1592N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 1592N/A * This code is free software; you can redistribute it and/or modify it 1592N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 1592N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 1592N/A * This code is distributed in the hope that it will be useful, but WITHOUT 1592N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1592N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1592N/A * version 2 for more details (a copy is included in the LICENSE file that 1592N/A * You should have received a copy of the GNU General Public License version 1592N/A * 2 along with this work; if not, write to the Free Software Foundation, 1592N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 1592N/A/* zlib.h -- interface of the 'zlib' general purpose compression library 1592N/A version 1.2.3, July 18th, 2005 1592N/A Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler 1592N/A This software is provided 'as-is', without any express or implied 1592N/A warranty. In no event will the authors be held liable for any damages 1592N/A arising from the use of this software. 1592N/A Permission is granted to anyone to use this software for any purpose, 1592N/A including commercial applications, and to alter it and redistribute it 1592N/A freely, subject to the following restrictions: 1592N/A 1. The origin of this software must not be misrepresented; you must not 1592N/A claim that you wrote the original software. If you use this software 1592N/A in a product, an acknowledgment in the product documentation would be 1592N/A appreciated but is not required. 1592N/A 2. Altered source versions must be plainly marked as such, and must not be 1592N/A misrepresented as being the original software. 1592N/A 3. This notice may not be removed or altered from any source distribution. 1592N/A Jean-loup Gailly Mark Adler 1592N/A jloup@gzip.org madler@alumni.caltech.edu 1592N/A The data format used by the zlib library is described by RFCs (Request for 1592N/A The 'zlib' compression library provides in-memory compression and 1592N/A decompression functions, including integrity checks of the uncompressed 1592N/A data. This version of the library supports only one compression method 1592N/A (deflation) but other algorithms will be added later and will have the same 1592N/A Compression can be done in a single step if the buffers are large 1592N/A enough (for example if an input file is mmap'ed), or can be done by 1592N/A repeated calls of the compression function. In the latter case, the 1592N/A application must provide more input and/or consume the output 1592N/A (providing more output space) before each call. 1592N/A The compressed data format used by default by the in-memory functions is 1592N/A the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 1592N/A around a deflate stream, which is itself documented in RFC 1951. 1592N/A The library also supports reading and writing files in gzip (.gz) format 1592N/A with an interface similar to that of stdio using the functions that start 1592N/A with "gz". The gzip format is different from the zlib format. gzip is a 1592N/A gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. 1592N/A This library can optionally read and write gzip streams in memory as well. 1592N/A The zlib format was designed to be compact and fast for use in memory 1592N/A and on communications channels. The gzip format was designed for single- 1592N/A file compression on file systems, has a larger header than zlib to maintain 1592N/A directory information, and uses a different, slower check method than zlib. 1592N/A The library does not install any signal handler. The decoder checks 1592N/A the consistency of the compressed data, so the library should never 1592N/A crash even in case of corrupted input. 1592N/A char *
msg;
/* last error message, NULL if no error */ 1592N/A gzip header information passed to and from zlib routines. See RFC 1952 1592N/A for more details on the meanings of these fields. 1592N/A int text;
/* true if compressed data believed to be text */ 1592N/A int xflags;
/* extra flags (not used when writing a gzip file) */ 1592N/A int hcrc;
/* true if there was or will be a header crc */ 1592N/A int done;
/* true when done reading gzip header (not used 1592N/A when writing a gzip file) */ 1592N/A The application must update next_in and avail_in when avail_in has 1592N/A dropped to zero. It must update next_out and avail_out when avail_out 1592N/A has dropped to zero. The application must initialize zalloc, zfree and 1592N/A opaque before calling the init function. All other fields are set by the 1592N/A compression library and must not be updated by the application. 1592N/A The opaque value provided by the application will be passed as the first 1592N/A parameter for calls of zalloc and zfree. This can be useful for custom 1592N/A memory management. The compression library attaches no meaning to the 1592N/A zalloc must return Z_NULL if there is not enough memory for the object. 1592N/A If zlib is used in a multi-threaded application, zalloc and zfree must be 1592N/A On 16-bit systems, the functions zalloc and zfree must be able to allocate 1592N/A exactly 65536 bytes, but will not be required to allocate more than this 1592N/A if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 1592N/A pointers returned by zalloc for objects of exactly 65536 bytes *must* 1592N/A have their offset normalized to zero. The default allocation function 1592N/A provided by this library ensures this (see zutil.c). To reduce memory 1592N/A requirements and avoid any allocation of 64K objects, at the expense of 1592N/A compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 1592N/A The fields total_in and total_out can be used for statistics or 1592N/A progress reports. After compression, total_in holds the total size of 1592N/A the uncompressed data and may be saved for use in the decompressor 1592N/A (particularly if the decompressor wants to decompress everything in 1592N/A/* Allowed flush values; see deflate() and inflate() below for details */ 1592N/A * values are errors, positive values are used for special but normal events. 1592N/A/* compression strategy; see deflateInit2() below for details */ 1592N/A/* Possible values of the data_type field (though see inflate()) */ 1592N/A/* The deflate compression method (the only one supported in this version) */ 1592N/A#
define Z_NULL 0
