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00001 /* zlib.h -- interface of the 'zlib' general purpose compression library 00002 version 1.2.2, October 3rd, 2004 00003 00004 Copyright (C) 1995-2004 Jean-loup Gailly and Mark Adler 00005 00006 This software is provided 'as-is', without any express or implied 00007 warranty. In no event will the authors be held liable for any damages 00008 arising from the use of this software. 00009 00010 Permission is granted to anyone to use this software for any purpose, 00011 including commercial applications, and to alter it and redistribute it 00012 freely, subject to the following restrictions: 00013 00014 1. The origin of this software must not be misrepresented; you must not 00015 claim that you wrote the original software. If you use this software 00016 in a product, an acknowledgment in the product documentation would be 00017 appreciated but is not required. 00018 2. Altered source versions must be plainly marked as such, and must not be 00019 misrepresented as being the original software. 00020 3. This notice may not be removed or altered from any source distribution. 00021 00022 Jean-loup Gailly Mark Adler 00023 jloup@gzip.org madler@alumni.caltech.edu 00024 00025 00026 The data format used by the zlib library is described by RFCs (Request for 00027 Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt 00028 (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 00029 */ 00030 00031 #ifndef ZLIB_H 00032 #define ZLIB_H 00033 00034 #include "zconf.h" 00035 00036 #ifdef __cplusplus 00037 extern "C" { 00038 #endif 00039 00040 #define ZLIB_VERSION "1.2.2" 00041 #define ZLIB_VERNUM 0x1220 00042 00043 #ifdef QT_MAKEDLL 00044 #define Q_ZEXPORT __declspec(dllexport) 00045 #else 00046 #if defined(QT_DLL) && !defined(QT_PLUGIN) 00047 #define Q_ZEXPORT __declspec(dllimport) 00048 #else 00049 #define Q_ZEXPORT ZEXPORT 00050 #endif 00051 #endif 00052 #ifdef Q_OS_TEMP 00053 #include <qfunctions_wce.h> 00054 #endif 00055 00056 /* 00057 The 'zlib' compression library provides in-memory compression and 00058 decompression functions, including integrity checks of the uncompressed 00059 data. This version of the library supports only one compression method 00060 (deflation) but other algorithms will be added later and will have the same 00061 stream interface. 00062 00063 Compression can be done in a single step if the buffers are large 00064 enough (for example if an input file is mmap'ed), or can be done by 00065 repeated calls of the compression function. In the latter case, the 00066 application must provide more input and/or consume the output 00067 (providing more output space) before each call. 00068 00069 The compressed data format used by default by the in-memory functions is 00070 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 00071 around a deflate stream, which is itself documented in RFC 1951. 00072 00073 The library also supports reading and writing files in gzip (.gz) format 00074 with an interface similar to that of stdio using the functions that start 00075 with "gz". The gzip format is different from the zlib format. gzip is a 00076 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 00077 00078 This library can optionally read and write gzip streams in memory as well. 00079 00080 The zlib format was designed to be compact and fast for use in memory 00081 and on communications channels. The gzip format was designed for single- 00082 file compression on file systems, has a larger header than zlib to maintain 00083 directory information, and uses a different, slower check method than zlib. 00084 00085 The library does not install any signal handler. The decoder checks 00086 the consistency of the compressed data, so the library should never 00087 crash even in case of corrupted input. 00088 */ 00089 00090 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 00091 typedef void (*free_func) OF((voidpf opaque, voidpf address)); 00092 00093 struct internal_state; 00094 00095 typedef struct z_stream_s { 00096 Bytef *next_in; /* next input byte */ 00097 uInt avail_in; /* number of bytes available at next_in */ 00098 uLong total_in; /* total nb of input bytes read so far */ 00099 00100 Bytef *next_out; /* next output byte should be put there */ 00101 uInt avail_out; /* remaining free space at next_out */ 00102 uLong total_out; /* total nb of bytes output so far */ 00103 00104 char *msg; /* last error message, NULL if no error */ 00105 struct internal_state FAR *state; /* not visible by applications */ 00106 00107 alloc_func zalloc; /* used to allocate the internal state */ 00108 free_func zfree; /* used to free the internal state */ 00109 voidpf opaque; /* private data object passed to zalloc and zfree */ 00110 00111 int data_type; /* best guess about the data type: ascii or binary */ 00112 uLong adler; /* adler32 value of the uncompressed data */ 00113 uLong reserved; /* reserved for future use */ 00114 } z_stream; 00115 00116 typedef z_stream FAR *z_streamp; 00117 00118 /* 00119 The application must update next_in and avail_in when avail_in has 00120 dropped to zero. It must update next_out and avail_out when avail_out 00121 has dropped to zero. The application must initialize zalloc, zfree and 00122 opaque before calling the init function. All other fields are set by the 00123 compression library and must not be updated by the application. 00124 00125 The opaque value provided by the application will be passed as the first 00126 parameter for calls of zalloc and zfree. This can be useful for custom 00127 memory management. The compression library attaches no meaning to the 00128 opaque value. 00129 00130 zalloc must return Z_NULL if there is not enough memory for the object. 00131 If zlib is used in a multi-threaded application, zalloc and zfree must be 00132 thread safe. 00133 00134 On 16-bit systems, the functions zalloc and zfree must be able to allocate 00135 exactly 65536 bytes, but will not be required to allocate more than this 00136 if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 00137 pointers returned by zalloc for objects of exactly 65536 bytes *must* 00138 have their offset normalized to zero. The default allocation function 00139 provided by this library ensures this (see zutil.c). To reduce memory 00140 requirements and avoid any allocation of 64K objects, at the expense of 00141 compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 00142 00143 The fields total_in and total_out can be used for statistics or 00144 progress reports. After compression, total_in holds the total size of 00145 the uncompressed data and may be saved for use in the decompressor 00146 (particularly if the decompressor wants to decompress everything in 00147 a single step). 00148 */ 00149 00150 /* constants */ 00151 00152 #define Z_NO_FLUSH 0 00153 #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ 00154 #define Z_SYNC_FLUSH 2 00155 #define Z_FULL_FLUSH 3 00156 #define Z_FINISH 4 00157 #define Z_BLOCK 5 00158 /* Allowed flush values; see deflate() and inflate() below for details */ 00159 00160 #define Z_OK 0 00161 #define Z_STREAM_END 1 00162 #define Z_NEED_DICT 2 00163 #define Z_ERRNO (-1) 00164 #define Z_STREAM_ERROR (-2) 00165 #define Z_DATA_ERROR (-3) 00166 #define Z_MEM_ERROR (-4) 00167 #define Z_BUF_ERROR (-5) 00168 #define Z_VERSION_ERROR (-6) 00169 /* Return codes for the compression/decompression functions. Negative 00170 * values are errors, positive values are used for special but normal events. 