero byte, and that if extra is not Z_NULL, that extra_len bytes are | 
 
 
 
 
 | 756 | available there.  If hcrc is true, a gzip header crc is included.  Note that | 
 
 
 
 
 | 757 | the current versions of the command-line version of gzip (up through version | 
 
 
 
 
 | 758 | 1.3.x) do not support header crc's, and will report that it is a "multi-part | 
 
 
 
 
 | 759 | gzip file" and give up. | 
 
 
 
 
 | 760 |  | 
 
 
 
 
 | 761 | If deflateSetHeader is not used, the default gzip header has text false, | 
 
 
 
 
 | 762 | the time set to zero, and os set to 255, with no extra, name, or comment | 
 
 
 
 
 | 763 | fields.  The gzip header is returned to the default state by deflateReset(). | 
 
 
 
 
 | 764 |  | 
 
 
 
 
 | 765 | deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 766 | stream state was inconsistent. | 
 
 
 
 
 | 767 | */ | 
 
 
 
 
 | 768 |  | 
 
 
 
 
 | 769 | /* | 
 
 
 
 
 | 770 | ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, | 
 
 
 
 
 | 771 | int  windowBits)); | 
 
 
 
 
 | 772 |  | 
 
 
 
 
 | 773 | This is another version of inflateInit with an extra parameter.  The | 
 
 
 
 
 | 774 | fields next_in, avail_in, zalloc, zfree and opaque must be initialized | 
 
 
 
 
 | 775 | before by the caller. | 
 
 
 
 
 | 776 |  | 
 
 
 
 
 | 777 | The windowBits parameter is the base two logarithm of the maximum window | 
 
 
 
 
 | 778 | size (the size of the history buffer).  It should be in the range 8..15 for | 
 
 
 
 
 | 779 | this version of the library.  The default value is 15 if inflateInit is used | 
 
 
 
 
 | 780 | instead.  windowBits must be greater than or equal to the windowBits value | 
 
 
 
 
 | 781 | provided to deflateInit2() while compressing, or it must be equal to 15 if | 
 
 
 
 
 | 782 | deflateInit2() was not used.  If a compressed stream with a larger window | 
 
 
 
 
 | 783 | size is given as input, inflate() will return with the error code | 
 
 
 
 
 | 784 | Z_DATA_ERROR instead of trying to allocate a larger window. | 
 
 
 
 
 | 785 |  | 
 
 
 
 
 | 786 | windowBits can also be zero to request that inflate use the window size in | 
 
 
 
 
 | 787 | the zlib header of the compressed stream. | 
 
 
 
 
 | 788 |  | 
 
 
 
 
 | 789 | windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits | 
 
 
 
 
 | 790 | determines the window size.  inflate() will then process raw deflate data, | 
 
 
 
 
 | 791 | not looking for a zlib or gzip header, not generating a check value, and not | 
 
 
 
 
 | 792 | looking for any check values for comparison at the end of the stream.  This | 
 
 
 
 
 | 793 | is for use with other formats that use the deflate compressed data format | 
 
 
 
 
 | 794 | such as zip.  Those formats provide their own check values.  If a custom | 
 
 
 
 
 | 795 | format is developed using the raw deflate format for compressed data, it is | 
 
 
 
 
 | 796 | recommended that a check value such as an adler32 or a crc32 be applied to | 
 
 
 
 
 | 797 | the uncompressed data as is done in the zlib, gzip, and zip formats.  For | 
 
 
 
 
 | 798 | most applications, the zlib format should be used as is.  Note that comments | 
 
 
 
 
 | 799 | above on the use in deflateInit2() applies to the magnitude of windowBits. | 
 
 
 
 
 | 800 |  | 
 
 
 
 
 | 801 | windowBits can also be greater than 15 for optional gzip decoding.  Add | 
 
 
 
 
 | 802 | 32 to windowBits to enable zlib and gzip decoding with automatic header | 
 
 
 
 
 | 803 | detection, or add 16 to decode only the gzip format (the zlib format will | 
 
 
 
 
 | 804 | return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a | 
 
 
 
 
 | 805 | crc32 instead of an adler32. | 
 
 
 
 
 | 806 |  | 
 
 
 
 
 | 807 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 
 
 
 
 | 808 | memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | 
 
 
 
 
 | 809 | version assumed by the caller, or Z_STREAM_ERROR if the parameters are | 
 
 
 
 
 | 810 | invalid, such as a null pointer to the structure.  msg is set to null if | 
 
 
 
 
 | 811 | there is no error message.  inflateInit2 does not perform any decompression | 
 
 
 
 
 | 812 | apart from possibly reading the zlib header if present: actual decompression | 
 
 
 
 
 | 813 | will be done by inflate().  (So next_in and avail_in may be modified, but | 
 
 
 
 
 | 814 | next_out and avail_out are unused and unchanged.) The current implementation | 
 
 
 
 
 | 815 | of inflateInit2() does not process any header information -- that is | 
 
 
 
 
 | 816 | deferred until inflate() is called. | 
 
 
 
 
 | 817 | */ | 
 
 
 
 
 | 818 |  | 
 
 
 
 
 | 819 | ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, | 
 
 
 
 
 | 820 | const Bytef *dictionary, | 
 
 
 
 
 | 821 | uInt  dictLength)); | 
 
 
 
 
 | 822 | /* | 
 
 
 
 
 | 823 | Initializes the decompression dictionary from the given uncompressed byte | 
 
 
 
 
 | 824 | sequence.  This function must be called immediately after a call of inflate, | 
 
 
 
 
 | 825 | if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor | 
 
 
 
 
 | 826 | can be determined from the adler32 value returned by that call of inflate. | 
 
 
 
 
 | 827 | The compressor and decompressor must use exactly the same dictionary (see | 
 
 
 
 
 | 828 | deflateSetDictionary).  For raw inflate, this function can be called at any | 
 
 
 
 
 | 829 | time to set the dictionary.  If the provided dictionary is smaller than the | 
 
 
 
 
 | 830 | window and there is already data in the window, then the provided dictionary | 
 
 
 
 
 | 831 | will amend what's there.  The application must insure that the dictionary | 
 
 
 
 
 | 832 | that was used for compression is provided. | 
 
 
 
 
 | 833 |  | 
 
 
 
 
 | 834 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a | 
 
 
 
 
 | 835 | parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is | 
 
 
 
 
 | 836 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the | 
 
 
 
 
 | 837 | expected one (incorrect adler32 value).  inflateSetDictionary does not | 
 
 
 
 
 | 838 | perform any decompression: this will be done by subsequent calls of | 
 
 
 
 
 | 839 | inflate(). | 
 
 
 
 
 | 840 | */ | 
 
 
 
 
 | 841 |  | 
 
 
 
 
 | 842 | ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, | 
 
 
 
 
 | 843 | Bytef *dictionary, | 
 
 
 
 
 | 844 | uInt  *dictLength)); | 
 
 
 
 
 | 845 | /* | 
 
 
 
 
 | 846 | Returns the sliding dictionary being maintained by inflate.  dictLength is | 
 
 
 
 
 | 847 | set to the number of bytes in the dictionary, and that many bytes are copied | 
 
 
 
 
 | 848 | to dictionary.  dictionary must have enough space, where 32768 bytes is | 
 
 
 
 
 | 849 | always enough.  If inflateGetDictionary() is called with dictionary equal to | 
 
 
 
 
 | 850 | Z_NULL, then only the dictionary length is returned, and nothing is copied. | 
 
 
 
 
 | 851 | Similary, if dictLength is Z_NULL, then it is not set. | 
 
 
 
 
 | 852 |  | 
 
 
 
 
 | 853 | inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the | 
 
 
 
 
 | 854 | stream state is inconsistent. | 
 
 
 
 
 | 855 | */ | 
 
 
 
 
 | 856 |  | 
 
 
 
 
 | 857 | ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); | 
 
 
 
 
 | 858 | /* | 
 
 
 
 
 | 859 | Skips invalid compressed data until a possible full flush point (see above | 
 
 
 
 
 | 860 | for the description of deflate with Z_FULL_FLUSH) can be found, or until all | 
 
 
 
 
 | 861 | available input is skipped.  No output is provided. | 
 
 
 
 
 | 862 |  | 
 
 
 
 
 | 863 | inflateSync searches for a 00 00 FF FF pattern in the compressed data. | 
 
 
 
 
 | 864 | All full flush points have this pattern, but not all occurrences of this | 
 
 
 
 
 | 865 | pattern are full flush points. | 
 
 
 
 
 | 866 |  | 
 
 
 
 
 | 867 | inflateSync returns Z_OK if a possible full flush point has been found, | 
 
 
 
 
 | 868 | Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point | 
 
 
 
 
 | 869 | has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. | 
 
 
 
 
 | 870 | In the success case, the application may save the current current value of | 
 
 
 
 
 | 871 | total_in which indicates where valid compressed data was found.  In the | 
 
 
 
 
 | 872 | error case, the application may repeatedly call inflateSync, providing more | 
 
 
 
 
 | 873 | input each time, until success or end of the input data. | 
 
 
 
 
 | 874 | */ | 
 
 
 
 
 | 875 |  | 
 
 
 
 
 | 876 | ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, | 
 
 
 
 
 | 877 | z_streamp source)); | 
 
 
 
 
 | 878 | /* | 
 
 
 
 
 | 879 | Sets the destination stream as a complete copy of the source stream. | 
 
 
 
 
 | 880 |  | 
 
 
 
 
 | 881 | This function can be useful when randomly accessing a large stream.  The | 
 