/* for initializing zalloc, zfree, opaque */ 1592N/A/* for compatibility with versions < 1.0.2 */ 1592N/A/* The application can compare zlibVersion and ZLIB_VERSION for consistency. 1592N/A If the first character differs, the library code actually used is 1592N/A not compatible with the zlib.h header file used by the application. 1592N/A This check is automatically made by deflateInit and inflateInit. 1592N/AZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); 1592N/A Initializes the internal stream state for compression. The fields 1592N/A zalloc, zfree and opaque must be initialized before by the caller. 1592N/A If zalloc and zfree are set to Z_NULL, deflateInit updates them to 1592N/A use default allocation functions. 1592N/A The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 1592N/A 1 gives best speed, 9 gives best compression, 0 gives no compression at 1592N/A all (the input data is simply copied a block at a time). 1592N/A Z_DEFAULT_COMPRESSION requests a default compromise between speed and 1592N/A compression (currently equivalent to level 6). 1592N/A deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 1592N/A enough memory, Z_STREAM_ERROR if level is not a valid compression level, 1592N/A Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 1592N/A with the version assumed by the caller (ZLIB_VERSION). 1592N/A msg is set to null if there is no error message. deflateInit does not 1592N/A perform any compression: this will be done by deflate(). 1592N/A deflate compresses as much data as possible, and stops when the input 1592N/A buffer becomes empty or the output buffer becomes full. It may introduce some 1592N/A output latency (reading input without producing any output) except when 1592N/A The detailed semantics are as follows. deflate performs one or both of the 1592N/A - Compress more input starting at next_in and update next_in and avail_in 1592N/A accordingly. If not all input can be processed (because there is not 1592N/A enough room in the output buffer), next_in and avail_in are updated and 1592N/A processing will resume at this point for the next call of deflate(). 1592N/A - Provide more output starting at next_out and update next_out and avail_out 1592N/A accordingly. This action is forced if the parameter flush is non zero. 1592N/A Forcing flush frequently degrades the compression ratio, so this parameter 1592N/A should be set only when necessary (in interactive applications). 1592N/A Some output may be provided even if flush is not set. 1592N/A Before the call of deflate(), the application should ensure that at least 1592N/A one of the actions is possible, by providing more input and/or consuming 1592N/A more output, and updating avail_in or avail_out accordingly; avail_out 1592N/A should never be zero before the call. The application can consume the 1592N/A compressed output when it wants, for example when the output buffer is full 1592N/A (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK 1592N/A and with zero avail_out, it must be called again after making room in the 1592N/A output buffer because there might be more output pending. 1592N/A Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to 1592N/A decide how much data to accumualte before producing output, in order to 1592N/A If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 1592N/A flushed to the output buffer and the output is aligned on a byte boundary, so 1592N/A that the decompressor can get all input data available so far. (In particular 1592N/A avail_in is zero after the call if enough output space has been provided 1592N/A before the call.) Flushing may degrade compression for some compression 1592N/A algorithms and so it should be used only when necessary. 1592N/A If flush is set to Z_FULL_FLUSH, all output is flushed as with 1592N/A Z_SYNC_FLUSH, and the compression state is reset so that decompression can 1592N/A restart from this point if previous compressed data has been damaged or if 1592N/A random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 1592N/A If deflate returns with avail_out == 0, this function must be called again 1592N/A with the same value of the flush parameter and more output space (updated 1592N/A avail_out), until the flush is complete (deflate returns with non-zero 1592N/A avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that 1592N/A avail_out is greater than six to avoid repeated flush markers due to 1592N/A If the parameter flush is set to Z_FINISH, pending input is processed, 1592N/A pending output is flushed and deflate returns with Z_STREAM_END if there 1592N/A was enough output space; if deflate returns with Z_OK, this function must be 1592N/A called again with Z_FINISH and more output space (updated avail_out) but no 1592N/A more input data, until it returns with Z_STREAM_END or an error. After 1592N/A deflate has returned Z_STREAM_END, the only possible operations on the 1592N/A stream are deflateReset or deflateEnd. 1592N/A Z_FINISH can be used immediately after deflateInit if all the compression 1592N/A is to be done in a single step. In this case, avail_out must be at least 1592N/A the value returned by deflateBound (see below). If deflate does not return 1592N/A Z_STREAM_END, then it must be called again as described above. 1592N/A deflate() sets strm->adler to the adler32 checksum of all input read 1592N/A so far (that is, total_in bytes). 1592N/A deflate() may update strm->data_type if it can make a good guess about 1592N/A the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered 1592N/A binary. This field is only for information purposes and does not affect 1592N/A the compression algorithm in any manner. 1592N/A deflate() returns Z_OK if some progress has been made (more input 1592N/A processed or more output produced), Z_STREAM_END if all input has been 1592N/A consumed and all output has been produced (only when flush is set to 1592N/A Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 1592N/A if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible 1592N/A (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not 1592N/A fatal, and deflate() can be called again with more input and more output 1592N/A space to continue compressing. 1592N/A All dynamically allocated data structures for this stream are freed. 1592N/A This function discards any unprocessed input and does not flush any 1592N/A deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 1592N/A stream state was inconsistent, Z_DATA_ERROR if the stream was freed 1592N/A prematurely (some input or output was discarded). In the error case, 1592N/A msg may be set but then points to a static string (which must not be 1592N/AZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); 1592N/A Initializes the internal stream state for decompression. The fields 1592N/A next_in, avail_in, zalloc, zfree and opaque must be initialized before by 1592N/A the caller. If next_in is not Z_NULL and avail_in is large enough (the exact 1592N/A value depends on the compression method), inflateInit determines the 1592N/A compression method from the zlib header and allocates all data structures 1592N/A accordingly; otherwise the allocation will be deferred to the first call of 1592N/A inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to 1592N/A use default allocation functions. 1592N/A inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 1592N/A memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 1592N/A version assumed by the caller. msg is set to null if there is no error 1592N/A message. inflateInit does not perform any decompression apart from reading 1592N/A the zlib header if present: this will be done by inflate(). (So next_in and 1592N/A avail_in may be modified, but next_out and avail_out are unchanged.) 