1c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* zlib.h -- interface of the 'zlib' general purpose compression library 2c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 3c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler 4c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 5c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This software is provided 'as-is', without any express or implied 6c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru warranty. In no event will the authors be held liable for any damages 7c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru arising from the use of this software. 8c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 9c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Permission is granted to anyone to use this software for any purpose, 10c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru including commercial applications, and to alter it and redistribute it 11c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru freely, subject to the following restrictions: 12c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 13c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 1. The origin of this software must not be misrepresented; you must not 14c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru claim that you wrote the original software. If you use this software 15c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru in a product, an acknowledgment in the product documentation would be 16c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru appreciated but is not required. 17c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 2. Altered source versions must be plainly marked as such, and must not be 18c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru misrepresented as being the original software. 19c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 3. This notice may not be removed or altered from any source distribution. 20c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 21c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Jean-loup Gailly Mark Adler 22c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru jloup@gzip.org madler@alumni.caltech.edu 23c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 24c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 25c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The data format used by the zlib library is described by RFCs (Request for 26c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt 27c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). 28c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 29c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 30c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifndef _ZLIB_H 31c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define _ZLIB_H 32c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 33c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/zconf.h> 34c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 35c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* zlib deflate based on ZLIB_VERSION "1.1.3" */ 36c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* zlib inflate based on ZLIB_VERSION "1.2.3" */ 37c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 38c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 39c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This is a modified version of zlib for use inside the Linux kernel. 40c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The main changes are to perform all memory allocation in advance. 41c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 42c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Inflation Changes: 43c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Z_PACKET_FLUSH is added and used by ppp_deflate. Before returning 44c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru this checks there is no more input data available and the next data 45c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is a STORED block. It also resets the mode to be read for the next 46c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru data, all as per PPP requirements. 47c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Addition of zlib_inflateIncomp which copies incompressible data into 48c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the history window and adjusts the accoutning without calling 49c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru zlib_inflate itself to inflate the data. 50c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 51c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 52c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 53c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The 'zlib' compression library provides in-memory compression and 54c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru decompression functions, including integrity checks of the uncompressed 55c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru data. This version of the library supports only one compression method 56c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (deflation) but other algorithms will be added later and will have the same 57c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream interface. 58c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 59c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Compression can be done in a single step if the buffers are large 60c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru enough (for example if an input file is mmap'ed), or can be done by 61c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru repeated calls of the compression function. In the latter case, the 62c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru application must provide more input and/or consume the output 63c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (providing more output space) before each call. 64c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 65c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The compressed data format used by default by the in-memory functions is 66c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped 67c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru around a deflate stream, which is itself documented in RFC 1951. 68c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 69c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The library also supports reading and writing files in gzip (.gz) format 70c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru with an interface similar to that of stdio. 71c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 72c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The zlib format was designed to be compact and fast for use in memory 73c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru and on communications channels. The gzip format was designed for single- 74c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru file compression on file systems, has a larger header than zlib to maintain 75c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru directory information, and uses a different, slower check method than zlib. 76c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 77c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The library does not install any signal handler. The decoder checks 78c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the consistency of the compressed data, so the library should never 79c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru crash even in case of corrupted input. 80c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 81c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 82c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct internal_state; 83c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 84c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querutypedef struct z_stream_s { 85c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Byte *next_in; /* next input byte */ 86c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uInt avail_in; /* number of bytes available at next_in */ 87c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uLong total_in; /* total nb of input bytes read so far */ 88c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 89c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Byte *next_out; /* next output byte should be put there */ 90c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uInt avail_out; /* remaining free space at next_out */ 91c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uLong total_out; /* total nb of bytes output so far */ 92c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 93c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru char *msg; /* last error message, NULL if no error */ 94c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct internal_state *state; /* not visible by applications */ 95c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 96c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru void *workspace; /* memory allocated for this stream */ 97c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 98c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int data_type; /* best guess about the data type: ascii or binary */ 99c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uLong adler; /* adler32 value of the uncompressed data */ 100c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uLong reserved; /* reserved for future use */ 101c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} z_stream; 102c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 103c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querutypedef z_stream *z_streamp; 104c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 105c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 106c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The application must update next_in and avail_in when avail_in has 107c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru dropped to zero. It must update next_out and avail_out when avail_out 108c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru has dropped to zero. The application must initialize zalloc, zfree and 109c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru opaque before calling the init function. All other fields are set by the 110c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compression library and must not be updated by the application. 