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* This file is derived from zlib.h and zconf.h from the zlib-0.95
* 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 0.95, Aug 16th, 1995.
Copyright (C) 1995 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
#ifndef _ZLIB_H
#define _ZLIB_H
/* #include "zconf.h" */ /* included directly here */
/* zconf.h -- configuration of the zlib compression library
* Copyright (C) 1995 Jean-loup Gailly.
* For conditions of distribution and use, see copyright notice in zlib.h
/* From: zconf.h,v 1.12 1995/05/03 17:27:12 jloup Exp */
The library does not install any signal handler. It is recommended to
add at least a handler for SIGSEGV when decompressing; the library checks
the consistency of the input data whenever possible but may go nuts
for some forms of corrupted input.
* Compile with -DMAXSEG_64K if the alloc function cannot allocate more
* than 64k bytes at a time (needed on systems with 16-bit int).
* Compile with -DUNALIGNED_OK if it is OK to access shorts or ints
* at addresses which are not a multiple of their size.
* Under DOS, -DFAR=far or -DFAR=__far may be needed.
#ifndef STDC
# if defined(MSDOS) || defined(__STDC__) || defined(__cplusplus)
# define STDC
# endif
#ifdef __MWERKS__ /* Metrowerks CodeWarrior declares fileno() in unix.h */
# include <unix.h>
/* Maximum value for memLevel in deflateInit2 */
# ifdef MAXSEG_64K
# define MAX_MEM_LEVEL 8
# else
# define MAX_MEM_LEVEL 9
# endif
#ifndef FAR
# define FAR
/* Maximum value for windowBits in deflateInit2 and inflateInit2 */
#ifndef MAX_WBITS
# define MAX_WBITS 15 /* 32K LZ77 window */
/* 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
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
typedef unsigned char Byte; /* 8 bits */
typedef unsigned int uInt; /* 16 bits or more */
typedef unsigned long uLong; /* 32 bits or more */
typedef Byte FAR Bytef;
typedef char FAR charf;
typedef int FAR intf;
typedef uInt FAR uIntf;
typedef uLong FAR uLongf;
#ifdef STDC
typedef void FAR *voidpf;
typedef void *voidp;
typedef Byte FAR *voidpf;
typedef Byte *voidp;
/* end of original zconf.h */
#define ZLIB_VERSION "0.95P"
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 may be added later and will have the same
stream interface.
For compression the application must provide the output buffer and
may optionally provide the input buffer for optimization. For decompression,
the application must provide the input buffer and may optionally provide
the output buffer for optimization.
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.
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
typedef void (*free_func) OF((voidpf opaque, voidpf address, uInt nbytes));
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 */
voidp opaque; /* private data object passed to zalloc and zfree */
Byte data_type; /* best guess about the data type: ascii or binary */
cb_func outcb; /* called regularly just before blocks of output */
} z_stream;
The application must update next_in and avail_in when avail_in has
dropped to zero. It must update next_out and avail_out when avail_out
has dropped to zero. The application must initialize zalloc, zfree and
opaque before calling the init function. All other fields are set by the
compression library and must not be updated by the application.
The opaque value provided by the application will be passed as the first
parameter for calls of zalloc and zfree. This can be useful for custom
memory management. The compression library attaches no meaning to the
opaque value.
zalloc must return Z_NULL if there is not enough memory for the object.
On 16-bit systems, the functions zalloc and zfree must be able to allocate
exactly 65536 bytes, but will not be required to allocate more than this
if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
pointers returned by zalloc for objects of exactly 65536 bytes *must*
have their offset normalized to zero. The default allocation function
provided by this library ensures this (see zutil.c). To reduce memory
requirements and avoid any allocation of 64K objects, at the expense of
compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
The fields total_in and total_out can be used for statistics or
progress reports. After compression, total_in holds the total size of
the uncompressed data and may be saved for use in the decompressor
(particularly if the decompressor wants to decompress everything in
a single step).