00171 */ 00172 00173 #define Z_NO_COMPRESSION 0 00174 #define Z_BEST_SPEED 1 00175 #define Z_BEST_COMPRESSION 9 00176 #define Z_DEFAULT_COMPRESSION (-1) 00177 /* compression levels */ 00178 00179 #define Z_FILTERED 1 00180 #define Z_HUFFMAN_ONLY 2 00181 #define Z_RLE 3 00182 #define Z_DEFAULT_STRATEGY 0 00183 /* compression strategy; see deflateInit2() below for details */ 00184 00185 #define Z_BINARY 0 00186 #define Z_ASCII 1 00187 #define Z_UNKNOWN 2 00188 /* Possible values of the data_type field (though see inflate()) */ 00189 00190 #define Z_DEFLATED 8 00191 /* The deflate compression method (the only one supported in this version) */ 00192 00193 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 00194 00195 #define zlib_version zlibVersion() 00196 /* for compatibility with versions < 1.0.2 */ 00197 00198 /* basic functions */ 00199 00200 ZEXTERN Q_ZEXPORT const char * zlibVersion OF((void)); 00201 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 00202 If the first character differs, the library code actually used is 00203 not compatible with the zlib.h header file used by the application. 00204 This check is automatically made by deflateInit and inflateInit. 00205 */ 00206 00207 /* 00208 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 00209 00210 Initializes the internal stream state for compression. The fields 00211 zalloc, zfree and opaque must be initialized before by the caller. 00212 If zalloc and zfree are set to Z_NULL, deflateInit updates them to 00213 use default allocation functions. 00214 00215 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 00216 1 gives best speed, 9 gives best compression, 0 gives no compression at 00217 all (the input data is simply copied a block at a time). 00218 Z_DEFAULT_COMPRESSION requests a default compromise between speed and 00219 compression (currently equivalent to level 6). 00220 00221 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 00222 enough memory, Z_STREAM_ERROR if level is not a valid compression level, 00223 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 00224 with the version assumed by the caller (ZLIB_VERSION). 00225 msg is set to null if there is no error message. deflateInit does not 00226 perform any compression: this will be done by deflate(). 00227 */ 00228 00229 00230 ZEXTERN int Q_ZEXPORT deflate OF((z_streamp strm, int flush)); 00231 /* 00232 deflate compresses as much data as possible, and stops when the input 00233 buffer becomes empty or the output buffer becomes full. It may introduce some 00234 output latency (reading input without producing any output) except when 00235 forced to flush. 00236 00237 The detailed semantics are as follows. deflate performs one or both of the 00238 following actions: 00239 00240 - Compress more input starting at next_in and update next_in and avail_in 00241 accordingly. If not all input can be processed (because there is not 00242 enough room in the output buffer), next_in and avail_in are updated and 00243 processing will resume at this point for the next call of deflate(). 00244 00245 - Provide more output starting at next_out and update next_out and avail_out 00246 accordingly. This action is forced if the parameter flush is non zero. 00247 Forcing flush frequently degrades the compression ratio, so this parameter 00248 should be set only when necessary (in interactive applications). 00249 Some output may be provided even if flush is not set. 00250 00251 Before the call of deflate(), the application should ensure that at least 00252 one of the actions is possible, by providing more input and/or consuming 00253 more output, and updating avail_in or avail_out accordingly; avail_out 00254 should never be zero before the call. The application can consume the 00255 compressed output when it wants, for example when the output buffer is full 00256 (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK 00257 and with zero avail_out, it must be called again after making room in the 00258 output buffer because there might be more output pending. 00259 00260 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 00261 flushed to the output buffer and the output is aligned on a byte boundary, so 00262 that the decompressor can get all input data available so far. (In particular 00263 avail_in is zero after the call if enough output space has been provided 00264 before the call.) Flushing may degrade compression for some compression 00265 algorithms and so it should be used only when necessary. 00266 00267 If flush is set to Z_FULL_FLUSH, all output is flushed as with 00268 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 00269 restart from this point if previous compressed data has been damaged or if 00270 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 00271 the compression. 00272 00273 If deflate returns with avail_out == 0, this function must be called again 00274 with the same value of the flush parameter and more output space (updated 00275 avail_out), until the flush is complete (deflate returns with non-zero 00276 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 00277 avail_out is greater than six to avoid repeated flush markers due to 00278 avail_out == 0 on return. 00279 00280 If the parameter flush is set to Z_FINISH, pending input is processed, 00281 pending output is flushed and deflate returns with Z_STREAM_END if there 00282 was enough output space; if deflate returns with Z_OK, this function must be 00283 called again with Z_FINISH and more output space (updated avail_out) but no 00284 more input data, until it returns with Z_STREAM_END or an error. After 00285 deflate has returned Z_STREAM_END, the only possible operations on the 00286 stream are deflateReset or deflateEnd. 00287 00288 Z_FINISH can be used immediately after deflateInit if all the compression 00289 is to be done in a single step. In this case, avail_out must be at least 00290 the value returned by deflateBound (see below). If deflate does not return 00291 Z_STREAM_END, then it must be called again as described above. 00292 00293 deflate() sets strm->adler to the adler32 checksum of all input read 00294 so far (that is, total_in bytes). 00295 00296 deflate() may update data_type if it can make a good guess about 00297 the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered 00298 binary. This field is only for information purposes and does not affect 00299 the compression algorithm in any manner. 00300 00301 deflate() returns Z_OK if some progress has been made (more input 00302 processed or more output produced), Z_STREAM_END if all input has been 00303 consumed and all output has been produced (only when flush is set to 00304 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 00305 if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible 00306 (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not 00307 fatal, and deflate() can be called again with more input and more output 00308 space to continue compressing. 00309 */ 00310 00311 00312 ZEXTERN int Q_ZEXPORT deflateEnd OF((z_streamp strm)); 00313 /* 00314 All dynamically allocated data structures for this stream are freed. 00315 This function discards any unprocessed input and does not flush any 00316 pending output. 