111c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 112c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The opaque value provided by the application will be passed as the first 113c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru parameter for calls of zalloc and zfree. This can be useful for custom 114c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru memory management. The compression library attaches no meaning to the 115c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru opaque value. 116c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 117c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru zalloc must return NULL if there is not enough memory for the object. 118c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If zlib is used in a multi-threaded application, zalloc and zfree must be 119c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru thread safe. 120c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 121c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru On 16-bit systems, the functions zalloc and zfree must be able to allocate 122c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru exactly 65536 bytes, but will not be required to allocate more than this 123c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, 124c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru pointers returned by zalloc for objects of exactly 65536 bytes *must* 125c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru have their offset normalized to zero. The default allocation function 126c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru provided by this library ensures this (see zutil.c). To reduce memory 127c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru requirements and avoid any allocation of 64K objects, at the expense of 128c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). 129c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 130c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The fields total_in and total_out can be used for statistics or 131c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru progress reports. After compression, total_in holds the total size of 132c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the uncompressed data and may be saved for use in the decompressor 133c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (particularly if the decompressor wants to decompress everything in 134c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru a single step). 135c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 136c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 137c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* constants */ 138c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 139c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_NO_FLUSH 0 140c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ 141c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_PACKET_FLUSH 2 142c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_SYNC_FLUSH 3 143c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_FULL_FLUSH 4 144c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_FINISH 5 145c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_BLOCK 6 /* Only for inflate at present */ 146c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* Allowed flush values; see deflate() and inflate() below for details */ 147c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 148c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_OK 0 149c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_STREAM_END 1 150c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_NEED_DICT 2 151c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_ERRNO (-1) 152c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_STREAM_ERROR (-2) 153c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_DATA_ERROR (-3) 154c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_MEM_ERROR (-4) 155c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_BUF_ERROR (-5) 156c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_VERSION_ERROR (-6) 157c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* Return codes for the compression/decompression functions. Negative 158c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * values are errors, positive values are used for special but normal events. 159c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */ 160c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 161c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_NO_COMPRESSION 0 162c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_BEST_SPEED 1 163c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_BEST_COMPRESSION 9 164c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_DEFAULT_COMPRESSION (-1) 165c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* compression levels */ 166c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 167c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_FILTERED 1 168c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_HUFFMAN_ONLY 2 169c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_DEFAULT_STRATEGY 0 170c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* compression strategy; see deflateInit2() below for details */ 171c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 172c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_BINARY 0 173c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_ASCII 1 174c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_UNKNOWN 2 175c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* Possible values of the data_type field */ 176c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 177c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define Z_DEFLATED 8 178c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* The deflate compression method (the only one supported in this version) */ 179c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 180c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* basic functions */ 181c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 182c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflate_workspacesize (void); 183c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 184c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Returns the number of bytes that needs to be allocated for a per- 185c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream workspace. A pointer to this number of bytes should be 186c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru returned in stream->workspace before calling zlib_deflateInit(). 187c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 188c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 189c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 190c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int deflateInit (z_streamp strm, int level); 191c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 192c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Initializes the internal stream state for compression. The fields 193c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru zalloc, zfree and opaque must be initialized before by the caller. 194c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If zalloc and zfree are set to NULL, deflateInit updates them to 195c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru use default allocation functions. 196c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 197c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 198c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 1 gives best speed, 9 gives best compression, 0 gives no compression at 199c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru all (the input data is simply copied a block at a time). 200c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_DEFAULT_COMPRESSION requests a default compromise between speed and 201c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compression (currently equivalent to level 6). 202c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 203c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not 204c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru enough memory, Z_STREAM_ERROR if level is not a valid compression level, 205c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible 206c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru with the version assumed by the caller (ZLIB_VERSION). 207c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru msg is set to null if there is no error message. deflateInit does not 208c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru perform any compression: this will be done by deflate(). 209c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 210c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 211c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 212c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflate (z_streamp strm, int flush); 213c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 214c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate compresses as much data as possible, and stops when the input 215c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru buffer becomes empty or the output buffer becomes full. It may introduce some 216c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru output latency (reading input without producing any output) except when 217c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru forced to flush. 