1 /* zlib.h -- interface of the 'zlib' general purpose compression library 2 version 1.2.11, January 15th, 2017 3 4 Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler 5 6 This software is provided 'as-is', without any express or implied 7 warranty. In no event will the authors be held liable for any damages 8 arising from the use of this software. 9 10 Permission is granted to anyone to use this software for any purpose, 11 including commercial applications, and to alter it and redistribute it 12 freely, subject to the following restrictions: 13 14 1. The origin of this software must not be misrepresented; you must not 15 claim that you wrote the original software. If you use this software 16 in a product, an acknowledgment in the product documentation would be 17 appreciated but is not required. 18 2. Altered source versions must be plainly marked as such, and must not be 19 misrepresented as being the original software. 20 3. This notice may not be removed or altered from any source distribution. 21 22 Jean-loup Gailly Mark Adler 23 [email protected] [email protected] 24 25 26 The data format used by the zlib library is described by RFCs (Request for 27 Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). 29 */ 30 31 #ifndef ZLIB_H 32 #define ZLIB_H 33 34 #include "zconf.h" 35 36 #ifdef __cplusplus 37 extern "C" { 38 #endif 39 40 #define ZLIB_VERSION "1.2.11" 41 #define ZLIB_VERNUM 0x12b0 42 #define ZLIB_VER_MAJOR 1 43 #define ZLIB_VER_MINOR 2 44 #define ZLIB_VER_REVISION 11 45 #define ZLIB_VER_SUBREVISION 0 46 47 /* 48 * In Android's NDK we have one zlib.h for all the versions. 49 * zlib users tend to use ZLIB_VERNUM to check API availability, 50 * so we need to translate __ANDROID_API__ appropriately. 51 * 52 * ZLIB_1.2.7.1 and ZLIB_1.2.9 are the only API changes in the NDK's 53 * supported range of API levels. 54 * 55 * jb-mr2-dev (18): 1.2.7 (but not 1.2.7.1, where the APIs were added!) 56 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/jb-mr2-dev/src/zlib.h 57 * kitkat-dev (19): 1.2.8 58 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/kitkat-dev/src/zlib.h 59 * 60 * oreo-mr1-dev (27): 1.2.8 61 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/oreo-mr1-dev/src/zlib.h 62 * pie-dev (28): 1.2.11 63 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/pie-dev/src/zlib.h 64 * 65 * So: 66 * >= 28 --> 1.2.11 67 * >= 19 --> 1.2.8 68 * < 19 --> 1.2.7 69 */ 70 #if defined(__ANDROID__) 71 # if __ANDROID_API__ >= 28 72 /* Already okay. */ 73 # elif __ANDROID_API__ >= 19 74 # undef ZLIB_VERSION 75 # define ZLIB_VERSION "1.2.8" 76 # undef ZLIB_VERNUM 77 # define ZLIB_VERNUM 0x1280 78 # undef ZLIB_VER_REVISION 79 # define ZLIB_VER_REVISION 8 80 # else 81 # undef ZLIB_VERSION 82 # define ZLIB_VERSION "1.2.6" 83 # undef ZLIB_VERNUM 84 # define ZLIB_VERNUM 0x1260 85 # undef ZLIB_VER_REVISION 86 # define ZLIB_VER_REVISION 6 87 # endif 88 #endif 89 90 /* 91 The 'zlib' compression library provides in-memory compression and 92 decompression functions, including integrity checks of the uncompressed data. 93 This version of the library supports only one compression method (deflation) 94 but other algorithms will be added later and will have the same stream 95 interface. 96 97 Compression can be done in a single step if the buffers are large enough, 98 or can be done by repeated calls of the compression function. In the latter 99 case, the application must provide more input and/or consume the output 100 (providing more output space) before each call. 101 102 The compressed data format used by default by the in-memory functions is 103 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 104 around a deflate stream, which is itself documented in RFC 1951. 105 106 The library also supports reading and writing files in gzip (.gz) format 107 with an interface similar to that of stdio using the functions that start 108 with "gz". The gzip format is different from the zlib format. gzip is a 109 gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 110 111 This library can optionally read and write gzip and raw deflate streams in 112 memory as well. 113 114 The zlib format was designed to be compact and fast for use in memory 115 and on communications channels. The gzip format was designed for single- 116 file compression on file systems, has a larger header than zlib to maintain 117 directory information, and uses a different, slower check method than zlib. 118 119 The library does not install any signal handler. The decoder checks 120 the consistency of the compressed data, so the library should never crash 121 even in the case of corrupted input. 122 */ 123 124 typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); 125 typedef void (*free_func) OF((voidpf opaque, voidpf address)); 126 127 struct internal_state; 128 129 typedef struct z_stream_s { 130 z_const Bytef *next_in; /* next input byte */ 131 uInt avail_in; /* number of bytes available at next_in */ 132 uLong total_in; /* total number of input bytes read so far */ 133 134 Bytef *next_out; /* next output byte will go here */ 135 uInt avail_out; /* remaining free space at next_out */ 136 uLong total_out; /* total number of bytes output so far */ 137 138 z_const char *msg; /* last error message, NULL if no error */ 139 struct internal_state FAR *state; /* not visible by applications */ 140 141 alloc_func zalloc; /* used to allocate the internal state */ 142 free_func zfree; /* used to free the internal state */ 143 voidpf opaque; /* private data object passed to zalloc and zfree */ 144 145 int data_type; /* best guess about the data type: binary or text 146 for deflate, or the decoding state for inflate */ 147 uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */ 148 uLong reserved; /* reserved for future use */ 149 } z_stream; 150 151 typedef z_stream FAR *z_streamp; 152 153 /* 154 gzip header information passed to and from zlib routines. See RFC 1952 155 for more details on the meanings of these fields. 156 */ 157 typedef struct gz_header_s { 158 int text; /* true if compressed data believed to be text */ 159 uLong time; /* modification time */ 160 int xflags; /* extra flags (not used when writing a gzip file) */ 161 int os; /* operating system */ 162 Bytef *extra; /* pointer to extra field or Z_NULL if none */ 163 uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ 164 uInt extra_max; /* space at extra (only when reading header) */ 165 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ 166 uInt name_max; /* space at name (only when reading header) */ 167 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ 168 uInt comm_max; /* space at comment (only when reading header) */ 169 int hcrc; /* true if there was or will be a header crc */ 170 int done; /* true when done reading gzip header (not used 171 when writing a gzip file) */ 172 } gz_header; 173 174 typedef gz_header FAR *gz_headerp; 175 176 /* 177 The application must update next_in and avail_in when avail_in has dropped 178 to zero. It must update next_out and avail_out when avail_out has dropped 179 to zero. The application must initialize zalloc, zfree and opaque before 180 calling the init function. All other fields are set by the compression 181 library and must not be updated by the application. 182 183 The opaque value provided by the application will be passed as the first 184 parameter for calls of zalloc and zfree. This can be useful for custom 185 memory management. The compression library attaches no meaning to the 186 opaque value. 187 188 zalloc must return Z_NULL if there is not enough memory for the object. 189 If zlib is used in a multi-threaded application, zalloc and zfree must be 190 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are 191 Z_NULL on entry to the initialization function, they are set to internal 192 routines that use the standard library functions malloc() and free(). 193 194 On 16-bit systems, the functions zalloc and zfree must be able to allocate 195 exactly 65536 bytes, but will not be required to allocate more than this if 196 the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers 197 returned by zalloc for objects of exactly 65536 bytes *must* have their 198 offset normalized to zero. The default allocation function provided by this 199 library ensures this (see zutil.c). To reduce memory requirements and avoid 200 any allocation of 64K objects, at the expense of compression ratio, compile 201 the library with -DMAX_WBITS=14 (see zconf.h). 202 203 The fields total_in and total_out can be used for statistics or progress 204 reports. After compression, total_in holds the total size of the 205 uncompressed data and may be saved for use by the decompressor (particularly 206 if the decompressor wants to decompress everything in a single step). 207 */ 208 209 /* constants */ 210 211 #define Z_NO_FLUSH 0 212 #define Z_PARTIAL_FLUSH 1 213 #define Z_SYNC_FLUSH 2 214 #define Z_FULL_FLUSH 3 215 #define Z_FINISH 4 216 #define Z_BLOCK 5 217 #define Z_TREES 6 218 /* Allowed flush values; see deflate() and inflate() below for details */ 219 220 #define Z_OK 0 221 #define Z_STREAM_END 1 222 #define Z_NEED_DICT 2 223 #define Z_ERRNO (-1) 224 #define Z_STREAM_ERROR (-2) 225 #define Z_DATA_ERROR (-3) 226 #define Z_MEM_ERROR (-4) 227 #define Z_BUF_ERROR (-5) 228 #define Z_VERSION_ERROR (-6) 229 /* Return codes for the compression/decompression functions. Negative values 230 * are errors, positive values are used for special but normal events. 231 */ 232 233 #define Z_NO_COMPRESSION 0 234 #define Z_BEST_SPEED 1 235 #define Z_BEST_COMPRESSION 9 236 #define Z_DEFAULT_COMPRESSION (-1) 237 /* compression levels */ 238 239 #define Z_FILTERED 1 240 #define Z_HUFFMAN_ONLY 2 241 #define Z_RLE 3 242 #define Z_FIXED 4 243 #define Z_DEFAULT_STRATEGY 0 244 /* compression strategy; see deflateInit2() below for details */ 245 246 #define Z_BINARY 0 247 #define Z_TEXT 1 248 #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ 249 #define Z_UNKNOWN 2 250 /* Possible values of the data_type field for deflate() */ 251 252 #define Z_DEFLATED 8 253 /* The deflate compression method (the only one supported in this version) */ 254 255 #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ 256 257 #define zlib_version zlibVersion() 258 /* for compatibility with versions < 1.0.2 */ 259 260 261 /* basic functions */ 262 263 ZEXTERN const char * ZEXPORT zlibVersion OF((void)); 264 /* The application can compare zlibVersion and ZLIB_VERSION for consistency. 265 If the first character differs, the library code actually used is not 266 compatible with the zlib.h header file used by the application. This check 267 is automatically made by deflateInit and inflateInit. 268 */ 269 270 /* 271 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 272 273 Initializes the internal stream state for compression. The fields 274 zalloc, zfree and opaque must be initialized before by the caller. If 275 zalloc and zfree are set to Z_NULL, deflateInit updates them to use default 276 allocation functions. 277 278 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 279 1 gives best speed, 9 gives best compression, 0 gives no compression at all 280 (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION 281 requests a default compromise between speed and compression (currently 282 equivalent to level 6). 283 284 deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 285 memory, Z_STREAM_ERROR if level is not a valid compression level, or 286 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 287 with the version assumed by the caller (ZLIB_VERSION). msg is set to null 288 if there is no error message. deflateInit does not perform any compression: 289 this will be done by deflate(). 290 */ 291 292 293 ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); 294 /* 295 deflate compresses as much data as possible, and stops when the input 296 buffer becomes empty or the output buffer becomes full. It may introduce 297 some output latency (reading input without producing any output) except when 298 forced to flush. 