00317 00318 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 00319 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 00320 prematurely (some input or output was discarded). In the error case, 00321 msg may be set but then points to a static string (which must not be 00322 deallocated). 00323 */ 00324 00325 00326 /* 00327 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 00328 00329 Initializes the internal stream state for decompression. The fields 00330 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 00331 the caller. If next_in is not Z_NULL and avail_in is large enough (the exact 00332 value depends on the compression method), inflateInit determines the 00333 compression method from the zlib header and allocates all data structures 00334 accordingly; otherwise the allocation will be deferred to the first call of 00335 inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 00336 use default allocation functions. 00337 00338 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 00339 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 00340 version assumed by the caller. msg is set to null if there is no error 00341 message. inflateInit does not perform any decompression apart from reading 00342 the zlib header if present: this will be done by inflate(). (So next_in and 00343 avail_in may be modified, but next_out and avail_out are unchanged.) 00344 */ 00345 00346 00347 ZEXTERN int Q_ZEXPORT inflate OF((z_streamp strm, int flush)); 00348 /* 00349 inflate decompresses as much data as possible, and stops when the input 00350 buffer becomes empty or the output buffer becomes full. It may introduce 00351 some output latency (reading input without producing any output) except when 00352 forced to flush. 00353 00354 The detailed semantics are as follows. inflate performs one or both of the 00355 following actions: 00356 00357 - Decompress more input starting at next_in and update next_in and avail_in 00358 accordingly. If not all input can be processed (because there is not 00359 enough room in the output buffer), next_in is updated and processing 00360 will resume at this point for the next call of inflate(). 00361 00362 - Provide more output starting at next_out and update next_out and avail_out 00363 accordingly. inflate() provides as much output as possible, until there 00364 is no more input data or no more space in the output buffer (see below 00365 about the flush parameter). 00366 00367 Before the call of inflate(), the application should ensure that at least 00368 one of the actions is possible, by providing more input and/or consuming 00369 more output, and updating the next_* and avail_* values accordingly. 00370 The application can consume the uncompressed output when it wants, for 00371 example when the output buffer is full (avail_out == 0), or after each 00372 call of inflate(). If inflate returns Z_OK and with zero avail_out, it 00373 must be called again after making room in the output buffer because there 00374 might be more output pending. 00375 00376 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, 00377 Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much 00378 output as possible to the output buffer. Z_BLOCK requests that inflate() stop 00379 if and when it get to the next deflate block boundary. When decoding the zlib 00380 or gzip format, this will cause inflate() to return immediately after the 00381 header and before the first block. When doing a raw inflate, inflate() will 00382 go ahead and process the first block, and will return when it gets to the end 00383 of that block, or when it runs out of data. 00384 00385 The Z_BLOCK option assists in appending to or combining deflate streams. 00386 Also to assist in this, on return inflate() will set strm->data_type to the 00387 number of unused bits in the last byte taken from strm->next_in, plus 64 00388 if inflate() is currently decoding the last block in the deflate stream, 00389 plus 128 if inflate() returned immediately after decoding an end-of-block 00390 code or decoding the complete header up to just before the first byte of the 00391 deflate stream. The end-of-block will not be indicated until all of the 00392 uncompressed data from that block has been written to strm->next_out. The 00393 number of unused bits may in general be greater than seven, except when 00394 bit 7 of data_type is set, in which case the number of unused bits will be 00395 less than eight. 00396 00397 inflate() should normally be called until it returns Z_STREAM_END or an 00398 error. However if all decompression is to be performed in a single step 00399 (a single call of inflate), the parameter flush should be set to 00400 Z_FINISH. In this case all pending input is processed and all pending 00401 output is flushed; avail_out must be large enough to hold all the 00402 uncompressed data. (The size of the uncompressed data may have been saved 00403 by the compressor for this purpose.) The next operation on this stream must 00404 be inflateEnd to deallocate the decompression state. The use of Z_FINISH 00405 is never required, but can be used to inform inflate that a faster approach 00406 may be used for the single inflate() call. 00407 00408 In this implementation, inflate() always flushes as much output as 00409 possible to the output buffer, and always uses the faster approach on the 00410 first call. So the only effect of the flush parameter in this implementation 00411 is on the return value of inflate(), as noted below, or when it returns early 00412 because Z_BLOCK is used. 00413 00414 If a preset dictionary is needed after this call (see inflateSetDictionary 00415 below), inflate sets strm->adler to the adler32 checksum of the dictionary 00416 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 00417 strm->adler to the adler32 checksum of all output produced so far (that is, 00418 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 00419 below. At the end of the stream, inflate() checks that its computed adler32 00420 checksum is equal to that saved by the compressor and returns Z_STREAM_END 00421 only if the checksum is correct. 00422 00423 inflate() will decompress and check either zlib-wrapped or gzip-wrapped 00424 deflate data. The header type is detected automatically. Any information 00425 contained in the gzip header is not retained, so applications that need that 00426 information should instead use raw inflate, see inflateInit2() below, or 00427 inflateBack() and perform their own processing of the gzip header and 00428 trailer. 00429 00430 inflate() returns Z_OK if some progress has been made (more input processed 00431 or more output produced), Z_STREAM_END if the end of the compressed data has 00432 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 00433 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 00434 corrupted (input stream not conforming to the zlib format or incorrect check 00435 value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 00436 if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, 00437 Z_BUF_ERROR if no progress is possible or if there was not enough room in the 00438 output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 00439 inflate() can be called again with more input and more output space to 00440 continue decompressing. If Z_DATA_ERROR is returned, the application may then 00441 call inflateSync() to look for a good compression block if a partial recovery 00442 of the data is desired. 