218c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 219c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The detailed semantics are as follows. deflate performs one or both of the 220c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru following actions: 221c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 222c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru - Compress more input starting at next_in and update next_in and avail_in 223c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru accordingly. If not all input can be processed (because there is not 224c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru enough room in the output buffer), next_in and avail_in are updated and 225c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru processing will resume at this point for the next call of deflate(). 226c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 227c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru - Provide more output starting at next_out and update next_out and avail_out 228c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru accordingly. This action is forced if the parameter flush is non zero. 229c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Forcing flush frequently degrades the compression ratio, so this parameter 230c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru should be set only when necessary (in interactive applications). 231c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Some output may be provided even if flush is not set. 232c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 233c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Before the call of deflate(), the application should ensure that at least 234c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru one of the actions is possible, by providing more input and/or consuming 235c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru more output, and updating avail_in or avail_out accordingly; avail_out 236c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru should never be zero before the call. The application can consume the 237c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compressed output when it wants, for example when the output buffer is full 238c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK 239c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru and with zero avail_out, it must be called again after making room in the 240c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru output buffer because there might be more output pending. 241c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 242c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If the parameter flush is set to Z_SYNC_FLUSH, all pending output is 243c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru flushed to the output buffer and the output is aligned on a byte boundary, so 244c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru that the decompressor can get all input data available so far. (In particular 245c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru avail_in is zero after the call if enough output space has been provided 246c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru before the call.) Flushing may degrade compression for some compression 247c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru algorithms and so it should be used only when necessary. 248c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 249c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If flush is set to Z_FULL_FLUSH, all output is flushed as with 250c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_SYNC_FLUSH, and the compression state is reset so that decompression can 251c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru restart from this point if previous compressed data has been damaged or if 252c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru random access is desired. Using Z_FULL_FLUSH too often can seriously degrade 253c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the compression. 254c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 255c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If deflate returns with avail_out == 0, this function must be called again 256c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru with the same value of the flush parameter and more output space (updated 257c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru avail_out), until the flush is complete (deflate returns with non-zero 258c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru avail_out). 259c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 260c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If the parameter flush is set to Z_FINISH, pending input is processed, 261c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru pending output is flushed and deflate returns with Z_STREAM_END if there 262c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru was enough output space; if deflate returns with Z_OK, this function must be 263c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru called again with Z_FINISH and more output space (updated avail_out) but no 264c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru more input data, until it returns with Z_STREAM_END or an error. After 265c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate has returned Z_STREAM_END, the only possible operations on the 266c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream are deflateReset or deflateEnd. 267c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 268c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_FINISH can be used immediately after deflateInit if all the compression 269c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is to be done in a single step. In this case, avail_out must be at least 270c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 0.1% larger than avail_in plus 12 bytes. If deflate does not return 271c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_STREAM_END, then it must be called again as described above. 272c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 273c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate() sets strm->adler to the adler32 checksum of all input read 274c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru so far (that is, total_in bytes). 275c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 276c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate() may update data_type if it can make a good guess about 277c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered 278c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru binary. This field is only for information purposes and does not affect 279c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the compression algorithm in any manner. 280c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 281c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate() returns Z_OK if some progress has been made (more input 282c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru processed or more output produced), Z_STREAM_END if all input has been 283c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru consumed and all output has been produced (only when flush is set to 284c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example 285c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible 286c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (for example avail_in or avail_out was zero). 287c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 288c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 289c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 290c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflateEnd (z_streamp strm); 291c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 292c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru All dynamically allocated data structures for this stream are freed. 293c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This function discards any unprocessed input and does not flush any 294c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru pending output. 295c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 296c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the 297c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream state was inconsistent, Z_DATA_ERROR if the stream was freed 298c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru prematurely (some input or output was discarded). In the error case, 299c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru msg may be set but then points to a static string (which must not be 300c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deallocated). 301c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 302c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 303c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 304c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflate_workspacesize (void); 305c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 306c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Returns the number of bytes that needs to be allocated for a per- 307c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream workspace. A pointer to this number of bytes should be 308c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru returned in stream->workspace before calling zlib_inflateInit(). 309c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 310c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 311c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 312c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateInit (z_streamp strm); 313c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 314c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Initializes the internal stream state for decompression. The fields 315c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru next_in, avail_in, and workspace must be initialized before by 316c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the caller. If next_in is not NULL and avail_in is large enough (the exact 317c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru value depends on the compression method), inflateInit determines the 318c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compression method from the zlib header and allocates all data structures 319c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru accordingly; otherwise the allocation will be deferred to the first call of 320c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate. If zalloc and zfree are set to NULL, inflateInit updates them to 321c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru use default allocation functions. 322c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 323c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough 324c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru memory, Z_VERSION_ERROR if the zlib library version is incompatible with the 325c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru version assumed by the caller. msg is set to null if there is no error 326c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru message. inflateInit does not perform any decompression apart from reading 327c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the zlib header if present: this will be done by inflate(). (So next_in and 328c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru avail_in may be modified, but next_out and avail_out are unchanged.) 329c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 330c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 331c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 332c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflate (z_streamp strm, int flush); 333c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 334c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate decompresses as much data as possible, and stops when the input 335c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru buffer becomes empty or the output buffer becomes full. It may introduce 336c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru some output latency (reading input without producing any output) except when 337c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru forced to flush. 338c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 339c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The detailed semantics are as follows. inflate performs one or both of the 340c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru following actions: 341c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 342c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru - Decompress more input starting at next_in and update next_in and avail_in 343c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru accordingly. If not all input can be processed (because there is not 344c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru enough room in the output buffer), next_in is updated and processing 345c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru will resume at this point for the next call of inflate(). 346c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 347c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru - Provide more output starting at next_out and update next_out and avail_out 348c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru accordingly. inflate() provides as much output as possible, until there 349c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is no more input data or no more space in the output buffer (see below 350c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru about the flush parameter). 351c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 352c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Before the call of inflate(), the application should ensure that at least 353c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru one of the actions is possible, by providing more input and/or consuming 354c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru more output, and updating the next_* and avail_* values accordingly. 355c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The application can consume the uncompressed output when it wants, for 356c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru example when the output buffer is full (avail_out == 0), or after each 357c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru call of inflate(). If inflate returns Z_OK and with zero avail_out, it 358c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru must be called again after making room in the output buffer because there 359c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru might be more output pending. 360c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 361c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, 362c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much 363c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru output as possible to the output buffer. Z_BLOCK requests that inflate() stop 364c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if and when it gets to the next deflate block boundary. When decoding the 365c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru zlib or gzip format, this will cause inflate() to return immediately after 366c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the header and before the first block. When doing a raw inflate, inflate() 367c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru will go ahead and process the first block, and will return when it gets to 368c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the end of that block, or when it runs out of data. 369c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 370c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The Z_BLOCK option assists in appending to or combining deflate streams. 371c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Also to assist in this, on return inflate() will set strm->data_type to the 372c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru number of unused bits in the last byte taken from strm->next_in, plus 64 373c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if inflate() is currently decoding the last block in the deflate stream, 374c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru plus 128 if inflate() returned immediately after decoding an end-of-block 375c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru code or decoding the complete header up to just before the first byte of the 376c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate stream. The end-of-block will not be indicated until all of the 377c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uncompressed data from that block has been written to strm->next_out. The 378c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru number of unused bits may in general be greater than seven, except when 379c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru bit 7 of data_type is set, in which case the number of unused bits will be 380c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru less than eight. 381c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 382c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate() should normally be called until it returns Z_STREAM_END or an 383c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru error. However if all decompression is to be performed in a single step 384c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (a single call of inflate), the parameter flush should be set to 385c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_FINISH. In this case all pending input is processed and all pending 386c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru output is flushed; avail_out must be large enough to hold all the 387c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uncompressed data. (The size of the uncompressed data may have been saved 388c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru by the compressor for this purpose.) The next operation on this stream must 389c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru be inflateEnd to deallocate the decompression state. The use of Z_FINISH 390c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is never required, but can be used to inform inflate that a faster approach 391c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru may be used for the single inflate() call. 392c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 393c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru In this implementation, inflate() always flushes as much output as 394c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru possible to the output buffer, and always uses the faster approach on the 395c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru first call. So the only effect of the flush parameter in this implementation 396c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is on the return value of inflate(), as noted below, or when it returns early 397c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru because Z_BLOCK is used. 398c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 399c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru If a preset dictionary is needed after this call (see inflateSetDictionary 400c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru below), inflate sets strm->adler to the adler32 checksum of the dictionary 401c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru chosen by the compressor and returns Z_NEED_DICT; otherwise it sets 402c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru strm->adler to the adler32 checksum of all output produced so far (that is, 403c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described 404c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru below. At the end of the stream, inflate() checks that its computed adler32 405c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru checksum is equal to that saved by the compressor and returns Z_STREAM_END 406c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru only if the checksum is correct. 407c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 408c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate() will decompress and check either zlib-wrapped or gzip-wrapped 409c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate data. The header type is detected automatically. Any information 410c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru contained in the gzip header is not retained, so applications that need that 411c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru information should instead use raw inflate, see inflateInit2() below, or 412c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateBack() and perform their own processing of the gzip header and 413c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru trailer. 414c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 415c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate() returns Z_OK if some progress has been made (more input processed 416c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru or more output produced), Z_STREAM_END if the end of the compressed data has 417c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru been reached and all uncompressed output has been produced, Z_NEED_DICT if a 418c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru preset dictionary is needed at this point, Z_DATA_ERROR if the input data was 419c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru corrupted (input stream not conforming to the zlib format or incorrect check 420c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru value), Z_STREAM_ERROR if the stream structure was inconsistent (for example 421c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, 422c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_BUF_ERROR if no progress is possible or if there was not enough room in the 423c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and 424c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate() can be called again with more input and more output space to 425c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru continue decompressing. If Z_DATA_ERROR is returned, the application may then 426c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru call inflateSync() to look for a good compression block if a partial recovery 427c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru of the data is desired. 428c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 429c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 430c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 431c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateEnd (z_streamp strm); 432c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 433c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru All dynamically allocated data structures for this stream are freed. 434c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This function discards any unprocessed input and does not flush any 435c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru pending output. 436c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 437c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state 438c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru was inconsistent. In the error case, msg may be set but then points to a 439c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru static string (which must not be deallocated). 440c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 441c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 442c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru /* Advanced functions */ 443c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 444c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 445c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The following functions are needed only in some special applications. 446c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 447c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 448c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 449c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int deflateInit2 (z_streamp strm, 450c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int level, 451c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int method, 452c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int windowBits, 453c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int memLevel, 454c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int strategy); 455c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 456c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This is another version of deflateInit with more compression options. The 457c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru fields next_in, zalloc, zfree and opaque must be initialized before by 458c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the caller. 459c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 460c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The method parameter is the compression method. It must be Z_DEFLATED in 461c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru this version of the library. 462c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 463c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The windowBits parameter is the base two logarithm of the window size 464c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (the size of the history buffer). It should be in the range 8..15 for this 465c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru version of the library. Larger values of this parameter result in better 466c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compression at the expense of memory usage. The default value is 15 if 467c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateInit is used instead. 468c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 469c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The memLevel parameter specifies how much memory should be allocated 470c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru for the internal compression state. memLevel=1 uses minimum memory but 471c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is slow and reduces compression ratio; memLevel=9 uses maximum memory 472c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru for optimal speed. The default value is 8. See zconf.h for total memory 473c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru usage as a function of windowBits and memLevel. 474c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 475c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The strategy parameter is used to tune the compression algorithm. Use the 476c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a 477c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no 478c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru string match). Filtered data consists mostly of small values with a 479c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru somewhat random distribution. In this case, the compression algorithm is 480c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru tuned to compress them better. The effect of Z_FILTERED is to force more 481c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Huffman coding and less string matching; it is somewhat intermediate 482c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects 483c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the compression ratio but not the correctness of the compressed output even 484c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if it is not set appropriately. 485c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 486c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 487c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid 488c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru method). msg is set to null if there is no error message. deflateInit2 does 489c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru not perform any compression: this will be done by deflate(). 490c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 491c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 492c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#if 0 493c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflateSetDictionary (z_streamp strm, 494c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru const Byte *dictionary, 495c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uInt dictLength); 496c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 497c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 498c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Initializes the compression dictionary from the given byte sequence 499c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru without producing any compressed output. This function must be called 500c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru immediately after deflateInit, deflateInit2 or deflateReset, before any 501c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru call of deflate. The compressor and decompressor must use exactly the same 502c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru dictionary (see inflateSetDictionary). 503c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 504c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The dictionary should consist of strings (byte sequences) that are likely 505c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru to be encountered later in the data to be compressed, with the most commonly 506c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru used strings preferably put towards the end of the dictionary. Using a 507c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru dictionary is most useful when the data to be compressed is short and can be 508c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru predicted with good accuracy; the data can then be compressed better than 509c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru with the default empty dictionary. 510c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 511c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Depending on the size of the compression data structures selected by 512c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateInit or deflateInit2, a part of the dictionary may in effect be 513c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru discarded, for example if the dictionary is larger than the window size in 514c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflate or deflate2. Thus the strings most likely to be useful should be 515c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru put at the end of the dictionary, not at the front. 516c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 517c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Upon return of this function, strm->adler is set to the Adler32 value 518c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru of the dictionary; the decompressor may later use this value to determine 519c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru which dictionary has been used by the compressor. (The Adler32 value 520c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru applies to the whole dictionary even if only a subset of the dictionary is 521c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru actually used by the compressor.) 522c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 523c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a 524c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru parameter is invalid (such as NULL dictionary) or the stream state is 525c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inconsistent (for example if deflate has already been called for this stream 526c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru or if the compression method is bsort). deflateSetDictionary does not 527c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru perform any compression: this will be done by deflate(). 528c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 529c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 530c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#if 0 531c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflateCopy (z_streamp dest, z_streamp source); 532c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 533c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 534c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 535c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Sets the destination stream as a complete copy of the source stream. 536c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 537c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This function can be useful when several compression strategies will be 538c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru tried, for example when there are several ways of pre-processing the input 539c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru data with a filter. The streams that will be discarded should then be freed 540c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru by calling deflateEnd. Note that deflateCopy duplicates the internal 541c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru compression state which can be quite large, so this strategy is slow and 542c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru can consume lots of memory. 543c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 544c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not 545c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru enough memory, Z_STREAM_ERROR if the source stream state was inconsistent 546c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru (such as zalloc being NULL). msg is left unchanged in both source and 547c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru destination. 548c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 549c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 550c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflateReset (z_streamp strm); 551c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 552c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This function is equivalent to deflateEnd followed by deflateInit, 553c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru but does not free and reallocate all the internal compression state. 554c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The stream will keep the same compression level and any other attributes 555c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru that may have been set by deflateInit2. 556c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 557c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 558c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream state was inconsistent (such as zalloc or state being NULL). 559c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 560c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 561c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic inline unsigned long deflateBound(unsigned long s) 562c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{ 563c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru return s + ((s + 7) >> 3) + ((s + 63) >> 6) + 11; 564c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} 565c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 566c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#if 0 567c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflateParams (z_streamp strm, int level, int strategy); 568c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 569c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 570c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Dynamically update the compression level and compression strategy. The 571c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru interpretation of level and strategy is as in deflateInit2. This can be 572c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru used to switch between compression and straight copy of the input data, or 573c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru to switch to a different kind of input data requiring a different 574c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru strategy. If the compression level is changed, the input available so far 575c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is compressed with the old level (and may be flushed); the new level will 576c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru take effect only at the next call of deflate(). 577c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 578c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Before the call of deflateParams, the stream state must be set as for 579c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru a call of deflate(), since the currently available input may have to 580c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru be compressed and flushed. In particular, strm->avail_out must be non-zero. 581c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 582c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source 583c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR 584c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if strm->avail_out was zero. 585c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 586c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 587c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 588c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int inflateInit2 (z_streamp strm, int windowBits); 589c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 590c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This is another version of inflateInit with an extra parameter. The 591c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru fields next_in, avail_in, zalloc, zfree and opaque must be initialized 592c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru before by the caller. 593c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 594c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The windowBits parameter is the base two logarithm of the maximum window 595c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru size (the size of the history buffer). It should be in the range 8..15 for 596c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru this version of the library. The default value is 15 if inflateInit is used 597c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru instead. windowBits must be greater than or equal to the windowBits value 598c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru provided to deflateInit2() while compressing, or it must be equal to 15 if 599c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateInit2() was not used. If a compressed stream with a larger window 600c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru size is given as input, inflate() will return with the error code 601c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Z_DATA_ERROR instead of trying to allocate a larger window. 602c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 603c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru windowBits can also be -8..