blob: e23ceb50ca038c835ce7f02c213c304b0c266a90 [file] [log] [blame]
/*
* This file is derived from zlib.h and zconf.h from the zlib-1.2.3
* distribution by Jean-loup Gailly and Mark Adler, with some additions
* by Paul Mackerras to aid in implementing Deflate compression and
* decompression for PPP packets.
*/
/*
* ==FILEVERSION 960122==
*
* This marker is used by the Linux installation script to determine
* whether an up-to-date version of this file is already installed.
*/
/* zlib.h -- interface of the 'zlib' general purpose compression library
version 1.2.3, July 18th, 2005
Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
(zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
*/
#ifndef ZLIB_H
#define ZLIB_H
#ifdef __cplusplus
extern "C" {
#endif
#define ZLIB_VERSION "1.2.3"
#define ZLIB_VERNUM 0x1230
/* #include "zconf.h" */ /* included directly here */
/* zconf.h -- configuration of the zlib compression library
* Copyright (C) 1995-2005 Jean-loup Gailly.
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/* Begin of new zconf.h */
/*
* If you *really* need a unique prefix for all types and library functions,
* compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
*/
#ifdef Z_PREFIX
# define deflateInit_ z_deflateInit_
# define deflate z_deflate
# define deflateEnd z_deflateEnd
# define inflateInit_ z_inflateInit_
# define inflate z_inflate
# define inflateEnd z_inflateEnd
# define deflateInit2_ z_deflateInit2_
# define deflateSetDictionary z_deflateSetDictionary
# define deflateCopy z_deflateCopy
# define deflateReset z_deflateReset
# define deflateParams z_deflateParams
# define deflateBound z_deflateBound
# define deflatePrime z_deflatePrime
# define inflateInit2_ z_inflateInit2_
# define inflateSetDictionary z_inflateSetDictionary
# define inflateSync z_inflateSync
# define inflateSyncPoint z_inflateSyncPoint
# define inflateCopy z_inflateCopy
# define inflateReset z_inflateReset
# define inflateBack z_inflateBack
# define inflateBackEnd z_inflateBackEnd
# define compress z_compress
# define compress2 z_compress2
# define compressBound z_compressBound
# define uncompress z_uncompress
# define adler32 z_adler32
# define crc32 z_crc32
# define get_crc_table z_get_crc_table
# define zError z_zError
# define alloc_func z_alloc_func
# define free_func z_free_func
# define in_func z_in_func
# define out_func z_out_func
# define Byte z_Byte
# define uInt z_uInt
# define uLong z_uLong
# define Bytef z_Bytef
# define charf z_charf
# define intf z_intf
# define uIntf z_uIntf
# define uLongf z_uLongf
# define voidpf z_voidpf
# define voidp z_voidp
#endif
#if defined(__MSDOS__) && !defined(MSDOS)
# define MSDOS
#endif
#if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
# define OS2
#endif
#if defined(_WINDOWS) && !defined(WINDOWS)
# define WINDOWS
#endif
#if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
# ifndef WIN32
# define WIN32
# endif
#endif
#if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
# if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
# ifndef SYS16BIT
# define SYS16BIT
# endif
# endif
#endif
/*
* Compile with -DMAXSEG_64K if the alloc function cannot allocate more
* than 64k bytes at a time (needed on systems with 16-bit int).
*/
#ifdef SYS16BIT
# define MAXSEG_64K
#endif
#ifdef MSDOS
# define UNALIGNED_OK
#endif
#ifdef __STDC_VERSION__
# ifndef STDC
# define STDC
# endif
# if __STDC_VERSION__ >= 199901L
# ifndef STDC99
# define STDC99
# endif
# endif
#endif
#if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
# define STDC
#endif
#if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
# define STDC
#endif
#if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
# define STDC
#endif
#if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
# define STDC
#endif
#if defined(__OS400__) && !defined(STDC) /* iSeries (formerly AS/400). */
# define STDC
#endif
#ifndef STDC
# ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
# define const /* note: need a more gentle solution here */
# endif
#endif
/* Some Mac compilers merge all .h files incorrectly: */
#if defined(__MWERKS__)||defined(applec)||defined(THINK_C)||defined(__SC__)
# define NO_DUMMY_DECL
#endif
/* Maximum value for memLevel in deflateInit2 */
#ifndef MAX_MEM_LEVEL
# ifdef MAXSEG_64K
# define MAX_MEM_LEVEL 8
# else
# define MAX_MEM_LEVEL 9
# endif
#endif
/* Maximum value for windowBits in deflateInit2 and inflateInit2.
* WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
* created by gzip. (Files created by minigzip can still be extracted by
* gzip.)
*/
#ifndef MAX_WBITS
# define MAX_WBITS 15 /* 32K LZ77 window */
#endif
/* The memory requirements for deflate are (in bytes):
(1 << (windowBits+2)) + (1 << (memLevel+9))
that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values)
plus a few kilobytes for small objects. For example, if you want to reduce
the default memory requirements from 256K to 128K, compile with
make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
Of course this will generally degrade compression (there's no free lunch).
The memory requirements for inflate are (in bytes) 1 << windowBits
that is, 32K for windowBits=15 (default value) plus a few kilobytes
for small objects.
*/
/* Type declarations */
#ifndef OF /* function prototypes */
# ifdef STDC
# define OF(args) args
# else
# define OF(args) ()
# endif
#endif
/* The following definitions for FAR are needed only for MSDOS mixed
* model programming (small or medium model with some far allocations).
* This was tested only with MSC; for other MSDOS compilers you may have
* to define NO_MEMCPY in zutil.h. If you don't need the mixed model,
* just define FAR to be empty.
*/
#ifdef SYS16BIT
# if defined(M_I86SM) || defined(M_I86MM)
/* MSC small or medium model */
# define SMALL_MEDIUM
# ifdef _MSC_VER
# define FAR _far
# else
# define FAR far
# endif
# endif
# if (defined(__SMALL__) || defined(__MEDIUM__))
/* Turbo C small or medium model */
# define SMALL_MEDIUM
# ifdef __BORLANDC__
# define FAR _far
# else
# define FAR far
# endif
# endif
#endif
#if defined(WINDOWS) || defined(WIN32)
/* If building or using zlib as a DLL, define ZLIB_DLL.
* This is not mandatory, but it offers a little performance increase.
*/
# ifdef ZLIB_DLL
# if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
# ifdef ZLIB_INTERNAL
# define ZEXTERN extern __declspec(dllexport)
# else
# define ZEXTERN extern __declspec(dllimport)
# endif
# endif
# endif /* ZLIB_DLL */
/* If building or using zlib with the WINAPI/WINAPIV calling convention,
* define ZLIB_WINAPI.
* Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
*/
# ifdef ZLIB_WINAPI
# ifdef FAR
# undef FAR
# endif
# include <windows.h>
/* No need for _export, use ZLIB.DEF instead. */
/* For complete Windows compatibility, use WINAPI, not __stdcall. */
# define ZEXPORT WINAPI
# ifdef WIN32
# define ZEXPORTVA WINAPIV
# else
# define ZEXPORTVA FAR CDECL
# endif
# endif
#endif
#if defined (__BEOS__)
# ifdef ZLIB_DLL
# ifdef ZLIB_INTERNAL
# define ZEXPORT __declspec(dllexport)
# define ZEXPORTVA __declspec(dllexport)
# else
# define ZEXPORT __declspec(dllimport)
# define ZEXPORTVA __declspec(dllimport)
# endif
# endif
#endif
#ifndef ZEXTERN
# define ZEXTERN extern
#endif
#ifndef ZEXPORT
# define ZEXPORT
#endif
#ifndef ZEXPORTVA
# define ZEXPORTVA
#endif
#ifndef FAR
# define FAR
#endif
#if !defined(__MACTYPES__)
typedef unsigned char Byte; /* 8 bits */
#endif
typedef unsigned int uInt; /* 16 bits or more */
typedef unsigned long uLong; /* 32 bits or more */
#ifdef SMALL_MEDIUM
/* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
# define Bytef Byte FAR
#else
typedef Byte FAR Bytef;
#endif
typedef char FAR charf;
typedef int FAR intf;
typedef uInt FAR uIntf;
typedef uLong FAR uLongf;
#ifdef STDC
typedef void const *voidpc;
typedef void FAR *voidpf;
typedef void *voidp;
#else
typedef Byte const *voidpc;
typedef Byte FAR *voidpf;
typedef Byte *voidp;
#endif
# ifdef VMS
# include <unixio.h> /* for off_t */
# endif
# define z_off_t off_t
#ifndef SEEK_SET
# define SEEK_SET 0 /* Seek from beginning of file. */
# define SEEK_CUR 1 /* Seek from current position. */
# define SEEK_END 2 /* Set file pointer to EOF plus "offset" */
#endif