 
 
 
 | 882 | first pass through the stream can periodically record the inflate state, | 
 
 
 
 
 | 883 | allowing restarting inflate at those points when randomly accessing the | 
 
 
 
 
 | 884 | stream. | 
 
 
 
 
 | 885 |  | 
 
 
 
 
 | 886 | inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | 
 
 
 
 
 | 887 | enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | 
 
 
 
 
 | 888 | (such as zalloc being Z_NULL).  msg is left unchanged in both source and | 
 
 
 
 
 | 889 | destination. | 
 
 
 
 
 | 890 | */ | 
 
 
 
 
 | 891 |  | 
 
 
 
 
 | 892 | ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); | 
 
 
 
 
 | 893 | /* | 
 
 
 
 
 | 894 | This function is equivalent to inflateEnd followed by inflateInit, | 
 
 
 
 
 | 895 | but does not free and reallocate all the internal decompression state.  The | 
 
 
 
 
 | 896 | stream will keep attributes that may have been set by inflateInit2. | 
 
 
 
 
 | 897 |  | 
 
 
 
 
 | 898 | inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 899 | stream state was inconsistent (such as zalloc or state being Z_NULL). | 
 
 
 
 
 | 900 | */ | 
 
 
 
 
 | 901 |  | 
 
 
 
 
 | 902 | ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, | 
 
 
 
 
 | 903 | int windowBits)); | 
 
 
 
 
 | 904 | /* | 
 
 
 
 
 | 905 | This function is the same as inflateReset, but it also permits changing | 
 
 
 
 
 | 906 | the wrap and window size requests.  The windowBits parameter is interpreted | 
 
 
 
 
 | 907 | the same as it is for inflateInit2. | 
 
 
 
 
 | 908 |  | 
 
 
 
 
 | 909 | inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 910 | stream state was inconsistent (such as zalloc or state being Z_NULL), or if | 
 
 
 
 
 | 911 | the windowBits parameter is invalid. | 
 
 
 
 
 | 912 | */ | 
 
 
 
 
 | 913 |  | 
 
 
 
 
 | 914 | ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, | 
 
 
 
 
 | 915 | int bits, | 
 
 
 
 
 | 916 | int value)); | 
 
 
 
 
 | 917 | /* | 
 
 
 
 
 | 918 | This function inserts bits in the inflate input stream.  The intent is | 
 
 
 
 
 | 919 | that this function is used to start inflating at a bit position in the | 
 
 
 
 
 | 920 | middle of a byte.  The provided bits will be used before any bytes are used | 
 
 
 
 
 | 921 | from next_in.  This function should only be used with raw inflate, and | 
 
 
 
 
 | 922 | should be used before the first inflate() call after inflateInit2() or | 
 
 
 
 
 | 923 | inflateReset().  bits must be less than or equal to 16, and that many of the | 
 
 
 
 
 | 924 | least significant bits of value will be inserted in the input. | 
 
 
 
 
 | 925 |  | 
 
 
 
 
 | 926 | If bits is negative, then the input stream bit buffer is emptied.  Then | 
 
 
 
 
 | 927 | inflatePrime() can be called again to put bits in the buffer.  This is used | 
 
 
 
 
 | 928 | to clear out bits leftover after feeding inflate a block description prior | 
 
 
 
 
 | 929 | to feeding inflate codes. | 
 
 
 
 
 | 930 |  | 
 
 
 
 
 | 931 | inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 932 | stream state was inconsistent. | 
 
 
 
 
 | 933 | */ | 
 
 
 
 
 | 934 |  | 
 
 
 
 
 | 935 | ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); | 
 
 
 
 
 | 936 | /* | 
 
 
 
 
 | 937 | This function returns two values, one in the lower 16 bits of the return | 
 
 
 
 
 | 938 | value, and the other in the remaining upper bits, obtained by shifting the | 
 
 
 
 
 | 939 | return value down 16 bits.  If the upper value is -1 and the lower value is | 
 
 
 
 
 | 940 | zero, then inflate() is currently decoding information outside of a block. | 
 
 
 
 
 | 941 | If the upper value is -1 and the lower value is non-zero, then inflate is in | 
 
 
 
 
 | 942 | the middle of a stored block, with the lower value equaling the number of | 
 
 
 
 
 | 943 | bytes from the input remaining to copy.  If the upper value is not -1, then | 
 
 
 
 
 | 944 | it is the number of bits back from the current bit position in the input of | 
 
 
 
 
 | 945 | the code (literal or length/distance pair) currently being processed.  In | 
 
 
 
 
 | 946 | that case the lower value is the number of bytes already emitted for that | 
 
 
 
 
 | 947 | code. | 
 
 
 
 
 | 948 |  | 
 
 
 
 
 | 949 | A code is being processed if inflate is waiting for more input to complete | 
 
 
 
 
 | 950 | decoding of the code, or if it has completed decoding but is waiting for | 
 
 
 
 
 | 951 | more output space to write the literal or match data. | 
 
 
 
 
 | 952 |  | 
 
 
 
 
 | 953 | inflateMark() is used to mark locations in the input data for random | 
 
 
 
 
 | 954 | access, which may be at bit positions, and to note those cases where the | 
 
 
 
 
 | 955 | output of a code may span boundaries of random access blocks.  The current | 
 
 
 
 
 | 956 | location in the input stream can be determined from avail_in and data_type | 
 
 
 
 
 | 957 | as noted in the description for the Z_BLOCK flush parameter for inflate. | 
 
 
 
 
 | 958 |  | 
 
 
 
 
 | 959 | inflateMark returns the value noted above or -1 << 16 if the provided | 
 
 
 
 
 | 960 | source stream state was inconsistent. | 
 
 
 
 
 | 961 | */ | 
 
 
 
 
 | 962 |  | 
 
 
 
 
 | 963 | ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, | 
 
 
 
 
 | 964 | gz_headerp head)); | 
 
 
 
 
 | 965 | /* | 
 
 
 
 
 | 966 | inflateGetHeader() requests that gzip header information be stored in the | 
 
 
 
 
 | 967 | provided gz_header structure.  inflateGetHeader() may be called after | 
 
 
 
 
 | 968 | inflateInit2() or inflateReset(), and before the first call of inflate(). | 
 
 
 
 
 | 969 | As inflate() processes the gzip stream, head->done is zero until the header | 
 
 
 
 
 | 970 | is completed, at which time head->done is set to one.  If a zlib stream is | 
 
 
 
 
 | 971 | being decoded, then head->done is set to -1 to indicate that there will be | 
 
 
 
 
 | 972 | no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be | 
 
 
 
 
 | 973 | used to force inflate() to return immediately after header processing is | 
 
 
 
 
 | 974 | complete and before any actual data is decompressed. | 
 
 
 
 
 | 975 |  | 
 
 
 
 
 | 976 | The text, time, xflags, and os fields are filled in with the gzip header | 
 
 
 
 
 | 977 | contents.  hcrc is set to true if there is a header CRC.  (The header CRC | 
 
 
 
 
 | 978 | was valid if done is set to one.) If extra is not Z_NULL, then extra_max | 
 
 
 
 
 | 979 | contains the maximum number of bytes to write to extra.  Once done is true, | 
 
 
 
 
 | 980 | extra_len contains the actual extra field length, and extra contains the | 
 
 
 
 
 | 981 | extra field, or that field truncated if extra_max is less than extra_len. | 
 
 
 
 
 | 982 | If name is not Z_NULL, then up to name_max characters are written there, | 
 
 
 
 
 | 983 | terminated with a zero unless the length is greater than name_max.  If | 
 
 
 
 
 | 984 | comment is not Z_NULL, then up to comm_max characters are written there, | 
 
 
 
 
 | 985 | terminated with a zero unless the length is greater than comm_max.  When any | 
 
 
 
 
 | 986 | of extra, name, or comment are not Z_NULL and the respective field is not | 
 
 
 
 
 | 987 | present in the header, then that field is set to Z_NULL to signal its | 
 
 
 
 
 | 988 | absence.  This allows the use of deflateSetHeader() with the returned | 
 
 
 
 
 | 989 | structure to duplicate the header.  However if those fields are set to | 
 
 
 
 
 | 990 | allocated memory, then the application will need to save those pointers | 
 
 
 
 
 | 991 | elsewhere so that they can be eventually freed. | 
 
 
 
 
 | 992 |  | 
 
 
 
 
 | 993 | If inflateGetHeader is not used, then the header information is simply | 
 
 
 
 
 | 994 | discarded.  The header is always checked for validity, including the header | 
 
 
 
 
 | 995 | CRC if present.  inflateReset() will reset the process to discard the header | 
 
 
 
 
 | 996 | information.  The application would need to call inflateGetHeader() again to | 
 
 
 
 
 | 997 | retrieve the header from the next gzip stream. | 
 
 
 
 
 | 998 |  | 
 
 
 
 
 | 999 | inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 
 
 
 
 | 1000 | stream state was inconsistent. | 
 
 
 
 
 | 1001 | */ | 
 
 
 
 
 | 1002 |  | 
 
 
 
 
 | 1003 | /* | 
 
 
 
 
 | 1004 | ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, | 
 
 
 
 
 | 1005 | unsigned char FAR *window)); | 
 
 
 
 
 | 1006 |  | 
 
 
 
 
 | 1007 | Initialize the internal stream state for decompression using inflateBack() | 
 