00443 */ 00444 00445 00446 ZEXTERN int Q_ZEXPORT inflateEnd OF((z_streamp strm)); 00447 /* 00448 All dynamically allocated data structures for this stream are freed. 00449 This function discards any unprocessed input and does not flush any 00450 pending output. 00451 00452 inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 00453 was inconsistent. In the error case, msg may be set but then points to a 00454 static string (which must not be deallocated). 00455 */ 00456 00457 /* Advanced functions */ 00458 00459 /* 00460 The following functions are needed only in some special applications. 00461 */ 00462 00463 /* 00464 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 00465 int level, 00466 int method, 00467 int windowBits, 00468 int memLevel, 00469 int strategy)); 00470 00471 This is another version of deflateInit with more compression options. The 00472 fields next_in, zalloc, zfree and opaque must be initialized before by 00473 the caller. 00474 00475 The method parameter is the compression method. It must be Z_DEFLATED in 00476 this version of the library. 00477 00478 The windowBits parameter is the base two logarithm of the window size 00479 (the size of the history buffer). It should be in the range 8..15 for this 00480 version of the library. Larger values of this parameter result in better 00481 compression at the expense of memory usage. The default value is 15 if 00482 deflateInit is used instead. 00483 00484 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 00485 determines the window size. deflate() will then generate raw deflate data 00486 with no zlib header or trailer, and will not compute an adler32 check value. 00487 00488 windowBits can also be greater than 15 for optional gzip encoding. Add 00489 16 to windowBits to write a simple gzip header and trailer around the 00490 compressed data instead of a zlib wrapper. The gzip header will have no 00491 file name, no extra data, no comment, no modification time (set to zero), 00492 no header crc, and the operating system will be set to 255 (unknown). If a 00493 gzip stream is being written, strm->adler is a crc32 instead of an adler32. 00494 00495 The memLevel parameter specifies how much memory should be allocated 00496 for the internal compression state. memLevel=1 uses minimum memory but 00497 is slow and reduces compression ratio; memLevel=9 uses maximum memory 00498 for optimal speed. The default value is 8. See zconf.h for total memory 00499 usage as a function of windowBits and memLevel. 00500 00501 The strategy parameter is used to tune the compression algorithm. Use the 00502 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 00503 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 00504 string match), or Z_RLE to limit match distances to one (run-length 00505 encoding). Filtered data consists mostly of small values with a somewhat 00506 random distribution. In this case, the compression algorithm is tuned to 00507 compress them better. The effect of Z_FILTERED is to force more Huffman 00508 coding and less string matching; it is somewhat intermediate between 00509 Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as 00510 Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy 00511 parameter only affects the compression ratio but not the correctness of the 00512 compressed output even if it is not set appropriately. 00513 00514 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 00515 memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid 00516 method). msg is set to null if there is no error message. deflateInit2 does 00517 not perform any compression: this will be done by deflate(). 00518 */ 00519 00520 ZEXTERN int Q_ZEXPORT deflateSetDictionary OF((z_streamp strm, 00521 const Bytef *dictionary, 00522 uInt dictLength)); 00523 /* 00524 Initializes the compression dictionary from the given byte sequence 00525 without producing any compressed output. This function must be called 00526 immediately after deflateInit, deflateInit2 or deflateReset, before any 00527 call of deflate. The compressor and decompressor must use exactly the same 00528 dictionary (see inflateSetDictionary). 00529 00530 The dictionary should consist of strings (byte sequences) that are likely 00531 to be encountered later in the data to be compressed, with the most commonly 00532 used strings preferably put towards the end of the dictionary. Using a 00533 dictionary is most useful when the data to be compressed is short and can be 00534 predicted with good accuracy; the data can then be compressed better than 00535 with the default empty dictionary. 00536 00537 Depending on the size of the compression data structures selected by 00538 deflateInit or deflateInit2, a part of the dictionary may in effect be 00539 discarded, for example if the dictionary is larger than the window size in 00540 deflate or deflate2. Thus the strings most likely to be useful should be 00541 put at the end of the dictionary, not at the front. 00542 00543 Upon return of this function, strm->adler is set to the adler32 value 00544 of the dictionary; the decompressor may later use this value to determine 00545 which dictionary has been used by the compressor. (The adler32 value 00546 applies to the whole dictionary even if only a subset of the dictionary is 00547 actually used by the compressor.) If a raw deflate was requested, then the 00548 adler32 value is not computed and strm->adler is not set. 00549 00550 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 00551 parameter is invalid (such as NULL dictionary) or the stream state is 00552 inconsistent (for example if deflate has already been called for this stream 00553 or if the compression method is bsort). deflateSetDictionary does not 00554 perform any compression: this will be done by deflate(). 00555 */ 00556 00557 ZEXTERN int Q_ZEXPORT deflateCopy OF((z_streamp dest, 00558 z_streamp source)); 00559 /* 00560 Sets the destination stream as a complete copy of the source stream. 00561 00562 This function can be useful when several compression strategies will be 00563 tried, for example when there are several ways of pre-processing the input 00564 data with a filter. The streams that will be discarded should then be freed 00565 by calling deflateEnd. Note that deflateCopy duplicates the internal 00566 compression state which can be quite large, so this strategy is slow and 00567 can consume lots of memory. 00568 00569 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 00570 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 00571 (such as zalloc being NULL). msg is left unchanged in both source and 00572 destination. 00573 */ 00574 00575 ZEXTERN int Q_ZEXPORT deflateReset OF((z_streamp strm)); 00576 /* 00577 This function is equivalent to deflateEnd followed by deflateInit, 00578 but does not free and reallocate all the internal compression state. 00579 The stream will keep the same compression level and any other attributes 00580 that may have been set by deflateInit2. 00581 00582 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 00583 stream state was inconsistent (such as zalloc or state being NULL). 