299 300 The detailed semantics are as follows. deflate performs one or both of the 301 following actions: 302 303 - Compress more input starting at next_in and update next_in and avail_in 304 accordingly. If not all input can be processed (because there is not 305 enough room in the output buffer), next_in and avail_in are updated and 306 processing will resume at this point for the next call of deflate(). 307 308 - Generate more output starting at next_out and update next_out and avail_out 309 accordingly. This action is forced if the parameter flush is non zero. 310 Forcing flush frequently degrades the compression ratio, so this parameter 311 should be set only when necessary. Some output may be provided even if 312 flush is zero. 313 314 Before the call of deflate(), the application should ensure that at least 315 one of the actions is possible, by providing more input and/or consuming more 316 output, and updating avail_in or avail_out accordingly; avail_out should 317 never be zero before the call. The application can consume the compressed 318 output when it wants, for example when the output buffer is full (avail_out 319 == 0), or after each call of deflate(). If deflate returns Z_OK and with 320 zero avail_out, it must be called again after making room in the output 321 buffer because there might be more output pending. See deflatePending(), 322 which can be used if desired to determine whether or not there is more ouput 323 in that case. 324 325 Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to 326 decide how much data to accumulate before producing output, in order to 327 maximize compression. 328 329 If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 330 flushed to the output buffer and the output is aligned on a byte boundary, so 331 that the decompressor can get all input data available so far. (In 332 particular avail_in is zero after the call if enough output space has been 333 provided before the call.) Flushing may degrade compression for some 334 compression algorithms and so it should be used only when necessary. This 335 completes the current deflate block and follows it with an empty stored block 336 that is three bits plus filler bits to the next byte, followed by four bytes 337 (00 00 ff ff). 338 339 If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the 340 output buffer, but the output is not aligned to a byte boundary. All of the 341 input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. 342 This completes the current deflate block and follows it with an empty fixed 343 codes block that is 10 bits long. This assures that enough bytes are output 344 in order for the decompressor to finish the block before the empty fixed 345 codes block. 346 347 If flush is set to Z_BLOCK, a deflate block is completed and emitted, as 348 for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to 349 seven bits of the current block are held to be written as the next byte after 350 the next deflate block is completed. In this case, the decompressor may not 351 be provided enough bits at this point in order to complete decompression of 352 the data provided so far to the compressor. It may need to wait for the next 353 block to be emitted. This is for advanced applications that need to control 354 the emission of deflate blocks. 355 356 If flush is set to Z_FULL_FLUSH, all output is flushed as with 357 Z_SYNC_FLUSH, and the compression state is reset so that decompression can 358 restart from this point if previous compressed data has been damaged or if 359 random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 360 compression. 361 362 If deflate returns with avail_out == 0, this function must be called again 363 with the same value of the flush parameter and more output space (updated 364 avail_out), until the flush is complete (deflate returns with non-zero 365 avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 366 avail_out is greater than six to avoid repeated flush markers due to 367 avail_out == 0 on return. 368 369 If the parameter flush is set to Z_FINISH, pending input is processed, 370 pending output is flushed and deflate returns with Z_STREAM_END if there was 371 enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this 372 function must be called again with Z_FINISH and more output space (updated 373 avail_out) but no more input data, until it returns with Z_STREAM_END or an 374 error. After deflate has returned Z_STREAM_END, the only possible operations 375 on the stream are deflateReset or deflateEnd. 376 377 Z_FINISH can be used in the first deflate call after deflateInit if all the 378 compression is to be done in a single step. In order to complete in one 379 call, avail_out must be at least the value returned by deflateBound (see 380 below). Then deflate is guaranteed to return Z_STREAM_END. If not enough 381 output space is provided, deflate will not return Z_STREAM_END, and it must 382 be called again as described above. 383 384 deflate() sets strm->adler to the Adler-32 checksum of all input read 385 so far (that is, total_in bytes). If a gzip stream is being generated, then 386 strm->adler will be the CRC-32 checksum of the input read so far. (See 387 deflateInit2 below.) 388 389 deflate() may update strm->data_type if it can make a good guess about 390 the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is 391 considered binary. This field is only for information purposes and does not 392 affect the compression algorithm in any manner. 393 394 deflate() returns Z_OK if some progress has been made (more input 395 processed or more output produced), Z_STREAM_END if all input has been 396 consumed and all output has been produced (only when flush is set to 397 Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 398 if next_in or next_out was Z_NULL or the state was inadvertently written over 399 by the application), or Z_BUF_ERROR if no progress is possible (for example 400 avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and 401 deflate() can be called again with more input and more output space to 402 continue compressing. 403 */ 404 405 406 ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); 407 /* 408 All dynamically allocated data structures for this stream are freed. 409 This function discards any unprocessed input and does not flush any pending 410 output. 411 412 deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 413 stream state was inconsistent, Z_DATA_ERROR if the stream was freed 414 prematurely (some input or output was discarded). In the error case, msg 415 may be set but then points to a static string (which must not be 416 deallocated). 417 */ 418 419 420 /* 421 ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 422 423 Initializes the internal stream state for decompression. The fields 424 next_in, avail_in, zalloc, zfree and opaque must be initialized before by 425 the caller. In the current version of inflate, the provided input is not 426 read or consumed. The allocation of a sliding window will be deferred to 427 the first call of inflate (if the decompression does not complete on the 428 first call). If zalloc and zfree are set to Z_NULL, inflateInit updates 429 them to use default allocation functions. 430 431 inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 432 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 433 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 434 invalid, such as a null pointer to the structure. msg is set to null if 435 there is no error message. inflateInit does not perform any decompression. 436 Actual decompression will be done by inflate(). So next_in, and avail_in, 437 next_out, and avail_out are unused and unchanged. The current 438 implementation of inflateInit() does not process any header information -- 439 that is deferred until inflate() is called. 440 */ 441 442 443 ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); 444 /* 445 inflate decompresses as much data as possible, and stops when the input 446 buffer becomes empty or the output buffer becomes full. It may introduce 447 some output latency (reading input without producing any output) except when 448 forced to flush. 449 450 The detailed semantics are as follows. inflate performs one or both of the 451 following actions: 452 453 - Decompress more input starting at next_in and update next_in and avail_in 454 accordingly. If not all input can be processed (because there is not 455 enough room in the output buffer), then next_in and avail_in are updated 456 accordingly, and processing will resume at this point for the next call of 457 inflate(). 458 459 - Generate more output starting at next_out and update next_out and avail_out 460 accordingly. inflate() provides as much output as possible, until there is 461 no more input data or no more space in the output buffer (see below about 462 the flush parameter). 463 464 Before the call of inflate(), the application should ensure that at least 465 one of the actions is possible, by providing more input and/or consuming more 466 output, and updating the next_* and avail_* values accordingly. If the 467 caller of inflate() does not provide both available input and available 468 output space, it is possible that there will be no progress made. The 469 application can consume the uncompressed output when it wants, for example 470 when the output buffer is full (avail_out == 0), or after each call of 471 inflate(). If inflate returns Z_OK and with zero avail_out, it must be 472 called again after making room in the output buffer because there might be 473 more output pending. 474 475 The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, 476 Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much 477 output as possible to the output buffer. Z_BLOCK requests that inflate() 478 stop if and when it gets to the next deflate block boundary. When decoding 479 the zlib or gzip format, this will cause inflate() to return immediately 480 after the header and before the first block. When doing a raw inflate, 481 inflate() will go ahead and process the first block, and will return when it 482 gets to the end of that block, or when it runs out of data. 483 484 The Z_BLOCK option assists in appending to or combining deflate streams. 485 To assist in this, on return inflate() always sets strm->data_type to the 486 number of unused bits in the last byte taken from strm->next_in, plus 64 if 487 inflate() is currently decoding the last block in the deflate stream, plus 488 128 if inflate() returned immediately after decoding an end-of-block code or 489 decoding the complete header up to just before the first byte of the deflate 490 stream. The end-of-block will not be indicated until all of the uncompressed 491 data from that block has been written to strm->next_out. The number of 492 unused bits may in general be greater than seven, except when bit 7 of 493 data_type is set, in which case the number of unused bits will be less than 494 eight. data_type is set as noted here every time inflate() returns for all 495 flush options, and so can be used to determine the amount of currently 496 consumed input in bits. 497 498 The Z_TREES option behaves as Z_BLOCK does, but it also returns when the 499 end of each deflate block header is reached, before any actual data in that 500 block is decoded. This allows the caller to determine the length of the 501 deflate block header for later use in random access within a deflate block. 502 256 is added to the value of strm->data_type when inflate() returns 503 immediately after reaching the end of the deflate block header. 