 
 
 
 | 1008 | calls.  The fields zalloc, zfree and opaque in strm must be initialized | 
 
 
 
 
 | 1009 | before the call.  If zalloc and zfree are Z_NULL, then the default library- | 
 
 
 
 
 | 1010 | derived memory allocation routines are used.  windowBits is the base two | 
 
 
 
 
 | 1011 | logarithm of the window size, in the range 8..15.  window is a caller | 
 
 
 
 
 | 1012 | supplied buffer of that size.  Except for special applications where it is | 
 
 
 
 
 | 1013 | assured that deflate was used with small window sizes, windowBits must be 15 | 
 
 
 
 
 | 1014 | and a 32K byte window must be supplied to be able to decompress general | 
 
 
 
 
 | 1015 | deflate streams. | 
 
 
 
 
 | 1016 |  | 
 
 
 
 
 | 1017 | See inflateBack() for the usage of these routines. | 
 
 
 
 
 | 1018 |  | 
 
 
 
 
 | 1019 | inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of | 
 
 
 
 
 | 1020 | the parameters are invalid, Z_MEM_ERROR if the internal state could not be | 
 
 
 
 
 | 1021 | allocated, or Z_VERSION_ERROR if the version of the library does not match | 
 
 
 
 
 | 1022 | the version of the header file. | 
 
 
 
 
 | 1023 | */ | 
 
 
 
 
 | 1024 |  | 
 
 
 
 
 | 1025 | typedef unsigned (*in_func) OF((void FAR *, | 
 
 
 
 
 | 1026 | z_const unsigned char FAR * FAR *)); | 
 
 
 
 
 | 1027 | typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); | 
 
 
 
 
 | 1028 |  | 
 
 
 
 
 | 1029 | ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, | 
 
 
 
 
 | 1030 | in_func in, void FAR *in_desc, | 
 
 
 
 
 | 1031 | out_func out, void FAR *out_desc)); | 
 
 
 
 
 | 1032 | /* | 
 
 
 
 
 | 1033 | inflateBack() does a raw inflate with a single call using a call-back | 
 
 
 
 
 | 1034 | interface for input and output.  This is potentially more efficient than | 
 
 
 
 
 | 1035 | inflate() for file i/o applications, in that it avoids copying between the | 
 
 
 
 
 | 1036 | output and the sliding window by simply making the window itself the output | 
 
 
 
 
 | 1037 | buffer.  inflate() can be faster on modern CPUs when used with large | 
 
 
 
 
 | 1038 | buffers.  inflateBack() trusts the application to not change the output | 
 
 
 
 
 | 1039 | buffer passed by the output function, at least until inflateBack() returns. | 
 
 
 
 
 | 1040 |  | 
 
 
 
 
 | 1041 | inflateBackInit() must be called first to allocate the internal state | 
 
 
 
 
 | 1042 | and to initialize the state with the user-provided window buffer. | 
 
 
 
 
 | 1043 | inflateBack() may then be used multiple times to inflate a complete, raw | 
 
 
 
 
 | 1044 | deflate stream with each call.  inflateBackEnd() is then called to free the | 
 
 
 
 
 | 1045 | allocated state. | 
 
 
 
 
 | 1046 |  | 
 
 
 
 
 | 1047 | A raw deflate stream is one with no zlib or gzip header or trailer. | 
 
 
 
 
 | 1048 | This routine would normally be used in a utility that reads zip or gzip | 
 
 
 
 
 | 1049 | files and writes out uncompressed files.  The utility would decode the | 
 
 
 
 
 | 1050 | header and process the trailer on its own, hence this routine expects only | 
 
 
 
 
 | 1051 | the raw deflate stream to decompress.  This is different from the normal | 
 
 
 
 
 | 1052 | behavior of inflate(), which expects either a zlib or gzip header and | 
 
 
 
 
 | 1053 | trailer around the deflate stream. | 
 
 
 
 
 | 1054 |  | 
 
 
 
 
 | 1055 | inflateBack() uses two subroutines supplied by the caller that are then | 
 
 
 
 
 | 1056 | called by inflateBack() for input and output.  inflateBack() calls those | 
 
 
 
 
 | 1057 | routines until it reads a complete deflate stream and writes out all of the | 
 
 
 
 
 | 1058 | uncompressed data, or until it encounters an error.  The function's | 
 
 
 
 
 | 1059 | parameters and return types are defined above in the in_func and out_func | 
 
 
 
 
 | 1060 | typedefs.  inflateBack() will call in(in_desc, &buf) which should return the | 
 
 
 
 
 | 1061 | number of bytes of provided input, and a pointer to that input in buf.  If | 
 
 
 
 
 | 1062 | there is no input available, in() must return zero--buf is ignored in that | 
 
 
 
 
 | 1063 | case--and inflateBack() will return a buffer error.  inflateBack() will call | 
 
 
 
 
 | 1064 | out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out() | 
 
 
 
 
 | 1065 | should return zero on success, or non-zero on failure.  If out() returns | 
 
 
 
 
 | 1066 | non-zero, inflateBack() will return with an error.  Neither in() nor out() | 
 
 
 
 
 | 1067 | are permitted to change the contents of the window provided to | 
 
 
 
 
 | 1068 | inflateBackInit(), which is also the buffer that out() uses to write from. | 
 
 
 
 
 | 1069 | The length written by out() will be at most the window size.  Any non-zero | 
 
 
 
 
 | 1070 | amount of input may be provided by in(). | 
 
 
 
 
 | 1071 |  | 
 
 
 
 
 | 1072 | For convenience, inflateBack() can be provided input on the first call by | 
 
 
 
 
 | 1073 | setting strm->next_in and strm->avail_in.  If that input is exhausted, then | 
 
 
 
 
 | 1074 | in() will be called.  Therefore strm->next_in must be initialized before | 
 
 
 
 
 | 1075 | calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called | 
 
 
 
 
 | 1076 | immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in | 
 
 
 
 
 | 1077 | must also be initialized, and then if strm->avail_in is not zero, input will | 
 
 
 
 
 | 1078 | initially be taken from strm->next_in[0 ..  strm->avail_in - 1]. | 
 
 
 
 
 | 1079 |  | 
 
 
 
 
 | 1080 | The in_desc and out_desc parameters of inflateBack() is passed as the | 
 
 
 
 
 | 1081 | first parameter of in() and out() respectively when they are called.  These | 
 
 
 
 
 | 1082 | descriptors can be optionally used to pass any information that the caller- | 
 
 
 
 
 | 1083 | supplied in() and out() functions need to do their job. | 
 
 
 
 
 | 1084 |  | 
 
 
 
 
 | 1085 | On return, inflateBack() will set strm->next_in and strm->avail_in to | 
 
 
 
 
 | 1086 | pass back any unused input that was provided by the last in() call.  The | 
 
 
 
 
 | 1087 | return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR | 
 
 
 
 
 | 1088 | if in() or out() returned an error, Z_DATA_ERROR if there was a format error | 
 
 
 
 
 | 1089 | in the deflate stream (in which case strm->msg is set to indicate the nature | 
 
 
 
 
 | 1090 | of the error), or Z_STREAM_ERROR if the stream was not properly initialized. | 
 
 
 
 
 | 1091 | In the case of Z_BUF_ERROR, an input or output error can be distinguished | 
 
 
 
 
 | 1092 | using strm->next_in which will be Z_NULL only if in() returned an error.  If | 
 
 
 
 
 | 1093 | strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning | 
 
 
 
 
 | 1094 | non-zero.  (in() will always be called before out(), so strm->next_in is | 
 
 
 
 
 | 1095 | assured to be defined if out() returns non-zero.) Note that inflateBack() | 
 
 
 
 
 | 1096 | cannot return Z_OK. | 
 
 
 
 
 | 1097 | */ | 
 
 
 
 
 | 1098 |  | 
 
 
 
 
 | 1099 | ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); | 
 
 
 
 
 | 1100 | /* | 
 
 
 
 
 | 1101 | All memory allocated by inflateBackInit() is freed. | 
 
 
 
 
 | 1102 |  | 
 
 
 
 
 | 1103 | inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream | 
 
 
 
 
 | 1104 | state was inconsistent. | 
 
 
 
 
 | 1105 | */ | 
 
 
 
 
 | 1106 |  | 
 
 
 
 
 | 1107 | ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); | 
 
 
 
 
 | 1108 | /* Return flags indicating compile-time options. | 
 
 
 
 
 | 1109 |  | 
 
 
 
 
 | 1110 | Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: | 
 
 
 
 
 | 1111 | 1.0: size of uInt | 
 
 
 
 
 | 1112 | 3.2: size of uLong | 
 
 
 
 
 | 1113 | 5.4: size of voidpf (pointer) | 
 
 
 
 
 | 1114 | 7.6: size of z_off_t | 
 
 
 
 
 | 1115 |  | 
 
 
 
 
 | 1116 | Compiler, assembler, and debug options: | 
 
 
 
 
 | 1117 | 8: DEBUG | 
 
 
 
 
 | 1118 | 9: ASMV or ASMINF -- use ASM code | 
 
 
 
 
 | 1119 | 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention | 
 
 
 
 
 | 1120 | 11: 0 (reserved) | 
 
 
 
 
 | 1121 |  | 
 
 
 
 
 | 1122 | One-time table building (smaller code, but not thread-safe if true): | 
 
 
 
 
 | 1123 | 12: BUILDFIXED -- build static block decoding tables when needed | 
 
 
 
 
 | 1124 | 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed | 
 
 
 
 
 | 1125 | 14,15: 0 (reserved) | 
 
 
 
 
 | 1126 |  | 
 
 
 
 
 | 1127 | Library content (indicates missing functionality): | 
 
 
 
 
 | 1128 | 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking | 
 
 
 
 
 | 1129 | deflate code when not needed) | 
 
 
 
 
 | 1130 | 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect | 
 
 
 
 
 | 1131 | and decode gzip streams (to avoid linking crc code) | 
 
 
 
 
 | 1132 | 18-19: 0 (reserved) | 
 
 
 
 
 | 1133 |  | 
 
 
 
 
 | 1134 | Operation variations (changes in library functionality): | 
 
 
 
 
 | 1135 | 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate | 
 
 
 
 
 | 1136 | 21: FASTEST -- deflate algorithm with only one, lowest compression level | 
 