00584 */ 00585 00586 ZEXTERN int Q_ZEXPORT deflateParams OF((z_streamp strm, 00587 int level, 00588 int strategy)); 00589 /* 00590 Dynamically update the compression level and compression strategy. The 00591 interpretation of level and strategy is as in deflateInit2. This can be 00592 used to switch between compression and straight copy of the input data, or 00593 to switch to a different kind of input data requiring a different 00594 strategy. If the compression level is changed, the input available so far 00595 is compressed with the old level (and may be flushed); the new level will 00596 take effect only at the next call of deflate(). 00597 00598 Before the call of deflateParams, the stream state must be set as for 00599 a call of deflate(), since the currently available input may have to 00600 be compressed and flushed. In particular, strm->avail_out must be non-zero. 00601 00602 deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 00603 stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR 00604 if strm->avail_out was zero. 00605 */ 00606 00607 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 00608 uLong sourceLen)); 00609 /* 00610 deflateBound() returns an upper bound on the compressed size after 00611 deflation of sourceLen bytes. It must be called after deflateInit() 00612 or deflateInit2(). This would be used to allocate an output buffer 00613 for deflation in a single pass, and so would be called before deflate(). 00614 */ 00615 00616 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 00617 int bits, 00618 int value)); 00619 /* 00620 deflatePrime() inserts bits in the deflate output stream. The intent 00621 is that this function is used to start off the deflate output with the 00622 bits leftover from a previous deflate stream when appending to it. As such, 00623 this function can only be used for raw deflate, and must be used before the 00624 first deflate() call after a deflateInit2() or deflateReset(). bits must be 00625 less than or equal to 16, and that many of the least significant bits of 00626 value will be inserted in the output. 00627 00628 deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 00629 stream state was inconsistent. 00630 */ 00631 00632 /* 00633 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 00634 int windowBits)); 00635 00636 This is another version of inflateInit with an extra parameter. The 00637 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 00638 before by the caller. 00639 00640 The windowBits parameter is the base two logarithm of the maximum window 00641 size (the size of the history buffer). It should be in the range 8..15 for 00642 this version of the library. The default value is 15 if inflateInit is used 00643 instead. windowBits must be greater than or equal to the windowBits value 00644 provided to deflateInit2() while compressing, or it must be equal to 15 if 00645 deflateInit2() was not used. If a compressed stream with a larger window 00646 size is given as input, inflate() will return with the error code 00647 Z_DATA_ERROR instead of trying to allocate a larger window. 00648 00649 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 00650 determines the window size. inflate() will then process raw deflate data, 00651 not looking for a zlib or gzip header, not generating a check value, and not 00652 looking for any check values for comparison at the end of the stream. This 00653 is for use with other formats that use the deflate compressed data format 00654 such as zip. Those formats provide their own check values. If a custom 00655 format is developed using the raw deflate format for compressed data, it is 00656 recommended that a check value such as an adler32 or a crc32 be applied to 00657 the uncompressed data as is done in the zlib, gzip, and zip formats. For 00658 most applications, the zlib format should be used as is. Note that comments 00659 above on the use in deflateInit2() applies to the magnitude of windowBits. 00660 00661 windowBits can also be greater than 15 for optional gzip decoding. Add 00662 32 to windowBits to enable zlib and gzip decoding with automatic header 00663 detection, or add 16 to decode only the gzip format (the zlib format will 00664 return a Z_DATA_ERROR. If a gzip stream is being decoded, strm->adler is 00665 a crc32 instead of an adler32. 00666 00667 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 00668 memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative 00669 memLevel). msg is set to null if there is no error message. inflateInit2 00670 does not perform any decompression apart from reading the zlib header if 00671 present: this will be done by inflate(). (So next_in and avail_in may be 00672 modified, but next_out and avail_out are unchanged.) 00673 */ 00674 00675 ZEXTERN int Q_ZEXPORT inflateSetDictionary OF((z_streamp strm, 00676 const Bytef *dictionary, 00677 uInt dictLength)); 00678 /* 00679 Initializes the decompression dictionary from the given uncompressed byte 00680 sequence. This function must be called immediately after a call of inflate 00681 if this call returned Z_NEED_DICT. The dictionary chosen by the compressor 00682 can be determined from the adler32 value returned by this call of 00683 inflate. The compressor and decompressor must use exactly the same 00684 dictionary (see deflateSetDictionary). 00685 00686 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 00687 parameter is invalid (such as NULL dictionary) or the stream state is 00688 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 00689 expected one (incorrect adler32 value). inflateSetDictionary does not 00690 perform any decompression: this will be done by subsequent calls of 00691 inflate(). 00692 */ 00693 00694 ZEXTERN int Q_ZEXPORT inflateSync OF((z_streamp strm)); 00695 /* 00696 Skips invalid compressed data until a full flush point (see above the 00697 description of deflate with Z_FULL_FLUSH) can be found, or until all 00698 available input is skipped. No output is provided. 00699 00700 inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR 00701 if no more input was provided, Z_DATA_ERROR if no flush point has been found, 00702 or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 00703 case, the application may save the current current value of total_in which 00704 indicates where valid compressed data was found. In the error case, the 00705 application may repeatedly call inflateSync, providing more input each time, 00706 until success or end of the input data. 00707 */ 00708 00709 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, 00710 z_streamp source)); 00711 /* 00712 Sets the destination stream as a complete copy of the source stream. 00713 00714 This function can be useful when randomly accessing a large stream. The 00715 first pass through the stream can periodically record the inflate state, 00716 allowing restarting inflate at those points when randomly accessing the 00717 stream. 00718 00719 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 00720 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 00721 (such as zalloc being NULL). msg is left unchanged in both source and 00722 destination. 00723 */ 00724 00725 ZEXTERN int Q_ZEXPORT inflateReset OF((z_streamp strm)); 00726 /* 00727 This function is equivalent to inflateEnd followed by inflateInit, 00728 but does not free and reallocate all the internal decompression state. 00729 The stream will keep attributes that may have been set by inflateInit2. 00730 00731 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 00732 stream state was inconsistent (such as zalloc or state being NULL). 