504 505 inflate() should normally be called until it returns Z_STREAM_END or an 506 error. However if all decompression is to be performed in a single step (a 507 single call of inflate), the parameter flush should be set to Z_FINISH. In 508 this case all pending input is processed and all pending output is flushed; 509 avail_out must be large enough to hold all of the uncompressed data for the 510 operation to complete. (The size of the uncompressed data may have been 511 saved by the compressor for this purpose.) The use of Z_FINISH is not 512 required to perform an inflation in one step. However it may be used to 513 inform inflate that a faster approach can be used for the single inflate() 514 call. Z_FINISH also informs inflate to not maintain a sliding window if the 515 stream completes, which reduces inflate's memory footprint. If the stream 516 does not complete, either because not all of the stream is provided or not 517 enough output space is provided, then a sliding window will be allocated and 518 inflate() can be called again to continue the operation as if Z_NO_FLUSH had 519 been used. 520 521 In this implementation, inflate() always flushes as much output as 522 possible to the output buffer, and always uses the faster approach on the 523 first call. So the effects of the flush parameter in this implementation are 524 on the return value of inflate() as noted below, when inflate() returns early 525 when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of 526 memory for a sliding window when Z_FINISH is used. 527 528 If a preset dictionary is needed after this call (see inflateSetDictionary 529 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary 530 chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 531 strm->adler to the Adler-32 checksum of all output produced so far (that is, 532 total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 533 below. At the end of the stream, inflate() checks that its computed Adler-32 534 checksum is equal to that saved by the compressor and returns Z_STREAM_END 535 only if the checksum is correct. 536 537 inflate() can decompress and check either zlib-wrapped or gzip-wrapped 538 deflate data. The header type is detected automatically, if requested when 539 initializing with inflateInit2(). Any information contained in the gzip 540 header is not retained unless inflateGetHeader() is used. When processing 541 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output 542 produced so far. The CRC-32 is checked against the gzip trailer, as is the 543 uncompressed length, modulo 2^32. 544 545 inflate() returns Z_OK if some progress has been made (more input processed 546 or more output produced), Z_STREAM_END if the end of the compressed data has 547 been reached and all uncompressed output has been produced, Z_NEED_DICT if a 548 preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 549 corrupted (input stream not conforming to the zlib format or incorrect check 550 value, in which case strm->msg points to a string with a more specific 551 error), Z_STREAM_ERROR if the stream structure was inconsistent (for example 552 next_in or next_out was Z_NULL, or the state was inadvertently written over 553 by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR 554 if no progress was possible or if there was not enough room in the output 555 buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 556 inflate() can be called again with more input and more output space to 557 continue decompressing. If Z_DATA_ERROR is returned, the application may 558 then call inflateSync() to look for a good compression block if a partial 559 recovery of the data is to be attempted. 560 */ 561 562 563 ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); 564 /* 565 All dynamically allocated data structures for this stream are freed. 566 This function discards any unprocessed input and does not flush any pending 567 output. 568 569 inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state 570 was inconsistent. 571 */ 572 573 574 /* Advanced functions */ 575 576 /* 577 The following functions are needed only in some special applications. 578 */ 579 580 /* 581 ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 582 int level, 583 int method, 584 int windowBits, 585 int memLevel, 586 int strategy)); 587 588 This is another version of deflateInit with more compression options. The 589 fields next_in, zalloc, zfree and opaque must be initialized before by the 590 caller. 591 592 The method parameter is the compression method. It must be Z_DEFLATED in 593 this version of the library. 594 595 The windowBits parameter is the base two logarithm of the window size 596 (the size of the history buffer). It should be in the range 8..15 for this 597 version of the library. Larger values of this parameter result in better 598 compression at the expense of memory usage. The default value is 15 if 599 deflateInit is used instead. 600 601 For the current implementation of deflate(), a windowBits value of 8 (a 602 window size of 256 bytes) is not supported. As a result, a request for 8 603 will result in 9 (a 512-byte window). In that case, providing 8 to 604 inflateInit2() will result in an error when the zlib header with 9 is 605 checked against the initialization of inflate(). The remedy is to not use 8 606 with deflateInit2() with this initialization, or at least in that case use 9 607 with inflateInit2(). 608 609 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 610 determines the window size. deflate() will then generate raw deflate data 611 with no zlib header or trailer, and will not compute a check value. 612 613 windowBits can also be greater than 15 for optional gzip encoding. Add 614 16 to windowBits to write a simple gzip header and trailer around the 615 compressed data instead of a zlib wrapper. The gzip header will have no 616 file name, no extra data, no comment, no modification time (set to zero), no 617 header crc, and the operating system will be set to the appropriate value, 618 if the operating system was determined at compile time. If a gzip stream is 619 being written, strm->adler is a CRC-32 instead of an Adler-32. 620 621 For raw deflate or gzip encoding, a request for a 256-byte window is 622 rejected as invalid, since only the zlib header provides a means of 623 transmitting the window size to the decompressor. 624 625 The memLevel parameter specifies how much memory should be allocated 626 for the internal compression state. memLevel=1 uses minimum memory but is 627 slow and reduces compression ratio; memLevel=9 uses maximum memory for 628 optimal speed. The default value is 8. See zconf.h for total memory usage 629 as a function of windowBits and memLevel. 630 631 The strategy parameter is used to tune the compression algorithm. Use the 632 value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 633 filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 634 string match), or Z_RLE to limit match distances to one (run-length 635 encoding). Filtered data consists mostly of small values with a somewhat 636 random distribution. In this case, the compression algorithm is tuned to 637 compress them better. The effect of Z_FILTERED is to force more Huffman 638 coding and less string matching; it is somewhat intermediate between 639 Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as 640 fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The 641 strategy parameter only affects the compression ratio but not the 642 correctness of the compressed output even if it is not set appropriately. 643 Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler 644 decoder for special applications. 645 646 deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 647 memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid 648 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is 649 incompatible with the version assumed by the caller (ZLIB_VERSION). msg is 650 set to null if there is no error message. deflateInit2 does not perform any 651 compression: this will be done by deflate(). 652 */ 653 654 ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, 655 const Bytef *dictionary, 656 uInt dictLength)); 657 /* 658 Initializes the compression dictionary from the given byte sequence 659 without producing any compressed output. When using the zlib format, this 660 function must be called immediately after deflateInit, deflateInit2 or 661 deflateReset, and before any call of deflate. When doing raw deflate, this 662 function must be called either before any call of deflate, or immediately 663 after the completion of a deflate block, i.e. after all input has been 664 consumed and all output has been delivered when using any of the flush 665 options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The 666 compressor and decompressor must use exactly the same dictionary (see 667 inflateSetDictionary). 668 669 The dictionary should consist of strings (byte sequences) that are likely 670 to be encountered later in the data to be compressed, with the most commonly 671 used strings preferably put towards the end of the dictionary. Using a 672 dictionary is most useful when the data to be compressed is short and can be 673 predicted with good accuracy; the data can then be compressed better than 674 with the default empty dictionary. 675 676 Depending on the size of the compression data structures selected by 677 deflateInit or deflateInit2, a part of the dictionary may in effect be 678 discarded, for example if the dictionary is larger than the window size 679 provided in deflateInit or deflateInit2. Thus the strings most likely to be 680 useful should be put at the end of the dictionary, not at the front. In 681 addition, the current implementation of deflate will use at most the window 682 size minus 262 bytes of the provided dictionary. 683 684 Upon return of this function, strm->adler is set to the Adler-32 value 685 of the dictionary; the decompressor may later use this value to determine 686 which dictionary has been used by the compressor. (The Adler-32 value 687 applies to the whole dictionary even if only a subset of the dictionary is 688 actually used by the compressor.) If a raw deflate was requested, then the 689 Adler-32 value is not computed and strm->adler is not set. 690 691 deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 692 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 693 inconsistent (for example if deflate has already been called for this stream 694 or if not at a block boundary for raw deflate). deflateSetDictionary does 695 not perform any compression: this will be done by deflate(). 696 */ 697 698 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 699 ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm, 700 Bytef *dictionary, 701 uInt *dictLength)); 702 #endif 703 /* 704 Returns the sliding dictionary being maintained by deflate. dictLength is 705 set to the number of bytes in the dictionary, and that many bytes are copied 706 to dictionary. dictionary must have enough space, where 32768 bytes is 707 always enough. If deflateGetDictionary() is called with dictionary equal to 708 Z_NULL, then only the dictionary length is returned, and nothing is copied. 709 Similary, if dictLength is Z_NULL, then it is not set. 710 711 deflateGetDictionary() may return a length less than the window size, even 712 when more than the window size in input has been provided. It may return up 713 to 258 bytes less in that case, due to how zlib's implementation of deflate 714 manages the sliding window and lookahead for matches, where matches can be 715 up to 258 bytes long. If the application needs the last window-size bytes of 716 input, then that would need to be saved by the application outside of zlib. 717 718 deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the 719 stream state is inconsistent. 720 */ 721 722 ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 723 z_streamp source)); 724 /* 725 Sets the destination stream as a complete copy of the source stream. 726 727 This function can be useful when several compression strategies will be 728 tried, for example when there are several ways of pre-processing the input 729 data with a filter. The streams that will be discarded should then be freed 730 by calling deflateEnd. Note that deflateCopy duplicates the internal 731 compression state which can be quite large, so this strategy is slow and can 732 consume lots of memory. 733 734 deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 735 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 736 (such as zalloc being Z_NULL). msg is left unchanged in both source and 737 destination. 