 
 
 
 | 1137 | 22,23: 0 (reserved) | 
 
 
 
 
 | 1138 |  | 
 
 
 
 
 | 1139 | The sprintf variant used by gzprintf (zero is best): | 
 
 
 
 
 | 1140 | 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format | 
 
 
 
 
 | 1141 | 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! | 
 
 
 
 
 | 1142 | 26: 0 = returns value, 1 = void -- 1 means inferred string length returned | 
 
 
 
 
 | 1143 |  | 
 
 
 
 
 | 1144 | Remainder: | 
 
 
 
 
 | 1145 | 27-31: 0 (reserved) | 
 
 
 
 
 | 1146 | */ | 
 
 
 
 
 | 1147 |  | 
 
 
 
 
 | 1148 | #ifndef Z_SOLO | 
 
 
 
 
 | 1149 |  | 
 
 
 
 
 | 1150 | /* utility functions */ | 
 
 
 
 
 | 1151 |  | 
 
 
 
 
 | 1152 | /* | 
 
 
 
 
 | 1153 | The following utility functions are implemented on top of the basic | 
 
 
 
 
 | 1154 | stream-oriented functions.  To simplify the interface, some default options | 
 
 
 
 
 | 1155 | are assumed (compression level and memory usage, standard memory allocation | 
 
 
 
 
 | 1156 | functions).  The source code of these utility functions can be modified if | 
 
 
 
 
 | 1157 | you need special options. | 
 
 
 
 
 | 1158 | */ | 
 
 
 
 
 | 1159 |  | 
 
 
 
 
 | 1160 | ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen, | 
 
 
 
 
 | 1161 | const Bytef *source, uLong sourceLen)); | 
 
 
 
 
 | 1162 | /* | 
 
 
 
 
 | 1163 | Compresses the source buffer into the destination buffer.  sourceLen is | 
 
 
 
 
 | 1164 | the byte length of the source buffer.  Upon entry, destLen is the total size | 
 
 
 
 
 | 1165 | of the destination buffer, which must be at least the value returned by | 
 
 
 
 
 | 1166 | compressBound(sourceLen).  Upon exit, destLen is the actual size of the | 
 
 
 
 
 | 1167 | compressed buffer. | 
 
 
 
 
 | 1168 |  | 
 
 
 
 
 | 1169 | compress returns Z_OK if success, Z_MEM_ERROR if there was not | 
 
 
 
 
 | 1170 | enough memory, Z_BUF_ERROR if there was not enough room in the output | 
 
 
 
 
 | 1171 | buffer. | 
 
 
 
 
 | 1172 | */ | 
 
 
 
 
 | 1173 |  | 
 
 
 
 
 | 1174 | ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen, | 
 
 
 
 
 | 1175 | const Bytef *source, uLong sourceLen, | 
 
 
 
 
 | 1176 | int level)); | 
 
 
 
 
 | 1177 | /* | 
 
 
 
 
 | 1178 | Compresses the source buffer into the destination buffer.  The level | 
 
 
 
 
 | 1179 | parameter has the same meaning as in deflateInit.  sourceLen is the byte | 
 
 
 
 
 | 1180 | length of the source buffer.  Upon entry, destLen is the total size of the | 
 
 
 
 
 | 1181 | destination buffer, which must be at least the value returned by | 
 
 
 
 
 | 1182 | compressBound(sourceLen).  Upon exit, destLen is the actual size of the | 
 
 
 
 
 | 1183 | compressed buffer. | 
 
 
 
 
 | 1184 |  | 
 
 
 
 
 | 1185 | compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 
 
 
 
 | 1186 | memory, Z_BUF_ERROR if there was not enough room in the output buffer, | 
 
 
 
 
 | 1187 | Z_STREAM_ERROR if the level parameter is invalid. | 
 
 
 
 
 | 1188 | */ | 
 
 
 
 
 | 1189 |  | 
 
 
 
 
 | 1190 | ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); | 
 
 
 
 
 | 1191 | /* | 
 
 
 
 
 | 1192 | compressBound() returns an upper bound on the compressed size after | 
 
 
 
 
 | 1193 | compress() or compress2() on sourceLen bytes.  It would be used before a | 
 
 
 
 
 | 1194 | compress() or compress2() call to allocate the destination buffer. | 
 
 
 
 
 | 1195 | */ | 
 
 
 
 
 | 1196 |  | 
 
 
 
 
 | 1197 | ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen, | 
 
 
 
 
 | 1198 | const Bytef *source, uLong sourceLen)); | 
 
 
 
 
 | 1199 | /* | 
 
 
 
 
 | 1200 | Decompresses the source buffer into the destination buffer.  sourceLen is | 
 
 
 
 
 | 1201 | the byte length of the source buffer.  Upon entry, destLen is the total size | 
 
 
 
 
 | 1202 | of the destination buffer, which must be large enough to hold the entire | 
 
 
 
 
 | 1203 | uncompressed data.  (The size of the uncompressed data must have been saved | 
 
 
 
 
 | 1204 | previously by the compressor and transmitted to the decompressor by some | 
 
 
 
 
 | 1205 | mechanism outside the scope of this compression library.) Upon exit, destLen | 
 
 
 
 
 | 1206 | is the actual size of the uncompressed buffer. | 
 
 
 
 
 | 1207 |  | 
 
 
 
 
 | 1208 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not | 
 
 
 
 
 | 1209 | enough memory, Z_BUF_ERROR if there was not enough room in the output | 
 
 
 
 
 | 1210 | buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In | 
 
 
 
 
 | 1211 | the case where there is not enough room, uncompress() will fill the output | 
 
 
 
 
 | 1212 | buffer with the uncompressed data up to that point. | 
 
 
 
 
 | 1213 | */ | 
 
 
 
 
 | 1214 |  | 
 
 
 
 
 | 1215 | /* gzip file access functions */ | 
 
 
 
 
 | 1216 |  | 
 
 
 
 
 | 1217 | /* | 
 
 
 
 
 | 1218 | This library supports reading and writing files in gzip (.gz) format with | 
 
 
 
 
 | 1219 | an interface similar to that of stdio, using the functions that start with | 
 
 
 
 
 | 1220 | "gz".  The gzip format is different from the zlib format.  gzip is a gzip | 
 
 
 
 
 | 1221 | wrapper, documented in RFC 1952, wrapped around a deflate stream. | 
 
 
 
 
 | 1222 | */ | 
 
 
 
 
 | 1223 |  | 
 
 
 
 
 | 1224 | typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */ | 
 
 
 
 
 | 1225 |  | 
 
 
 
 
 | 1226 | /* | 
 
 
 
 
 | 1227 | ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); | 
 
 
 
 
 | 1228 |  | 
 
 
 
 
 | 1229 | Opens a gzip (.gz) file for reading or writing.  The mode parameter is as | 
 
 
 
 
 | 1230 | in fopen ("rb" or "wb") but can also include a compression level ("wb9") or | 
 
 
 
 
 | 1231 | a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only | 
 
 
 
 
 | 1232 | compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' | 
 
 
 
 
 | 1233 | for fixed code compression as in "wb9F".  (See the description of | 
 
 
 
 
 | 1234 | deflateInit2 for more information about the strategy parameter.)  'T' will | 
 
 
 
 
 | 1235 | request transparent writing or appending with no compression and not using | 
 
 
 
 
 | 1236 | the gzip format. | 
 
 
 
 
 | 1237 |  | 
 
 
 
 
 | 1238 | "a" can be used instead of "w" to request that the gzip stream that will | 
 
 
 
 
 | 1239 | be written be appended to the file.  "+" will result in an error, since | 
 
 
 
 
 | 1240 | reading and writing to the same gzip file is not supported.  The addition of | 
 
 
 
 
 | 1241 | "x" when writing will create the file exclusively, which fails if the file | 
 
 
 
 
 | 1242 | already exists.  On systems that support it, the addition of "e" when | 
 
 
 
 
 | 1243 | reading or writing will set the flag to close the file on an execve() call. | 
 
 
 
 
 | 1244 |  | 
 
 
 
 
 | 1245 | These functions, as well as gzip, will read and decode a sequence of gzip | 
 
 
 
 
 | 1246 | streams in a file.  The append function of gzopen() can be used to create | 
 