00733 */ 00734 00735 /* 00736 ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *strm, int windowBits, 00737 unsigned char FAR *window)); 00738 00739 Initialize the internal stream state for decompression using inflateBack() 00740 calls. The fields zalloc, zfree and opaque in strm must be initialized 00741 before the call. If zalloc and zfree are Z_NULL, then the default library- 00742 derived memory allocation routines are used. windowBits is the base two 00743 logarithm of the window size, in the range 8..15. window is a caller 00744 supplied buffer of that size. Except for special applications where it is 00745 assured that deflate was used with small window sizes, windowBits must be 15 00746 and a 32K byte window must be supplied to be able to decompress general 00747 deflate streams. 00748 00749 See inflateBack() for the usage of these routines. 00750 00751 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 00752 the paramaters are invalid, Z_MEM_ERROR if the internal state could not 00753 be allocated, or Z_VERSION_ERROR if the version of the library does not 00754 match the version of the header file. 00755 */ 00756 00757 typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); 00758 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); 00759 00760 ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm, 00761 in_func in, void FAR *in_desc, 00762 out_func out, void FAR *out_desc)); 00763 /* 00764 inflateBack() does a raw inflate with a single call using a call-back 00765 interface for input and output. This is more efficient than inflate() for 00766 file i/o applications in that it avoids copying between the output and the 00767 sliding window by simply making the window itself the output buffer. This 00768 function trusts the application to not change the output buffer passed by 00769 the output function, at least until inflateBack() returns. 00770 00771 inflateBackInit() must be called first to allocate the internal state 00772 and to initialize the state with the user-provided window buffer. 00773 inflateBack() may then be used multiple times to inflate a complete, raw 00774 deflate stream with each call. inflateBackEnd() is then called to free 00775 the allocated state. 00776 00777 A raw deflate stream is one with no zlib or gzip header or trailer. 00778 This routine would normally be used in a utility that reads zip or gzip 00779 files and writes out uncompressed files. The utility would decode the 00780 header and process the trailer on its own, hence this routine expects 00781 only the raw deflate stream to decompress. This is different from the 00782 normal behavior of inflate(), which expects either a zlib or gzip header and 00783 trailer around the deflate stream. 00784 00785 inflateBack() uses two subroutines supplied by the caller that are then 00786 called by inflateBack() for input and output. inflateBack() calls those 00787 routines until it reads a complete deflate stream and writes out all of the 00788 uncompressed data, or until it encounters an error. The function's 00789 parameters and return types are defined above in the in_func and out_func 00790 typedefs. inflateBack() will call in(in_desc, &buf) which should return the 00791 number of bytes of provided input, and a pointer to that input in buf. If 00792 there is no input available, in() must return zero--buf is ignored in that 00793 case--and inflateBack() will return a buffer error. inflateBack() will call 00794 out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() 00795 should return zero on success, or non-zero on failure. If out() returns 00796 non-zero, inflateBack() will return with an error. Neither in() nor out() 00797 are permitted to change the contents of the window provided to 00798 inflateBackInit(), which is also the buffer that out() uses to write from. 00799 The length written by out() will be at most the window size. Any non-zero 00800 amount of input may be provided by in(). 00801 00802 For convenience, inflateBack() can be provided input on the first call by 00803 setting strm->next_in and strm->avail_in. If that input is exhausted, then 00804 in() will be called. Therefore strm->next_in must be initialized before 00805 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called 00806 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in 00807 must also be initialized, and then if strm->avail_in is not zero, input will 00808 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 00809 00810 The in_desc and out_desc parameters of inflateBack() is passed as the 00811 first parameter of in() and out() respectively when they are called. These 00812 descriptors can be optionally used to pass any information that the caller- 00813 supplied in() and out() functions need to do their job. 00814 00815 On return, inflateBack() will set strm->next_in and strm->avail_in to 00816 pass back any unused input that was provided by the last in() call. The 00817 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 00818 if in() or out() returned an error, Z_DATA_ERROR if there was a format 00819 error in the deflate stream (in which case strm->msg is set to indicate the 00820 nature of the error), or Z_STREAM_ERROR if the stream was not properly 00821 initialized. In the case of Z_BUF_ERROR, an input or output error can be 00822 distinguished using strm->next_in which will be Z_NULL only if in() returned 00823 an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to 00824 out() returning non-zero. (in() will always be called before out(), so 00825 strm->next_in is assured to be defined if out() returns non-zero.) Note 00826 that inflateBack() cannot return Z_OK. 00827 */ 00828 00829 ZEXTERN int ZEXPORT inflateBackEnd OF((z_stream FAR *strm)); 00830 /* 00831 All memory allocated by inflateBackInit() is freed. 00832 00833 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 00834 state was inconsistent. 00835 */ 00836 00837 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); 00838 /* Return flags indicating compile-time options. 00839 00840 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 00841 1.0: size of uInt 00842 3.2: size of uLong 00843 5.4: size of voidpf (pointer) 00844 7.6: size of z_off_t 00845 00846 Compiler, assembler, and debug options: 00847 8: DEBUG 00848 9: ASMV or ASMINF -- use ASM code 00849 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 00850 11: 0 (reserved) 00851 00852 One-time table building (smaller code, but not thread-safe if true): 00853 12: BUILDFIXED -- build static block decoding tables when needed 00854 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 00855 14,15: 0 (reserved) 00856 00857 Library content (indicates missing functionality): 00858 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 00859 deflate code when not needed) 00860 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 00861 and decode gzip streams (to avoid linking crc code) 00862 18-19: 0 (reserved) 00863 00864 Operation variations (changes in library functionality): 00865 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 00866 21: FASTEST -- deflate algorithm with only one, lowest compression level 00867 22,23: 0 (reserved) 00868 00869 The sprintf variant used by gzprintf (zero is best): 00870 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 00871 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 00872 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 00873 00874 Remainder: 00875 27-31: 0 (reserved) 00876 */ 00877 00878 00879 /* utility functions */ 00880 00881 /* 00882 The following utility functions are implemented on top of the 00883 basic stream-oriented functions. To simplify the interface, some 00884 default options are assumed (compression level and memory usage, 00885 standard memory allocation functions). The source code of these 00886 utility functions can easily be modified if you need special options. 