738 */ 739 740 ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); 741 /* 742 This function is equivalent to deflateEnd followed by deflateInit, but 743 does not free and reallocate the internal compression state. The stream 744 will leave the compression level and any other attributes that may have been 745 set unchanged. 746 747 deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 748 stream state was inconsistent (such as zalloc or state being Z_NULL). 749 */ 750 751 ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 752 int level, 753 int strategy)); 754 /* 755 Dynamically update the compression level and compression strategy. The 756 interpretation of level and strategy is as in deflateInit2(). This can be 757 used to switch between compression and straight copy of the input data, or 758 to switch to a different kind of input data requiring a different strategy. 759 If the compression approach (which is a function of the level) or the 760 strategy is changed, and if any input has been consumed in a previous 761 deflate() call, then the input available so far is compressed with the old 762 level and strategy using deflate(strm, Z_BLOCK). There are three approaches 763 for the compression levels 0, 1..3, and 4..9 respectively. The new level 764 and strategy will take effect at the next call of deflate(). 765 766 If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does 767 not have enough output space to complete, then the parameter change will not 768 take effect. In this case, deflateParams() can be called again with the 769 same parameters and more output space to try again. 770 771 In order to assure a change in the parameters on the first try, the 772 deflate stream should be flushed using deflate() with Z_BLOCK or other flush 773 request until strm.avail_out is not zero, before calling deflateParams(). 774 Then no more input data should be provided before the deflateParams() call. 775 If this is done, the old level and strategy will be applied to the data 776 compressed before deflateParams(), and the new level and strategy will be 777 applied to the the data compressed after deflateParams(). 778 779 deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream 780 state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if 781 there was not enough output space to complete the compression of the 782 available input data before a change in the strategy or approach. Note that 783 in the case of a Z_BUF_ERROR, the parameters are not changed. A return 784 value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be 785 retried with more output space. 786 */ 787 788 ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, 789 int good_length, 790 int max_lazy, 791 int nice_length, 792 int max_chain)); 793 /* 794 Fine tune deflate's internal compression parameters. This should only be 795 used by someone who understands the algorithm used by zlib's deflate for 796 searching for the best matching string, and even then only by the most 797 fanatic optimizer trying to squeeze out the last compressed bit for their 798 specific input data. Read the deflate.c source code for the meaning of the 799 max_lazy, good_length, nice_length, and max_chain parameters. 800 801 deflateTune() can be called after deflateInit() or deflateInit2(), and 802 returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. 803 */ 804 805 ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, 806 uLong sourceLen)); 807 /* 808 deflateBound() returns an upper bound on the compressed size after 809 deflation of sourceLen bytes. It must be called after deflateInit() or 810 deflateInit2(), and after deflateSetHeader(), if used. This would be used 811 to allocate an output buffer for deflation in a single pass, and so would be 812 called before deflate(). If that first deflate() call is provided the 813 sourceLen input bytes, an output buffer allocated to the size returned by 814 deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed 815 to return Z_STREAM_END. Note that it is possible for the compressed size to 816 be larger than the value returned by deflateBound() if flush options other 817 than Z_FINISH or Z_NO_FLUSH are used. 818 */ 819 820 ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, 821 unsigned *pending, 822 int *bits)); 823 /* 824 deflatePending() returns the number of bytes and bits of output that have 825 been generated, but not yet provided in the available output. The bytes not 826 provided would be due to the available output space having being consumed. 827 The number of bits of output not provided are between 0 and 7, where they 828 await more bits to join them in order to fill out a full byte. If pending 829 or bits are Z_NULL, then those values are not set. 830 831 deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source 832 stream state was inconsistent. 833 */ 834 835 ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, 836 int bits, 837 int value)); 838 /* 839 deflatePrime() inserts bits in the deflate output stream. The intent 840 is that this function is used to start off the deflate output with the bits 841 leftover from a previous deflate stream when appending to it. As such, this 842 function can only be used for raw deflate, and must be used before the first 843 deflate() call after a deflateInit2() or deflateReset(). bits must be less 844 than or equal to 16, and that many of the least significant bits of value 845 will be inserted in the output. 846 847 deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough 848 room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the 849 source stream state was inconsistent. 850 */ 851 852 ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 853 gz_headerp head)); 854 /* 855 deflateSetHeader() provides gzip header information for when a gzip 856 stream is requested by deflateInit2(). deflateSetHeader() may be called 857 after deflateInit2() or deflateReset() and before the first call of 858 deflate(). The text, time, os, extra field, name, and comment information 859 in the provided gz_header structure are written to the gzip header (xflag is 860 ignored -- the extra flags are set according to the compression level). The 861 caller must assure that, if not Z_NULL, name and comment are terminated with 862 a zero byte, and that if extra is not Z_NULL, that extra_len bytes are 863 available there. If hcrc is true, a gzip header crc is included. Note that 864 the current versions of the command-line version of gzip (up through version 865 1.3.x) do not support header crc's, and will report that it is a "multi-part 866 gzip file" and give up. 867 868 If deflateSetHeader is not used, the default gzip header has text false, 869 the time set to zero, and os set to 255, with no extra, name, or comment 870 fields. The gzip header is returned to the default state by deflateReset(). 871 872 deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 873 stream state was inconsistent. 874 */ 875 876 /* 877 ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 878 int windowBits)); 879 880 This is another version of inflateInit with an extra parameter. The 881 fields next_in, avail_in, zalloc, zfree and opaque must be initialized 882 before by the caller. 883 884 The windowBits parameter is the base two logarithm of the maximum window 885 size (the size of the history buffer). It should be in the range 8..15 for 886 this version of the library. The default value is 15 if inflateInit is used 887 instead. windowBits must be greater than or equal to the windowBits value 888 provided to deflateInit2() while compressing, or it must be equal to 15 if 889 deflateInit2() was not used. If a compressed stream with a larger window 890 size is given as input, inflate() will return with the error code 891 Z_DATA_ERROR instead of trying to allocate a larger window. 892 893 windowBits can also be zero to request that inflate use the window size in 894 the zlib header of the compressed stream. 895 896 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 897 determines the window size. inflate() will then process raw deflate data, 898 not looking for a zlib or gzip header, not generating a check value, and not 899 looking for any check values for comparison at the end of the stream. This 900 is for use with other formats that use the deflate compressed data format 901 such as zip. Those formats provide their own check values. If a custom 902 format is developed using the raw deflate format for compressed data, it is 903 recommended that a check value such as an Adler-32 or a CRC-32 be applied to 904 the uncompressed data as is done in the zlib, gzip, and zip formats. For 905 most applications, the zlib format should be used as is. Note that comments 906 above on the use in deflateInit2() applies to the magnitude of windowBits. 907 908 windowBits can also be greater than 15 for optional gzip decoding. Add 909 32 to windowBits to enable zlib and gzip decoding with automatic header 910 detection, or add 16 to decode only the gzip format (the zlib format will 911 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a 912 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see 913 below), inflate() will not automatically decode concatenated gzip streams. 914 inflate() will return Z_STREAM_END at the end of the gzip stream. The state 915 would need to be reset to continue decoding a subsequent gzip stream. 916 917 inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 918 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 919 version assumed by the caller, or Z_STREAM_ERROR if the parameters are 920 invalid, such as a null pointer to the structure. msg is set to null if 921 there is no error message. inflateInit2 does not perform any decompression 922 apart from possibly reading the zlib header if present: actual decompression 923 will be done by inflate(). (So next_in and avail_in may be modified, but 924 next_out and avail_out are unused and unchanged.) The current implementation 925 of inflateInit2() does not process any header information -- that is 926 deferred until inflate() is called. 927 */ 928 929 ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 930 const Bytef *dictionary, 931 uInt dictLength)); 932 /* 933 Initializes the decompression dictionary from the given uncompressed byte 934 sequence. This function must be called immediately after a call of inflate, 935 if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 936 can be determined from the Adler-32 value returned by that call of inflate. 937 The compressor and decompressor must use exactly the same dictionary (see 938 deflateSetDictionary). For raw inflate, this function can be called at any 939 time to set the dictionary. If the provided dictionary is smaller than the 940 window and there is already data in the window, then the provided dictionary 941 will amend what's there. The application must insure that the dictionary 942 that was used for compression is provided. 943 944 inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 945 parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is 946 inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 947 expected one (incorrect Adler-32 value). inflateSetDictionary does not 948 perform any decompression: this will be done by subsequent calls of 949 inflate(). 950 */ 951 952 #if !defined(__ANDROID__) || __ANDROID_API__ >= 19 953 ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, 954 Bytef *dictionary, 955 uInt *dictLength)); 956 #endif 957 /* 958 Returns the sliding dictionary being maintained by inflate. dictLength is 959 set to the number of bytes in the dictionary, and that many bytes are copied 960 to dictionary. dictionary must have enough space, where 32768 bytes is 961 always enough. If inflateGetDictionary() is called with dictionary equal to 962 Z_NULL, then only the dictionary length is returned, and nothing is copied. 963 Similary, if dictLength is Z_NULL, then it is not set. 964 965 inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the 966 stream state is inconsistent. 