/* constants */
#define Z_NO_FLUSH 0
#define Z_FULL_FLUSH 2
#define Z_SYNC_FLUSH 3 /* experimental: partial_flush + byte align */
#define Z_FINISH 4
#define Z_PACKET_FLUSH 5
/* See deflate() below for the usage of these constants */
#define Z_OK 0
#define Z_STREAM_END 1
#define Z_ERRNO (-1)
#define Z_STREAM_ERROR (-2)
#define Z_DATA_ERROR (-3)
#define Z_MEM_ERROR (-4)
#define Z_BUF_ERROR (-5)
/* error codes for the compression/decompression functions */
#define Z_BEST_SPEED 1
/* compression levels */
#define Z_FILTERED 1
#define Z_HUFFMAN_ONLY 2
#define Z_BINARY 0
#define Z_ASCII 1
#define Z_UNKNOWN 2
/* Used to set the data_type field */
#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
extern char *zlib_version;
/* The application can compare zlib_version 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.
/* basic functions */
extern int inflateInit OF((z_stream *strm));
Initializes the internal stream state for decompression. The fields
zalloc and zfree must be initialized before by the caller. If zalloc and
zfree are set to Z_NULL, inflateInit updates them to use default allocation
inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory. msg is set to null if there is no error message.
inflateInit does not perform any decompression: this will be done by
extern int inflate OF((z_stream *strm, int flush));
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() always provides as much output as possible
(until there is no more input data or no more space in the output buffer).
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 the parameter flush is set to Z_PARTIAL_FLUSH or Z_PACKET_FLUSH,
inflate flushes as much output as possible to the output buffer. The
flushing behavior of inflate is not specified for values of the flush
parameter other than Z_PARTIAL_FLUSH, Z_PACKET_FLUSH or Z_FINISH, but the
current implementation actually flushes as much output as possible
anyway. For Z_PACKET_FLUSH, inflate checks that once all the input data
has been consumed, it is expecting to see the length field of a stored
block; if not, it returns Z_DATA_ERROR.
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 routine
may be used for the single inflate() call.
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_DATA_ERROR if the input data was corrupted, 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. In the Z_DATA_ERROR case, the application may then
call inflateSync to look for a good compression block. */
extern int inflateEnd OF((z_stream *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 */
extern int inflateInit2 OF((z_stream *strm,
int windowBits));
This is another version of inflateInit with more compression options. The
fields next_out, zalloc and zfree must be initialized before by the caller.
The windowBits parameter is the base two logarithm of the maximum window
size (the size of the history buffer). It should be in the range 8..15 for
this version of the library (the value 16 will be allowed soon). The
default value is 15 if inflateInit is used instead. If a compressed stream
with a larger window size is given as input, inflate() will return with
the error code Z_DATA_ERROR instead of trying to allocate a larger window.
If next_out is not null, the library will use this buffer for the history
buffer; the buffer must either be large enough to hold the entire output
data, or have at least 1<<windowBits bytes. If next_out is null, the
library will allocate its own buffer (and leave next_out null). next_in
need not be provided here but must be provided by the application for the
next call of inflate().
If the history buffer is provided by the application, next_out must
never be changed by the application since the decompressor maintains
history information inside this buffer from call to call; the application
can only reset next_out to the beginning of the history buffer when
avail_out is zero and all output has been consumed.
inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was
not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as
windowBits < 8). msg is set to null if there is no error message.
inflateInit2 does not perform any decompression: this will be done by
extern int inflateSync OF((z_stream *strm));
Skips invalid compressed data until the special marker (see deflate()
above) can be found, or until all available input is skipped. No output
is provided.
inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR
if no more input was provided, Z_DATA_ERROR if no marker has been found,
or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
case, the application may save the current current value of total_in which
indicates where valid compressed data was found. In the error case, the
application may repeatedly call inflateSync, providing more input each time,
until success or end of the input data.
extern int inflateReset OF((z_stream *strm));
This function is equivalent to inflateEnd followed by inflateInit,
but does not free and reallocate all the internal decompression state.
The stream will keep attributes that may have been set by inflateInit2.
inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent (such as zalloc or state being NULL).
extern int inflateIncomp OF((z_stream *strm));
This function adds the data at next_in (avail_in bytes) to the output
history without performing any output. There must be no pending output,
and the decompressor must be expecting to see the start of a block.
Calling this function is equivalent to decompressing a stored block
containing the data at next_in (except that the data is not output).
/* checksum functions */
This function is not related to compression but is exported
anyway because it might be useful in applications using the
compression library.
extern uLong adler32 OF((uLong adler, 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();
#ifndef _Z_UTIL_H
struct internal_state {int dummy;}; /* hack for buggy compilers */
#endif /* _ZLIB_H */