1592N/A inflate decompresses as much data as possible, and stops when the input 1592N/A buffer becomes empty or the output buffer becomes full. It may introduce 1592N/A some output latency (reading input without producing any output) except when 1592N/A The detailed semantics are as follows. inflate performs one or both of the 1592N/A - Decompress more input starting at next_in and update next_in and avail_in 1592N/A accordingly. If not all input can be processed (because there is not 1592N/A enough room in the output buffer), next_in is updated and processing 1592N/A will resume at this point for the next call of inflate(). 1592N/A - Provide more output starting at next_out and update next_out and avail_out 1592N/A accordingly. inflate() provides as much output as possible, until there 1592N/A is no more input data or no more space in the output buffer (see below 1592N/A about the flush parameter). 1592N/A Before the call of inflate(), the application should ensure that at least 1592N/A one of the actions is possible, by providing more input and/or consuming 1592N/A more output, and updating the next_* and avail_* values accordingly. 1592N/A The application can consume the uncompressed output when it wants, for 1592N/A example when the output buffer is full (avail_out == 0), or after each 1592N/A call of inflate(). If inflate returns Z_OK and with zero avail_out, it 1592N/A must be called again after making room in the output buffer because there 1592N/A might be more output pending. 1592N/A The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, 1592N/A Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much 1592N/A output as possible to the output buffer. Z_BLOCK requests that inflate() stop 1592N/A if and when it gets to the next deflate block boundary. When decoding the 1592N/A zlib or gzip format, this will cause inflate() to return immediately after 1592N/A the header and before the first block. When doing a raw inflate, inflate() 1592N/A will go ahead and process the first block, and will return when it gets to 1592N/A the end of that block, or when it runs out of data. 1592N/A The Z_BLOCK option assists in appending to or combining deflate streams. 1592N/A Also to assist in this, on return inflate() will set strm->data_type to the 1592N/A number of unused bits in the last byte taken from strm->next_in, plus 64 1592N/A if inflate() is currently decoding the last block in the deflate stream, 1592N/A plus 128 if inflate() returned immediately after decoding an end-of-block 1592N/A code or decoding the complete header up to just before the first byte of the 1592N/A deflate stream. The end-of-block will not be indicated until all of the 1592N/A uncompressed data from that block has been written to strm->next_out. The 1592N/A number of unused bits may in general be greater than seven, except when 1592N/A bit 7 of data_type is set, in which case the number of unused bits will be 1592N/A inflate() should normally be called until it returns Z_STREAM_END or an 1592N/A error. However if all decompression is to be performed in a single step 1592N/A (a single call of inflate), the parameter flush should be set to 1592N/A Z_FINISH. In this case all pending input is processed and all pending 1592N/A output is flushed; avail_out must be large enough to hold all the 1592N/A uncompressed data. (The size of the uncompressed data may have been saved 1592N/A by the compressor for this purpose.) The next operation on this stream must 1592N/A be inflateEnd to deallocate the decompression state. The use of Z_FINISH 1592N/A is never required, but can be used to inform inflate that a faster approach 1592N/A may be used for the single inflate() call. 1592N/A In this implementation, inflate() always flushes as much output as 1592N/A possible to the output buffer, and always uses the faster approach on the 1592N/A first call. So the only effect of the flush parameter in this implementation 1592N/A is on the return value of inflate(), as noted below, or when it returns early 1592N/A If a preset dictionary is needed after this call (see inflateSetDictionary 1592N/A below), inflate sets strm->adler to the adler32 checksum of the dictionary 1592N/A chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 1592N/A strm->adler to the adler32 checksum of all output produced so far (that is, 1592N/A total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 1592N/A below. At the end of the stream, inflate() checks that its computed adler32 1592N/A checksum is equal to that saved by the compressor and returns Z_STREAM_END 1592N/A only if the checksum is correct. 1592N/A inflate() will decompress and check either zlib-wrapped or gzip-wrapped 1592N/A deflate data. The header type is detected automatically. Any information 1592N/A contained in the gzip header is not retained, so applications that need that 1592N/A information should instead use raw inflate, see inflateInit2() below, or 1592N/A inflateBack() and perform their own processing of the gzip header and 1592N/A inflate() returns Z_OK if some progress has been made (more input processed 1592N/A or more output produced), Z_STREAM_END if the end of the compressed data has 1592N/A been reached and all uncompressed output has been produced, Z_NEED_DICT if a 1592N/A preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 1592N/A corrupted (input stream not conforming to the zlib format or incorrect check 1592N/A value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 1592N/A if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, 1592N/A Z_BUF_ERROR if no progress is possible or if there was not enough room in the 1592N/A output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 1592N/A inflate() can be called again with more input and more output space to 1592N/A continue decompressing. If Z_DATA_ERROR is returned, the application may then 1592N/A call inflateSync() to look for a good compression block if a partial recovery 1592N/A All dynamically allocated data structures for this stream are freed. 1592N/A This function discards any unprocessed input and does not flush any 1592N/A inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 1592N/A was inconsistent. In the error case, msg may be set but then points to a 1592N/A static string (which must not be deallocated). 1592N/A The following functions are needed only in some special applications. 1592N/AZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 1592N/A This is another version of deflateInit with more compression options. The 1592N/A fields next_in, zalloc, zfree and opaque must be initialized before by 1592N/A The method parameter is the compression method. It must be Z_DEFLATED in 1592N/A this version of the library. 1592N/A The windowBits parameter is the base two logarithm of the window size 1592N/A (the size of the history buffer). It should be in the range 8..15 for this 1592N/A version of the library. Larger values of this parameter result in better 1592N/A compression at the expense of memory usage. The default value is 15 if 1592N/A deflateInit is used instead. 