967 */ 968 969 ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); 970 /* 971 Skips invalid compressed data until a possible full flush point (see above 972 for the description of deflate with Z_FULL_FLUSH) can be found, or until all 973 available input is skipped. No output is provided. 974 975 inflateSync searches for a 00 00 FF FF pattern in the compressed data. 976 All full flush points have this pattern, but not all occurrences of this 977 pattern are full flush points. 978 979 inflateSync returns Z_OK if a possible full flush point has been found, 980 Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point 981 has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. 982 In the success case, the application may save the current current value of 983 total_in which indicates where valid compressed data was found. In the 984 error case, the application may repeatedly call inflateSync, providing more 985 input each time, until success or end of the input data. 986 */ 987 988 ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, 989 z_streamp source)); 990 /* 991 Sets the destination stream as a complete copy of the source stream. 992 993 This function can be useful when randomly accessing a large stream. The 994 first pass through the stream can periodically record the inflate state, 995 allowing restarting inflate at those points when randomly accessing the 996 stream. 997 998 inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 999 enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 1000 (such as zalloc being Z_NULL). msg is left unchanged in both source and 1001 destination. 1002 */ 1003 1004 ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); 1005 /* 1006 This function is equivalent to inflateEnd followed by inflateInit, 1007 but does not free and reallocate the internal decompression state. The 1008 stream will keep attributes that may have been set by inflateInit2. 1009 1010 inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 1011 stream state was inconsistent (such as zalloc or state being Z_NULL). 1012 */ 1013 1014 ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, 1015 int windowBits)); 1016 /* 1017 This function is the same as inflateReset, but it also permits changing 1018 the wrap and window size requests. The windowBits parameter is interpreted 1019 the same as it is for inflateInit2. If the window size is changed, then the 1020 memory allocated for the window is freed, and the window will be reallocated 1021 by inflate() if needed. 1022 1023 inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source 1024 stream state was inconsistent (such as zalloc or state being Z_NULL), or if 1025 the windowBits parameter is invalid. 1026 */ 1027 1028 ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, 1029 int bits, 1030 int value)); 1031 /* 1032 This function inserts bits in the inflate input stream. The intent is 1033 that this function is used to start inflating at a bit position in the 1034 middle of a byte. The provided bits will be used before any bytes are used 1035 from next_in. This function should only be used with raw inflate, and 1036 should be used before the first inflate() call after inflateInit2() or 1037 inflateReset(). bits must be less than or equal to 16, and that many of the 1038 least significant bits of value will be inserted in the input. 1039 1040 If bits is negative, then the input stream bit buffer is emptied. Then 1041 inflatePrime() can be called again to put bits in the buffer. This is used 1042 to clear out bits leftover after feeding inflate a block description prior 1043 to feeding inflate codes. 1044 1045 inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 1046 stream state was inconsistent. 1047 */ 1048 1049 ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); 1050 /* 1051 This function returns two values, one in the lower 16 bits of the return 1052 value, and the other in the remaining upper bits, obtained by shifting the 1053 return value down 16 bits. If the upper value is -1 and the lower value is 1054 zero, then inflate() is currently decoding information outside of a block. 1055 If the upper value is -1 and the lower value is non-zero, then inflate is in 1056 the middle of a stored block, with the lower value equaling the number of 1057 bytes from the input remaining to copy. If the upper value is not -1, then 1058 it is the number of bits back from the current bit position in the input of 1059 the code (literal or length/distance pair) currently being processed. In 1060 that case the lower value is the number of bytes already emitted for that 1061 code. 1062 1063 A code is being processed if inflate is waiting for more input to complete 1064 decoding of the code, or if it has completed decoding but is waiting for 1065 more output space to write the literal or match data. 1066 1067 inflateMark() is used to mark locations in the input data for random 1068 access, which may be at bit positions, and to note those cases where the 1069 output of a code may span boundaries of random access blocks. The current 1070 location in the input stream can be determined from avail_in and data_type 1071 as noted in the description for the Z_BLOCK flush parameter for inflate. 1072 1073 inflateMark returns the value noted above, or -65536 if the provided 1074 source stream state was inconsistent. 1075 */ 1076 1077 ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, 1078 gz_headerp head)); 1079 /* 1080 inflateGetHeader() requests that gzip header information be stored in the 1081 provided gz_header structure. inflateGetHeader() may be called after 1082 inflateInit2() or inflateReset(), and before the first call of inflate(). 1083 As inflate() processes the gzip stream, head->done is zero until the header 1084 is completed, at which time head->done is set to one. If a zlib stream is 1085 being decoded, then head->done is set to -1 to indicate that there will be 1086 no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be 1087 used to force inflate() to return immediately after header processing is 1088 complete and before any actual data is decompressed. 1089 1090 The text, time, xflags, and os fields are filled in with the gzip header 1091 contents. hcrc is set to true if there is a header CRC. (The header CRC 1092 was valid if done is set to one.) If extra is not Z_NULL, then extra_max 1093 contains the maximum number of bytes to write to extra. Once done is true, 1094 extra_len contains the actual extra field length, and extra contains the 1095 extra field, or that field truncated if extra_max is less than extra_len. 1096 If name is not Z_NULL, then up to name_max characters are written there, 1097 terminated with a zero unless the length is greater than name_max. If 1098 comment is not Z_NULL, then up to comm_max characters are written there, 1099 terminated with a zero unless the length is greater than comm_max. When any 1100 of extra, name, or comment are not Z_NULL and the respective field is not 1101 present in the header, then that field is set to Z_NULL to signal its 1102 absence. This allows the use of deflateSetHeader() with the returned 1103 structure to duplicate the header. However if those fields are set to 1104 allocated memory, then the application will need to save those pointers 1105 elsewhere so that they can be eventually freed. 1106 1107 If inflateGetHeader is not used, then the header information is simply 1108 discarded. The header is always checked for validity, including the header 1109 CRC if present. inflateReset() will reset the process to discard the header 1110 information. The application would need to call inflateGetHeader() again to 1111 retrieve the header from the next gzip stream. 1112 1113 inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 1114 stream state was inconsistent. 1115 */ 1116 1117 /* 1118 ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, 1119 unsigned char FAR *window)); 1120 1121 Initialize the internal stream state for decompression using inflateBack() 1122 calls. The fields zalloc, zfree and opaque in strm must be initialized 1123 before the call. If zalloc and zfree are Z_NULL, then the default library- 1124 derived memory allocation routines are used. windowBits is the base two 1125 logarithm of the window size, in the range 8..15. window is a caller 1126 supplied buffer of that size. Except for special applications where it is 1127 assured that deflate was used with small window sizes, windowBits must be 15 1128 and a 32K byte window must be supplied to be able to decompress general 1129 deflate streams. 1130 1131 See inflateBack() for the usage of these routines. 1132 1133 inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 1134 the parameters are invalid, Z_MEM_ERROR if the internal state could not be 1135 allocated, or Z_VERSION_ERROR if the version of the library does not match 1136 the version of the header file. 1137 */ 1138 1139 typedef unsigned (*in_func) OF((void FAR *, 1140 z_const unsigned char FAR * FAR *)); 1141 typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); 1142 1143 ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, 1144 in_func in, void FAR *in_desc, 1145 out_func out, void FAR *out_desc)); 1146 /* 1147 inflateBack() does a raw inflate with a single call using a call-back 1148 interface for input and output. This is potentially more efficient than 1149 inflate() for file i/o applications, in that it avoids copying between the 1150 output and the sliding window by simply making the window itself the output 1151 buffer. inflate() can be faster on modern CPUs when used with large 1152 buffers. inflateBack() trusts the application to not change the output 1153 buffer passed by the output function, at least until inflateBack() returns. 1154 1155 inflateBackInit() must be called first to allocate the internal state 1156 and to initialize the state with the user-provided window buffer. 1157 inflateBack() may then be used multiple times to inflate a complete, raw 1158 deflate stream with each call. inflateBackEnd() is then called to free the 1159 allocated state. 1160 1161 A raw deflate stream is one with no zlib or gzip header or trailer. 1162 This routine would normally be used in a utility that reads zip or gzip 1163 files and writes out uncompressed files. The utility would decode the 1164 header and process the trailer on its own, hence this routine expects only 1165 the raw deflate stream to decompress. This is different from the default 1166 behavior of inflate(), which expects a zlib header and trailer around the 1167 deflate stream. 1168 1169 inflateBack() uses two subroutines supplied by the caller that are then 1170 called by inflateBack() for input and output. inflateBack() calls those 1171 routines until it reads a complete deflate stream and writes out all of the 1172 uncompressed data, or until it encounters an error. The function's 1173 parameters and return types are defined above in the in_func and out_func 1174 typedefs. inflateBack() will call in(in_desc, &buf) which should return the 1175 number of bytes of provided input, and a pointer to that input in buf. If 1176 there is no input available, in() must return zero -- buf is ignored in that 1177 case -- and inflateBack() will return a buffer error. inflateBack() will 1178 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. 1179 out() should return zero on success, or non-zero on failure. If out() 1180 returns non-zero, inflateBack() will return with an error. Neither in() nor 1181 out() are permitted to change the contents of the window provided to 1182 inflateBackInit(), which is also the buffer that out() uses to write from. 1183 The length written by out() will be at most the window size. Any non-zero 1184 amount of input may be provided by in(). 