 
 
 
 | 1247 | such a file.  (Also see gzflush() for another way to do this.)  When | 
 
 
 
 
 | 1248 | appending, gzopen does not test whether the file begins with a gzip stream, | 
 
 
 
 
 | 1249 | nor does it look for the end of the gzip streams to begin appending.  gzopen | 
 
 
 
 
 | 1250 | will simply append a gzip stream to the existing file. | 
 
 
 
 
 | 1251 |  | 
 
 
 
 
 | 1252 | gzopen can be used to read a file which is not in gzip format; in this | 
 
 
 
 
 | 1253 | case gzread will directly read from the file without decompression.  When | 
 
 
 
 
 | 1254 | reading, this will be detected automatically by looking for the magic two- | 
 
 
 
 
 | 1255 | byte gzip header. | 
 
 
 
 
 | 1256 |  | 
 
 
 
 
 | 1257 | gzopen returns NULL if the file could not be opened, if there was | 
 
 
 
 
 | 1258 | insufficient memory to allocate the gzFile state, or if an invalid mode was | 
 
 
 
 
 | 1259 | specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). | 
 
 
 
 
 | 1260 | errno can be checked to determine if the reason gzopen failed was that the | 
 
 
 
 
 | 1261 | file could not be opened. | 
 
 
 
 
 | 1262 | */ | 
 
 
 
 
 | 1263 |  | 
 
 
 
 
 | 1264 | ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); | 
 
 
 
 
 | 1265 | /* | 
 
 
 
 
 | 1266 | gzdopen associates a gzFile with the file descriptor fd.  File descriptors | 
 
 
 
 
 | 1267 | are obtained from calls like open, dup, creat, pipe or fileno (if the file | 
 
 
 
 
 | 1268 | has been previously opened with fopen).  The mode parameter is as in gzopen. | 
 
 
 
 
 | 1269 |  | 
 
 
 
 
 | 1270 | The next call of gzclose on the returned gzFile will also close the file | 
 
 
 
 
 | 1271 | descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor | 
 
 
 
 
 | 1272 | fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, | 
 
 
 
 
 | 1273 | mode);.  The duplicated descriptor should be saved to avoid a leak, since | 
 
 
 
 
 | 1274 | gzdopen does not close fd if it fails.  If you are using fileno() to get the | 
 
 
 
 
 | 1275 | file descriptor from a FILE *, then you will have to use dup() to avoid | 
 
 
 
 
 | 1276 | double-close()ing the file descriptor.  Both gzclose() and fclose() will | 
 
 
 
 
 | 1277 | close the associated file descriptor, so they need to have different file | 
 
 
 
 
 | 1278 | descriptors. | 
 
 
 
 
 | 1279 |  | 
 
 
 
 
 | 1280 | gzdopen returns NULL if there was insufficient memory to allocate the | 
 
 
 
 
 | 1281 | gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not | 
 
 
 
 
 | 1282 | provided, or '+' was provided), or if fd is -1.  The file descriptor is not | 
 
 
 
 
 | 1283 | used until the next gz* read, write, seek, or close operation, so gzdopen | 
 
 
 
 
 | 1284 | will not detect if fd is invalid (unless fd is -1). | 
 
 
 
 
 | 1285 | */ | 
 
 
 
 
 | 1286 |  | 
 
 
 
 
 | 1287 | ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); | 
 
 
 
 
 | 1288 | /* | 
 
 
 
 
 | 1289 | Set the internal buffer size used by this library's functions.  The | 
 
 
 
 
 | 1290 | default buffer size is 8192 bytes.  This function must be called after | 
 
 
 
 
 | 1291 | gzopen() or gzdopen(), and before any other calls that read or write the | 
 
 
 
 
 | 1292 | file.  The buffer memory allocation is always deferred to the first read or | 
 
 
 
 
 | 1293 | write.  Two buffers are allocated, either both of the specified size when | 
 
 
 
 
 | 1294 | writing, or one of the specified size and the other twice that size when | 
 
 
 
 
 | 1295 | reading.  A larger buffer size of, for example, 64K or 128K bytes will | 
 
 
 
 
 | 1296 | noticeably increase the speed of decompression (reading). | 
 
 
 
 
 | 1297 |  | 
 
 
 
 
 | 1298 | The new buffer size also affects the maximum length for gzprintf(). | 
 
 
 
 
 | 1299 |  | 
 
 
 
 
 | 1300 | gzbuffer() returns 0 on success, or -1 on failure, such as being called | 
 
 
 
 
 | 1301 | too late. | 
 
 
 
 
 | 1302 | */ | 
 
 
 
 
 | 1303 |  | 
 
 
 
 
 | 1304 | ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); | 
 
 
 
 
 | 1305 | /* | 
 
 
 
 
 | 1306 | Dynamically update the compression level or strategy.  See the description | 
 
 
 
 
 | 1307 | of deflateInit2 for the meaning of these parameters. | 
 
 
 
 
 | 1308 |  | 
 
 
 
 
 | 1309 | gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not | 
 
 
 
 
 | 1310 | opened for writing. | 
 
 
 
 
 | 1311 | */ | 
 
 
 
 
 | 1312 |  | 
 
 
 
 
 | 1313 | ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); | 
 
 
 
 
 | 1314 | /* | 
 
 
 
 
 | 1315 | Reads the given number of uncompressed bytes from the compressed file.  If | 
 
 
 
 
 | 1316 | the input file is not in gzip format, gzread copies the given number of | 
 
 
 
 
 | 1317 | bytes into the buffer directly from the file. | 
 
 
 
 
 | 1318 |  | 
 
 
 
 
 | 1319 | After reaching the end of a gzip stream in the input, gzread will continue | 
 
 
 
 
 | 1320 | to read, looking for another gzip stream.  Any number of gzip streams may be | 
 
 
 
 
 | 1321 | concatenated in the input file, and will all be decompressed by gzread(). | 
 
 
 
 
 | 1322 | If something other than a gzip stream is encountered after a gzip stream, | 
 
 
 
 
 | 1323 | that remaining trailing garbage is ignored (and no error is returned). | 
 
 
 
 
 | 1324 |  | 
 
 
 
 
 | 1325 | gzread can be used to read a gzip file that is being concurrently written. | 
 
 
 
 
 | 1326 | Upon reaching the end of the input, gzread will return with the available | 
 
 
 
 
 | 1327 | data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then | 
 
 
 
 
 | 1328 | gzclearerr can be used to clear the end of file indicator in order to permit | 
 
 
 
 
 | 1329 | gzread to be tried again.  Z_OK indicates that a gzip stream was completed | 
 
 
 
 
 | 1330 | on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the | 
 
 
 
 
 | 1331 | middle of a gzip stream.  Note that gzread does not return -1 in the event | 
 
 
 
 
 | 1332 | of an incomplete gzip stream.  This error is deferred until gzclose(), which | 
 
 
 
 
 | 1333 | will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip | 
 
 
 
 
 | 1334 | stream.  Alternatively, gzerror can be used before gzclose to detect this | 
 
 
 
 
 | 1335 | case. | 
 
 
 
 
 | 1336 |  | 
 
 
 
 
 | 1337 | gzread returns the number of uncompressed bytes actually read, less than | 
 
 
 
 
 | 1338 | len for end of file, or -1 for error. | 
 
 
 
 
 | 1339 | */ | 
 
 
 
 
 | 1340 |  | 
 
 
 
 
 | 1341 | ZEXTERN int ZEXPORT gzwrite OF((gzFile file, | 
 
 
 
 
 | 1342 | voidpc buf, unsigned len)); | 
 
 
 
 
 | 1343 | /* | 
 
 
 
 
 | 1344 | Writes the given number of uncompressed bytes into the compressed file. | 
 
 
 
 
 | 1345 | gzwrite returns the number of uncompressed bytes written or 0 in case of | 
 
 
 
 
 | 1346 | error. | 
 
 
 
 
 | 1347 | */ | 
 
 
 
 
 | 1348 |  | 
 
 
 
 
 | 1349 | ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); | 
 
 
 
 
 | 1350 | /* | 
 
 
 
 
 | 1351 | Converts, formats, and writes the arguments to the compressed file under | 
 
 
 
 
 | 1352 | control of the format string, as in fprintf.  gzprintf returns the number of | 
 
 
 
 
 | 1353 | uncompressed bytes actually written, or 0 in case of error.  The number of | 
 
 
 
 
 | 1354 | uncompressed bytes written is limited to 8191, or one less than the buffer | 
 
 
 
 
 | 1355 | size given to gzbuffer().  The caller should assure that this limit is not | 
 
 
 
 
 | 1356 | exceeded.  If it is exceeded, then gzprintf() will return an error (0) with | 
 
 
 
 
 | 1357 | nothing written.  In this case, there may also be a buffer overflow with | 
 
 
 
 
 | 1358 | unpredictable consequences, which is possible only if zlib was compiled with | 
 
 
 
 
 | 1359 | the insecure functions sprintf() or vsprintf() because the secure snprintf() | 
 
 
 
 
 | 1360 | or vsnprintf() functions were not available.  This can be determined using | 
 
 
 
 
 | 1361 | zlibCompileFlags(). | 
 
 
 
 
 | 1362 | */ | 
 
 
 
 
 | 1363 |  | 
 
 
 
 
 | 1364 | ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); | 
 
 
 
 
 | 1365 | /* | 
 
 
 
 
 | 1366 | Writes the given null-terminated string to the compressed file, excluding | 
 