1592N/A windowBits can also be -8..-15 for raw deflate. In this case, -windowBits 1592N/A determines the window size. deflate() will then generate raw deflate data 1592N/A with no zlib header or trailer, and will not compute an adler32 check value. 1592N/A windowBits can also be greater than 15 for optional gzip encoding. Add 1592N/A 16 to windowBits to write a simple gzip header and trailer around the 1592N/A compressed data instead of a zlib wrapper. The gzip header will have no 1592N/A file name, no extra data, no comment, no modification time (set to zero), 1592N/A no header crc, and the operating system will be set to 255 (unknown). If a 1592N/A gzip stream is being written, strm->adler is a crc32 instead of an adler32. 1592N/A The memLevel parameter specifies how much memory should be allocated 1592N/A for the internal compression state. memLevel=1 uses minimum memory but 1592N/A is slow and reduces compression ratio; memLevel=9 uses maximum memory 1592N/A for optimal speed. The default value is 8. See zconf.h for total memory 1592N/A usage as a function of windowBits and memLevel. 1592N/A The strategy parameter is used to tune the compression algorithm. Use the 1592N/A value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 1592N/A filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no 1592N/A string match), or Z_RLE to limit match distances to one (run-length 1592N/A encoding). Filtered data consists mostly of small values with a somewhat 1592N/A random distribution. In this case, the compression algorithm is tuned to 1592N/A compress them better. The effect of Z_FILTERED is to force more Huffman 1592N/A coding and less string matching; it is somewhat intermediate between 1592N/A Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as 1592N/A Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy 1592N/A parameter only affects the compression ratio but not the correctness of the 1592N/A compressed output even if it is not set appropriately. Z_FIXED prevents the 1592N/A use of dynamic Huffman codes, allowing for a simpler decoder for special 1592N/A deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1592N/A memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid 1592N/A method). msg is set to null if there is no error message. deflateInit2 does 1592N/A not perform any compression: this will be done by deflate(). 1592N/A Initializes the compression dictionary from the given byte sequence 1592N/A without producing any compressed output. This function must be called 1592N/A immediately after deflateInit, deflateInit2 or deflateReset, before any 1592N/A call of deflate. The compressor and decompressor must use exactly the same 1592N/A dictionary (see inflateSetDictionary). 1592N/A The dictionary should consist of strings (byte sequences) that are likely 1592N/A to be encountered later in the data to be compressed, with the most commonly 1592N/A used strings preferably put towards the end of the dictionary. Using a 1592N/A dictionary is most useful when the data to be compressed is short and can be 1592N/A predicted with good accuracy; the data can then be compressed better than 1592N/A with the default empty dictionary. 1592N/A Depending on the size of the compression data structures selected by 1592N/A deflateInit or deflateInit2, a part of the dictionary may in effect be 1592N/A discarded, for example if the dictionary is larger than the window size in 1592N/A deflate or deflate2. Thus the strings most likely to be useful should be 1592N/A put at the end of the dictionary, not at the front. In addition, the 1592N/A current implementation of deflate will use at most the window size minus 1592N/A 262 bytes of the provided dictionary. 1592N/A Upon return of this function, strm->adler is set to the adler32 value 1592N/A of the dictionary; the decompressor may later use this value to determine 1592N/A which dictionary has been used by the compressor. (The adler32 value 1592N/A applies to the whole dictionary even if only a subset of the dictionary is 1592N/A actually used by the compressor.) If a raw deflate was requested, then the 1592N/A adler32 value is not computed and strm->adler is not set. 1592N/A deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 1592N/A parameter is invalid (such as NULL dictionary) or the stream state is 1592N/A inconsistent (for example if deflate has already been called for this stream 1592N/A or if the compression method is bsort). deflateSetDictionary does not 1592N/A perform any compression: this will be done by deflate(). 1592N/A Sets the destination stream as a complete copy of the source stream. 1592N/A This function can be useful when several compression strategies will be 1592N/A tried, for example when there are several ways of pre-processing the input 1592N/A data with a filter. The streams that will be discarded should then be freed 1592N/A by calling deflateEnd. Note that deflateCopy duplicates the internal 1592N/A compression state which can be quite large, so this strategy is slow and 1592N/A can consume lots of memory. 1592N/A deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 1592N/A enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 1592N/A (such as zalloc being NULL). msg is left unchanged in both source and 1592N/A This function is equivalent to deflateEnd followed by deflateInit, 1592N/A but does not free and reallocate all the internal compression state. 1592N/A The stream will keep the same compression level and any other attributes 1592N/A that may have been set by deflateInit2. 1592N/A deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent (such as zalloc or state being NULL). 1592N/A Dynamically update the compression level and compression strategy. The 1592N/A interpretation of level and strategy is as in deflateInit2. This can be 1592N/A used to switch between compression and straight copy of the input data, or 1592N/A to switch to a different kind of input data requiring a different 1592N/A strategy. If the compression level is changed, the input available so far 1592N/A is compressed with the old level (and may be flushed); the new level will 1592N/A take effect only at the next call of deflate(). 1592N/A Before the call of deflateParams, the stream state must be set as for 1592N/A a call of deflate(), since the currently available input may have to 1592N/A be compressed and flushed. In particular, strm->avail_out must be non-zero. 1592N/A deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR 1592N/A if strm->avail_out was zero. 1592N/A Fine tune deflate's internal compression parameters. This should only be 1592N/A used by someone who understands the algorithm used by zlib's deflate for 1592N/A searching for the best matching string, and even then only by the most 1592N/A fanatic optimizer trying to squeeze out the last compressed bit for their 1592N/A specific input data. Read the deflate.c source code for the meaning of the 1592N/A max_lazy, good_length, nice_length, and max_chain parameters. 