00887 */ 00888 00889 ZEXTERN int Q_ZEXPORT compress OF((Bytef *dest, uLongf *destLen, 00890 const Bytef *source, uLong sourceLen)); 00891 /* 00892 Compresses the source buffer into the destination buffer. sourceLen is 00893 the byte length of the source buffer. Upon entry, destLen is the total 00894 size of the destination buffer, which must be at least the value returned 00895 by compressBound(sourceLen). Upon exit, destLen is the actual size of the 00896 compressed buffer. 00897 This function can be used to compress a whole file at once if the 00898 input file is mmap'ed. 00899 compress returns Z_OK if success, Z_MEM_ERROR if there was not 00900 enough memory, Z_BUF_ERROR if there was not enough room in the output 00901 buffer. 00902 */ 00903 00904 ZEXTERN int Q_ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, 00905 const Bytef *source, uLong sourceLen, 00906 int level)); 00907 /* 00908 Compresses the source buffer into the destination buffer. The level 00909 parameter has the same meaning as in deflateInit. sourceLen is the byte 00910 length of the source buffer. Upon entry, destLen is the total size of the 00911 destination buffer, which must be at least the value returned by 00912 compressBound(sourceLen). Upon exit, destLen is the actual size of the 00913 compressed buffer. 00914 00915 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 00916 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 00917 Z_STREAM_ERROR if the level parameter is invalid. 00918 */ 00919 00920 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); 00921 /* 00922 compressBound() returns an upper bound on the compressed size after 00923 compress() or compress2() on sourceLen bytes. It would be used before 00924 a compress() or compress2() call to allocate the destination buffer. 00925 */ 00926 00927 ZEXTERN int Q_ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 00928 const Bytef *source, uLong sourceLen)); 00929 /* 00930 Decompresses the source buffer into the destination buffer. sourceLen is 00931 the byte length of the source buffer. Upon entry, destLen is the total 00932 size of the destination buffer, which must be large enough to hold the 00933 entire uncompressed data. (The size of the uncompressed data must have 00934 been saved previously by the compressor and transmitted to the decompressor 00935 by some mechanism outside the scope of this compression library.) 00936 Upon exit, destLen is the actual size of the compressed buffer. 00937 This function can be used to decompress a whole file at once if the 00938 input file is mmap'ed. 00939 00940 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 00941 enough memory, Z_BUF_ERROR if there was not enough room in the output 00942 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. 00943 */ 00944 00945 00946 typedef voidp gzFile; 00947 00948 ZEXTERN gzFile Q_ZEXPORT gzopen OF((const char *path, const char *mode)); 00949 /* 00950 Opens a gzip (.gz) file for reading or writing. The mode parameter 00951 is as in fopen ("rb" or "wb") but can also include a compression level 00952 ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for 00953 Huffman only compression as in "wb1h", or 'R' for run-length encoding 00954 as in "wb1R". (See the description of deflateInit2 for more information 00955 about the strategy parameter.) 00956 00957 gzopen can be used to read a file which is not in gzip format; in this 00958 case gzread will directly read from the file without decompression. 00959 00960 gzopen returns NULL if the file could not be opened or if there was 00961 insufficient memory to allocate the (de)compression state; errno 00962 can be checked to distinguish the two cases (if errno is zero, the 00963 zlib error is Z_MEM_ERROR). */ 00964 00965 ZEXTERN gzFile Q_ZEXPORT gzdopen OF((int fd, const char *mode)); 00966 /* 00967 gzdopen() associates a gzFile with the file descriptor fd. File 00968 descriptors are obtained from calls like open, dup, creat, pipe or 00969 fileno (in the file has been previously opened with fopen). 00970 The mode parameter is as in gzopen. 00971 The next call of gzclose on the returned gzFile will also close the 00972 file descriptor fd, just like fclose(fdopen(fd), mode) closes the file 00973 descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). 00974 gzdopen returns NULL if there was insufficient memory to allocate 00975 the (de)compression state. 00976 */ 00977 00978 ZEXTERN int Q_ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); 00979 /* 00980 Dynamically update the compression level or strategy. See the description 00981 of deflateInit2 for the meaning of these parameters. 00982 gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not 00983 opened for writing. 00984 */ 00985 00986 ZEXTERN int Q_ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 00987 /* 00988 Reads the given number of uncompressed bytes from the compressed file. 00989 If the input file was not in gzip format, gzread copies the given number 00990 of bytes into the buffer. 00991 gzread returns the number of uncompressed bytes actually read (0 for 00992 end of file, -1 for error). */ 00993 00994 ZEXTERN int Q_ZEXPORT gzwrite OF((gzFile file, 00995 voidpc buf, unsigned len)); 00996 /* 00997 Writes the given number of uncompressed bytes into the compressed file. 00998 gzwrite returns the number of uncompressed bytes actually written 00999 (0 in case of error). 01000 */ 01001 01002 ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); 01003 /* 01004 Converts, formats, and writes the args to the compressed file under 01005 control of the format string, as in fprintf. gzprintf returns the number of 01006 uncompressed bytes actually written (0 in case of error). The number of 01007 uncompressed bytes written is limited to 4095. The caller should assure that 01008 this limit is not exceeded. If it is exceeded, then gzprintf() will return 01009 return an error (0) with nothing written. In this case, there may also be a 01010 buffer overflow with unpredictable consequences, which is possible only if 01011 zlib was compiled with the insecure functions sprintf() or vsprintf() 01012 because the secure snprintf() or vsnprintf() functions were not available. 01013 */ 01014 01015 ZEXTERN int Q_ZEXPORT gzputs OF((gzFile file, const char *s)); 01016 /* 01017 Writes the given null-terminated string to the compressed file, excluding 01018 the terminating null character. 01019 gzputs returns the number of characters written, or -1 in case of error. 01020 */ 01021 01022 ZEXTERN Q_ZEXPORT char * gzgets OF((gzFile file, char *buf, int len)); 01023 /* 01024 Reads bytes from the compressed file until len-1 characters are read, or 01025 a newline character is read and transferred to buf, or an end-of-file 01026 condition is encountered. The string is then terminated with a null 01027 character. 01028 gzgets returns buf, or Z_NULL in case of error. 