-15 for raw inflate. In this case, -windowBits 604c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru determines the window size. inflate() will then process raw deflate data, 605c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru not looking for a zlib or gzip header, not generating a check value, and not 606c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru looking for any check values for comparison at the end of the stream. This 607c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is for use with other formats that use the deflate compressed data format 608c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru such as zip. Those formats provide their own check values. If a custom 609c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru format is developed using the raw deflate format for compressed data, it is 610c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru recommended that a check value such as an adler32 or a crc32 be applied to 611c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru the uncompressed data as is done in the zlib, gzip, and zip formats. For 612c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru most applications, the zlib format should be used as is. Note that comments 613c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru above on the use in deflateInit2() applies to the magnitude of windowBits. 614c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 615c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru windowBits can also be greater than 15 for optional gzip decoding. Add 616c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 32 to windowBits to enable zlib and gzip decoding with automatic header 617c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru detection, or add 16 to decode only the gzip format (the zlib format will 618c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is 619c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru a crc32 instead of an adler32. 620c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 621c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough 622c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg 623c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru is set to null if there is no error message. inflateInit2 does not perform 624c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru any decompression apart from reading the zlib header if present: this will 625c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru be done by inflate(). (So next_in and avail_in may be modified, but next_out 626c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru and avail_out are unchanged.) 627c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 628c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 629c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateSetDictionary (z_streamp strm, 630c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru const Byte *dictionary, 631c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru uInt dictLength); 632c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 633c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Initializes the decompression dictionary from the given uncompressed byte 634c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru sequence. This function must be called immediately after a call of inflate, 635c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if that call returned Z_NEED_DICT. The dictionary chosen by the compressor 636c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru can be determined from the adler32 value returned by that call of inflate. 637c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The compressor and decompressor must use exactly the same dictionary (see 638c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru deflateSetDictionary). For raw inflate, this function can be called 639c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru immediately after inflateInit2() or inflateReset() and before any call of 640c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate() to set the dictionary. The application must insure that the 641c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru dictionary that was used for compression is provided. 642c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 643c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a 644c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru parameter is invalid (such as NULL dictionary) or the stream state is 645c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the 646c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru expected one (incorrect adler32 value). inflateSetDictionary does not 647c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru perform any decompression: this will be done by subsequent calls of 648c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflate(). 649c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 650c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 651c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#if 0 652c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateSync (z_streamp strm); 653c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 654c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 655c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Skips invalid compressed data until a full flush point (see above the 656c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru description of deflate with Z_FULL_FLUSH) can be found, or until all 657c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru available input is skipped. No output is provided. 658c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 659c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR 660c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru if no more input was provided, Z_DATA_ERROR if no flush point has been found, 661c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru or Z_STREAM_ERROR if the stream structure was inconsistent. In the success 662c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru case, the application may save the current current value of total_in which 663c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru indicates where valid compressed data was found. In the error case, the 664c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru application may repeatedly call inflateSync, providing more input each time, 665c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru until success or end of the input data. 666c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 667c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 668c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateReset (z_streamp strm); 669c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 670c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This function is equivalent to inflateEnd followed by inflateInit, 671c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru but does not free and reallocate all the internal decompression state. 672c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru The stream will keep attributes that may have been set by inflateInit2. 673c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 674c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source 675c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru stream state was inconsistent (such as zalloc or state being NULL). 676c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 677c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 678c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateIncomp (z_stream *strm); 679c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* 680c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru This function adds the data at next_in (avail_in bytes) to the output 681c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru history without performing any output. There must be no pending output, 682c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru and the decompressor must be expecting to see the start of a block. 683c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru Calling this function is equivalent to decompressing a stored block 684c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru containing the data at next_in (except that the data is not output). 685c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru*/ 686c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 687c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define zlib_deflateInit(strm, level) \ 688c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru zlib_deflateInit2((strm), (level), Z_DEFLATED, MAX_WBITS, \ 689c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY) 690c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define zlib_inflateInit(strm) \ 691c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru zlib_inflateInit2((strm), DEF_WBITS) 692c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 693c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_deflateInit2(z_streamp strm, int level, int method, 694c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int windowBits, int memLevel, 695c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru int strategy); 696c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int zlib_inflateInit2(z_streamp strm, int windowBits); 697c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 698c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) 699c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru struct internal_state {int dummy;}; /* hack for buggy compilers */ 700c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif 701c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 702c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif /* _ZLIB_H */ 703