 
 
 
 | 1367 | the terminating null character. | 
 
 
 
 
 | 1368 |  | 
 
 
 
 
 | 1369 | gzputs returns the number of characters written, or -1 in case of error. | 
 
 
 
 
 | 1370 | */ | 
 
 
 
 
 | 1371 |  | 
 
 
 
 
 | 1372 | ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); | 
 
 
 
 
 | 1373 | /* | 
 
 
 
 
 | 1374 | Reads bytes from the compressed file until len-1 characters are read, or a | 
 
 
 
 
 | 1375 | newline character is read and transferred to buf, or an end-of-file | 
 
 
 
 
 | 1376 | condition is encountered.  If any characters are read or if len == 1, the | 
 
 
 
 
 | 1377 | string is terminated with a null character.  If no characters are read due | 
 
 
 
 
 | 1378 | to an end-of-file or len < 1, then the buffer is left untouched. | 
 
 
 
 
 | 1379 |  | 
 
 
 
 
 | 1380 | gzgets returns buf which is a null-terminated string, or it returns NULL | 
 
 
 
 
 | 1381 | for end-of-file or in case of error.  If there was an error, the contents at | 
 
 
 
 
 | 1382 | buf are indeterminate. | 
 
 
 
 
 | 1383 | */ | 
 
 
 
 
 | 1384 |  | 
 
 
 
 
 | 1385 | ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); | 
 
 
 
 
 | 1386 | /* | 
 
 
 
 
 | 1387 | Writes c, converted to an unsigned char, into the compressed file.  gzputc | 
 
 
 
 
 | 1388 | returns the value that was written, or -1 in case of error. | 
 
 
 
 
 | 1389 | */ | 
 
 
 
 
 | 1390 |  | 
 
 
 
 
 | 1391 | ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); | 
 
 
 
 
 | 1392 | /* | 
 
 
 
 
 | 1393 | Reads one byte from the compressed file.  gzgetc returns this byte or -1 | 
 
 
 
 
 | 1394 | in case of end of file or error.  This is implemented as a macro for speed. | 
 
 
 
 
 | 1395 | As such, it does not do all of the checking the other functions do.  I.e. | 
 
 
 
 
 | 1396 | it does not check to see if file is NULL, nor whether the structure file | 
 
 
 
 
 | 1397 | points to has been clobbered or not. | 
 
 
 
 
 | 1398 | */ | 
 
 
 
 
 | 1399 |  | 
 
 
 
 
 | 1400 | ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); | 
 
 
 
 
 | 1401 | /* | 
 
 
 
 
 | 1402 | Push one character back onto the stream to be read as the first character | 
 
 
 
 
 | 1403 | on the next read.  At least one character of push-back is allowed. | 
 
 
 
 
 | 1404 | gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will | 
 
 
 
 
 | 1405 | fail if c is -1, and may fail if a character has been pushed but not read | 
 
 
 
 
 | 1406 | yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the | 
 
 
 
 
 | 1407 | output buffer size of pushed characters is allowed.  (See gzbuffer above.) | 
 
 
 
 
 | 1408 | The pushed character will be discarded if the stream is repositioned with | 
 
 
 
 
 | 1409 | gzseek() or gzrewind(). | 
 
 
 
 
 | 1410 | */ | 
 
 
 
 
 | 1411 |  | 
 
 
 
 
 | 1412 | ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); | 
 
 
 
 
 | 1413 | /* | 
 
 
 
 
 | 1414 | Flushes all pending output into the compressed file.  The parameter flush | 
 
 
 
 
 | 1415 | is as in the deflate() function.  The return value is the zlib error number | 
 
 
 
 
 | 1416 | (see function gzerror below).  gzflush is only permitted when writing. | 
 
 
 
 
 | 1417 |  | 
 
 
 
 
 | 1418 | If the flush parameter is Z_FINISH, the remaining data is written and the | 
 
 
 
 
 | 1419 | gzip stream is completed in the output.  If gzwrite() is called again, a new | 
 
 
 
 
 | 1420 | gzip stream will be started in the output.  gzread() is able to read such | 
 
 
 
 
 | 1421 | concatented gzip streams. | 
 
 
 
 
 | 1422 |  | 
 
 
 
 
 | 1423 | gzflush should be called only when strictly necessary because it will | 
 
 
 
 
 | 1424 | degrade compression if called too often. | 
 
 
 
 
 | 1425 | */ | 
 
 
 
 
 | 1426 |  | 
 
 
 
 
 | 1427 | /* | 
 
 
 
 
 | 1428 | ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, | 
 
 
 
 
 | 1429 | z_off_t offset, int whence)); | 
 
 
 
 
 | 1430 |  | 
 
 
 
 
 | 1431 | Sets the starting position for the next gzread or gzwrite on the given | 
 
 
 
 
 | 1432 | compressed file.  The offset represents a number of bytes in the | 
 
 
 
 
 | 1433 | uncompressed data stream.  The whence parameter is defined as in lseek(2); | 
 
 
 
 
 | 1434 | the value SEEK_END is not supported. | 
 
 
 
 
 | 1435 |  | 
 
 
 
 
 | 1436 | If the file is opened for reading, this function is emulated but can be | 
 
 
 
 
 | 1437 | extremely slow.  If the file is opened for writing, only forward seeks are | 
 
 
 
 
 | 1438 | supported; gzseek then compresses a sequence of zeroes up to the new | 
 
 
 
 
 | 1439 | starting position. | 
 
 
 
 
 | 1440 |  | 
 
 
 
 
 | 1441 | gzseek returns the resulting offset location as measured in bytes from | 
 
 
 
 
 | 1442 | the beginning of the uncompressed stream, or -1 in case of error, in | 
 
 
 
 
 | 1443 | particular if the file is opened for writing and the new starting position | 
 
 
 
 
 | 1444 | would be before the current position. | 
 
 
 
 
 | 1445 | */ | 
 
 
 
 
 | 1446 |  | 
 
 
 
 
 | 1447 | ZEXTERN int ZEXPORT    gzrewind OF((gzFile file)); | 
 
 
 
 
 | 1448 | /* | 
 
 
 
 
 | 1449 | Rewinds the given file. This function is supported only for reading. | 
 
 
 
 
 | 1450 |  | 
 
 
 
 
 | 1451 | gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) | 
 
 
 
 
 | 1452 | */ | 
 
 
 
 
 | 1453 |  | 
 
 
 
 
 | 1454 | /* | 
 
 
 
 
 | 1455 | ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file)); | 
 
 
 
 
 | 1456 |  | 
 
 
 
 
 | 1457 | Returns the starting position for the next gzread or gzwrite on the given | 
 
 
 
 
 | 1458 | compressed file.  This position represents a number of bytes in the | 
 
 
 
 
 | 1459 | uncompressed data stream, and is zero when starting, even if appending or | 
 
 
 
 
 | 1460 | reading a gzip stream from the middle of a file using gzdopen(). | 
 
 
 
 
 | 1461 |  | 
 
 
 
 
 | 1462 | gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) | 
 
 
 
 
 | 1463 | */ | 
 
 
 
 
 | 1464 |  | 
 
 
 
 
 | 1465 | /* | 
 
 
 
 
 | 1466 | ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); | 
 
 
 
 
 | 1467 |  | 
 
 
 
 
 | 1468 | Returns the current offset in the file being read or written.  This offset | 
 
 
 
 
 | 1469 | includes the count of bytes that precede the gzip stream, for example when | 
 
 
 
 
 | 1470 | appending or when using gzdopen() for reading.  When reading, the offset | 
 
 
 
 
 | 1471 | does not include as yet unused buffered input.  This information can be used | 
 
 
 
 
 | 1472 | for a progress indicator.  On error, gzoffset() returns -1. | 
 
 
 
 
 | 1473 | */ | 
 
 
 
 
 | 1474 |  | 
 
 
 
 
 | 1475 | ZEXTERN int ZEXPORT gzeof OF((gzFile file)); | 
 
 
 
 
 | 1476 | /* | 
 
 
 
 
 | 1477 | Returns true (1) if the end-of-file indicator has been set while reading, | 
 
 
 
 
 | 1478 | false (0) otherwise.  Note that the end-of-file indicator is set only if the | 
 
 
 
 
 | 1479 | read tried to go past the end of the input, but came up short.  Therefore, | 
 
 
 
 
 | 1480 | just like feof(), gzeof() may return false even if there is no more data to | 
 
 
 
 
 | 1481 | read, in the event that the last read request was for the exact number of | 
 
 
 
 
 | 1482 | bytes remaining in the input file.  This will happen if the input file size | 
 
 
 
 
 | 1483 | is an exact multiple of the buffer size. | 
 
 
 
 
 | 1484 |  | 
 
 
 
 
 | 1485 | If gzeof() returns true, then the read functions will return no more data, | 
 
 
 
 
 | 1486 | unless the end-of-file indicator is reset by gzclearerr() and the input file | 
 
 
 
 
 | 1487 | has grown since the previous end of file was detected. | 
 
 
 
 
 | 1488 | */ | 
 
 
 
 
 | 1489 |  | 
 
 
 
 
 | 1490 | ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); | 
 
 
 
 
 | 1491 | /* | 
 
 
 
 
 | 1492 | Returns true (1) if file is being copied directly while reading, or false | 
 