1185 1186 For convenience, inflateBack() can be provided input on the first call by 1187 setting strm->next_in and strm->avail_in. If that input is exhausted, then 1188 in() will be called. Therefore strm->next_in must be initialized before 1189 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called 1190 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in 1191 must also be initialized, and then if strm->avail_in is not zero, input will 1192 initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 1193 1194 The in_desc and out_desc parameters of inflateBack() is passed as the 1195 first parameter of in() and out() respectively when they are called. These 1196 descriptors can be optionally used to pass any information that the caller- 1197 supplied in() and out() functions need to do their job. 1198 1199 On return, inflateBack() will set strm->next_in and strm->avail_in to 1200 pass back any unused input that was provided by the last in() call. The 1201 return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 1202 if in() or out() returned an error, Z_DATA_ERROR if there was a format error 1203 in the deflate stream (in which case strm->msg is set to indicate the nature 1204 of the error), or Z_STREAM_ERROR if the stream was not properly initialized. 1205 In the case of Z_BUF_ERROR, an input or output error can be distinguished 1206 using strm->next_in which will be Z_NULL only if in() returned an error. If 1207 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning 1208 non-zero. (in() will always be called before out(), so strm->next_in is 1209 assured to be defined if out() returns non-zero.) Note that inflateBack() 1210 cannot return Z_OK. 1211 */ 1212 1213 ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); 1214 /* 1215 All memory allocated by inflateBackInit() is freed. 1216 1217 inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 1218 state was inconsistent. 1219 */ 1220 1221 ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); 1222 /* Return flags indicating compile-time options. 1223 1224 Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1225 1.0: size of uInt 1226 3.2: size of uLong 1227 5.4: size of voidpf (pointer) 1228 7.6: size of z_off_t 1229 1230 Compiler, assembler, and debug options: 1231 8: ZLIB_DEBUG 1232 9: ASMV or ASMINF -- use ASM code 1233 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 1234 11: 0 (reserved) 1235 1236 One-time table building (smaller code, but not thread-safe if true): 1237 12: BUILDFIXED -- build static block decoding tables when needed 1238 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 1239 14,15: 0 (reserved) 1240 1241 Library content (indicates missing functionality): 1242 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 1243 deflate code when not needed) 1244 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 1245 and decode gzip streams (to avoid linking crc code) 1246 18-19: 0 (reserved) 1247 1248 Operation variations (changes in library functionality): 1249 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 1250 21: FASTEST -- deflate algorithm with only one, lowest compression level 1251 22,23: 0 (reserved) 1252 1253 The sprintf variant used by gzprintf (zero is best): 1254 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 1255 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 1256 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 1257 1258 Remainder: 1259 27-31: 0 (reserved) 1260 */ 1261 1262 #ifndef Z_SOLO 1263 1264 /* utility functions */ 1265 1266 /* 1267 The following utility functions are implemented on top of the basic 1268 stream-oriented functions. To simplify the interface, some default options 1269 are assumed (compression level and memory usage, standard memory allocation 1270 functions). The source code of these utility functions can be modified if 1271 you need special options. 1272 */ 1273 1274 ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, 1275 const Bytef *source, uLong sourceLen)); 1276 /* 1277 Compresses the source buffer into the destination buffer. sourceLen is 1278 the byte length of the source buffer. Upon entry, destLen is the total size 1279 of the destination buffer, which must be at least the value returned by 1280 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1281 compressed data. compress() is equivalent to compress2() with a level 1282 parameter of Z_DEFAULT_COMPRESSION. 1283 1284 compress returns Z_OK if success, Z_MEM_ERROR if there was not 1285 enough memory, Z_BUF_ERROR if there was not enough room in the output 1286 buffer. 1287 */ 1288 1289 ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, 1290 const Bytef *source, uLong sourceLen, 1291 int level)); 1292 /* 1293 Compresses the source buffer into the destination buffer. The level 1294 parameter has the same meaning as in deflateInit. sourceLen is the byte 1295 length of the source buffer. Upon entry, destLen is the total size of the 1296 destination buffer, which must be at least the value returned by 1297 compressBound(sourceLen). Upon exit, destLen is the actual size of the 1298 compressed data. 1299 1300 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1301 memory, Z_BUF_ERROR if there was not enough room in the output buffer, 1302 Z_STREAM_ERROR if the level parameter is invalid. 1303 */ 1304 1305 ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); 1306 /* 1307 compressBound() returns an upper bound on the compressed size after 1308 compress() or compress2() on sourceLen bytes. It would be used before a 1309 compress() or compress2() call to allocate the destination buffer. 1310 */ 1311 1312 ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, 1313 const Bytef *source, uLong sourceLen)); 1314 /* 1315 Decompresses the source buffer into the destination buffer. sourceLen is 1316 the byte length of the source buffer. Upon entry, destLen is the total size 1317 of the destination buffer, which must be large enough to hold the entire 1318 uncompressed data. (The size of the uncompressed data must have been saved 1319 previously by the compressor and transmitted to the decompressor by some 1320 mechanism outside the scope of this compression library.) Upon exit, destLen 1321 is the actual size of the uncompressed data. 1322 1323 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 1324 enough memory, Z_BUF_ERROR if there was not enough room in the output 1325 buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In 1326 the case where there is not enough room, uncompress() will fill the output 1327 buffer with the uncompressed data up to that point. 1328 */ 1329 1330 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1331 ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen, 1332 const Bytef *source, uLong *sourceLen)); 1333 #endif 1334 /* 1335 Same as uncompress, except that sourceLen is a pointer, where the 1336 length of the source is *sourceLen. On return, *sourceLen is the number of 1337 source bytes consumed. 1338 */ 1339 1340 /* gzip file access functions */ 1341 1342 /* 1343 This library supports reading and writing files in gzip (.gz) format with 1344 an interface similar to that of stdio, using the functions that start with 1345 "gz". The gzip format is different from the zlib format. gzip is a gzip 1346 wrapper, documented in RFC 1952, wrapped around a deflate stream. 1347 */ 1348 1349 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ 1350 1351 /* 1352 ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); 1353 1354 Opens a gzip (.gz) file for reading or writing. The mode parameter is as 1355 in fopen ("rb" or "wb") but can also include a compression level ("wb9") or 1356 a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only 1357 compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' 1358 for fixed code compression as in "wb9F". (See the description of 1359 deflateInit2 for more information about the strategy parameter.) 'T' will 1360 request transparent writing or appending with no compression and not using 1361 the gzip format. 1362 1363 "a" can be used instead of "w" to request that the gzip stream that will 1364 be written be appended to the file. "+" will result in an error, since 1365 reading and writing to the same gzip file is not supported. The addition of 1366 "x" when writing will create the file exclusively, which fails if the file 1367 already exists. On systems that support it, the addition of "e" when 1368 reading or writing will set the flag to close the file on an execve() call. 1369 1370 These functions, as well as gzip, will read and decode a sequence of gzip 1371 streams in a file. The append function of gzopen() can be used to create 1372 such a file. (Also see gzflush() for another way to do this.) When 1373 appending, gzopen does not test whether the file begins with a gzip stream, 1374 nor does it look for the end of the gzip streams to begin appending. gzopen 1375 will simply append a gzip stream to the existing file. 1376 1377 gzopen can be used to read a file which is not in gzip format; in this 1378 case gzread will directly read from the file without decompression. When 1379 reading, this will be detected automatically by looking for the magic two- 1380 byte gzip header. 1381 1382 gzopen returns NULL if the file could not be opened, if there was 1383 insufficient memory to allocate the gzFile state, or if an invalid mode was 1384 specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). 1385 errno can be checked to determine if the reason gzopen failed was that the 1386 file could not be opened. 1387 */ 1388 1389 ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); 1390 /* 1391 gzdopen associates a gzFile with the file descriptor fd. File descriptors 1392 are obtained from calls like open, dup, creat, pipe or fileno (if the file 1393 has been previously opened with fopen). The mode parameter is as in gzopen. 1394 1395 The next call of gzclose on the returned gzFile will also close the file 1396 descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor 1397 fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, 1398 mode);. The duplicated descriptor should be saved to avoid a leak, since 1399 gzdopen does not close fd if it fails. If you are using fileno() to get the 1400 file descriptor from a FILE *, then you will have to use dup() to avoid 1401 double-close()ing the file descriptor. Both gzclose() and fclose() will 1402 close the associated file descriptor, so they need to have different file 1403 descriptors. 1404 1405 gzdopen returns NULL if there was insufficient memory to allocate the 1406 gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not 1407 provided, or '+' was provided), or if fd is -1. The file descriptor is not 1408 used until the next gz* read, write, seek, or close operation, so gzdopen 1409 will not detect if fd is invalid (unless fd is -1). 1410 */ 1411 1412 ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); 1413 /* 1414 Set the internal buffer size used by this library's functions. The 1415 default buffer size is 8192 bytes. This function must be called after 1416 gzopen() or gzdopen(), and before any other calls that read or write the 1417 file. The buffer memory allocation is always deferred to the first read or 1418 write. Three times that size in buffer space is allocated. A larger buffer 1419 size of, for example, 64K or 128K bytes will noticeably increase the speed 1420 of decompression (reading). 1421 1422 The new buffer size also affects the maximum length for gzprintf(). 1423 1424 gzbuffer() returns 0 on success, or -1 on failure, such as being called 1425 too late. 1426 */ 1427 1428 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); 1429 /* 1430 Dynamically update the compression level or strategy. See the description 1431 of deflateInit2 for the meaning of these parameters. Previously provided 1432 data is flushed before the parameter change. 1433 1434 gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not 1435 opened for writing, Z_ERRNO if there is an error writing the flushed data, 1436 or Z_MEM_ERROR if there is a memory allocation error. 