1592N/A deflateTune() can be called after deflateInit() or deflateInit2(), and 1592N/A returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. 1592N/A deflateBound() returns an upper bound on the compressed size after 1592N/A deflation of sourceLen bytes. It must be called after deflateInit() 1592N/A or deflateInit2(). This would be used to allocate an output buffer 1592N/A for deflation in a single pass, and so would be called before deflate(). 1592N/A deflatePrime() inserts bits in the deflate output stream. The intent 1592N/A is that this function is used to start off the deflate output with the 1592N/A bits leftover from a previous deflate stream when appending to it. As such, 1592N/A this function can only be used for raw deflate, and must be used before the 1592N/A first deflate() call after a deflateInit2() or deflateReset(). bits must be 1592N/A less than or equal to 16, and that many of the least significant bits of 1592N/A value will be inserted in the output. 1592N/A deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent. 1592N/A deflateSetHeader() provides gzip header information for when a gzip 1592N/A stream is requested by deflateInit2(). deflateSetHeader() may be called 1592N/A after deflateInit2() or deflateReset() and before the first call of 1592N/A deflate(). The text, time, os, extra field, name, and comment information 1592N/A in the provided gz_header structure are written to the gzip header (xflag is 1592N/A ignored -- the extra flags are set according to the compression level). The 1592N/A caller must assure that, if not Z_NULL, name and comment are terminated with 1592N/A a zero byte, and that if extra is not Z_NULL, that extra_len bytes are 1592N/A available there. If hcrc is true, a gzip header crc is included. Note that 1592N/A the current versions of the command-line version of gzip (up through version 1592N/A 1.3.x) do not support header crc's, and will report that it is a "multi-part 1592N/A If deflateSetHeader is not used, the default gzip header has text false, 1592N/A the time set to zero, and os set to 255, with no extra, name, or comment 1592N/A fields. The gzip header is returned to the default state by deflateReset(). 1592N/A deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent. 1592N/AZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, 1592N/A This is another version of inflateInit with an extra parameter. The 1592N/A fields next_in, avail_in, zalloc, zfree and opaque must be initialized 1592N/A The windowBits parameter is the base two logarithm of the maximum window 1592N/A size (the size of the history buffer). It should be in the range 8..15 for 1592N/A this version of the library. The default value is 15 if inflateInit is used 1592N/A instead. windowBits must be greater than or equal to the windowBits value 1592N/A provided to deflateInit2() while compressing, or it must be equal to 15 if 1592N/A deflateInit2() was not used. If a compressed stream with a larger window 1592N/A size is given as input, inflate() will return with the error code 1592N/A Z_DATA_ERROR instead of trying to allocate a larger window. 1592N/A windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 1592N/A determines the window size. inflate() will then process raw deflate data, 1592N/A not looking for a zlib or gzip header, not generating a check value, and not 1592N/A looking for any check values for comparison at the end of the stream. This 1592N/A is for use with other formats that use the deflate compressed data format 1592N/A such as zip. Those formats provide their own check values. If a custom 1592N/A format is developed using the raw deflate format for compressed data, it is 1592N/A recommended that a check value such as an adler32 or a crc32 be applied to 1592N/A the uncompressed data as is done in the zlib, gzip, and zip formats. For 1592N/A most applications, the zlib format should be used as is. Note that comments 1592N/A above on the use in deflateInit2() applies to the magnitude of windowBits. 1592N/A windowBits can also be greater than 15 for optional gzip decoding. Add 1592N/A 32 to windowBits to enable zlib and gzip decoding with automatic header 1592N/A detection, or add 16 to decode only the gzip format (the zlib format will 1592N/A return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is 1592N/A a crc32 instead of an adler32. 1592N/A inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1592N/A memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg 1592N/A is set to null if there is no error message. inflateInit2 does not perform 1592N/A any decompression apart from reading the zlib header if present: this will 1592N/A be done by inflate(). (So next_in and avail_in may be modified, but next_out 1592N/A and avail_out are unchanged.) 1592N/A Initializes the decompression dictionary from the given uncompressed byte 1592N/A sequence. This function must be called immediately after a call of inflate, 1592N/A if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 1592N/A can be determined from the adler32 value returned by that call of inflate. 1592N/A The compressor and decompressor must use exactly the same dictionary (see 1592N/A deflateSetDictionary). For raw inflate, this function can be called 1592N/A immediately after inflateInit2() or inflateReset() and before any call of 1592N/A inflate() to set the dictionary. The application must insure that the 1592N/A dictionary that was used for compression is provided. 1592N/A inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 1592N/A parameter is invalid (such as NULL dictionary) or the stream state is 1592N/A inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 1592N/A expected one (incorrect adler32 value). inflateSetDictionary does not 1592N/A perform any decompression: this will be done by subsequent calls of 1592N/A Skips invalid compressed data until a full flush point (see above the 1592N/A description of deflate with Z_FULL_FLUSH) can be found, or until all 1592N/A available input is skipped. No output is provided. 1592N/A inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR 1592N/A if no more input was provided, Z_DATA_ERROR if no flush point has been found, 1592N/A or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 1592N/A case, the application may save the current current value of total_in which 1592N/A indicates where valid compressed data was found. In the error case, the 1592N/A application may repeatedly call inflateSync, providing more input each time, 1592N/A until success or end of the input data. 1592N/A Sets the destination stream as a complete copy of the source stream. 1592N/A This function can be useful when randomly accessing a large stream. The 1592N/A first pass through the stream can periodically record the inflate state, 1592N/A allowing restarting inflate at those points when randomly accessing the 1592N/A inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 1592N/A enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 1592N/A (such as zalloc being NULL). msg is left unchanged in both source and 1592N/A This function is equivalent to inflateEnd followed by inflateInit, 1592N/A but does not free and reallocate all the internal decompression state. 