 
 
 
 | 1493 | (0) if file is a gzip stream being decompressed. | 
 
 
 
 
 | 1494 |  | 
 
 
 
 
 | 1495 | If the input file is empty, gzdirect() will return true, since the input | 
 
 
 
 
 | 1496 | does not contain a gzip stream. | 
 
 
 
 
 | 1497 |  | 
 
 
 
 
 | 1498 | If gzdirect() is used immediately after gzopen() or gzdopen() it will | 
 
 
 
 
 | 1499 | cause buffers to be allocated to allow reading the file to determine if it | 
 
 
 
 
 | 1500 | is a gzip file.  Therefore if gzbuffer() is used, it should be called before | 
 
 
 
 
 | 1501 | gzdirect(). | 
 
 
 
 
 | 1502 |  | 
 
 
 
 
 | 1503 | When writing, gzdirect() returns true (1) if transparent writing was | 
 
 
 
 
 | 1504 | requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note: | 
 
 
 
 
 | 1505 | gzdirect() is not needed when writing.  Transparent writing must be | 
 
 
 
 
 | 1506 | explicitly requested, so the application already knows the answer.  When | 
 
 
 
 
 | 1507 | linking statically, using gzdirect() will include all of the zlib code for | 
 
 
 
 
 | 1508 | gzip file reading and decompression, which may not be desired.) | 
 
 
 
 
 | 1509 | */ | 
 
 
 
 
 | 1510 |  | 
 
 
 
 
 | 1511 | ZEXTERN int ZEXPORT    gzclose OF((gzFile file)); | 
 
 
 
 
 | 1512 | /* | 
 
 
 
 
 | 1513 | Flushes all pending output if necessary, closes the compressed file and | 
 
 
 
 
 | 1514 | deallocates the (de)compression state.  Note that once file is closed, you | 
 
 
 
 
 | 1515 | cannot call gzerror with file, since its structures have been deallocated. | 
 
 
 
 
 | 1516 | gzclose must not be called more than once on the same file, just as free | 
 
 
 
 
 | 1517 | must not be called more than once on the same allocation. | 
 
 
 
 
 | 1518 |  | 
 
 
 
 
 | 1519 | gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a | 
 
 
 
 
 | 1520 | file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the | 
 
 
 
 
 | 1521 | last read ended in the middle of a gzip stream, or Z_OK on success. | 
 
 
 
 
 | 1522 | */ | 
 
 
 
 
 | 1523 |  | 
 
 
 
 
 | 1524 | ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); | 
 
 
 
 
 | 1525 | ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); | 
 
 
 
 
 | 1526 | /* | 
 
 
 
 
 | 1527 | Same as gzclose(), but gzclose_r() is only for use when reading, and | 
 
 
 
 
 | 1528 | gzclose_w() is only for use when writing or appending.  The advantage to | 
 
 
 
 
 | 1529 | using these instead of gzclose() is that they avoid linking in zlib | 
 
 
 
 
 | 1530 | compression or decompression code that is not used when only reading or only | 
 
 
 
 
 | 1531 | writing respectively.  If gzclose() is used, then both compression and | 
 
 
 
 
 | 1532 | decompression code will be included the application when linking to a static | 
 
 
 
 
 | 1533 | zlib library. | 
 
 
 
 
 | 1534 | */ | 
 
 
 
 
 | 1535 |  | 
 
 
 
 
 | 1536 | ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); | 
 
 
 
 
 | 1537 | /* | 
 
 
 
 
 | 1538 | Returns the error message for the last error which occurred on the given | 
 
 
 
 
 | 1539 | compressed file.  errnum is set to zlib error number.  If an error occurred | 
 
 
 
 
 | 1540 | in the file system and not in the compression library, errnum is set to | 
 
 
 
 
 | 1541 | Z_ERRNO and the application may consult errno to get the exact error code. | 
 
 
 
 
 | 1542 |  | 
 
 
 
 
 | 1543 | The application must not modify the returned string.  Future calls to | 
 
 
 
 
 | 1544 | this function may invalidate the previously returned string.  If file is | 
 
 
 
 
 | 1545 | closed, then the string previously returned by gzerror will no longer be | 
 
 
 
 
 | 1546 | available. | 
 
 
 
 
 | 1547 |  | 
 
 
 
 
 | 1548 | gzerror() should be used to distinguish errors from end-of-file for those | 
 
 
 
 
 | 1549 | functions above that do not distinguish those cases in their return values. | 
 
 
 
 
 | 1550 | */ | 
 
 
 
 
 | 1551 |  | 
 
 
 
 
 | 1552 | ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); | 
 
 
 
 
 | 1553 | /* | 
 
 
 
 
 | 1554 | Clears the error and end-of-file flags for file.  This is analogous to the | 
 
 
 
 
 | 1555 | clearerr() function in stdio.  This is useful for continuing to read a gzip | 
 
 
 
 
 | 1556 | file that is being written concurrently. | 
 
 
 
 
 | 1557 | */ | 
 
 
 
 
 | 1558 |  | 
 
 
 
 
 | 1559 | #endif /* !Z_SOLO */ | 
 
 
 
 
 | 1560 |  | 
 
 
 
 
 | 1561 | /* checksum functions */ | 
 
 
 
 
 | 1562 |  | 
 
 
 
 
 | 1563 | /* | 
 
 
 
 
 | 1564 | These functions are not related to compression but are exported | 
 
 
 
 
 | 1565 | anyway because they might be useful in applications using the compression | 
 
 
 
 
 | 1566 | library. | 
 
 
 
 
 | 1567 | */ | 
 
 
 
 
 | 1568 |  | 
 
 
 
 
 | 1569 | ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); | 
 
 
 
 
 | 1570 | /* | 
 
 
 
 
 | 1571 | Update a running Adler-32 checksum with the bytes buf[0..len-1] and | 
 
 
 
 
 | 1572 | return the updated checksum.  If buf is Z_NULL, this function returns the | 
 
 
 
 
 | 1573 | required initial value for the checksum. | 
 
 
 
 
 | 1574 |  | 
 
 
 
 
 | 1575 | An Adler-32 checksum is almost as reliable as a CRC32 but can be computed | 
 
 
 
 
 | 1576 | much faster. | 
 
 
 
 
 | 1577 |  | 
 
 
 
 
 | 1578 | Usage example: | 
 
 
 
 
 | 1579 |  | 
 
 
 
 
 | 1580 | uLong adler = adler32(0L, Z_NULL, 0); | 
 
 
 
 
 | 1581 |  | 
 
 
 
 
 | 1582 | while (read_buffer(buffer, length) != EOF) { | 
 
 
 
 
 | 1583 | adler = adler32(adler, buffer, length); | 
 
 
 
 
 | 1584 | } | 
 
 
 
 
 | 1585 | if (adler != original_adler) error(); | 
 
 
 
 
 | 1586 | */ | 
 
 
 
 
 | 1587 |  | 
 
 
 
 
 | 1588 | /* | 
 
 
 
 
 | 1589 | ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, | 
 
 
 
 
 | 1590 | z_off_t len2)); | 
 
 
 
 
 | 1591 |  | 
 
 
 
 
 | 1592 | Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1 | 
 
 
 
 
 | 1593 | and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for | 
 
 
 
 
 | 1594 | each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of | 
 
 
 
 
 | 1595 | seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note | 
 
 
 
 
 | 1596 | that the z_off_t type (like off_t) is a signed integer.  If len2 is | 
 
 
 
 
 | 1597 | negative, the result has no meaning or utility. | 
 
 
 
 
 | 1598 | */ | 
 
 
 
 
 | 1599 |  | 
 
 
 
 
 | 1600 | ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len)); | 
 
 
 
 
 | 1601 | /* | 
 
 
 
 
 | 1602 | Update a running CRC-32 with the bytes buf[0..len-1] and return the | 
 
 
 
 
 | 1603 | updated CRC-32.  If buf is Z_NULL, this function returns the required | 
 
 
 
 
 | 1604 | initial value for the crc.  Pre- and post-conditioning (one's complement) is | 
 
 
 
 
 | 1605 | performed within this function so it shouldn't be done by the application. | 
 
 
 
 
 | 1606 |  | 
 
 
 
 
 | 1607 | Usage example: | 
 
 
 
 
 | 1608 |  | 
 
 
 
 
 | 1609 | uLong crc = crc32(0L, Z_NULL, 0); | 
 
 
 
 
 | 1610 |  | 
 
 
 
 
 | 1611 | while (read_buffer(buffer, length) != EOF) { | 
 
 
 
 
 | 1612 | crc = crc32(crc, buffer, length); | 
 
 
 
 
 | 1613 | } | 
 
 
 
 
 | 1614 | if (crc != original_crc) error(); | 
 
 
 
 
 | 1615 | */ | 
 
 
 
 
 | 1616 |  | 
 
 
 
 
 | 1617 | /* | 
 
 
 
 
 | 1618 | ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); | 
 
 
 
 
 | 1619 |  | 
 
 
 
 
 | 1620 | Combine two CRC-32 check values into one.  For two sequences of bytes, | 
 
 
 
 
 | 1621 | seq1 and seq2 with lengths len1 and len2, CRC-32 check values were | 
 
 
 
 
 | 1622 | calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32 | 
 
 
 
 
 | 1623 | check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and | 
 
 
 
 
 | 1624 | len2. | 
 
 
 
 
 | 1625 | */ | 
 
 
 
 
 | 1626 |  | 
 
 
 
 
 | 1627 |  | 
 
 
 
 
 | 1628 | /* various hacks, don't look :) */ | 
 
 
 
 
 | 1629 |  | 
 
 
 
 
 | 1630 | /* deflateInit and inflateInit are macros to allow checking the zlib version | 
 