1437 */ 1438 1439 ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 1440 /* 1441 Reads the given number of uncompressed bytes from the compressed file. If 1442 the input file is not in gzip format, gzread copies the given number of 1443 bytes into the buffer directly from the file. 1444 1445 After reaching the end of a gzip stream in the input, gzread will continue 1446 to read, looking for another gzip stream. Any number of gzip streams may be 1447 concatenated in the input file, and will all be decompressed by gzread(). 1448 If something other than a gzip stream is encountered after a gzip stream, 1449 that remaining trailing garbage is ignored (and no error is returned). 1450 1451 gzread can be used to read a gzip file that is being concurrently written. 1452 Upon reaching the end of the input, gzread will return with the available 1453 data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then 1454 gzclearerr can be used to clear the end of file indicator in order to permit 1455 gzread to be tried again. Z_OK indicates that a gzip stream was completed 1456 on the last gzread. Z_BUF_ERROR indicates that the input file ended in the 1457 middle of a gzip stream. Note that gzread does not return -1 in the event 1458 of an incomplete gzip stream. This error is deferred until gzclose(), which 1459 will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip 1460 stream. Alternatively, gzerror can be used before gzclose to detect this 1461 case. 1462 1463 gzread returns the number of uncompressed bytes actually read, less than 1464 len for end of file, or -1 for error. If len is too large to fit in an int, 1465 then nothing is read, -1 is returned, and the error state is set to 1466 Z_STREAM_ERROR. 1467 */ 1468 1469 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1470 ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems, 1471 gzFile file)); 1472 #endif 1473 /* 1474 Read up to nitems items of size size from file to buf, otherwise operating 1475 as gzread() does. This duplicates the interface of stdio's fread(), with 1476 size_t request and return types. If the library defines size_t, then 1477 z_size_t is identical to size_t. If not, then z_size_t is an unsigned 1478 integer type that can contain a pointer. 1479 1480 gzfread() returns the number of full items read of size size, or zero if 1481 the end of the file was reached and a full item could not be read, or if 1482 there was an error. gzerror() must be consulted if zero is returned in 1483 order to determine if there was an error. If the multiplication of size and 1484 nitems overflows, i.e. the product does not fit in a z_size_t, then nothing 1485 is read, zero is returned, and the error state is set to Z_STREAM_ERROR. 1486 1487 In the event that the end of file is reached and only a partial item is 1488 available at the end, i.e. the remaining uncompressed data length is not a 1489 multiple of size, then the final partial item is nevetheless read into buf 1490 and the end-of-file flag is set. The length of the partial item read is not 1491 provided, but could be inferred from the result of gztell(). This behavior 1492 is the same as the behavior of fread() implementations in common libraries, 1493 but it prevents the direct use of gzfread() to read a concurrently written 1494 file, reseting and retrying on end-of-file, when size is not 1. 1495 */ 1496 1497 ZEXTERN int ZEXPORT gzwrite OF((gzFile file, 1498 voidpc buf, unsigned len)); 1499 /* 1500 Writes the given number of uncompressed bytes into the compressed file. 1501 gzwrite returns the number of uncompressed bytes written or 0 in case of 1502 error. 1503 */ 1504 1505 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1506 ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size, 1507 z_size_t nitems, gzFile file)); 1508 #endif 1509 /* 1510 gzfwrite() writes nitems items of size size from buf to file, duplicating 1511 the interface of stdio's fwrite(), with size_t request and return types. If 1512 the library defines size_t, then z_size_t is identical to size_t. If not, 1513 then z_size_t is an unsigned integer type that can contain a pointer. 1514 1515 gzfwrite() returns the number of full items written of size size, or zero 1516 if there was an error. If the multiplication of size and nitems overflows, 1517 i.e. the product does not fit in a z_size_t, then nothing is written, zero 1518 is returned, and the error state is set to Z_STREAM_ERROR. 1519 */ 1520 1521 ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); 1522 /* 1523 Converts, formats, and writes the arguments to the compressed file under 1524 control of the format string, as in fprintf. gzprintf returns the number of 1525 uncompressed bytes actually written, or a negative zlib error code in case 1526 of error. The number of uncompressed bytes written is limited to 8191, or 1527 one less than the buffer size given to gzbuffer(). The caller should assure 1528 that this limit is not exceeded. If it is exceeded, then gzprintf() will 1529 return an error (0) with nothing written. In this case, there may also be a 1530 buffer overflow with unpredictable consequences, which is possible only if 1531 zlib was compiled with the insecure functions sprintf() or vsprintf() 1532 because the secure snprintf() or vsnprintf() functions were not available. 1533 This can be determined using zlibCompileFlags(). 1534 */ 1535 1536 ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); 1537 /* 1538 Writes the given null-terminated string to the compressed file, excluding 1539 the terminating null character. 1540 1541 gzputs returns the number of characters written, or -1 in case of error. 1542 */ 1543 1544 ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); 1545 /* 1546 Reads bytes from the compressed file until len-1 characters are read, or a 1547 newline character is read and transferred to buf, or an end-of-file 1548 condition is encountered. If any characters are read or if len == 1, the 1549 string is terminated with a null character. If no characters are read due 1550 to an end-of-file or len < 1, then the buffer is left untouched. 1551 1552 gzgets returns buf which is a null-terminated string, or it returns NULL 1553 for end-of-file or in case of error. If there was an error, the contents at 1554 buf are indeterminate. 1555 */ 1556 1557 ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); 1558 /* 1559 Writes c, converted to an unsigned char, into the compressed file. gzputc 1560 returns the value that was written, or -1 in case of error. 1561 */ 1562 1563 ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); 1564 /* 1565 Reads one byte from the compressed file. gzgetc returns this byte or -1 1566 in case of end of file or error. This is implemented as a macro for speed. 1567 As such, it does not do all of the checking the other functions do. I.e. 1568 it does not check to see if file is NULL, nor whether the structure file 1569 points to has been clobbered or not. 1570 */ 1571 1572 ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); 1573 /* 1574 Push one character back onto the stream to be read as the first character 1575 on the next read. At least one character of push-back is allowed. 1576 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will 1577 fail if c is -1, and may fail if a character has been pushed but not read 1578 yet. If gzungetc is used immediately after gzopen or gzdopen, at least the 1579 output buffer size of pushed characters is allowed. (See gzbuffer above.) 1580 The pushed character will be discarded if the stream is repositioned with 1581 gzseek() or gzrewind(). 1582 */ 1583 1584 ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); 1585 /* 1586 Flushes all pending output into the compressed file. The parameter flush 1587 is as in the deflate() function. The return value is the zlib error number 1588 (see function gzerror below). gzflush is only permitted when writing. 1589 1590 If the flush parameter is Z_FINISH, the remaining data is written and the 1591 gzip stream is completed in the output. If gzwrite() is called again, a new 1592 gzip stream will be started in the output. gzread() is able to read such 1593 concatenated gzip streams. 1594 1595 gzflush should be called only when strictly necessary because it will 1596 degrade compression if called too often. 1597 */ 1598 1599 /* 1600 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, 1601 z_off_t offset, int whence)); 1602 1603 Sets the starting position for the next gzread or gzwrite on the given 1604 compressed file. The offset represents a number of bytes in the 1605 uncompressed data stream. The whence parameter is defined as in lseek(2); 1606 the value SEEK_END is not supported. 1607 1608 If the file is opened for reading, this function is emulated but can be 1609 extremely slow. If the file is opened for writing, only forward seeks are 1610 supported; gzseek then compresses a sequence of zeroes up to the new 1611 starting position. 1612 1613 gzseek returns the resulting offset location as measured in bytes from 1614 the beginning of the uncompressed stream, or -1 in case of error, in 1615 particular if the file is opened for writing and the new starting position 1616 would be before the current position. 1617 */ 1618 1619 ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); 1620 /* 1621 Rewinds the given file. This function is supported only for reading. 1622 1623 gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 1624 */ 1625 1626 /* 1627 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); 1628 1629 Returns the starting position for the next gzread or gzwrite on the given 1630 compressed file. This position represents a number of bytes in the 1631 uncompressed data stream, and is zero when starting, even if appending or 1632 reading a gzip stream from the middle of a file using gzdopen(). 1633 1634 gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 1635 */ 1636 1637 /* 1638 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); 1639 1640 Returns the current offset in the file being read or written. This offset 1641 includes the count of bytes that precede the gzip stream, for example when 1642 appending or when using gzdopen() for reading. When reading, the offset 1643 does not include as yet unused buffered input. This information can be used 1644 for a progress indicator. On error, gzoffset() returns -1. 1645 */ 1646 1647 ZEXTERN int ZEXPORT gzeof OF((gzFile file)); 1648 /* 1649 Returns true (1) if the end-of-file indicator has been set while reading, 1650 false (0) otherwise. Note that the end-of-file indicator is set only if the 1651 read tried to go past the end of the input, but came up short. Therefore, 1652 just like feof(), gzeof() may return false even if there is no more data to 1653 read, in the event that the last read request was for the exact number of 1654 bytes remaining in the input file. This will happen if the input file size 1655 is an exact multiple of the buffer size. 1656 1657 If gzeof() returns true, then the read functions will return no more data, 1658 unless the end-of-file indicator is reset by gzclearerr() and the input file 1659 has grown since the previous end of file was detected. 1660 */ 1661 1662 ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); 1663 /* 1664 Returns true (1) if file is being copied directly while reading, or false 1665 (0) if file is a gzip stream being decompressed. 1666 1667 If the input file is empty, gzdirect() will return true, since the input 1668 does not contain a gzip stream. 1669 1670 If gzdirect() is used immediately after gzopen() or gzdopen() it will 1671 cause buffers to be allocated to allow reading the file to determine if it 1672 is a gzip file. Therefore if gzbuffer() is used, it should be called before 1673 gzdirect(). 1674 1675 When writing, gzdirect() returns true (1) if transparent writing was 1676 requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: 1677 gzdirect() is not needed when writing. Transparent writing must be 1678 explicitly requested, so the application already knows the answer. When 1679 linking statically, using gzdirect() will include all of the zlib code for 1680 gzip file reading and decompression, which may not be desired.) 