01029 */ 01030 01031 ZEXTERN int Q_ZEXPORT gzputc OF((gzFile file, int c)); 01032 /* 01033 Writes c, converted to an unsigned char, into the compressed file. 01034 gzputc returns the value that was written, or -1 in case of error. 01035 */ 01036 01037 ZEXTERN int Q_ZEXPORT gzgetc OF((gzFile file)); 01038 /* 01039 Reads one byte from the compressed file. gzgetc returns this byte 01040 or -1 in case of end of file or error. 01041 */ 01042 01043 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); 01044 /* 01045 Push one character back onto the stream to be read again later. 01046 Only one character of push-back is allowed. gzungetc() returns the 01047 character pushed, or -1 on failure. gzungetc() will fail if a 01048 character has been pushed but not read yet, or if c is -1. The pushed 01049 character will be discarded if the stream is repositioned with gzseek() 01050 or gzrewind(). 01051 */ 01052 01053 ZEXTERN int Q_ZEXPORT gzflush OF((gzFile file, int flush)); 01054 /* 01055 Flushes all pending output into the compressed file. The parameter 01056 flush is as in the deflate() function. The return value is the zlib 01057 error number (see function gzerror below). gzflush returns Z_OK if 01058 the flush parameter is Z_FINISH and all output could be flushed. 01059 gzflush should be called only when strictly necessary because it can 01060 degrade compression. 01061 */ 01062 01063 ZEXTERN z_off_t Q_ZEXPORT gzseek OF((gzFile file, 01064 z_off_t offset, int whence)); 01065 /* 01066 Sets the starting position for the next gzread or gzwrite on the 01067 given compressed file. The offset represents a number of bytes in the 01068 uncompressed data stream. The whence parameter is defined as in lseek(2); 01069 the value SEEK_END is not supported. 01070 If the file is opened for reading, this function is emulated but can be 01071 extremely slow. If the file is opened for writing, only forward seeks are 01072 supported; gzseek then compresses a sequence of zeroes up to the new 01073 starting position. 01074 01075 gzseek returns the resulting offset location as measured in bytes from 01076 the beginning of the uncompressed stream, or -1 in case of error, in 01077 particular if the file is opened for writing and the new starting position 01078 would be before the current position. 01079 */ 01080 01081 ZEXTERN int Q_ZEXPORT gzrewind OF((gzFile file)); 01082 /* 01083 Rewinds the given file. This function is supported only for reading. 01084 01085 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 01086 */ 01087 01088 ZEXTERN z_off_t Q_ZEXPORT gztell OF((gzFile file)); 01089 /* 01090 Returns the starting position for the next gzread or gzwrite on the 01091 given compressed file. This position represents a number of bytes in the 01092 uncompressed data stream. 01093 01094 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 01095 */ 01096 01097 ZEXTERN int Q_ZEXPORT gzeof OF((gzFile file)); 01098 /* 01099 Returns 1 when EOF has previously been detected reading the given 01100 input stream, otherwise zero. 01101 */ 01102 01103 ZEXTERN int Q_ZEXPORT gzclose OF((gzFile file)); 01104 /* 01105 Flushes all pending output if necessary, closes the compressed file 01106 and deallocates all the (de)compression state. The return value is the zlib 01107 error number (see function gzerror below). 01108 */ 01109 01110 ZEXTERN Q_ZEXPORT const char * gzerror OF((gzFile file, int *errnum)); 01111 /* 01112 Returns the error message for the last error which occurred on the 01113 given compressed file. errnum is set to zlib error number. If an 01114 error occurred in the file system and not in the compression library, 01115 errnum is set to Z_ERRNO and the application may consult errno 01116 to get the exact error code. 01117 */ 01118 01119 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); 01120 /* 01121 Clears the error and end-of-file flags for file. This is analogous to the 01122 clearerr() function in stdio. This is useful for continuing to read a gzip 01123 file that is being written concurrently. 01124 */ 01125 01126 /* checksum functions */ 01127 01128 /* 01129 These functions are not related to compression but are exported 01130 anyway because they might be useful in applications using the 01131 compression library. 01132 */ 01133 01134 ZEXTERN uLong Q_ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 01135 01136 /* 01137 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 01138 return the updated checksum. If buf is NULL, this function returns 01139 the required initial value for the checksum. 01140 An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 01141 much faster. Usage example: 01142 01143 uLong adler = adler32(0L, Z_NULL, 0); 01144 01145 while (read_buffer(buffer, length) != EOF) { 01146 adler = adler32(adler, buffer, length); 01147 } 01148 if (adler != original_adler) error(); 01149 */ 01150 01151 ZEXTERN uLong Q_ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 01152 /* 01153 Update a running crc with the bytes buf[0..len-1] and return the updated 01154 crc. If buf is NULL, this function returns the required initial value 01155 for the crc. Pre- and post-conditioning (one's complement) is performed 01156 within this function so it shouldn't be done by the application. 01157 Usage example: 01158 01159 uLong crc = crc32(0L, Z_NULL, 0); 01160 01161 while (read_buffer(buffer, length) != EOF) { 01162 crc = crc32(crc, buffer, length); 01163 } 01164 if (crc != original_crc) error(); 01165 */ 01166 01167 01168 /* various hacks, don't look :) */ 01169 01170 /* deflateInit and inflateInit are macros to allow checking the zlib version 01171 * and the compiler's view of z_stream: 01172 */ 01173 ZEXTERN int Q_ZEXPORT deflateInit_ OF((z_streamp strm, int level, 01174 const char *version, int stream_size)); 01175 ZEXTERN int Q_ZEXPORT inflateInit_ OF((z_streamp strm, 01176 const char *version, int stream_size)); 01177 ZEXTERN int Q_ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 01178 int windowBits, int memLevel, 01179 int strategy, const char *version, 01180 int stream_size)); 01181 ZEXTERN int Q_ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 01182 const char *version, int stream_size)); 01183 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits, 01184 unsigned char FAR *window, 01185 const char *version, 01186 int stream_size)); 01187 #define deflateInit(strm, level) \ 01188 deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) 01189 #define inflateInit(strm) \ 01190 inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) 01191 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 01192 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 01193 (strategy), ZLIB_VERSION, sizeof(z_stream)) 01194 #define inflateInit2(strm, windowBits) \ 01195 inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) 01196 #define inflateBackInit(strm, windowBits, window) \ 01197 inflateBackInit_((strm), (windowBits), (window), \ 01198 ZLIB_VERSION, sizeof(z_stream)) 01199 01200 01201 #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) 01202 struct internal_state {int dummy;}; /* hack for buggy compilers */ 01203 #endif 01204 01205 ZEXTERN Q_ZEXPORT const char * zError OF((int)); 01206 ZEXTERN int Q_ZEXPORT inflateSyncPoint OF((z_streamp z)); 01207 ZEXTERN Q_ZEXPORT const uLongf * get_crc_table OF((void)); 01208 01209 #ifdef __cplusplus 01210 } 01211 #endif 01212 01213 #endif /* ZLIB_H */