 
 
 
 | 1631 | * and the compiler's view of z_stream: | 
 
 
 
 
 | 1632 | */ | 
 
 
 
 
 | 1633 | ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, | 
 
 
 
 
 | 1634 | const char *version, int stream_size)); | 
 
 
 
 
 | 1635 | ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, | 
 
 
 
 
 | 1636 | const char *version, int stream_size)); | 
 
 
 
 
 | 1637 | ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method, | 
 
 
 
 
 | 1638 | int windowBits, int memLevel, | 
 
 
 
 
 | 1639 | int strategy, const char *version, | 
 
 
 
 
 | 1640 | int stream_size)); | 
 
 
 
 
 | 1641 | ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits, | 
 
 
 
 
 | 1642 | const char *version, int stream_size)); | 
 
 
 
 
 | 1643 | ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, | 
 
 
 
 
 | 1644 | unsigned char FAR *window, | 
 
 
 
 
 | 1645 | const char *version, | 
 
 
 
 
 | 1646 | int stream_size)); | 
 
 
 
 
 | 1647 | #define deflateInit(strm, level) \ | 
 
 
 
 
 | 1648 | deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) | 
 
 
 
 
 | 1649 | #define inflateInit(strm) \ | 
 
 
 
 
 | 1650 | inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) | 
 
 
 
 
 | 1651 | #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | 
 
 
 
 
 | 1652 | deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | 
 
 
 
 
 | 1653 | (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) | 
 
 
 
 
 | 1654 | #define inflateInit2(strm, windowBits) \ | 
 
 
 
 
 | 1655 | inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ | 
 
 
 
 
 | 1656 | (int)sizeof(z_stream)) | 
 
 
 
 
 | 1657 | #define inflateBackInit(strm, windowBits, window) \ | 
 
 
 
 
 | 1658 | inflateBackInit_((strm), (windowBits), (window), \ | 
 
 
 
 
 | 1659 | ZLIB_VERSION, (int)sizeof(z_stream)) | 
 
 
 
 
 | 1660 |  | 
 
 
 
 
 | 1661 | #ifndef Z_SOLO | 
 
 
 
 
 | 1662 |  | 
 
 
 
 
 | 1663 | /* gzgetc() macro and its supporting function and exposed data structure.  Note | 
 
 
 
 
 | 1664 | * that the real internal state is much larger than the exposed structure. | 
 
 
 
 
 | 1665 | * This abbreviated structure exposes just enough for the gzgetc() macro.  The | 
 
 
 
 
 | 1666 | * user should not mess with these exposed elements, since their names or | 
 
 
 
 
 | 1667 | * behavior could change in the future, perhaps even capriciously.  They can | 
 
 
 
 
 | 1668 | * only be used by the gzgetc() macro.  You have been warned. | 
 
 
 
 
 | 1669 | */ | 
 
 
 
 
 | 1670 | struct gzFile_s { | 
 
 
 
 
 | 1671 | unsigned have; | 
 
 
 
 
 | 1672 | unsigned char *next; | 
 
 
 
 
 | 1673 | z_off64_t pos; | 
 
 
 
 
 | 1674 | }; | 
 
 
 
 
 | 1675 | ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */ | 
 
 
 
 
 | 1676 | #ifdef Z_PREFIX_SET | 
 
 
 
 
 | 1677 | #  undef z_gzgetc | 
 
 
 
 
 | 1678 | #  define z_gzgetc(g) \ | 
 
 
 
 
 | 1679 | ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) | 
 
 
 
 
 | 1680 | #else | 
 
 
 
 
 | 1681 | #  define gzgetc(g) \ | 
 
 
 
 
 | 1682 | ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) | 
 
 
 
 
 | 1683 | #endif | 
 
 
 
 
 | 1684 |  | 
 
 
 
 
 | 1685 | /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or | 
 
 
 
 
 | 1686 | * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if | 
 
 
 
 
 | 1687 | * both are true, the application gets the *64 functions, and the regular | 
 
 
 
 
 | 1688 | * functions are changed to 64 bits) -- in case these are set on systems | 
 
 
 
 
 | 1689 | * without large file support, _LFS64_LARGEFILE must also be true | 
 
 
 
 
 | 1690 | */ | 
 
 
 
 
 | 1691 | #ifdef Z_LARGE64 | 
 
 
 
 
 | 1692 | ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); | 
 
 
 
 
 | 1693 | ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); | 
 
 
 
 
 | 1694 | ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); | 
 
 
 
 
 | 1695 | ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); | 
 
 
 
 
 | 1696 | ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); | 
 
 
 
 
 | 1697 | ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); | 
 
 
 
 
 | 1698 | #endif | 
 
 
 
 
 | 1699 |  | 
 
 
 
 
 | 1700 | #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) | 
 
 
 
 
 | 1701 | #  ifdef Z_PREFIX_SET | 
 
 
 
 
 | 1702 | #    define z_gzopen z_gzopen64 | 
 
 
 
 
 | 1703 | #    define z_gzseek z_gzseek64 | 
 
 
 
 
 | 1704 | #    define z_gztell z_gztell64 | 
 
 
 
 
 | 1705 | #    define z_gzoffset z_gzoffset64 | 
 
 
 
 
 | 1706 | #    define z_adler32_combine z_adler32_combine64 | 
 
 
 
 
 | 1707 | #    define z_crc32_combine z_crc32_combine64 | 
 
 
 
 
 | 1708 | #  else | 
 
 
 
 
 | 1709 | #    define gzopen gzopen64 | 
 
 
 
 
 | 1710 | #    define gzseek gzseek64 | 
 
 
 
 
 | 1711 | #    define gztell gztell64 | 
 
 
 
 
 | 1712 | #    define gzoffset gzoffset64 | 
 
 
 
 
 | 1713 | #    define adler32_combine adler32_combine64 | 
 
 
 
 
 | 1714 | #    define crc32_combine crc32_combine64 | 
 
 
 
 
 | 1715 | #  endif | 
 
 
 
 
 | 1716 | #  ifndef Z_LARGE64 | 
 
 
 
 
 | 1717 | ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); | 
 
 
 
 
 | 1718 | ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); | 
 
 
 
 
 | 1719 | ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); | 
 
 
 
 
 | 1720 | ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); | 
 
 
 
 
 | 1721 | ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); | 
 
 
 
 
 | 1722 | ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); | 
 
 
 
 
 | 1723 | #  endif | 
 
 
 
 
 | 1724 | #else | 
 
 
 
 
 | 1725 | ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); | 
 
 
 
 
 | 1726 | ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); | 
 
 
 
 
 | 1727 | ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); | 
 
 
 
 
 | 1728 | ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); | 
 
 
 
 
 | 1729 | ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); | 
 
 
 
 
 | 1730 | ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); | 
 
 
 
 
 | 1731 | #endif | 
 
 
 
 
 | 1732 |  | 
 
 
 
 
 | 1733 | #else /* Z_SOLO */ | 
 
 
 
 
 | 1734 |  | 
 
 
 
 
 | 1735 | ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); | 
 
 
 
 
 | 1736 | ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); | 
 
 
 
 
 | 1737 |  | 
 
 
 
 
 | 1738 | #endif /* !Z_SOLO */ | 
 
 
 
 
 | 1739 |  | 
 
 
 
 
 | 1740 | /* hack for buggy compilers */ | 
 
 
 
 
 | 1741 | #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) | 
 
 
 
 
 | 1742 | struct internal_state {int dummy;}; | 
 
 
 
 
 | 1743 | #endif | 
 
 
 
 
 | 1744 |  | 
 
 
 
 
 | 1745 | /* undocumented functions */ | 
 
 
 
 
 | 1746 | ZEXTERN const char   * ZEXPORT zError           OF((int)); | 
 
 
 
 
 | 1747 | ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp)); | 
 
 
 
 
 | 1748 | ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void)); | 
 
 
 
 
 | 1749 | ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int)); | 
 
 
 
 
 | 1750 | ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp)); | 
 
 
 
 
 | 1751 | ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp)); | 
 
 
 
 
 | 1752 | #if defined(_WIN32) && !defined(Z_SOLO) | 
 
 
 
 
 | 1753 | ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path, | 
 
 
 
 
 | 1754 | const char *mode)); | 
 
 
 
 
 | 1755 | #endif | 
 
 
 
 
 | 1756 | #if defined(STDC) || defined(Z_HAVE_STDARG_H) | 
 
 
 
 
 | 1757 | #  ifndef Z_SOLO | 
 
 
 
 
 | 1758 | ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file, | 
 
 
 
 
 | 1759 | const char *format, | 
 
 
 
 
 | 1760 | va_list va)); | 
 
 
 
 
 | 1761 | #  endif | 
 
 
 
 
 | 1762 | #endif | 
 
 
 
 
 | 1763 |  | 
 
 
 
 
 | 1764 | #ifdef __cplusplus | 
 
 
 
 
 | 1765 | } | 
 
 
 
 
 | 1766 | #endif | 
 
 
 
 
 | 1767 |  | 
 
 
 
 
 | 1768 | #endif /* ZLIB_H */ |