1592N/A The stream will keep attributes that may have been set by inflateInit2. 1592N/A inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent (such as zalloc or state being NULL). 1592N/A This function inserts bits in the inflate input stream. The intent is 1592N/A that this function is used to start inflating at a bit position in the 1592N/A middle of a byte. The provided bits will be used before any bytes are used 1592N/A from next_in. This function should only be used with raw inflate, and 1592N/A should be used before the first inflate() call after inflateInit2() or 1592N/A inflateReset(). bits must be less than or equal to 16, and that many of the 1592N/A least significant bits of value will be inserted in the input. 1592N/A inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent. 1592N/A inflateGetHeader() requests that gzip header information be stored in the 1592N/A provided gz_header structure. inflateGetHeader() may be called after 1592N/A inflateInit2() or inflateReset(), and before the first call of inflate(). 1592N/A As inflate() processes the gzip stream, head->done is zero until the header 1592N/A is completed, at which time head->done is set to one. If a zlib stream is 1592N/A being decoded, then head->done is set to -1 to indicate that there will be 1592N/A no gzip header information forthcoming. Note that Z_BLOCK can be used to 1592N/A force inflate() to return immediately after header processing is complete 1592N/A and before any actual data is decompressed. 1592N/A The text, time, xflags, and os fields are filled in with the gzip header 1592N/A contents. hcrc is set to true if there is a header CRC. (The header CRC 1592N/A was valid if done is set to one.) If extra is not Z_NULL, then extra_max 1592N/A contains the maximum number of bytes to write to extra. Once done is true, 1592N/A extra_len contains the actual extra field length, and extra contains the 1592N/A extra field, or that field truncated if extra_max is less than extra_len. 1592N/A If name is not Z_NULL, then up to name_max characters are written there, 1592N/A terminated with a zero unless the length is greater than name_max. If 1592N/A comment is not Z_NULL, then up to comm_max characters are written there, 1592N/A terminated with a zero unless the length is greater than comm_max. When 1592N/A any of extra, name, or comment are not Z_NULL and the respective field is 1592N/A not present in the header, then that field is set to Z_NULL to signal its 1592N/A absence. This allows the use of deflateSetHeader() with the returned 1592N/A structure to duplicate the header. However if those fields are set to 1592N/A allocated memory, then the application will need to save those pointers 1592N/A elsewhere so that they can be eventually freed. 1592N/A If inflateGetHeader is not used, then the header information is simply 1592N/A discarded. The header is always checked for validity, including the header 1592N/A CRC if present. inflateReset() will reset the process to discard the header 1592N/A information. The application would need to call inflateGetHeader() again to 1592N/A retrieve the header from the next gzip stream. 1592N/A inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source 1592N/A stream state was inconsistent. 1592N/AZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, 1592N/A unsigned char FAR *window)); 1592N/A Initialize the internal stream state for decompression using inflateBack() 1592N/A calls. The fields zalloc, zfree and opaque in strm must be initialized 1592N/A before the call. If zalloc and zfree are Z_NULL, then the default library- 1592N/A derived memory allocation routines are used. windowBits is the base two 1592N/A logarithm of the window size, in the range 8..15. window is a caller 1592N/A supplied buffer of that size. Except for special applications where it is 1592N/A assured that deflate was used with small window sizes, windowBits must be 15 1592N/A and a 32K byte window must be supplied to be able to decompress general 1592N/A See inflateBack() for the usage of these routines. 1592N/A inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of 1592N/A the paramaters are invalid, Z_MEM_ERROR if the internal state could not 1592N/A be allocated, or Z_VERSION_ERROR if the version of the library does not 1592N/A match the version of the header file. 1592N/A inflateBack() does a raw inflate with a single call using a call-back 1592N/A interface for input and output. This is more efficient than inflate() for 1592N/A file i/o applications in that it avoids copying between the output and the 1592N/A sliding window by simply making the window itself the output buffer. This 1592N/A function trusts the application to not change the output buffer passed by 1592N/A the output function, at least until inflateBack() returns. 1592N/A inflateBackInit() must be called first to allocate the internal state 1592N/A and to initialize the state with the user-provided window buffer. 1592N/A inflateBack() may then be used multiple times to inflate a complete, raw 1592N/A deflate stream with each call. inflateBackEnd() is then called to free 1592N/A A raw deflate stream is one with no zlib or gzip header or trailer. 1592N/A This routine would normally be used in a utility that reads zip or gzip 1592N/A files and writes out uncompressed files. The utility would decode the 1592N/A header and process the trailer on its own, hence this routine expects 1592N/A only the raw deflate stream to decompress. This is different from the 1592N/A normal behavior of inflate(), which expects either a zlib or gzip header and 1592N/A trailer around the deflate stream. 1592N/A inflateBack() uses two subroutines supplied by the caller that are then 1592N/A called by inflateBack() for input and output. inflateBack() calls those 1592N/A routines until it reads a complete deflate stream and writes out all of the 1592N/A uncompressed data, or until it encounters an error. The function's 1592N/A parameters and return types are defined above in the in_func and out_func 1592N/A typedefs. inflateBack() will call in(in_desc, &buf) which should return the 1592N/A number of bytes of provided input, and a pointer to that input in buf. If 1592N/A there is no input available, in() must return zero--buf is ignored in that 1592N/A case--and inflateBack() will return a buffer error. inflateBack() will call 1592N/A out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() 1592N/A should return zero on success, or non-zero on failure. If out() returns 1592N/A non-zero, inflateBack() will return with an error. Neither in() nor out() 1592N/A are permitted to change the contents of the window provided to 1592N/A inflateBackInit(), which is also the buffer that out() uses to write from. 1592N/A The length written by out() will be at most the window size. Any non-zero 1592N/A amount of input may be provided by in(). 