1681 */ 1682 1683 ZEXTERN int ZEXPORT gzclose OF((gzFile file)); 1684 /* 1685 Flushes all pending output if necessary, closes the compressed file and 1686 deallocates the (de)compression state. Note that once file is closed, you 1687 cannot call gzerror with file, since its structures have been deallocated. 1688 gzclose must not be called more than once on the same file, just as free 1689 must not be called more than once on the same allocation. 1690 1691 gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a 1692 file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the 1693 last read ended in the middle of a gzip stream, or Z_OK on success. 1694 */ 1695 1696 ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); 1697 ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); 1698 /* 1699 Same as gzclose(), but gzclose_r() is only for use when reading, and 1700 gzclose_w() is only for use when writing or appending. The advantage to 1701 using these instead of gzclose() is that they avoid linking in zlib 1702 compression or decompression code that is not used when only reading or only 1703 writing respectively. If gzclose() is used, then both compression and 1704 decompression code will be included the application when linking to a static 1705 zlib library. 1706 */ 1707 1708 ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); 1709 /* 1710 Returns the error message for the last error which occurred on the given 1711 compressed file. errnum is set to zlib error number. If an error occurred 1712 in the file system and not in the compression library, errnum is set to 1713 Z_ERRNO and the application may consult errno to get the exact error code. 1714 1715 The application must not modify the returned string. Future calls to 1716 this function may invalidate the previously returned string. If file is 1717 closed, then the string previously returned by gzerror will no longer be 1718 available. 1719 1720 gzerror() should be used to distinguish errors from end-of-file for those 1721 functions above that do not distinguish those cases in their return values. 1722 */ 1723 1724 ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); 1725 /* 1726 Clears the error and end-of-file flags for file. This is analogous to the 1727 clearerr() function in stdio. This is useful for continuing to read a gzip 1728 file that is being written concurrently. 1729 */ 1730 1731 #endif /* !Z_SOLO */ 1732 1733 /* checksum functions */ 1734 1735 /* 1736 These functions are not related to compression but are exported 1737 anyway because they might be useful in applications using the compression 1738 library. 1739 */ 1740 1741 ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); 1742 /* 1743 Update a running Adler-32 checksum with the bytes buf[0..len-1] and 1744 return the updated checksum. If buf is Z_NULL, this function returns the 1745 required initial value for the checksum. 1746 1747 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed 1748 much faster. 1749 1750 Usage example: 1751 1752 uLong adler = adler32(0L, Z_NULL, 0); 1753 1754 while (read_buffer(buffer, length) != EOF) { 1755 adler = adler32(adler, buffer, length); 1756 } 1757 if (adler != original_adler) error(); 1758 */ 1759 1760 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1761 ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf, 1762 z_size_t len)); 1763 #endif 1764 /* 1765 Same as adler32(), but with a size_t length. 1766 */ 1767 1768 /* 1769 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, 1770 z_off_t len2)); 1771 1772 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 1773 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 1774 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 1775 seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note 1776 that the z_off_t type (like off_t) is a signed integer. If len2 is 1777 negative, the result has no meaning or utility. 1778 */ 1779 1780 ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); 1781 /* 1782 Update a running CRC-32 with the bytes buf[0..len-1] and return the 1783 updated CRC-32. If buf is Z_NULL, this function returns the required 1784 initial value for the crc. Pre- and post-conditioning (one's complement) is 1785 performed within this function so it shouldn't be done by the application. 1786 1787 Usage example: 1788 1789 uLong crc = crc32(0L, Z_NULL, 0); 1790 1791 while (read_buffer(buffer, length) != EOF) { 1792 crc = crc32(crc, buffer, length); 1793 } 1794 if (crc != original_crc) error(); 1795 */ 1796 1797 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1798 ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf, 1799 z_size_t len)); 1800 #endif 1801 /* 1802 Same as crc32(), but with a size_t length. 1803 */ 1804 1805 /* 1806 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); 1807 1808 Combine two CRC-32 check values into one. For two sequences of bytes, 1809 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were 1810 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 1811 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and 1812 len2. 1813 */ 1814 1815 1816 /* various hacks, don't look :) */ 1817 1818 /* deflateInit and inflateInit are macros to allow checking the zlib version 1819 * and the compiler's view of z_stream: 1820 */ 1821 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, 1822 const char *version, int stream_size)); 1823 ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, 1824 const char *version, int stream_size)); 1825 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, 1826 int windowBits, int memLevel, 1827 int strategy, const char *version, 1828 int stream_size)); 1829 ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, 1830 const char *version, int stream_size)); 1831 ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, 1832 unsigned char FAR *window, 1833 const char *version, 1834 int stream_size)); 1835 #ifdef Z_PREFIX_SET 1836 # define z_deflateInit(strm, level) \ 1837 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) 1838 # define z_inflateInit(strm) \ 1839 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) 1840 # define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 1841 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 1842 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) 1843 # define z_inflateInit2(strm, windowBits) \ 1844 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ 1845 (int)sizeof(z_stream)) 1846 # define z_inflateBackInit(strm, windowBits, window) \ 1847 inflateBackInit_((strm), (windowBits), (window), \ 1848 ZLIB_VERSION, (int)sizeof(z_stream)) 1849 #else 1850 # define deflateInit(strm, level) \ 1851 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) 1852 # define inflateInit(strm) \ 1853 inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) 1854 # define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ 1855 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ 1856 (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) 1857 # define inflateInit2(strm, windowBits) \ 1858 inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ 1859 (int)sizeof(z_stream)) 1860 # define inflateBackInit(strm, windowBits, window) \ 1861 inflateBackInit_((strm), (windowBits), (window), \ 1862 ZLIB_VERSION, (int)sizeof(z_stream)) 1863 #endif 1864 1865 #ifndef Z_SOLO 1866 1867 /* gzgetc() macro and its supporting function and exposed data structure. Note 1868 * that the real internal state is much larger than the exposed structure. 1869 * This abbreviated structure exposes just enough for the gzgetc() macro. The 1870 * user should not mess with these exposed elements, since their names or 1871 * behavior could change in the future, perhaps even capriciously. They can 1872 * only be used by the gzgetc() macro. You have been warned. 1873 */ 1874 struct gzFile_s { 1875 unsigned have; 1876 unsigned char *next; 1877 z_off64_t pos; 1878 }; 1879 ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ 1880 #ifdef Z_PREFIX_SET 1881 # undef z_gzgetc 1882 # define z_gzgetc(g) \ 1883 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) 1884 #elif defined(Z_CR_PREFIX_SET) 1885 # undef gzgetc 1886 # define gzgetc(g) \ 1887 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) \ 1888 : (Cr_z_gzgetc)(g)) 1889 #else 1890 # define gzgetc(g) \ 1891 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) 1892 #endif 1893 1894 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or 1895 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if 1896 * both are true, the application gets the *64 functions, and the regular 1897 * functions are changed to 64 bits) -- in case these are set on systems 1898 * without large file support, _LFS64_LARGEFILE must also be true 1899 */ 1900 #ifdef Z_LARGE64 1901 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1902 ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); 1903 ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); 1904 ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); 1905 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); 1906 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); 1907 #endif 1908 1909 #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) 1910 # ifdef Z_PREFIX_SET 1911 # define z_gzopen z_gzopen64 1912 # define z_gzseek z_gzseek64 1913 # define z_gztell z_gztell64 1914 # define z_gzoffset z_gzoffset64 1915 # define z_adler32_combine z_adler32_combine64 1916 # define z_crc32_combine z_crc32_combine64 1917 # else 1918 # ifdef gzopen 1919 # undef gzopen 1920 # endif 1921 # define gzopen gzopen64 1922 # ifdef gzseek 1923 # undef gzseek 1924 # endif 1925 # define gzseek gzseek64 1926 # ifdef gztell 1927 # undef gztell 1928 # endif 1929 # define gztell gztell64 1930 # ifdef gzoffset 1931 # undef gzoffset 1932 # endif 1933 # define gzoffset gzoffset64 1934 # ifdef adler32_combine 1935 # undef adler32_combine 1936 # endif 1937 # define adler32_combine adler32_combine64 1938 # ifdef crc32_combine 1939 # undef crc32_combine 1940 # endif 1941 # define crc32_combine crc32_combine64 1942 # endif 1943 # ifndef Z_LARGE64 1944 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); 1945 ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); 1946 ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); 1947 ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); 1948 ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); 1949 ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); 1950 # endif 1951 #else 1952 ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); 1953 ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); 1954 ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); 1955 ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); 1956 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1957 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1958 #endif 1959 1960 #else /* Z_SOLO */ 1961 1962 ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); 1963 ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); 1964 1965 #endif /* !Z_SOLO */ 1966 1967 /* undocumented functions */ 1968 ZEXTERN const char * ZEXPORT zError OF((int)); 1969 ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); 1970 ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); 1971 ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); 1972 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1973 ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int)); 1974 #endif 1975 #if !defined(__ANDROID__) || __ANDROID_API__ >= 28 1976 ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF ((z_streamp)); 1977 #endif 1978 ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); 1979 ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); 1980 #if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO) 1981 ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, 1982 const char *mode)); 1983 #endif 1984 #if defined(STDC) || defined(Z_HAVE_STDARG_H) 1985 # ifndef Z_SOLO 1986 # if !defined(__ANDROID__) || __ANDROID_API__ >= 19 1987 ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, 1988 const char *format, 1989 va_list va)); 1990 # endif 1991 # endif 1992 #endif 1993 1994 #ifdef __cplusplus 1995 } 1996 #endif 1997 1998 #endif /* ZLIB_H */ 1999