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0001 #ifndef ZLIB_H_ 0002 #define ZLIB_H_ 0003 /* zlib.h -- interface of the 'zlib-ng' compression library 0004 Forked from and compatible with zlib 1.2.13 0005 0006 Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler 0007 0008 This software is provided 'as-is', without any express or implied 0009 warranty. In no event will the authors be held liable for any damages 0010 arising from the use of this software. 0011 0012 Permission is granted to anyone to use this software for any purpose, 0013 including commercial applications, and to alter it and redistribute it 0014 freely, subject to the following restrictions: 0015 0016 1. The origin of this software must not be misrepresented; you must not 0017 claim that you wrote the original software. If you use this software 0018 in a product, an acknowledgment in the product documentation would be 0019 appreciated but is not required. 0020 2. Altered source versions must be plainly marked as such, and must not be 0021 misrepresented as being the original software. 0022 3. This notice may not be removed or altered from any source distribution. 0023 0024 Jean-loup Gailly Mark Adler 0025 jloup@gzip.org madler@alumni.caltech.edu 0026 0027 0028 The data format used by the zlib library is described by RFCs (Request for 0029 Comments) 1950 to 1952 in the files https://tools.ietf.org/html/rfc1950 0030 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). 0031 */ 0032 0033 #ifdef ZNGLIB_H_ 0034 # error Include zlib-ng.h for zlib-ng API or zlib.h for zlib-compat API but not both 0035 #endif 0036 0037 #ifndef RC_INVOKED 0038 #include <stdint.h> 0039 #include <stdarg.h> 0040 0041 #include "zconf.h" 0042 0043 #ifndef ZCONF_H 0044 # error Missing zconf.h add binary output directory to include directories 0045 #endif 0046 #endif /* RC_INVOKED */ 0047 0048 #ifdef __cplusplus 0049 extern "C" { 0050 #endif 0051 0052 #define ZLIBNG_VERSION "2.1.4" 0053 #define ZLIBNG_VERNUM 0x020104F0L /* MMNNRRSM: major minor revision status modified */ 0054 #define ZLIBNG_VER_MAJOR 2 0055 #define ZLIBNG_VER_MINOR 1 0056 #define ZLIBNG_VER_REVISION 4 0057 #define ZLIBNG_VER_STATUS F /* 0=devel, 1-E=beta, F=Release (DEPRECATED) */ 0058 #define ZLIBNG_VER_STATUSH 0xF /* Hex values: 0=devel, 1-E=beta, F=Release */ 0059 #define ZLIBNG_VER_MODIFIED 0 /* non-zero if modified externally from zlib-ng */ 0060 0061 #define ZLIB_VERSION "1.3.0.zlib-ng" 0062 #define ZLIB_VERNUM 0x130f 0063 #define ZLIB_VER_MAJOR 1 0064 #define ZLIB_VER_MINOR 3 0065 #define ZLIB_VER_REVISION 0 0066 #define ZLIB_VER_SUBREVISION 15 /* 15=fork (0xf) */ 0067 0068 /* 0069 The 'zlib' compression library provides in-memory compression and 0070 decompression functions, including integrity checks of the uncompressed data. 0071 This version of the library supports only one compression method (deflation) 0072 but other algorithms will be added later and will have the same stream 0073 interface. 0074 0075 Compression can be done in a single step if the buffers are large enough, 0076 or can be done by repeated calls of the compression function. In the latter 0077 case, the application must provide more input and/or consume the output 0078 (providing more output space) before each call. 0079 0080 The compressed data format used by default by the in-memory functions is 0081 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 0082 around a deflate stream, which is itself documented in RFC 1951. 0083 0084 The library also supports reading and writing files in gzip (.gz) format 0085 with an interface similar to that of stdio using the functions that start 0086 with "gz". The gzip format is different from the zlib format. gzip is a 0087 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 0088 0089 This library can optionally read and write gzip and raw deflate streams in 0090 memory as well. 0091 0092 The zlib format was designed to be compact and fast for use in memory 0093 and on communications channels. The gzip format was designed for single- 0094 file compression on file systems, has a larger header than zlib to maintain 0095 directory information, and uses a different, slower check method than zlib. 0096 0097 The library does not install any signal handler. The decoder checks 0098 the consistency of the compressed data, so the library should never crash 0099 even in the case of corrupted input. 0100 */ 0101 0102 typedef void *(*alloc_func) (void *opaque, unsigned int items, unsigned int size); 0103 typedef void (*free_func) (void *opaque, void *address); 0104 0105 struct internal_state; 0106 0107 typedef struct z_stream_s { 0108 z_const unsigned char *next_in; /* next input byte */ 0109 uint32_t avail_in; /* number of bytes available at next_in */ 0110 unsigned long total_in; /* total number of input bytes read so far */ 0111 0112 unsigned char *next_out; /* next output byte will go here */ 0113 uint32_t avail_out; /* remaining free space at next_out */ 0114 unsigned long total_out; /* total number of bytes output so far */ 0115 0116 z_const char *msg; /* last error message, NULL if no error */ 0117 struct internal_state *state; /* not visible by applications */ 0118 0119 alloc_func zalloc; /* used to allocate the internal state */ 0120 free_func zfree; /* used to free the internal state */ 0121 void *opaque; /* private data object passed to zalloc and zfree */ 0122 0123 int data_type; /* best guess about the data type: binary or text 0124 for deflate, or the decoding state for inflate */ 0125 unsigned long adler; /* Adler-32 or CRC-32 value of the uncompressed data */ 0126 unsigned long reserved; /* reserved for future use */ 0127 } z_stream; 0128 0129 typedef z_stream *z_streamp; /* Obsolete type, retained for compatibility only */ 0130 0131 /* 0132 gzip header information passed to and from zlib routines. See RFC 1952 0133 for more details on the meanings of these fields. 0134 */ 0135 typedef struct gz_header_s { 0136 int text; /* true if compressed data believed to be text */ 0137 unsigned long time; /* modification time */ 0138 int xflags; /* extra flags (not used when writing a gzip file) */ 0139 int os; /* operating system */ 0140 unsigned char *extra; /* pointer to extra field or NULL if none */ 0141 unsigned int extra_len; /* extra field length (valid if extra != NULL) */ 0142 unsigned int extra_max; /* space at extra (only when reading header) */ 0143 unsigned char *name; /* pointer to zero-terminated file name or NULL */ 0144 unsigned int name_max; /* space at name (only when reading header) */ 0145 unsigned char *comment; /* pointer to zero-terminated comment or NULL */ 0146 unsigned int comm_max; /* space at comment (only when reading header) */ 0147 int hcrc; /* true if there was or will be a header crc */ 0148 int done; /* true when done reading gzip header (not used when writing a gzip file) */ 0149 } gz_header; 0150 0151 typedef gz_header *gz_headerp; 0152 0153 /* 0154 The application must update next_in and avail_in when avail_in has dropped 0155 to zero. It must update next_out and avail_out when avail_out has dropped 0156 to zero. The application must initialize zalloc, zfree and opaque before 0157 calling the init function. All other fields are set by the compression 0158 library and must not be updated by the application. 0159 0160 The opaque value provided by the application will be passed as the first 0161 parameter for calls of zalloc and zfree. This can be useful for custom 0162 memory management. The compression library attaches no meaning to the 0163 opaque value. 0164 0165 zalloc must return NULL if there is not enough memory for the object. 0166 If zlib is used in a multi-threaded application, zalloc and zfree must be 0167 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are 0168 Z_NULL on entry to the initialization function, they are set to internal 0169 routines that use the standard library functions malloc() and free(). 0170 0171 The fields total_in and total_out can be used for statistics or progress 0172 reports. After compression, total_in holds the total size of the 0173 uncompressed data and may be saved for use by the decompressor (particularly 0174 if the decompressor wants to decompress everything in a single step). 0175 */ 0176 0177 /* constants */ 0178 0179 #define Z_NO_FLUSH 0 0180 #define Z_PARTIAL_FLUSH 1 0181 #define Z_SYNC_FLUSH 2 0182 #define Z_FULL_FLUSH 3 0183 #define Z_FINISH 4 0184 #define Z_BLOCK 5 0185 #define Z_TREES 6 0186 /* Allowed flush values; see deflate() and inflate() below for details */ 0187 0188 #define Z_OK 0 0189 #define Z_STREAM_END 1 0190 #define Z_NEED_DICT 2 0191 #define Z_ERRNO (-1) 0192 #define Z_STREAM_ERROR (-2) 0193 #define Z_DATA_ERROR (-3) 0194 #define Z_MEM_ERROR (-4) 0195 #define Z_BUF_ERROR (-5) 0196 #define Z_VERSION_ERROR (-6) 0197 /* Return codes for the compression/decompression functions. Negative values 0198 * are errors, positive values are used for special but normal events. 0199 */ 0200 0201 #define Z_NO_COMPRESSION 0 0202 #define Z_BEST_SPEED 1 0203 #define Z_BEST_COMPRESSION 9 0204 #define Z_DEFAULT_COMPRESSION (-1) 0205 /* compression levels */ 0206 0207 #define Z_FILTERED 1 0208 #define Z_HUFFMAN_ONLY 2 0209 #define Z_RLE 3 0210 #define Z_FIXED 4 0211 #define Z_DEFAULT_STRATEGY 0 0212 /* compression strategy; see deflateInit2() below for details */ 0213 0214 #define Z_BINARY 0 0215 #define Z_TEXT 1 0216 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 0217 #define Z_UNKNOWN 2 0218 /* Possible values of the data_type field for deflate() */ 0219 0220 #define Z_DEFLATED 8 0221 /* The deflate compression method (the only one supported in this version) */ 0222 0223 #define Z_NULL NULL /* for compatibility with zlib, was for initializing zalloc, zfree, opaque */ 0224 0225 #define zlib_version zlibVersion() 0226 /* for compatibility with versions < 1.0.2 */ 0227 0228 0229 /* basic functions */ 0230 0231 Z_EXTERN const char * Z_EXPORT zlibVersion(void); 0232 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 0233 If the first character differs, the library code actually used is not 0234 compatible with the zlib.h header file used by the application. This check 0235 is automatically made by deflateInit and inflateInit. 0236 */ 0237 0238 /* 0239 Z_EXTERN int Z_EXPORT deflateInit (z_stream *strm, int level); 0240 0241 Initializes the internal stream state for compression. The fields 0242 zalloc, zfree and opaque must be initialized before by the caller. If 0243 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default 0244 allocation functions. total_in, total_out, adler, and msg are initialized. 0245 0246 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 0247 1 gives best speed, 9 gives best compression, 0 gives no compression at all 0248 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION 0249 requests a default compromise between speed and compression (currently 0250 equivalent to level 6). 0251 0252 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 0253 memory, Z_STREAM_ERROR if level is not a valid compression level, or 0254 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 0255 with the version assumed by the caller (ZLIB_VERSION). msg is set to null 0256 if there is no error message. deflateInit does not perform any compression: 0257 this will be done by deflate(). 0258 */ 0259 0260 0261 Z_EXTERN int Z_EXPORT deflate(z_stream *strm, int flush); 0262 /* 0263 deflate compresses as much data as possible, and stops when the input 0264 buffer becomes empty or the output buffer becomes full. It may introduce 0265 some output latency (reading input without producing any output) except when 0266 forced to flush. 0267 0268 The detailed semantics are as follows. deflate performs one or both of the 0269 following actions: 0270 0271 - Compress more input starting at next_in and update next_in and avail_in 0272 accordingly. If not all input can be processed (because there is not 0273 enough room in the output buffer), next_in and avail_in are updated and 0274 processing will resume at this point for the next call of deflate(). 0275 0276 - Generate more output starting at next_out and update next_out and avail_out 0277 accordingly. This action is forced if the parameter flush is non zero. 0278 Forcing flush frequently degrades the compression ratio, so this parameter 0279 should be set only when necessary. Some output may be provided even if 0280 flush is zero. 0281 0282 Before the call of deflate(), the application should ensure that at least 0283 one of the actions is possible, by providing more input and/or consuming more 0284 output, and updating avail_in or avail_out accordingly; avail_out should 0285 never be zero before the call. The application can consume the compressed 0286 output when it wants, for example when the output buffer is full (avail_out 0287 == 0), or after each call of deflate(). If deflate returns Z_OK and with 0288 zero avail_out, it must be called again after making room in the output 0289 buffer because there might be more output pending. See deflatePending(), 0290 which can be used if desired to determine whether or not there is more output 0291 in that case. 0292 0293 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to 0294 decide how much data to accumulate before producing output, in order to 0295 maximize compression. 0296 0297 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 0298 flushed to the output buffer and the output is aligned on a byte boundary, so 0299 that the decompressor can get all input data available so far. (In 0300 particular avail_in is zero after the call if enough output space has been 0301 provided before the call.) Flushing may degrade compression for some 0302 compression algorithms and so it should be used only when necessary. This 0303 completes the current deflate block and follows it with an empty stored block 0304 that is three bits plus filler bits to the next byte, followed by four bytes 0305 (00 00 ff ff). 0306 0307 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the 0308 output buffer, but the output is not aligned to a byte boundary. All of the 0309 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. 0310 This completes the current deflate block and follows it with an empty fixed 0311 codes block that is 10 bits long. This assures that enough bytes are output 0312 in order for the decompressor to finish the block before the empty fixed 0313 codes block. 0314 0315 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as 0316 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to 0317 seven bits of the current block are held to be written as the next byte after 0318 the next deflate block is completed. In this case, the decompressor may not 0319 be provided enough bits at this point in order to complete decompression of 0320 the data provided so far to the compressor. It may need to wait for the next 0321 block to be emitted. This is for advanced applications that need to control 0322 the emission of deflate blocks. 0323 0324 If flush is set to Z_FULL_FLUSH, all output is flushed as with 0325 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 0326 restart from this point if previous compressed data has been damaged or if 0327 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 0328 compression. 0329 0330 If deflate returns with avail_out == 0, this function must be called again 0331 with the same value of the flush parameter and more output space (updated 0332 avail_out), until the flush is complete (deflate returns with non-zero 0333 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 0334 avail_out is greater than six when the flush marker begins, in order to avoid 0335 repeated flush markers upon calling deflate() again when avail_out == 0. 0336 0337 If the parameter flush is set to Z_FINISH, pending input is processed, 0338 pending output is flushed and deflate returns with Z_STREAM_END if there was 0339 enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this 0340 function must be called again with Z_FINISH and more output space (updated 0341 avail_out) but no more input data, until it returns with Z_STREAM_END or an 0342 error. After deflate has returned Z_STREAM_END, the only possible operations 0343 on the stream are deflateReset or deflateEnd. 0344 0345 Z_FINISH can be used in the first deflate call after deflateInit if all the 0346 compression is to be done in a single step. In order to complete in one 0347 call, avail_out must be at least the value returned by deflateBound (see 0348 below). Then deflate is guaranteed to return Z_STREAM_END. If not enough 0349 output space is provided, deflate will not return Z_STREAM_END, and it must 0350 be called again as described above. 0351 0352 deflate() sets strm->adler to the Adler-32 checksum of all input read 0353 so far (that is, total_in bytes). If a gzip stream is being generated, then 0354 strm->adler will be the CRC-32 checksum of the input read so far. (See 0355 deflateInit2 below.) 0356 0357 deflate() may update strm->data_type if it can make a good guess about 0358 the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is 0359 considered binary. This field is only for information purposes and does not 0360 affect the compression algorithm in any manner. 0361 0362 deflate() returns Z_OK if some progress has been made (more input 0363 processed or more output produced), Z_STREAM_END if all input has been 0364 consumed and all output has been produced (only when flush is set to 0365 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 0366 if next_in or next_out was NULL) or the state was inadvertently written over 0367 by the application), or Z_BUF_ERROR if no progress is possible (for example 0368 avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and 0369 deflate() can be called again with more input and more output space to 0370 continue compressing. 0371 */ 0372 0373 0374 Z_EXTERN int Z_EXPORT deflateEnd(z_stream *strm); 0375 /* 0376 All dynamically allocated data structures for this stream are freed. 0377 This function discards any unprocessed input and does not flush any pending 0378 output. 0379 0380 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 0381 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 0382 prematurely (some input or output was discarded). In the error case, msg 0383 may be set but then points to a static string (which must not be 0384 deallocated). 0385 */ 0386 0387 0388 /* 0389 Z_EXTERN int Z_EXPORT inflateInit (z_stream *strm); 0390 0391 Initializes the internal stream state for decompression. The fields 0392 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 0393 the caller. In the current version of inflate, the provided input is not 0394 read or consumed. The allocation of a sliding window will be deferred to 0395 the first call of inflate (if the decompression does not complete on the 0396 first call). If zalloc and zfree are set to Z_NULL, inflateInit updates 0397 them to use default allocation functions. total_in, total_out, adler, and 0398 msg are initialized. 0399 0400 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 0401 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 0402 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 0403 invalid, such as a null pointer to the structure. msg is set to null if 0404 there is no error message. inflateInit does not perform any decompression. 0405 Actual decompression will be done by inflate(). So next_in, and avail_in, 0406 next_out, and avail_out are unused and unchanged. The current 0407 implementation of inflateInit() does not process any header information -- 0408 that is deferred until inflate() is called. 0409 */ 0410 0411 0412 Z_EXTERN int Z_EXPORT inflate(z_stream *strm, int flush); 0413 /* 0414 inflate decompresses as much data as possible, and stops when the input 0415 buffer becomes empty or the output buffer becomes full. It may introduce 0416 some output latency (reading input without producing any output) except when 0417 forced to flush. 0418 0419 The detailed semantics are as follows. inflate performs one or both of the 0420 following actions: 0421 0422 - Decompress more input starting at next_in and update next_in and avail_in 0423 accordingly. If not all input can be processed (because there is not 0424 enough room in the output buffer), then next_in and avail_in are updated 0425 accordingly, and processing will resume at this point for the next call of 0426 inflate(). 0427 0428 - Generate more output starting at next_out and update next_out and avail_out 0429 accordingly. inflate() provides as much output as possible, until there is 0430 no more input data or no more space in the output buffer (see below about 0431 the flush parameter). 0432 0433 Before the call of inflate(), the application should ensure that at least 0434 one of the actions is possible, by providing more input and/or consuming more 0435 output, and updating the next_* and avail_* values accordingly. If the 0436 caller of inflate() does not provide both available input and available 0437 output space, it is possible that there will be no progress made. The 0438 application can consume the uncompressed output when it wants, for example 0439 when the output buffer is full (avail_out == 0), or after each call of 0440 inflate(). If inflate returns Z_OK and with zero avail_out, it must be 0441 called again after making room in the output buffer because there might be 0442 more output pending. 0443 0444 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, 0445 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much 0446 output as possible to the output buffer. Z_BLOCK requests that inflate() 0447 stop if and when it gets to the next deflate block boundary. When decoding 0448 the zlib or gzip format, this will cause inflate() to return immediately 0449 after the header and before the first block. When doing a raw inflate, 0450 inflate() will go ahead and process the first block, and will return when it 0451 gets to the end of that block, or when it runs out of data. 0452 0453 The Z_BLOCK option assists in appending to or combining deflate streams. 0454 To assist in this, on return inflate() always sets strm->data_type to the 0455 number of unused bits in the last byte taken from strm->next_in, plus 64 if 0456 inflate() is currently decoding the last block in the deflate stream, plus 0457 128 if inflate() returned immediately after decoding an end-of-block code or 0458 decoding the complete header up to just before the first byte of the deflate 0459 stream. The end-of-block will not be indicated until all of the uncompressed 0460 data from that block has been written to strm->next_out. The number of 0461 unused bits may in general be greater than seven, except when bit 7 of 0462 data_type is set, in which case the number of unused bits will be less than 0463 eight. data_type is set as noted here every time inflate() returns for all 0464 flush options, and so can be used to determine the amount of currently 0465 consumed input in bits. 0466 0467 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the 0468 end of each deflate block header is reached, before any actual data in that 0469 block is decoded. This allows the caller to determine the length of the 0470 deflate block header for later use in random access within a deflate block. 0471 256 is added to the value of strm->data_type when inflate() returns 0472 immediately after reaching the end of the deflate block header. 0473 0474 inflate() should normally be called until it returns Z_STREAM_END or an 0475 error. However if all decompression is to be performed in a single step (a 0476 single call of inflate), the parameter flush should be set to Z_FINISH. In 0477 this case all pending input is processed and all pending output is flushed; 0478 avail_out must be large enough to hold all of the uncompressed data for the 0479 operation to complete. (The size of the uncompressed data may have been 0480 saved by the compressor for this purpose.) The use of Z_FINISH is not 0481 required to perform an inflation in one step. However it may be used to 0482 inform inflate that a faster approach can be used for the single inflate() 0483 call. Z_FINISH also informs inflate to not maintain a sliding window if the 0484 stream completes, which reduces inflate's memory footprint. If the stream 0485 does not complete, either because not all of the stream is provided or not 0486 enough output space is provided, then a sliding window will be allocated and 0487 inflate() can be called again to continue the operation as if Z_NO_FLUSH had 0488 been used. 0489 0490 In this implementation, inflate() always flushes as much output as 0491 possible to the output buffer, and always uses the faster approach on the 0492 first call. So the effects of the flush parameter in this implementation are 0493 on the return value of inflate() as noted below, when inflate() returns early 0494 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of 0495 memory for a sliding window when Z_FINISH is used. 0496 0497 If a preset dictionary is needed after this call (see inflateSetDictionary 0498 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary 0499 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 0500 strm->adler to the Adler-32 checksum of all output produced so far (that is, 0501 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 0502 below. At the end of the stream, inflate() checks that its computed Adler-32 0503 checksum is equal to that saved by the compressor and returns Z_STREAM_END 0504 only if the checksum is correct. 0505 0506 inflate() can decompress and check either zlib-wrapped or gzip-wrapped 0507 deflate data. The header type is detected automatically, if requested when 0508 initializing with inflateInit2(). Any information contained in the gzip 0509 header is not retained unless inflateGetHeader() is used. When processing 0510 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output 0511 produced so far. The CRC-32 is checked against the gzip trailer, as is the 0512 uncompressed length, modulo 2^32. 0513 0514 inflate() returns Z_OK if some progress has been made (more input processed 0515 or more output produced), Z_STREAM_END if the end of the compressed data has 0516 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 0517 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 0518 corrupted (input stream not conforming to the zlib format or incorrect check 0519 value, in which case strm->msg points to a string with a more specific 0520 error), Z_STREAM_ERROR if the stream structure was inconsistent (for example 0521 next_in or next_out was NULL, or the state was inadvertently written over 0522 by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR 0523 if no progress is possible or if there was not enough room in the output 0524 buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 0525 inflate() can be called again with more input and more output space to 0526 continue decompressing. If Z_DATA_ERROR is returned, the application may 0527 then call inflateSync() to look for a good compression block if a partial 0528 recovery of the data is to be attempted. 0529 */ 0530 0531 0532 Z_EXTERN int Z_EXPORT inflateEnd(z_stream *strm); 0533 /* 0534 All dynamically allocated data structures for this stream are freed. 0535 This function discards any unprocessed input and does not flush any pending 0536 output. 0537 0538 inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state 0539 was inconsistent. 0540 */ 0541 0542 0543 /* Advanced functions */ 0544 0545 /* 0546 The following functions are needed only in some special applications. 0547 */ 0548 0549 /* 0550 Z_EXTERN int Z_EXPORT deflateInit2 (z_stream *strm, 0551 int level, 0552 int method, 0553 int windowBits, 0554 int memLevel, 0555 int strategy); 0556 0557 This is another version of deflateInit with more compression options. The 0558 fields zalloc, zfree and opaque must be initialized before by the caller. 0559 0560 The method parameter is the compression method. It must be Z_DEFLATED in 0561 this version of the library. 0562 0563 The windowBits parameter is the base two logarithm of the window size 0564 (the size of the history buffer). It should be in the range 8..15 for this 0565 version of the library. Larger values of this parameter result in better 0566 compression at the expense of memory usage. The default value is 15 if 0567 deflateInit is used instead. 0568 0569 For the current implementation of deflate(), a windowBits value of 8 (a 0570 window size of 256 bytes) is not supported. As a result, a request for 8 0571 will result in 9 (a 512-byte window). In that case, providing 8 to 0572 inflateInit2() will result in an error when the zlib header with 9 is 0573 checked against the initialization of inflate(). The remedy is to not use 8 0574 with deflateInit2() with this initialization, or at least in that case use 9 0575 with inflateInit2(). 0576 0577 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 0578 determines the window size. deflate() will then generate raw deflate data 0579 with no zlib header or trailer, and will not compute a check value. 0580 0581 windowBits can also be greater than 15 for optional gzip encoding. Add 0582 16 to windowBits to write a simple gzip header and trailer around the 0583 compressed data instead of a zlib wrapper. The gzip header will have no 0584 file name, no extra data, no comment, no modification time (set to zero), no 0585 header crc, and the operating system will be set to the appropriate value, 0586 if the operating system was determined at compile time. If a gzip stream is 0587 being written, strm->adler is a CRC-32 instead of an Adler-32. 0588 0589 For raw deflate or gzip encoding, a request for a 256-byte window is 0590 rejected as invalid, since only the zlib header provides a means of 0591 transmitting the window size to the decompressor. 0592 0593 The memLevel parameter specifies how much memory should be allocated 0594 for the internal compression state. memLevel=1 uses minimum memory but is 0595 slow and reduces compression ratio; memLevel=9 uses maximum memory for 0596 optimal speed. The default value is 8. See zconf.h for total memory usage 0597 as a function of windowBits and memLevel. 0598 0599 The strategy parameter is used to tune the compression algorithm. Use the 0600 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 0601 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 0602 string match), or Z_RLE to limit match distances to one (run-length 0603 encoding). Filtered data consists mostly of small values with a somewhat 0604 random distribution. In this case, the compression algorithm is tuned to 0605 compress them better. The effect of Z_FILTERED is to force more Huffman 0606 coding and less string matching; it is somewhat intermediate between 0607 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as 0608 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The 0609 strategy parameter only affects the compression ratio but not the 0610 correctness of the compressed output even if it is not set appropriately. 0611 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler 0612 decoder for special applications. 0613 0614 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 0615 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid 0616 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is 0617 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is 0618 set to null if there is no error message. deflateInit2 does not perform any 0619 compression: this will be done by deflate(). 0620 */ 0621 0622 Z_EXTERN int Z_EXPORT deflateSetDictionary(z_stream *strm, 0623 const unsigned char *dictionary, 0624 unsigned int dictLength); 0625 /* 0626 Initializes the compression dictionary from the given byte sequence 0627 without producing any compressed output. When using the zlib format, this 0628 function must be called immediately after deflateInit, deflateInit2 or 0629 deflateReset, and before any call of deflate. When doing raw deflate, this 0630 function must be called either before any call of deflate, or immediately 0631 after the completion of a deflate block, i.e. after all input has been 0632 consumed and all output has been delivered when using any of the flush 0633 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The 0634 compressor and decompressor must use exactly the same dictionary (see 0635 inflateSetDictionary). 0636 0637 The dictionary should consist of strings (byte sequences) that are likely 0638 to be encountered later in the data to be compressed, with the most commonly 0639 used strings preferably put towards the end of the dictionary. Using a 0640 dictionary is most useful when the data to be compressed is short and can be 0641 predicted with good accuracy; the data can then be compressed better than 0642 with the default empty dictionary. 0643 0644 Depending on the size of the compression data structures selected by 0645 deflateInit or deflateInit2, a part of the dictionary may in effect be 0646 discarded, for example if the dictionary is larger than the window size 0647 provided in deflateInit or deflateInit2. Thus the strings most likely to be 0648 useful should be put at the end of the dictionary, not at the front. In 0649 addition, the current implementation of deflate will use at most the window 0650 size minus 262 bytes of the provided dictionary. 0651 0652 Upon return of this function, strm->adler is set to the Adler-32 value 0653 of the dictionary; the decompressor may later use this value to determine 0654 which dictionary has been used by the compressor. (The Adler-32 value 0655 applies to the whole dictionary even if only a subset of the dictionary is 0656 actually used by the compressor.) If a raw deflate was requested, then the 0657 Adler-32 value is not computed and strm->adler is not set. 0658 0659 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 0660 parameter is invalid (e.g. dictionary being NULL) or the stream state is 0661 inconsistent (for example if deflate has already been called for this stream 0662 or if not at a block boundary for raw deflate). deflateSetDictionary does 0663 not perform any compression: this will be done by deflate(). 0664 */ 0665 0666 Z_EXTERN int Z_EXPORT deflateGetDictionary (z_stream *strm, unsigned char *dictionary, unsigned int *dictLength); 0667 /* 0668 Returns the sliding dictionary being maintained by deflate. dictLength is 0669 set to the number of bytes in the dictionary, and that many bytes are copied 0670 to dictionary. dictionary must have enough space, where 32768 bytes is 0671 always enough. If deflateGetDictionary() is called with dictionary equal to 0672 Z_NULL, then only the dictionary length is returned, and nothing is copied. 0673 Similarly, if dictLength is Z_NULL, then it is not set. 0674 0675 deflateGetDictionary() may return a length less than the window size, even 0676 when more than the window size in input has been provided. It may return up 0677 to 258 bytes less in that case, due to how zlib's implementation of deflate 0678 manages the sliding window and lookahead for matches, where matches can be 0679 up to 258 bytes long. If the application needs the last window-size bytes of 0680 input, then that would need to be saved by the application outside of zlib. 0681 0682 deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the 0683 stream state is inconsistent. 0684 */ 0685 0686 Z_EXTERN int Z_EXPORT deflateCopy(z_stream *dest, z_stream *source); 0687 /* 0688 Sets the destination stream as a complete copy of the source stream. 0689 0690 This function can be useful when several compression strategies will be 0691 tried, for example when there are several ways of pre-processing the input 0692 data with a filter. The streams that will be discarded should then be freed 0693 by calling deflateEnd. Note that deflateCopy duplicates the internal 0694 compression state which can be quite large, so this strategy is slow and can 0695 consume lots of memory. 0696 0697 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 0698 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 0699 (such as zalloc being NULL). msg is left unchanged in both source and 0700 destination. 0701 */ 0702 0703 Z_EXTERN int Z_EXPORT deflateReset(z_stream *strm); 0704 /* 0705 This function is equivalent to deflateEnd followed by deflateInit, but 0706 does not free and reallocate the internal compression state. The stream 0707 will leave the compression level and any other attributes that may have been 0708 set unchanged. total_in, total_out, adler, and msg are initialized. 0709 0710 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 0711 stream state was inconsistent (such as zalloc or state being NULL). 0712 */ 0713 0714 Z_EXTERN int Z_EXPORT deflateParams(z_stream *strm, int level, int strategy); 0715 /* 0716 Dynamically update the compression level and compression strategy. The 0717 interpretation of level and strategy is as in deflateInit2(). This can be 0718 used to switch between compression and straight copy of the input data, or 0719 to switch to a different kind of input data requiring a different strategy. 0720 If the compression approach (which is a function of the level) or the 0721 strategy is changed, and if there have been any deflate() calls since the 0722 state was initialized or reset, then the input available so far is 0723 compressed with the old level and strategy using deflate(strm, Z_BLOCK). 0724 There are three approaches for the compression levels 0, 1..3, and 4..9 0725 respectively. The new level and strategy will take effect at the next call 0726 of deflate(). 0727 0728 If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does 0729 not have enough output space to complete, then the parameter change will not 0730 take effect. In this case, deflateParams() can be called again with the 0731 same parameters and more output space to try again. 0732 0733 In order to assure a change in the parameters on the first try, the 0734 deflate stream should be flushed using deflate() with Z_BLOCK or other flush 0735 request until strm.avail_out is not zero, before calling deflateParams(). 0736 Then no more input data should be provided before the deflateParams() call. 0737 If this is done, the old level and strategy will be applied to the data 0738 compressed before deflateParams(), and the new level and strategy will be 0739 applied to the data compressed after deflateParams(). 0740 0741 deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream 0742 state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if 0743 there was not enough output space to complete the compression of the 0744 available input data before a change in the strategy or approach. Note that 0745 in the case of a Z_BUF_ERROR, the parameters are not changed. A return 0746 value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be 0747 retried with more output space. 0748 */ 0749 0750 Z_EXTERN int Z_EXPORT deflateTune(z_stream *strm, int good_length, int max_lazy, int nice_length, int max_chain); 0751 /* 0752 Fine tune deflate's internal compression parameters. This should only be 0753 used by someone who understands the algorithm used by zlib's deflate for 0754 searching for the best matching string, and even then only by the most 0755 fanatic optimizer trying to squeeze out the last compressed bit for their 0756 specific input data. Read the deflate.c source code for the meaning of the 0757 max_lazy, good_length, nice_length, and max_chain parameters. 0758 0759 deflateTune() can be called after deflateInit() or deflateInit2(), and 0760 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. 0761 */ 0762 0763 Z_EXTERN unsigned long Z_EXPORT deflateBound(z_stream *strm, unsigned long sourceLen); 0764 /* 0765 deflateBound() returns an upper bound on the compressed size after 0766 deflation of sourceLen bytes. It must be called after deflateInit() or 0767 deflateInit2(), and after deflateSetHeader(), if used. This would be used 0768 to allocate an output buffer for deflation in a single pass, and so would be 0769 called before deflate(). If that first deflate() call is provided the 0770 sourceLen input bytes, an output buffer allocated to the size returned by 0771 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed 0772 to return Z_STREAM_END. Note that it is possible for the compressed size to 0773 be larger than the value returned by deflateBound() if flush options other 0774 than Z_FINISH or Z_NO_FLUSH are used. 0775 */ 0776 0777 Z_EXTERN int Z_EXPORT deflatePending(z_stream *strm, uint32_t *pending, int *bits); 0778 /* 0779 deflatePending() returns the number of bytes and bits of output that have 0780 been generated, but not yet provided in the available output. The bytes not 0781 provided would be due to the available output space having being consumed. 0782 The number of bits of output not provided are between 0 and 7, where they 0783 await more bits to join them in order to fill out a full byte. If pending 0784 or bits are NULL, then those values are not set. 0785 0786 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source 0787 stream state was inconsistent. 0788 */ 0789 0790 Z_EXTERN int Z_EXPORT deflatePrime(z_stream *strm, int bits, int value); 0791 /* 0792 deflatePrime() inserts bits in the deflate output stream. The intent 0793 is that this function is used to start off the deflate output with the bits 0794 leftover from a previous deflate stream when appending to it. As such, this 0795 function can only be used for raw deflate, and must be used before the first 0796 deflate() call after a deflateInit2() or deflateReset(). bits must be less 0797 than or equal to 16, and that many of the least significant bits of value 0798 will be inserted in the output. 0799 0800 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough 0801 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the 0802 source stream state was inconsistent. 0803 */ 0804 0805 Z_EXTERN int Z_EXPORT deflateSetHeader(z_stream *strm, gz_headerp head); 0806 /* 0807 deflateSetHeader() provides gzip header information for when a gzip 0808 stream is requested by deflateInit2(). deflateSetHeader() may be called 0809 after deflateInit2() or deflateReset() and before the first call of 0810 deflate(). The text, time, os, extra field, name, and comment information 0811 in the provided gz_header structure are written to the gzip header (xflag is 0812 ignored -- the extra flags are set according to the compression level). The 0813 caller must assure that, if not NULL, name and comment are terminated with 0814 a zero byte, and that if extra is not NULL, that extra_len bytes are 0815 available there. If hcrc is true, a gzip header crc is included. Note that 0816 the current versions of the command-line version of gzip (up through version 0817 1.3.x) do not support header crc's, and will report that it is a "multi-part 0818 gzip file" and give up. 0819 0820 If deflateSetHeader is not used, the default gzip header has text false, 0821 the time set to zero, and os set to the current operating system, with no 0822 extra, name, or comment fields. The gzip header is returned to the default 0823 state by deflateReset(). 0824 0825 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 0826 stream state was inconsistent. 0827 */ 0828 0829 /* 0830 Z_EXTERN int Z_EXPORT inflateInit2(z_stream *strm, int windowBits); 0831 0832 This is another version of inflateInit with an extra parameter. The 0833 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 0834 before by the caller. 0835 0836 The windowBits parameter is the base two logarithm of the maximum window 0837 size (the size of the history buffer). It should be in the range 8..15 for 0838 this version of the library. The default value is 15 if inflateInit is used 0839 instead. windowBits must be greater than or equal to the windowBits value 0840 provided to deflateInit2() while compressing, or it must be equal to 15 if 0841 deflateInit2() was not used. If a compressed stream with a larger window 0842 size is given as input, inflate() will return with the error code 0843 Z_DATA_ERROR instead of trying to allocate a larger window. 0844 0845 windowBits can also be zero to request that inflate use the window size in 0846 the zlib header of the compressed stream. 0847 0848 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 0849 determines the window size. inflate() will then process raw deflate data, 0850 not looking for a zlib or gzip header, not generating a check value, and not 0851 looking for any check values for comparison at the end of the stream. This 0852 is for use with other formats that use the deflate compressed data format 0853 such as zip. Those formats provide their own check values. If a custom 0854 format is developed using the raw deflate format for compressed data, it is 0855 recommended that a check value such as an Adler-32 or a CRC-32 be applied to 0856 the uncompressed data as is done in the zlib, gzip, and zip formats. For 0857 most applications, the zlib format should be used as is. Note that comments 0858 above on the use in deflateInit2() applies to the magnitude of windowBits. 0859 0860 windowBits can also be greater than 15 for optional gzip decoding. Add 0861 32 to windowBits to enable zlib and gzip decoding with automatic header 0862 detection, or add 16 to decode only the gzip format (the zlib format will 0863 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a 0864 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see 0865 below), inflate() will *not* automatically decode concatenated gzip members. 0866 inflate() will return Z_STREAM_END at the end of the gzip member. The state 0867 would need to be reset to continue decoding a subsequent gzip member. This 0868 *must* be done if there is more data after a gzip member, in order for the 0869 decompression to be compliant with the gzip standard (RFC 1952). 0870 0871 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 0872 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 0873 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 0874 invalid, such as a null pointer to the structure. msg is set to null if 0875 there is no error message. inflateInit2 does not perform any decompression 0876 apart from possibly reading the zlib header if present: actual decompression 0877 will be done by inflate(). (So next_in and avail_in may be modified, but 0878 next_out and avail_out are unused and unchanged.) The current implementation 0879 of inflateInit2() does not process any header information -- that is 0880 deferred until inflate() is called. 0881 */ 0882 0883 Z_EXTERN int Z_EXPORT inflateSetDictionary(z_stream *strm, const unsigned char *dictionary, unsigned int dictLength); 0884 /* 0885 Initializes the decompression dictionary from the given uncompressed byte 0886 sequence. This function must be called immediately after a call of inflate, 0887 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 0888 can be determined from the Adler-32 value returned by that call of inflate. 0889 The compressor and decompressor must use exactly the same dictionary (see 0890 deflateSetDictionary). For raw inflate, this function can be called at any 0891 time to set the dictionary. If the provided dictionary is smaller than the 0892 window and there is already data in the window, then the provided dictionary 0893 will amend what's there. The application must insure that the dictionary 0894 that was used for compression is provided. 0895 0896 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 0897 parameter is invalid (e.g. dictionary being NULL) or the stream state is 0898 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 0899 expected one (incorrect Adler-32 value). inflateSetDictionary does not 0900 perform any decompression: this will be done by subsequent calls of 0901 inflate(). 0902 */ 0903 0904 Z_EXTERN int Z_EXPORT inflateGetDictionary(z_stream *strm, unsigned char *dictionary, unsigned int *dictLength); 0905 /* 0906 Returns the sliding dictionary being maintained by inflate. dictLength is 0907 set to the number of bytes in the dictionary, and that many bytes are copied 0908 to dictionary. dictionary must have enough space, where 32768 bytes is 0909 always enough. If inflateGetDictionary() is called with dictionary equal to 0910 NULL, then only the dictionary length is returned, and nothing is copied. 0911 Similarly, if dictLength is NULL, then it is not set. 0912 0913 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the 0914 stream state is inconsistent. 0915 */ 0916 0917 Z_EXTERN int Z_EXPORT inflateSync(z_stream *strm); 0918 /* 0919 Skips invalid compressed data until a possible full flush point (see above 0920 for the description of deflate with Z_FULL_FLUSH) can be found, or until all 0921 available input is skipped. No output is provided. 0922 0923 inflateSync searches for a 00 00 FF FF pattern in the compressed data. 0924 All full flush points have this pattern, but not all occurrences of this 0925 pattern are full flush points. 0926 0927 inflateSync returns Z_OK if a possible full flush point has been found, 0928 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point 0929 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. 0930 In the success case, the application may save the current value of 0931 total_in which indicates where valid compressed data was found. In the 0932 error case, the application may repeatedly call inflateSync, providing more 0933 input each time, until success or end of the input data. 0934 */ 0935 0936 Z_EXTERN int Z_EXPORT inflateCopy(z_stream *dest, z_stream *source); 0937 /* 0938 Sets the destination stream as a complete copy of the source stream. 0939 0940 This function can be useful when randomly accessing a large stream. The 0941 first pass through the stream can periodically record the inflate state, 0942 allowing restarting inflate at those points when randomly accessing the 0943 stream. 0944 0945 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 0946 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 0947 (such as zalloc being NULL). msg is left unchanged in both source and 0948 destination. 0949 */ 0950 0951 Z_EXTERN int Z_EXPORT inflateReset(z_stream *strm); 0952 /* 0953 This function is equivalent to inflateEnd followed by inflateInit, 0954 but does not free and reallocate the internal decompression state. The 0955 stream will keep attributes that may have been set by inflateInit2. 0956 total_in, total_out, adler, and msg are initialized. 0957 0958 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 0959 stream state was inconsistent (such as zalloc or state being NULL). 0960 */ 0961 0962 Z_EXTERN int Z_EXPORT inflateReset2(z_stream *strm, int windowBits); 0963 /* 0964 This function is the same as inflateReset, but it also permits changing 0965 the wrap and window size requests. The windowBits parameter is interpreted 0966 the same as it is for inflateInit2. If the window size is changed, then the 0967 memory allocated for the window is freed, and the window will be reallocated 0968 by inflate() if needed. 0969 0970 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source 0971 stream state was inconsistent (such as zalloc or state being NULL), or if 0972 the windowBits parameter is invalid. 0973 */ 0974 0975 Z_EXTERN int Z_EXPORT inflatePrime(z_stream *strm, int bits, int value); 0976 /* 0977 This function inserts bits in the inflate input stream. The intent is 0978 that this function is used to start inflating at a bit position in the 0979 middle of a byte. The provided bits will be used before any bytes are used 0980 from next_in. This function should only be used with raw inflate, and 0981 should be used before the first inflate() call after inflateInit2() or 0982 inflateReset(). bits must be less than or equal to 16, and that many of the 0983 least significant bits of value will be inserted in the input. 0984 0985 If bits is negative, then the input stream bit buffer is emptied. Then 0986 inflatePrime() can be called again to put bits in the buffer. This is used 0987 to clear out bits leftover after feeding inflate a block description prior 0988 to feeding inflate codes. 0989 0990 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 0991 stream state was inconsistent. 0992 */ 0993 0994 Z_EXTERN long Z_EXPORT inflateMark(z_stream *strm); 0995 /* 0996 This function returns two values, one in the lower 16 bits of the return 0997 value, and the other in the remaining upper bits, obtained by shifting the 0998 return value down 16 bits. If the upper value is -1 and the lower value is 0999 zero, then inflate() is currently decoding information outside of a block. 1000 If the upper value is -1 and the lower value is non-zero, then inflate is in 1001 the middle of a stored block, with the lower value equaling the number of 1002 bytes from the input remaining to copy. If the upper value is not -1, then 1003 it is the number of bits back from the current bit position in the input of 1004 the code (literal or length/distance pair) currently being processed. In 1005 that case the lower value is the number of bytes already emitted for that 1006 code. 1007 1008 A code is being processed if inflate is waiting for more input to complete 1009 decoding of the code, or if it has completed decoding but is waiting for 1010 more output space to write the literal or match data. 1011 1012 inflateMark() is used to mark locations in the input data for random 1013 access, which may be at bit positions, and to note those cases where the 1014 output of a code may span boundaries of random access blocks. The current 1015 location in the input stream can be determined from avail_in and data_type 1016 as noted in the description for the Z_BLOCK flush parameter for inflate. 1017 1018 inflateMark returns the value noted above, or -65536 if the provided 1019 source stream state was inconsistent. 1020 */ 1021 1022 Z_EXTERN int Z_EXPORT inflateGetHeader(z_stream *strm, gz_headerp head); 1023 /* 1024 inflateGetHeader() requests that gzip header information be stored in the 1025 provided gz_header structure. inflateGetHeader() may be called after 1026 inflateInit2() or inflateReset(), and before the first call of inflate(). 1027 As inflate() processes the gzip stream, head->done is zero until the header 1028 is completed, at which time head->done is set to one. If a zlib stream is 1029 being decoded, then head->done is set to -1 to indicate that there will be 1030 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be 1031 used to force inflate() to return immediately after header processing is 1032 complete and before any actual data is decompressed. 1033 1034 The text, time, xflags, and os fields are filled in with the gzip header 1035 contents. hcrc is set to true if there is a header CRC. (The header CRC 1036 was valid if done is set to one.) If extra is not NULL, then extra_max 1037 contains the maximum number of bytes to write to extra. Once done is true, 1038 extra_len contains the actual extra field length, and extra contains the 1039 extra field, or that field truncated if extra_max is less than extra_len. 1040 If name is not NULL, then up to name_max characters are written there, 1041 terminated with a zero unless the length is greater than name_max. If 1042 comment is not NULL, then up to comm_max characters are written there, 1043 terminated with a zero unless the length is greater than comm_max. When any 1044 of extra, name, or comment are not NULL and the respective field is not 1045 present in the header, then that field is set to NULL to signal its 1046 absence. This allows the use of deflateSetHeader() with the returned 1047 structure to duplicate the header. However if those fields are set to 1048 allocated memory, then the application will need to save those pointers 1049 elsewhere so that they can be eventually freed. 1050 1051 If inflateGetHeader is not used, then the header information is simply 1052 discarded. The header is always checked for validity, including the header 1053 CRC if present. inflateReset() will reset the process to discard the header 1054 information. The application would need to call inflateGetHeader() again to 1055 retrieve the header from the next gzip stream. 1056 1057 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 1058 stream state was inconsistent. 1059 */ 1060 1061 /* 1062 Z_EXTERN int Z_EXPORT inflateBackInit (z_stream *strm, int windowBits, unsigned char *window); 1063 1064 Initialize the internal stream state for decompression using inflateBack() 1065 calls. The fields zalloc, zfree and opaque in strm must be initialized 1066 before the call. If zalloc and zfree are NULL, then the default library- 1067 derived memory allocation routines are used. windowBits is the base two 1068 logarithm of the window size, in the range 8..15. window is a caller 1069 supplied buffer of that size. Except for special applications where it is 1070 assured that deflate was used with small window sizes, windowBits must be 15 1071 and a 32K byte window must be supplied to be able to decompress general 1072 deflate streams. 1073 1074 See inflateBack() for the usage of these routines. 1075 1076 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 1077 the parameters are invalid, Z_MEM_ERROR if the internal state could not be 1078 allocated, or Z_VERSION_ERROR if the version of the library does not match 1079 the version of the header file. 1080 */ 1081 1082 typedef uint32_t (*in_func) (void *, z_const unsigned char * *); 1083 typedef int (*out_func) (void *, unsigned char *, uint32_t); 1084 1085 Z_EXTERN int Z_EXPORT inflateBack(z_stream *strm, in_func in, void *in_desc, out_func out, void *out_desc); 1086 /* 1087 inflateBack() does a raw inflate with a single call using a call-back 1088 interface for input and output. This is potentially more efficient than 1089 inflate() for file i/o applications, in that it avoids copying between the 1090 output and the sliding window by simply making the window itself the output 1091 buffer. inflate() can be faster on modern CPUs when used with large 1092 buffers. inflateBack() trusts the application to not change the output 1093 buffer passed by the output function, at least until inflateBack() returns. 1094 1095 inflateBackInit() must be called first to allocate the internal state 1096 and to initialize the state with the user-provided window buffer. 1097 inflateBack() may then be used multiple times to inflate a complete, raw 1098 deflate stream with each call. inflateBackEnd() is then called to free the 1099 allocated state. 1100 1101 A raw deflate stream is one with no zlib or gzip header or trailer. 1102 This routine would normally be used in a utility that reads zip or gzip 1103 files and writes out uncompressed files. The utility would decode the 1104 header and process the trailer on its own, hence this routine expects only 1105 the raw deflate stream to decompress. This is different from the default 1106 behavior of inflate(), which expects a zlib header and trailer around the 1107 deflate stream. 1108 1109 inflateBack() uses two subroutines supplied by the caller that are then 1110 called by inflateBack() for input and output. inflateBack() calls those 1111 routines until it reads a complete deflate stream and writes out all of the 1112 uncompressed data, or until it encounters an error. The function's 1113 parameters and return types are defined above in the in_func and out_func 1114 typedefs. inflateBack() will call in(in_desc, &buf) which should return the 1115 number of bytes of provided input, and a pointer to that input in buf. If 1116 there is no input available, in() must return zero -- buf is ignored in that 1117 case -- and inflateBack() will return a buffer error. inflateBack() will 1118 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. 1119 out() should return zero on success, or non-zero on failure. If out() 1120 returns non-zero, inflateBack() will return with an error. Neither in() nor 1121 out() are permitted to change the contents of the window provided to 1122 inflateBackInit(), which is also the buffer that out() uses to write from. 1123 The length written by out() will be at most the window size. Any non-zero 1124 amount of input may be provided by in(). 1125 1126 For convenience, inflateBack() can be provided input on the first call by 1127 setting strm->next_in and strm->avail_in. If that input is exhausted, then 1128 in() will be called. Therefore strm->next_in must be initialized before 1129 calling inflateBack(). If strm->next_in is NULL, then in() will be called 1130 immediately for input. If strm->next_in is not NULL, then strm->avail_in 1131 must also be initialized, and then if strm->avail_in is not zero, input will 1132 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 1133 1134 The in_desc and out_desc parameters of inflateBack() is passed as the 1135 first parameter of in() and out() respectively when they are called. These 1136 descriptors can be optionally used to pass any information that the caller- 1137 supplied in() and out() functions need to do their job. 1138 1139 On return, inflateBack() will set strm->next_in and strm->avail_in to 1140 pass back any unused input that was provided by the last in() call. The 1141 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 1142 if in() or out() returned an error, Z_DATA_ERROR if there was a format error 1143 in the deflate stream (in which case strm->msg is set to indicate the nature 1144 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. 1145 In the case of Z_BUF_ERROR, an input or output error can be distinguished 1146 using strm->next_in which will be NULL only if in() returned an error. If 1147 strm->next_in is not NULL, then the Z_BUF_ERROR was due to out() returning 1148 non-zero. (in() will always be called before out(), so strm->next_in is 1149 assured to be defined if out() returns non-zero.) Note that inflateBack() 1150 cannot return Z_OK. 1151 */ 1152 1153 Z_EXTERN int Z_EXPORT inflateBackEnd(z_stream *strm); 1154 /* 1155 All memory allocated by inflateBackInit() is freed. 1156 1157 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 1158 state was inconsistent. 1159 */ 1160 1161 Z_EXTERN unsigned long Z_EXPORT zlibCompileFlags(void); 1162 /* Return flags indicating compile-time options. 1163 1164 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1165 1.0: size of unsigned int 1166 3.2: size of unsigned long 1167 5.4: size of void * (pointer) 1168 7.6: size of z_off_t 1169 1170 Compiler, assembler, and debug options: 1171 8: ZLIB_DEBUG 1172 9: ASMV or ASMINF -- use ASM code 1173 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 1174 11: 0 (reserved) 1175 1176 One-time table building (smaller code, but not thread-safe if true): 1177 12: BUILDFIXED -- build static block decoding tables when needed (not supported by zlib-ng) 1178 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 1179 14,15: 0 (reserved) 1180 1181 Library content (indicates missing functionality): 1182 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 1183 deflate code when not needed) 1184 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 1185 and decode gzip streams (to avoid linking crc code) 1186 18-19: 0 (reserved) 1187 1188 Operation variations (changes in library functionality): 1189 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 1190 21: FASTEST -- deflate algorithm with only one, lowest compression level 1191 22,23: 0 (reserved) 1192 1193 The sprintf variant used by gzprintf (zero is best): 1194 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 1195 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 1196 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 1197 1198 Remainder: 1199 27-31: 0 (reserved) 1200 */ 1201 1202 1203 #ifndef Z_SOLO 1204 1205 /* utility functions */ 1206 1207 /* 1208 The following utility functions are implemented on top of the basic 1209 stream-oriented functions. To simplify the interface, some default options 1210 are assumed (compression level and memory usage, standard memory allocation 1211 functions). The source code of these utility functions can be modified if 1212 you need special options. 1213 */ 1214 1215 Z_EXTERN int Z_EXPORT compress(unsigned char *dest, unsigned long *destLen, const unsigned char *source, unsigned long sourceLen); 1216 /* 1217 Compresses the source buffer into the destination buffer. sourceLen is 1218 the byte length of the source buffer. Upon entry, destLen is the total size 1219 of the destination buffer, which must be at least the value returned by 1220 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1221 compressed data. compress() is equivalent to compress2() with a level 1222 parameter of Z_DEFAULT_COMPRESSION. 1223 1224 compress returns Z_OK if success, Z_MEM_ERROR if there was not 1225 enough memory, Z_BUF_ERROR if there was not enough room in the output 1226 buffer. 1227 */ 1228 1229 Z_EXTERN int Z_EXPORT compress2(unsigned char *dest, unsigned long *destLen, const unsigned char *source, 1230 unsigned long sourceLen, int level); 1231 /* 1232 Compresses the source buffer into the destination buffer. The level 1233 parameter has the same meaning as in deflateInit. sourceLen is the byte 1234 length of the source buffer. Upon entry, destLen is the total size of the 1235 destination buffer, which must be at least the value returned by 1236 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1237 compressed data. 1238 1239 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1240 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 1241 Z_STREAM_ERROR if the level parameter is invalid. 1242 */ 1243 1244 Z_EXTERN unsigned long Z_EXPORT compressBound(unsigned long sourceLen); 1245 /* 1246 compressBound() returns an upper bound on the compressed size after 1247 compress() or compress2() on sourceLen bytes. It would be used before a 1248 compress() or compress2() call to allocate the destination buffer. 1249 */ 1250 1251 Z_EXTERN int Z_EXPORT uncompress(unsigned char *dest, unsigned long *destLen, const unsigned char *source, unsigned long sourceLen); 1252 /* 1253 Decompresses the source buffer into the destination buffer. sourceLen is 1254 the byte length of the source buffer. Upon entry, destLen is the total size 1255 of the destination buffer, which must be large enough to hold the entire 1256 uncompressed data. (The size of the uncompressed data must have been saved 1257 previously by the compressor and transmitted to the decompressor by some 1258 mechanism outside the scope of this compression library.) Upon exit, destLen 1259 is the actual size of the uncompressed data. 1260 1261 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 1262 enough memory, Z_BUF_ERROR if there was not enough room in the output 1263 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In 1264 the case where there is not enough room, uncompress() will fill the output 1265 buffer with the uncompressed data up to that point. 1266 */ 1267 1268 1269 Z_EXTERN int Z_EXPORT uncompress2 (unsigned char *dest, unsigned long *destLen, 1270 const unsigned char *source, unsigned long *sourceLen); 1271 /* 1272 Same as uncompress, except that sourceLen is a pointer, where the 1273 length of the source is *sourceLen. On return, *sourceLen is the number of 1274 source bytes consumed. 1275 */ 1276 1277 1278 /* gzip file access functions */ 1279 1280 /* 1281 This library supports reading and writing files in gzip (.gz) format with 1282 an interface similar to that of stdio, using the functions that start with 1283 "gz". The gzip format is different from the zlib format. gzip is a gzip 1284 wrapper, documented in RFC 1952, wrapped around a deflate stream. 1285 */ 1286 1287 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ 1288 1289 /* 1290 Z_EXTERN gzFile Z_EXPORT gzopen(const char *path, const char *mode); 1291 1292 Open the gzip (.gz) file at path for reading and decompressing, or 1293 compressing and writing. The mode parameter is as in fopen ("rb" or "wb") 1294 but can also include a compression level ("wb9") or a strategy: 'f' for 1295 filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h", 1296 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression 1297 as in "wb9F". (See the description of deflateInit2 for more information 1298 about the strategy parameter.) 'T' will request transparent writing or 1299 appending with no compression and not using the gzip format. 1300 1301 "a" can be used instead of "w" to request that the gzip stream that will 1302 be written be appended to the file. "+" will result in an error, since 1303 reading and writing to the same gzip file is not supported. The addition of 1304 "x" when writing will create the file exclusively, which fails if the file 1305 already exists. On systems that support it, the addition of "e" when 1306 reading or writing will set the flag to close the file on an execve() call. 1307 1308 These functions, as well as gzip, will read and decode a sequence of gzip 1309 streams in a file. The append function of gzopen() can be used to create 1310 such a file. (Also see gzflush() for another way to do this.) When 1311 appending, gzopen does not test whether the file begins with a gzip stream, 1312 nor does it look for the end of the gzip streams to begin appending. gzopen 1313 will simply append a gzip stream to the existing file. 1314 1315 gzopen can be used to read a file which is not in gzip format; in this 1316 case gzread will directly read from the file without decompression. When 1317 reading, this will be detected automatically by looking for the magic two- 1318 byte gzip header. 1319 1320 gzopen returns NULL if the file could not be opened, if there was 1321 insufficient memory to allocate the gzFile state, or if an invalid mode was 1322 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). 1323 errno can be checked to determine if the reason gzopen failed was that the 1324 file could not be opened. 1325 */ 1326 1327 Z_EXTERN gzFile Z_EXPORT gzdopen(int fd, const char *mode); 1328 /* 1329 Associate a gzFile with the file descriptor fd. File descriptors are 1330 obtained from calls like open, dup, creat, pipe or fileno (if the file has 1331 been previously opened with fopen). The mode parameter is as in gzopen. 1332 1333 The next call of gzclose on the returned gzFile will also close the file 1334 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor 1335 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, 1336 mode);. The duplicated descriptor should be saved to avoid a leak, since 1337 gzdopen does not close fd if it fails. If you are using fileno() to get the 1338 file descriptor from a FILE *, then you will have to use dup() to avoid 1339 double-close()ing the file descriptor. Both gzclose() and fclose() will 1340 close the associated file descriptor, so they need to have different file 1341 descriptors. 1342 1343 gzdopen returns NULL if there was insufficient memory to allocate the 1344 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not 1345 provided, or '+' was provided), or if fd is -1. The file descriptor is not 1346 used until the next gz* read, write, seek, or close operation, so gzdopen 1347 will not detect if fd is invalid (unless fd is -1). 1348 */ 1349 1350 Z_EXTERN int Z_EXPORT gzbuffer(gzFile file, unsigned size); 1351 /* 1352 Set the internal buffer size used by this library's functions for file to 1353 size. The default buffer size is 8192 bytes. This function must be called 1354 after gzopen() or gzdopen(), and before any other calls that read or write 1355 the file. The buffer memory allocation is always deferred to the first read 1356 or write. Three times that size in buffer space is allocated. A larger 1357 buffer size of, for example, 64K or 128K bytes will noticeably increase the 1358 speed of decompression (reading). 1359 1360 The new buffer size also affects the maximum length for gzprintf(). 1361 1362 gzbuffer() returns 0 on success, or -1 on failure, such as being called 1363 too late. 1364 */ 1365 1366 Z_EXTERN int Z_EXPORT gzsetparams(gzFile file, int level, int strategy); 1367 /* 1368 Dynamically update the compression level and strategy for file. See the 1369 description of deflateInit2 for the meaning of these parameters. Previously 1370 provided data is flushed before applying the parameter changes. 1371 1372 gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not 1373 opened for writing, Z_ERRNO if there is an error writing the flushed data, 1374 or Z_MEM_ERROR if there is a memory allocation error. 1375 */ 1376 1377 Z_EXTERN int Z_EXPORT gzread(gzFile file, void *buf, unsigned len); 1378 /* 1379 Read and decompress up to len uncompressed bytes from file into buf. If 1380 the input file is not in gzip format, gzread copies the given number of 1381 bytes into the buffer directly from the file. 1382 1383 After reaching the end of a gzip stream in the input, gzread will continue 1384 to read, looking for another gzip stream. Any number of gzip streams may be 1385 concatenated in the input file, and will all be decompressed by gzread(). 1386 If something other than a gzip stream is encountered after a gzip stream, 1387 that remaining trailing garbage is ignored (and no error is returned). 1388 1389 gzread can be used to read a gzip file that is being concurrently written. 1390 Upon reaching the end of the input, gzread will return with the available 1391 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then 1392 gzclearerr can be used to clear the end of file indicator in order to permit 1393 gzread to be tried again. Z_OK indicates that a gzip stream was completed 1394 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the 1395 middle of a gzip stream. Note that gzread does not return -1 in the event 1396 of an incomplete gzip stream. This error is deferred until gzclose(), which 1397 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip 1398 stream. Alternatively, gzerror can be used before gzclose to detect this 1399 case. 1400 1401 gzread returns the number of uncompressed bytes actually read, less than 1402 len for end of file, or -1 for error. If len is too large to fit in an int, 1403 then nothing is read, -1 is returned, and the error state is set to 1404 Z_STREAM_ERROR. 1405 */ 1406 1407 Z_EXTERN size_t Z_EXPORT gzfread (void *buf, size_t size, size_t nitems, gzFile file); 1408 /* 1409 Read and decompress up to nitems items of size size from file into buf, 1410 otherwise operating as gzread() does. This duplicates the interface of 1411 stdio's fread(), with size_t request and return types. If the library 1412 defines size_t, then z_size_t is identical to size_t. If not, then z_size_t 1413 is an unsigned integer type that can contain a pointer. 1414 1415 gzfread() returns the number of full items read of size size, or zero if 1416 the end of the file was reached and a full item could not be read, or if 1417 there was an error. gzerror() must be consulted if zero is returned in 1418 order to determine if there was an error. If the multiplication of size and 1419 nitems overflows, i.e. the product does not fit in a size_t, then nothing 1420 is read, zero is returned, and the error state is set to Z_STREAM_ERROR. 1421 1422 In the event that the end of file is reached and only a partial item is 1423 available at the end, i.e. the remaining uncompressed data length is not a 1424 multiple of size, then the final partial item is nevertheless read into buf 1425 and the end-of-file flag is set. The length of the partial item read is not 1426 provided, but could be inferred from the result of gztell(). This behavior 1427 is the same as the behavior of fread() implementations in common libraries, 1428 but it prevents the direct use of gzfread() to read a concurrently written 1429 file, resetting and retrying on end-of-file, when size is not 1. 1430 */ 1431 1432 Z_EXTERN int Z_EXPORT gzwrite(gzFile file, void const *buf, unsigned len); 1433 /* 1434 Compress and write the len uncompressed bytes at buf to file. gzwrite 1435 returns the number of uncompressed bytes written or 0 in case of error. 1436 */ 1437 1438 Z_EXTERN size_t Z_EXPORT gzfwrite(void const *buf, size_t size, size_t nitems, gzFile file); 1439 /* 1440 Compress and write nitems items of size size from buf to file, duplicating 1441 the interface of stdio's fwrite(), with size_t request and return types. 1442 1443 gzfwrite() returns the number of full items written of size size, or zero 1444 if there was an error. If the multiplication of size and nitems overflows, 1445 i.e. the product does not fit in a size_t, then nothing is written, zero 1446 is returned, and the error state is set to Z_STREAM_ERROR. 1447 */ 1448 1449 Z_EXTERN int Z_EXPORTVA gzprintf(gzFile file, const char *format, ...); 1450 /* 1451 Convert, format, compress, and write the arguments (...) to file under 1452 control of the string format, as in fprintf. gzprintf returns the number of 1453 uncompressed bytes actually written, or a negative zlib error code in case 1454 of error. The number of uncompressed bytes written is limited to 8191, or 1455 one less than the buffer size given to gzbuffer(). The caller should assure 1456 that this limit is not exceeded. If it is exceeded, then gzprintf() will 1457 return an error (0) with nothing written. In this case, there may also be a 1458 buffer overflow with unpredictable consequences, which is possible only if 1459 zlib was compiled with the insecure functions sprintf() or vsprintf(), 1460 because the secure snprintf() or vsnprintf() functions were not available. 1461 This can be determined using zlibCompileFlags(). 1462 */ 1463 1464 Z_EXTERN int Z_EXPORT gzputs(gzFile file, const char *s); 1465 /* 1466 Compress and write the given null-terminated string s to file, excluding 1467 the terminating null character. 1468 1469 gzputs returns the number of characters written, or -1 in case of error. 1470 */ 1471 1472 Z_EXTERN char * Z_EXPORT gzgets(gzFile file, char *buf, int len); 1473 /* 1474 Read and decompress bytes from file into buf, until len-1 characters are 1475 read, or until a newline character is read and transferred to buf, or an 1476 end-of-file condition is encountered. If any characters are read or if len 1477 is one, the string is terminated with a null character. If no characters 1478 are read due to an end-of-file or len is less than one, then the buffer is 1479 left untouched. 1480 1481 gzgets returns buf which is a null-terminated string, or it returns NULL 1482 for end-of-file or in case of error. If there was an error, the contents at 1483 buf are indeterminate. 1484 */ 1485 1486 Z_EXTERN int Z_EXPORT gzputc(gzFile file, int c); 1487 /* 1488 Compress and write c, converted to an unsigned char, into file. gzputc 1489 returns the value that was written, or -1 in case of error. 1490 */ 1491 1492 Z_EXTERN int Z_EXPORT gzgetc(gzFile file); 1493 /* 1494 Read and decompress one byte from file. gzgetc returns this byte or -1 1495 in case of end of file or error. This is implemented as a macro for speed. 1496 As such, it does not do all of the checking the other functions do. I.e. 1497 it does not check to see if file is NULL, nor whether the structure file 1498 points to has been clobbered or not. 1499 */ 1500 1501 Z_EXTERN int Z_EXPORT gzungetc(int c, gzFile file); 1502 /* 1503 Push c back onto the stream for file to be read as the first character on 1504 the next read. At least one character of push-back is always allowed. 1505 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will 1506 fail if c is -1, and may fail if a character has been pushed but not read 1507 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the 1508 output buffer size of pushed characters is allowed. (See gzbuffer above.) 1509 The pushed character will be discarded if the stream is repositioned with 1510 gzseek() or gzrewind(). 1511 */ 1512 1513 Z_EXTERN int Z_EXPORT gzflush(gzFile file, int flush); 1514 /* 1515 Flush all pending output to file. The parameter flush is as in the 1516 deflate() function. The return value is the zlib error number (see function 1517 gzerror below). gzflush is only permitted when writing. 1518 1519 If the flush parameter is Z_FINISH, the remaining data is written and the 1520 gzip stream is completed in the output. If gzwrite() is called again, a new 1521 gzip stream will be started in the output. gzread() is able to read such 1522 concatenated gzip streams. 1523 1524 gzflush should be called only when strictly necessary because it will 1525 degrade compression if called too often. 1526 */ 1527 1528 /* 1529 Z_EXTERN z_off_t Z_EXPORT gzseek (gzFile file, z_off_t offset, int whence); 1530 1531 Set the starting position to offset relative to whence for the next gzread 1532 or gzwrite on file. The offset represents a number of bytes in the 1533 uncompressed data stream. The whence parameter is defined as in lseek(2); 1534 the value SEEK_END is not supported. 1535 1536 If the file is opened for reading, this function is emulated but can be 1537 extremely slow. If the file is opened for writing, only forward seeks are 1538 supported; gzseek then compresses a sequence of zeroes up to the new 1539 starting position. 1540 1541 gzseek returns the resulting offset location as measured in bytes from 1542 the beginning of the uncompressed stream, or -1 in case of error, in 1543 particular if the file is opened for writing and the new starting position 1544 would be before the current position. 1545 */ 1546 1547 Z_EXTERN int Z_EXPORT gzrewind(gzFile file); 1548 /* 1549 Rewind file. This function is supported only for reading. 1550 1551 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET). 1552 */ 1553 1554 /* 1555 Z_EXTERN z_off_t Z_EXPORT gztell(gzFile file); 1556 1557 Return the starting position for the next gzread or gzwrite on file. 1558 This position represents a number of bytes in the uncompressed data stream, 1559 and is zero when starting, even if appending or reading a gzip stream from 1560 the middle of a file using gzdopen(). 1561 1562 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 1563 */ 1564 1565 /* 1566 Z_EXTERN z_off_t Z_EXPORT gzoffset(gzFile file); 1567 1568 Return the current compressed (actual) read or write offset of file. This 1569 offset includes the count of bytes that precede the gzip stream, for example 1570 when appending or when using gzdopen() for reading. When reading, the 1571 offset does not include as yet unused buffered input. This information can 1572 be used for a progress indicator. On error, gzoffset() returns -1. 1573 */ 1574 1575 Z_EXTERN int Z_EXPORT gzeof(gzFile file); 1576 /* 1577 Return true (1) if the end-of-file indicator for file has been set while 1578 reading, false (0) otherwise. Note that the end-of-file indicator is set 1579 only if the read tried to go past the end of the input, but came up short. 1580 Therefore, just like feof(), gzeof() may return false even if there is no 1581 more data to read, in the event that the last read request was for the exact 1582 number of bytes remaining in the input file. This will happen if the input 1583 file size is an exact multiple of the buffer size. 1584 1585 If gzeof() returns true, then the read functions will return no more data, 1586 unless the end-of-file indicator is reset by gzclearerr() and the input file 1587 has grown since the previous end of file was detected. 1588 */ 1589 1590 Z_EXTERN int Z_EXPORT gzdirect(gzFile file); 1591 /* 1592 Return true (1) if file is being copied directly while reading, or false 1593 (0) if file is a gzip stream being decompressed. 1594 1595 If the input file is empty, gzdirect() will return true, since the input 1596 does not contain a gzip stream. 1597 1598 If gzdirect() is used immediately after gzopen() or gzdopen() it will 1599 cause buffers to be allocated to allow reading the file to determine if it 1600 is a gzip file. Therefore if gzbuffer() is used, it should be called before 1601 gzdirect(). 1602 1603 When writing, gzdirect() returns true (1) if transparent writing was 1604 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: 1605 gzdirect() is not needed when writing. Transparent writing must be 1606 explicitly requested, so the application already knows the answer. When 1607 linking statically, using gzdirect() will include all of the zlib code for 1608 gzip file reading and decompression, which may not be desired.) 1609 */ 1610 1611 Z_EXTERN int Z_EXPORT gzclose(gzFile file); 1612 /* 1613 Flush all pending output for file, if necessary, close file and 1614 deallocate the (de)compression state. Note that once file is closed, you 1615 cannot call gzerror with file, since its structures have been deallocated. 1616 gzclose must not be called more than once on the same file, just as free 1617 must not be called more than once on the same allocation. 1618 1619 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a 1620 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the 1621 last read ended in the middle of a gzip stream, or Z_OK on success. 1622 */ 1623 1624 Z_EXTERN int Z_EXPORT gzclose_r(gzFile file); 1625 Z_EXTERN int Z_EXPORT gzclose_w(gzFile file); 1626 /* 1627 Same as gzclose(), but gzclose_r() is only for use when reading, and 1628 gzclose_w() is only for use when writing or appending. The advantage to 1629 using these instead of gzclose() is that they avoid linking in zlib 1630 compression or decompression code that is not used when only reading or only 1631 writing respectively. If gzclose() is used, then both compression and 1632 decompression code will be included the application when linking to a static 1633 zlib library. 1634 */ 1635 1636 Z_EXTERN const char * Z_EXPORT gzerror(gzFile file, int *errnum); 1637 /* 1638 Return the error message for the last error which occurred on file. 1639 errnum is set to zlib error number. If an error occurred in the file system 1640 and not in the compression library, errnum is set to Z_ERRNO and the 1641 application may consult errno to get the exact error code. 1642 1643 The application must not modify the returned string. Future calls to 1644 this function may invalidate the previously returned string. If file is 1645 closed, then the string previously returned by gzerror will no longer be 1646 available. 1647 1648 gzerror() should be used to distinguish errors from end-of-file for those 1649 functions above that do not distinguish those cases in their return values. 1650 */ 1651 1652 Z_EXTERN void Z_EXPORT gzclearerr(gzFile file); 1653 /* 1654 Clear the error and end-of-file flags for file. This is analogous to the 1655 clearerr() function in stdio. This is useful for continuing to read a gzip 1656 file that is being written concurrently. 1657 */ 1658 1659 #endif 1660 1661 /* checksum functions */ 1662 1663 /* 1664 These functions are not related to compression but are exported 1665 anyway because they might be useful in applications using the compression 1666 library. 1667 */ 1668 1669 Z_EXTERN unsigned long Z_EXPORT adler32(unsigned long adler, const unsigned char *buf, unsigned int len); 1670 /* 1671 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 1672 return the updated checksum. An Adler-32 value is in the range of a 32-bit 1673 unsigned integer. If buf is Z_NULL, this function returns the required 1674 initial value for the checksum. 1675 1676 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed 1677 much faster. 1678 1679 Usage example: 1680 1681 uint32_t adler = adler32(0L, NULL, 0); 1682 1683 while (read_buffer(buffer, length) != EOF) { 1684 adler = adler32(adler, buffer, length); 1685 } 1686 if (adler != original_adler) error(); 1687 */ 1688 1689 Z_EXTERN unsigned long Z_EXPORT adler32_z(unsigned long adler, const unsigned char *buf, size_t len); 1690 /* 1691 Same as adler32(), but with a size_t length. 1692 */ 1693 1694 /* 1695 Z_EXTERN unsigned long Z_EXPORT adler32_combine(unsigned long adler1, unsigned long adler2, z_off_t len2); 1696 1697 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 1698 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 1699 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 1700 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note 1701 that the z_off_t type (like off_t) is a signed integer. If len2 is 1702 negative, the result has no meaning or utility. 1703 */ 1704 1705 Z_EXTERN unsigned long Z_EXPORT crc32(unsigned long crc, const unsigned char *buf, unsigned int len); 1706 /* 1707 Update a running CRC-32 with the bytes buf[0..len-1] and return the 1708 updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer. 1709 If buf is Z_NULL, this function returns the required initial value for the 1710 crc. Pre- and post-conditioning (one's complement) is performed within this 1711 function so it shouldn't be done by the application. 1712 1713 Usage example: 1714 1715 uint32_t crc = crc32(0L, NULL, 0); 1716 1717 while (read_buffer(buffer, length) != EOF) { 1718 crc = crc32(crc, buffer, length); 1719 } 1720 if (crc != original_crc) error(); 1721 */ 1722 1723 Z_EXTERN unsigned long Z_EXPORT crc32_z(unsigned long crc, const unsigned char *buf, size_t len); 1724 /* 1725 Same as crc32(), but with a size_t length. 1726 */ 1727 1728 /* 1729 Z_EXTERN unsigned long Z_EXPORT crc32_combine(unsigned long crc1, unsigned long crc2, z_off64_t len2); 1730 1731 Combine two CRC-32 check values into one. For two sequences of bytes, 1732 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were 1733 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 1734 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and 1735 len2. 1736 */ 1737 1738 /* 1739 Z_EXTERN unsigned long Z_EXPORT crc32_combine_gen(z_off_t len2); 1740 1741 Return the operator corresponding to length len2, to be used with 1742 crc32_combine_op(). 1743 */ 1744 1745 Z_EXTERN unsigned long Z_EXPORT crc32_combine_op(unsigned long crc1, unsigned long crc2, 1746 const unsigned long op); 1747 /* 1748 Give the same result as crc32_combine(), using op in place of len2. op is 1749 is generated from len2 by crc32_combine_gen(). This will be faster than 1750 crc32_combine() if the generated op is used more than once. 1751 */ 1752 1753 1754 /* various hacks, don't look :) */ 1755 1756 /* deflateInit and inflateInit are macros to allow checking the zlib version 1757 * and the compiler's view of z_stream: 1758 */ 1759 Z_EXTERN int Z_EXPORT deflateInit_(z_stream *strm, int level, const char *version, int stream_size); 1760 Z_EXTERN int Z_EXPORT inflateInit_(z_stream *strm, const char *version, int stream_size); 1761 Z_EXTERN int Z_EXPORT deflateInit2_(z_stream *strm, int level, int method, int windowBits, int memLevel, 1762 int strategy, const char *version, int stream_size); 1763 Z_EXTERN int Z_EXPORT inflateInit2_(z_stream *strm, int windowBits, const char *version, int stream_size); 1764 Z_EXTERN int Z_EXPORT inflateBackInit_(z_stream *strm, int windowBits, unsigned char *window, 1765 const char *version, int stream_size); 1766 #define deflateInit(strm, level) deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) 1767 #define inflateInit(strm) inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) 1768 #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 1769 deflateInit2_((strm), (level), (method), (windowBits), (memLevel), \ 1770 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) 1771 #define inflateInit2(strm, windowBits) inflateInit2_((strm), (windowBits), ZLIB_VERSION, (int)sizeof(z_stream)) 1772 #define inflateBackInit(strm, windowBits, window) \ 1773 inflateBackInit_((strm), (windowBits), (window), ZLIB_VERSION, (int)sizeof(z_stream)) 1774 1775 1776 #ifndef Z_SOLO 1777 /* gzgetc() macro and its supporting function and exposed data structure. Note 1778 * that the real internal state is much larger than the exposed structure. 1779 * This abbreviated structure exposes just enough for the gzgetc() macro. The 1780 * user should not mess with these exposed elements, since their names or 1781 * behavior could change in the future, perhaps even capriciously. They can 1782 * only be used by the gzgetc() macro. You have been warned. 1783 */ 1784 struct gzFile_s { 1785 unsigned have; 1786 unsigned char *next; 1787 z_off64_t pos; 1788 }; 1789 Z_EXTERN int Z_EXPORT gzgetc_(gzFile file); /* backward compatibility */ 1790 # define gzgetc(g) ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) 1791 1792 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or 1793 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if 1794 * both are true, the application gets the *64 functions, and the regular 1795 * functions are changed to 64 bits) -- in case these are set on systems 1796 * without large file support, _LFS64_LARGEFILE must also be true 1797 */ 1798 #ifdef Z_LARGE64 1799 Z_EXTERN gzFile Z_EXPORT gzopen64(const char *, const char *); 1800 Z_EXTERN z_off64_t Z_EXPORT gzseek64(gzFile, z_off64_t, int); 1801 Z_EXTERN z_off64_t Z_EXPORT gztell64(gzFile); 1802 Z_EXTERN z_off64_t Z_EXPORT gzoffset64(gzFile); 1803 Z_EXTERN unsigned long Z_EXPORT adler32_combine64(unsigned long, unsigned long, z_off64_t); 1804 Z_EXTERN unsigned long Z_EXPORT crc32_combine64(unsigned long, unsigned long, z_off64_t); 1805 Z_EXTERN unsigned long Z_EXPORT crc32_combine_gen64(z_off64_t); 1806 #endif 1807 #endif 1808 1809 #if !defined(Z_SOLO) && !defined(Z_INTERNAL) && defined(Z_WANT64) 1810 # define gzopen gzopen64 1811 # define gzseek gzseek64 1812 # define gztell gztell64 1813 # define gzoffset gzoffset64 1814 # define adler32_combine adler32_combine64 1815 # define crc32_combine crc32_combine64 1816 # define crc32_combine_gen crc32_combine_gen64 1817 # ifndef Z_LARGE64 1818 Z_EXTERN gzFile Z_EXPORT gzopen64(const char *, const char *); 1819 Z_EXTERN z_off_t Z_EXPORT gzseek64(gzFile, z_off_t, int); 1820 Z_EXTERN z_off_t Z_EXPORT gztell64(gzFile); 1821 Z_EXTERN z_off_t Z_EXPORT gzoffset64(gzFile); 1822 Z_EXTERN unsigned long Z_EXPORT adler32_combine64(unsigned long, unsigned long, z_off_t); 1823 Z_EXTERN unsigned long Z_EXPORT crc32_combine64(unsigned long, unsigned long, z_off_t); 1824 Z_EXTERN unsigned long Z_EXPORT crc32_combine_gen64(z_off64_t); 1825 # endif 1826 #else 1827 # ifndef Z_SOLO 1828 Z_EXTERN gzFile Z_EXPORT gzopen(const char *, const char *); 1829 Z_EXTERN z_off_t Z_EXPORT gzseek(gzFile, z_off_t, int); 1830 Z_EXTERN z_off_t Z_EXPORT gztell(gzFile); 1831 Z_EXTERN z_off_t Z_EXPORT gzoffset(gzFile); 1832 # endif 1833 Z_EXTERN unsigned long Z_EXPORT adler32_combine(unsigned long, unsigned long, z_off_t); 1834 Z_EXTERN unsigned long Z_EXPORT crc32_combine(unsigned long, unsigned long, z_off_t); 1835 Z_EXTERN unsigned long Z_EXPORT crc32_combine_gen(z_off_t); 1836 #endif 1837 1838 /* undocumented functions */ 1839 Z_EXTERN const char * Z_EXPORT zError (int); 1840 Z_EXTERN int Z_EXPORT inflateSyncPoint (z_stream *); 1841 Z_EXTERN const uint32_t * Z_EXPORT get_crc_table (void); 1842 Z_EXTERN int Z_EXPORT inflateUndermine (z_stream *, int); 1843 Z_EXTERN int Z_EXPORT inflateValidate (z_stream *, int); 1844 Z_EXTERN unsigned long Z_EXPORT inflateCodesUsed (z_stream *); 1845 Z_EXTERN int Z_EXPORT inflateResetKeep (z_stream *); 1846 Z_EXTERN int Z_EXPORT deflateResetKeep (z_stream *); 1847 1848 #ifndef Z_SOLO 1849 #if defined(_WIN32) 1850 Z_EXTERN gzFile Z_EXPORT gzopen_w(const wchar_t *path, const char *mode); 1851 #endif 1852 Z_EXTERN int Z_EXPORTVA gzvprintf(gzFile file, const char *format, va_list va); 1853 #endif 1854 1855 #ifdef __cplusplus 1856 } 1857 #endif 1858 1859 #endif /* ZLIB_H_ */
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