1592N/A For convenience, inflateBack() can be provided input on the first call by 1592N/A setting strm->next_in and strm->avail_in. If that input is exhausted, then 1592N/A in() will be called. Therefore strm->next_in must be initialized before 1592N/A calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called 1592N/A immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in 1592N/A must also be initialized, and then if strm->avail_in is not zero, input will 1592N/A initially be taken from strm->next_in[0 .. strm->avail_in - 1]. 1592N/A The in_desc and out_desc parameters of inflateBack() is passed as the 1592N/A first parameter of in() and out() respectively when they are called. These 1592N/A descriptors can be optionally used to pass any information that the caller- 1592N/A supplied in() and out() functions need to do their job. 1592N/A On return, inflateBack() will set strm->next_in and strm->avail_in to 1592N/A pass back any unused input that was provided by the last in() call. The 1592N/A return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR 1592N/A if in() or out() returned an error, Z_DATA_ERROR if there was a format 1592N/A error in the deflate stream (in which case strm->msg is set to indicate the 1592N/A nature of the error), or Z_STREAM_ERROR if the stream was not properly 1592N/A initialized. In the case of Z_BUF_ERROR, an input or output error can be 1592N/A distinguished using strm->next_in which will be Z_NULL only if in() returned 1592N/A an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to 1592N/A out() returning non-zero. (in() will always be called before out(), so 1592N/A strm->next_in is assured to be defined if out() returns non-zero.) Note 1592N/A that inflateBack() cannot return Z_OK. 1592N/A All memory allocated by inflateBackInit() is freed. 1592N/A inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream 1592N/A/* Return flags indicating compile-time options. 1592N/A Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1592N/A 5.4: size of voidpf (pointer) 1592N/A Compiler, assembler, and debug options: 1592N/A 9: ASMV or ASMINF -- use ASM code 1592N/A 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 1592N/A One-time table building (smaller code, but not thread-safe if true): 1592N/A 12: BUILDFIXED -- build static block decoding tables when needed 1592N/A 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 1592N/A Library content (indicates missing functionality): 1592N/A 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking 1592N/A deflate code when not needed) 1592N/A 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect 1592N/A and decode gzip streams (to avoid linking crc code) 1592N/A Operation variations (changes in library functionality): 1592N/A 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 1592N/A 21: FASTEST -- deflate algorithm with only one, lowest compression level 1592N/A The sprintf variant used by gzprintf (zero is best): 1592N/A 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 1592N/A 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 1592N/A 26: 0 = returns value, 1 = void -- 1 means inferred string length returned 1592N/A The following utility functions are implemented on top of the 1592N/A basic stream-oriented functions. To simplify the interface, some 1592N/A default options are assumed (compression level and memory usage, 1592N/A standard memory allocation functions). The source code of these 1592N/A utility functions can easily be modified if you need special options. 1592N/A Compresses the source buffer into the destination buffer. sourceLen is 1592N/A the byte length of the source buffer. Upon entry, destLen is the total 1592N/A size of the destination buffer, which must be at least the value returned 1592N/A by compressBound(sourceLen). Upon exit, destLen is the actual size of the 1592N/A This function can be used to compress a whole file at once if the 1592N/A compress returns Z_OK if success, Z_MEM_ERROR if there was not 1592N/A enough memory, Z_BUF_ERROR if there was not enough room in the output 1592N/A Compresses the source buffer into the destination buffer. The level 1592N/A parameter has the same meaning as in deflateInit. sourceLen is the byte 1592N/A length of the source buffer. Upon entry, destLen is the total size of the 1592N/A destination buffer, which must be at least the value returned by 1592N/A compressBound(sourceLen). Upon exit, destLen is the actual size of the 1592N/A compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 1592N/A memory, Z_BUF_ERROR if there was not enough room in the output buffer, 1592N/A Z_STREAM_ERROR if the level parameter is invalid. 1592N/A compressBound() returns an upper bound on the compressed size after 1592N/A compress() or compress2() on sourceLen bytes. It would be used before 1592N/A a compress() or compress2() call to allocate the destination buffer. 1592N/A Decompresses the source buffer into the destination buffer. sourceLen is 1592N/A the byte length of the source buffer. Upon entry, destLen is the total 1592N/A size of the destination buffer, which must be large enough to hold the 1592N/A entire uncompressed data. (The size of the uncompressed data must have 1592N/A been saved previously by the compressor and transmitted to the decompressor 1592N/A by some mechanism outside the scope of this compression library.) 1592N/A Upon exit, destLen is the actual size of the compressed buffer. 1592N/A This function can be used to decompress a whole file at once if the 1592N/A uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 1592N/A enough memory, Z_BUF_ERROR if there was not enough room in the output 1592N/A buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. 1592N/A Opens a gzip (.gz) file for reading or writing. The mode parameter 1592N/A is as in fopen ("rb" or "wb") but can also include a compression level 1592N/A ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for 1592N/A Huffman only compression as in "wb1h", or 'R' for run-length encoding 1592N/A as in "wb1R". (See the description of deflateInit2 for more information 1592N/A about the strategy parameter.) 1592N/A gzopen can be used to read a file which is not in gzip format; in this 1592N/A case gzread will directly read from the file without decompression. 1592N/A gzopen returns NULL if the file could not be opened or if there was 1592N/A insufficient memory to allocate the (de)compression state; errno 1592N/A can be checked to distinguish the two cases (if errno is zero, the 1592N/A zlib error is Z_MEM_ERROR). */ 1592N/A gzdopen() associates a gzFile with the file descriptor fd. File 1592N/A descriptors are obtained from calls like open, dup, creat, pipe or 1592N/A fileno (in the file has been previously opened with fopen). 1592N/A The mode parameter is as in gzopen. 1592N/A The next call of gzclose on the returned gzFile will also close the 1592N/A file descriptor fd, just like fclose(fdopen(fd), mode) closes the file 1592N/A descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). 