#ifndef z_off_t
# define z_off_t long
#endif
#if defined(__OS400__)
# define NO_vsnprintf
#endif
#if defined(__MVS__)
# define NO_vsnprintf
# ifdef FAR
# undef FAR
# endif
#endif
/* MVS linker does not support external names larger than 8 bytes */
#if defined(__MVS__)
# pragma map(deflateInit_,"DEIN")
# pragma map(deflateInit2_,"DEIN2")
# pragma map(deflateEnd,"DEEND")
# pragma map(deflateBound,"DEBND")
# pragma map(inflateInit_,"ININ")
# pragma map(inflateInit2_,"ININ2")
# pragma map(inflateEnd,"INEND")
# pragma map(inflateSync,"INSY")
# pragma map(inflateSetDictionary,"INSEDI")
# pragma map(compressBound,"CMBND")
# pragma map(inflate_table,"INTABL")
# pragma map(inflate_fast,"INFA")
# pragma map(inflate_copyright,"INCOPY")
#endif
/* End of new zconf.h */
/*
The 'zlib' compression library provides in-memory compression and
decompression functions, including integrity checks of the uncompressed
data. This version of the library supports only one compression method
(deflation) but other algorithms will be added later and will have the same
stream interface.
Compression can be done in a single step if the buffers are large
enough (for example if an input file is mmap'ed), or can be done by
repeated calls of the compression function. In the latter case, the
application must provide more input and/or consume the output
(providing more output space) before each call.
The compressed data format used by default by the in-memory functions is
the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
around a deflate stream, which is itself documented in RFC 1951.
The library also supports reading and writing files in gzip (.gz) format
with an interface similar to that of stdio using the functions that start
with "gz". The gzip format is different from the zlib format. gzip is a
gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
This library can optionally read and write gzip streams in memory as well.
The zlib format was designed to be compact and fast for use in memory
and on communications channels. The gzip format was designed for single-
file compression on file systems, has a larger header than zlib to maintain
directory information, and uses a different, slower check method than zlib.
The library does not install any signal handler. The decoder checks
the consistency of the compressed data, so the library should never
crash even in case of corrupted input.
*/
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
typedef void (*free_func) OF((voidpf opaque, voidpf address, uInt size));
typedef void (*cb_func) OF((Bytef *buf, uInt len));
struct internal_state;
typedef struct z_stream_s {
Bytef *next_in; /* next input byte */
uInt avail_in; /* number of bytes available at next_in */
uLong total_in; /* total nb of input bytes read so far */
Bytef *next_out; /* next output byte should be put there */
uInt avail_out; /* remaining free space at next_out */
uLong total_out; /* total nb of bytes output so far */
char *msg; /* last error message, NULL if no error */
struct internal_state FAR *state; /* not visible by applications */
alloc_func zalloc; /* used to allocate the internal state */
free_func zfree; /* used to free the internal state */
voidpf opaque; /* private data object passed to zalloc and zfree */
int data_type; /* best guess about the data type:
binary or text */
cb_func outcb; /* called regularly just before blocks of output */
uLong adler; /* adler32 value of the uncompressed data */
uLong reserved; /* reserved for future use */
} z_stream;
typedef z_stream FAR *z_streamp;
/*
gzip header information passed to and from zlib routines. See RFC 1952
for more details on the meanings of these fields.
*/
typedef struct gz_header_s {
int text; /* true if compressed data believed to be text */
uLong time; /* modification time */
int xflags; /* extra flags (not used when writing a gzip file) */
int os; /* operating system */
Bytef *extra; /* pointer to extra field or Z_NULL if none */
uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
uInt extra_max; /* space at extra (only when reading header) */
Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
uInt name_max; /* space at name (only when reading header) */
Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
uInt comm_max; /* space at comment (only when reading header) */
int hcrc; /* true if there was or will be a header crc */
int done; /* true when done reading gzip header (not used
when writing a gzip file) */
} gz_header;
typedef gz_header FAR *gz_headerp;
/* constants */
#define Z_NO_FLUSH 0
#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
#define Z_SYNC_FLUSH 2
#define Z_FULL_FLUSH 3
#define Z_FINISH 4
#define Z_BLOCK 5
/* Allowed flush values; see deflate() and inflate() below for details */
#define Z_OK 0
#define Z_STREAM_END 1
#define Z_NEED_DICT 2
#define Z_ERRNO (-1)
#define Z_STREAM_ERROR (-2)
#define Z_DATA_ERROR (-3)
#define Z_MEM_ERROR (-4)
#define Z_BUF_ERROR (-5)
#define Z_VERSION_ERROR (-6)
/* Return codes for the compression/decompression functions. Negative
* values are errors, positive values are used for special but normal events.
*/
#define Z_NO_COMPRESSION 0
#define Z_BEST_SPEED 1
#define Z_BEST_COMPRESSION 9
#define Z_DEFAULT_COMPRESSION (-1)
/* compression levels */
#define Z_FILTERED 1
#define Z_HUFFMAN_ONLY 2
#define Z_RLE 3
#define Z_FIXED 4
#define Z_DEFAULT_STRATEGY 0
/* compression strategy; see deflateInit2() below for details */
#define Z_BINARY 0
#define Z_TEXT 1
#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
#define Z_UNKNOWN 2
/* Possible values of the data_type field (though see inflate()) */
#define Z_DEFLATED 8
/* The deflate compression method (the only one supported in this version) */
#define Z_NULL (void *)0 /* for initializing zalloc, zfree, opaque */
/* basic functions */
/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
If the first character differs, the library code actually used is
not compatible with the zlib.h header file used by the application.
This check is automatically made by deflateInit and inflateInit.
*/
ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
const char *version, int stream_size));
ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
int windowBits, int memLevel,
int strategy, const char *version,
int stream_size));
ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
const Bytef *dictionary,
uInt dictLength));
ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
gz_headerp head));
ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
int bits,
int value));
ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
int level,
int strategy));
ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
int good_length,
int max_lazy,
int nice_length,
int max_chain));
ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
uLong sourceLen));
ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
z_streamp source));
ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
const char *version, int stream_size));
ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
/*
inflate decompresses as much data as possible, and stops when the input
buffer becomes empty or the output buffer becomes full. It may introduce
some output latency (reading input without producing any output) except when
forced to flush.
The detailed semantics are as follows. inflate performs one or both of the
following actions:
- Decompress more input starting at next_in and update next_in and avail_in
accordingly. If not all input can be processed (because there is not
enough room in the output buffer), next_in is updated and processing
will resume at this point for the next call of inflate().
- Provide more output starting at next_out and update next_out and avail_out
accordingly. inflate() provides as much output as possible, until there
is no more input data or no more space in the output buffer (see below
about the flush parameter).
Before the call of inflate(), the application should ensure that at least
one of the actions is possible, by providing more input and/or consuming
more output, and updating the next_* and avail_* values accordingly.
The application can consume the uncompressed output when it wants, for
example when the output buffer is full (avail_out == 0), or after each
call of inflate(). If inflate returns Z_OK and with zero avail_out, it
must be called again after making room in the output buffer because there
might be more output pending.
The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
output as possible to the output buffer. Z_BLOCK requests that inflate() stop
if and when it gets to the next deflate block boundary. When decoding the
zlib or gzip format, this will cause inflate() to return immediately after
the header and before the first block. When doing a raw inflate, inflate()
will go ahead and process the first block, and will return when it gets to
the end of that block, or when it runs out of data.
The Z_BLOCK option assists in appending to or combining deflate streams.
Also to assist in this, on return inflate() will set strm->data_type to the
number of unused bits in the last byte taken from strm->next_in, plus 64
if inflate() is currently decoding the last block in the deflate stream,
plus 128 if inflate() returned immediately after decoding an end-of-block
code or decoding the complete header up to just before the first byte of the
deflate stream. The end-of-block will not be indicated until all of the
uncompressed data from that block has been written to strm->next_out. The
number of unused bits may in general be greater than seven, except when
bit 7 of data_type is set, in which case the number of unused bits will be
less than eight.
inflate() should normally be called until it returns Z_STREAM_END or an
error. However if all decompression is to be performed in a single step
(a single call of inflate), the parameter flush should be set to
Z_FINISH. In this case all pending input is processed and all pending
output is flushed; avail_out must be large enough to hold all the
uncompressed data. (The size of the uncompressed data may have been saved
by the compressor for this purpose.) The next operation on this stream must
be inflateEnd to deallocate the decompression state. The use of Z_FINISH
is never required, but can be used to inform inflate that a faster approach
may be used for the single inflate() call.
In this implementation, inflate() always flushes as much output as
possible to the output buffer, and always uses the faster approach on the
first call. So the only effect of the flush parameter in this implementation
is on the return value of inflate(), as noted below, or when it returns early
because Z_BLOCK is used.
If a preset dictionary is needed after this call (see inflateSetDictionary
below), inflate sets strm->adler to the adler32 checksum of the dictionary
chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
strm->adler to the adler32 checksum of all output produced so far (that is,
total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
below. At the end of the stream, inflate() checks that its computed adler32
checksum is equal to that saved by the compressor and returns Z_STREAM_END
only if the checksum is correct.
inflate() will decompress and check either zlib-wrapped or gzip-wrapped
deflate data. The header type is detected automatically. Any information
contained in the gzip header is not retained, so applications that need that
information should instead use raw inflate, see inflateInit2() below, or
inflateBack() and perform their own processing of the gzip header and
trailer.
inflate() returns Z_OK if some progress has been made (more input processed
or more output produced), Z_STREAM_END if the end of the compressed data has
been reached and all uncompressed output has been produced, Z_NEED_DICT if a
preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
corrupted (input stream not conforming to the zlib format or incorrect check
value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
Z_BUF_ERROR if no progress is possible or if there was not enough room in the
output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
inflate() can be called again with more input and more output space to
continue decompressing. If Z_DATA_ERROR is returned, the application may then
call inflateSync() to look for a good compression block if a partial recovery
of the data is desired.
*/
ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
/*
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
pending output.
inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
was inconsistent. In the error case, msg may be set but then points to a
static string (which must not be deallocated).
*/
/* Advanced functions */
ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
/* utility functions */
/*
The following utility functions are implemented on top of the
basic stream-oriented functions. To simplify the interface, some
default options are assumed (compression level and memory usage,
standard memory allocation functions). The source code of these
utility functions can easily be modified if you need special options.
*/
ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
/*
Update a running Adler-32 checksum with the bytes buf[0..len-1] and
return the updated checksum. If buf is NULL, this function returns
the required initial value for the checksum.
An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
much faster. Usage example:
uLong adler = adler32(0L, Z_NULL, 0);
while (read_buffer(buffer, length) != EOF) {
adler = adler32(adler, buffer, length);
}
if (adler != original_adler) error();
*/
/*
Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
*/
ZEXTERN uInt ZEXPORT crc32 OF((uInt crc, const Bytef *buf, uInt len));
/*
Update a running CRC-32 with the bytes buf[0..len-1] and return the
updated CRC-32. If buf is NULL, this function returns the required initial
value for the for the crc. Pre- and post-conditioning (one's complement) is
performed within this function so it shouldn't be done by the application.
Usage example:
uLong crc = crc32(0L, Z_NULL, 0);
while (read_buffer(buffer, length) != EOF) {
crc = crc32(crc, buffer, length);
}
if (crc != original_crc) error();
*/
ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
const char *version, int stream_size));
#define inflateInit(strm) \
inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
#define inflateInit2(strm, windowBits) \
inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
struct internal_state {int dummy;}; /* hack for buggy compilers */
#endif
extern void *gzalloc(void *, unsigned, unsigned);
extern void gzfree(void *, void *, unsigned);
#ifdef __cplusplus
}
#endif
#endif /* ZLIB_H */