1592N/A gzdopen returns NULL if there was insufficient memory to allocate 1592N/A Dynamically update the compression level or strategy. See the description 1592N/A of deflateInit2 for the meaning of these parameters. 1592N/A gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not 1592N/A Reads the given number of uncompressed bytes from the compressed file. 1592N/A If the input file was not in gzip format, gzread copies the given number 1592N/A gzread returns the number of uncompressed bytes actually read (0 for 1592N/A end of file, -1 for error). */ 1592N/A Writes the given number of uncompressed bytes into the compressed file. 1592N/A gzwrite returns the number of uncompressed bytes actually written 1592N/A Converts, formats, and writes the args to the compressed file under 1592N/A control of the format string, as in fprintf. gzprintf returns the number of 1592N/A uncompressed bytes actually written (0 in case of error). The number of 1592N/A uncompressed bytes written is limited to 4095. The caller should assure that 1592N/A this limit is not exceeded. If it is exceeded, then gzprintf() will return 1592N/A return an error (0) with nothing written. In this case, there may also be a 1592N/A buffer overflow with unpredictable consequences, which is possible only if 1592N/A zlib was compiled with the insecure functions sprintf() or vsprintf() 1592N/A because the secure snprintf() or vsnprintf() functions were not available. 1592N/A Writes the given null-terminated string to the compressed file, excluding 1592N/A the terminating null character. 1592N/A gzputs returns the number of characters written, or -1 in case of error. 1592N/A Reads bytes from the compressed file until len-1 characters are read, or 1592N/A a newline character is read and transferred to buf, or an end-of-file 1592N/A condition is encountered. The string is then terminated with a null 1592N/A gzgets returns buf, or Z_NULL in case of error. 1592N/A Writes c, converted to an unsigned char, into the compressed file. 1592N/A gzputc returns the value that was written, or -1 in case of error. 1592N/A Reads one byte from the compressed file. gzgetc returns this byte 1592N/A or -1 in case of end of file or error. 1592N/A Push one character back onto the stream to be read again later. 1592N/A Only one character of push-back is allowed. gzungetc() returns the 1592N/A character pushed, or -1 on failure. gzungetc() will fail if a 1592N/A character has been pushed but not read yet, or if c is -1. The pushed 1592N/A character will be discarded if the stream is repositioned with gzseek() 1592N/A Flushes all pending output into the compressed file. The parameter 1592N/A flush is as in the deflate() function. The return value is the zlib 1592N/A error number (see function gzerror below). gzflush returns Z_OK if 1592N/A the flush parameter is Z_FINISH and all output could be flushed. 1592N/A gzflush should be called only when strictly necessary because it can 1592N/A Sets the starting position for the next gzread or gzwrite on the 1592N/A given compressed file. The offset represents a number of bytes in the 1592N/A uncompressed data stream. The whence parameter is defined as in lseek(2); 1592N/A the value SEEK_END is not supported. 1592N/A If the file is opened for reading, this function is emulated but can be 1592N/A extremely slow. If the file is opened for writing, only forward seeks are 1592N/A supported; gzseek then compresses a sequence of zeroes up to the new 1592N/A gzseek returns the resulting offset location as measured in bytes from 1592N/A the beginning of the uncompressed stream, or -1 in case of error, in 1592N/A particular if the file is opened for writing and the new starting position 1592N/A would be before the current position. 1592N/A Rewinds the given file. This function is supported only for reading. 1592N/A gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) 1592N/A Returns the starting position for the next gzread or gzwrite on the 1592N/A given compressed file. This position represents a number of bytes in the 1592N/A gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) 1592N/A Returns 1 when EOF has previously been detected reading the given 1592N/A input stream, otherwise zero. 1592N/A Returns 1 if file is being read directly without decompression, otherwise 1592N/A Flushes all pending output if necessary, closes the compressed file 1592N/A and deallocates all the (de)compression state. The return value is the zlib 1592N/A error number (see function gzerror below). 1592N/A Returns the error message for the last error which occurred on the 1592N/A given compressed file. errnum is set to zlib error number. If an 1592N/A error occurred in the file system and not in the compression library, 1592N/A errnum is set to Z_ERRNO and the application may consult errno 1592N/A to get the exact error code. 1592N/A Clears the error and end-of-file flags for file. This is analogous to the 1592N/A clearerr() function in stdio. This is useful for continuing to read a gzip 1592N/A file that is being written concurrently. 1592N/A These functions are not related to compression but are exported 1592N/A anyway because they might be useful in applications using the 1592N/A Update a running Adler-32 checksum with the bytes buf[0..len-1] and 1592N/A return the updated checksum. If buf is NULL, this function returns 1592N/A the required initial value for the checksum. 1592N/A An Adler-32 checksum is almost as reliable as a CRC32 but can be computed 1592N/A much faster. Usage example: 1592N/A uLong adler = adler32(0L, Z_NULL, 0); 1592N/A while (read_buffer(buffer, length) != EOF) { 1592N/A adler = adler32(adler, buffer, length); 1592N/A if (adler != original_adler) error(); 1592N/A Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 1592N/A and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for 1592N/A each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of 1592N/A seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. 1592N/A Update a running CRC-32 with the bytes buf[0..len-1] and return the 1592N/A updated CRC-32. If buf is NULL, this function returns the required initial 1592N/A value for the for the crc. Pre- and post-conditioning (one's complement) is 1592N/A performed within this function so it shouldn't be done by the application. 1592N/A uLong crc = crc32(0L, Z_NULL, 0); 1592N/A while (read_buffer(buffer, length) != EOF) { 1592N/A crc = crc32(crc, buffer, length); 1592N/A if (crc != original_crc) error(); 1592N/A Combine two CRC-32 check values into one. For two sequences of bytes, 1592N/A seq1 and seq2 with lengths len1 and len2, CRC-32 check values were 1592N/A calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 1592N/A check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and 1592N/A /* various hacks, don't look :) */ 1592N/A/* deflateInit and inflateInit are macros to allow checking the zlib version 1592N/A * and the compiler's view of z_stream: