/* Portions Copyright (c) 2005-2007 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
*/
/**
@file
@publishedAll
@externallyDefinedApi
*/
/* 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
#if (defined(__TOOLS2__) || defined(__TOOLS__))
// A tools build picks up the zconf.h file from the user include path
#include "zconf.h"
#else
// Any other build picks up zconf.h from stdapis system include directory
#include <zconf.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
/** Zlib version */
#define ZLIB_VERSION "1.2.3"
/** Zlib version Number */
#define ZLIB_VERNUM 0x1230
/**
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.
*/
/** Function pointer - used to allocate the internal state */
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
/** Function pointer - used to free the internal state */
typedef void (*free_func) OF((voidpf opaque, voidpf address));
struct internal_state;
/**
Encapsulates a zip stream
*/
typedef struct z_stream_s {
/** Next input byte */
Bytef *next_in;
/** Number of bytes available at next_in */
uInt avail_in;
/** Total nb of input bytes read so far */
uLong total_in;
/** Next output byte should be put there */
Bytef *next_out;
/** Remaining free space at next_out */
uInt avail_out;
/** Total nb of bytes output so far */
uLong total_out;
/** Last error message, NULL if no error */
char *msg;
/** Not visible by applications */
struct internal_state FAR *state;
/** Used to allocate the internal state */
alloc_func zalloc;
/** Used to free the internal state */
free_func zfree;
/** Private data object passed to zalloc and zfree */
voidpf opaque;
/** Best guess about the data type: binary or text */
int data_type;
/** Adler32 value of the uncompressed data */
uLong adler;
/** Reserved for future use */
uLong reserved;
} z_stream;
/** typedef z_stream* as z_streamp. Refer to z_stream_s for more details */
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 {
/** True if compressed data believed to be text */
int text;
/** Modification time */
uLong time;
/** Extra flags (not used when writing a gzip file) */
int xflags;
/** Operating system */
int os;
/** Pointer to extra field or Z_NULL if none */
Bytef *extra;
/** Extra field length (valid if extra != Z_NULL) */
uInt extra_len;
/** Space at extra (only when reading header) */
uInt extra_max;
/** Pointer to zero-terminated file name or Z_NULL */
Bytef *name;
/** Space at name (only when reading header) */
uInt name_max;
/** Pointer to zero-terminated comment or Z_NULL */
Bytef *comment;
/** Space at comment (only when reading header) */
uInt comm_max;
/** True if there was or will be a header crc */
int hcrc;
/** True when done reading gzip header (not used when writing a gzip file) */
int done;
} gz_header;
/** gz_headerp is typedef gz_header* */
typedef gz_header FAR *gz_headerp;
/*
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.
If zlib is used in a multi-threaded application, zalloc and zfree must be
thread safe.
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 */
/** Allowed flush values; see deflate() and inflate() below for details */
#define Z_NO_FLUSH 0
/** Allowed flush values; see deflate() and inflate() below for details. This constant will be removed, use Z_SYNC_FLUSH instead*/
#define Z_PARTIAL_FLUSH 1
/** Allowed flush values; see deflate() and inflate() below for details */
#define Z_SYNC_FLUSH 2
/** Allowed flush values; see deflate() and inflate() below for details */
#define Z_FULL_FLUSH 3
/** Allowed flush values; see deflate() and inflate() below for details */
#define Z_FINISH 4
/** Allowed flush values; see deflate() and inflate() below for details */
#define Z_BLOCK 5
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_OK 0
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_STREAM_END 1
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_NEED_DICT 2
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_ERRNO (-1)
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_STREAM_ERROR (-2)
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_DATA_ERROR (-3)
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_MEM_ERROR (-4)
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_BUF_ERROR (-5)
/** Return codes for the compression/decompression functions. Negative
values are errors, positive values are used for special but normal events. */
#define Z_VERSION_ERROR (-6)
/** Compression level as no compression */
#define Z_NO_COMPRESSION 0
/** Compression level for best speed */
#define Z_BEST_SPEED 1
/** Compression level for best compression */
#define Z_BEST_COMPRESSION 9
/** Compression level for default compression */
#define Z_DEFAULT_COMPRESSION (-1)
/** Compression strategy; see deflateInit2() below for details */
#define Z_FILTERED 1
/** Compression strategy; see deflateInit2() below for details */
#define Z_HUFFMAN_ONLY 2
/** Compression strategy; see deflateInit2() below for details */
#define Z_RLE 3
/** Compression strategy; see deflateInit2() below for details */
#define Z_FIXED 4
/** Compression strategy; see deflateInit2() below for details */
#define Z_DEFAULT_STRATEGY 0
/** Possible values of the data_type field (though see inflate()) */
#define Z_BINARY 0
/** Possible values of the data_type field (though see inflate()) */
#define Z_TEXT 1
/** Possible values of the data_type field (though see inflate()). It is used for compatibility with 1.2.2 and earlier */
#define Z_ASCII Z_TEXT
/** Possible values of the data_type field (though see inflate()) */
#define Z_UNKNOWN 2
/** The deflate compression method (the only one supported in this version) */
#define Z_DEFLATED 8
/** For initializing zalloc, zfree, opaque */
#define Z_NULL 0
/** For compatibility with versions < 1.0.2 */
#define zlib_version zlibVersion()
/* 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.
@return returns zlib version
*/
ZEXTERN const char * ZEXPORT zlibVersion OF((void));
/*
ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
Initializes the internal stream state for compression. The fields
zalloc, zfree and opaque must be initialized before by the caller.
If zalloc and zfree are set to Z_NULL, deflateInit updates them to
use default allocation functions.
The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
1 gives best speed, 9 gives best compression, 0 gives no compression at
all (the input data is simply copied a block at a time).
Z_DEFAULT_COMPRESSION requests a default compromise between speed and
compression (currently equivalent to level 6).
deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory, Z_STREAM_ERROR if level is not a valid compression level,
Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
with the version assumed by the caller (ZLIB_VERSION).
msg is set to null if there is no error message. deflateInit does not
perform any compression: this will be done by deflate().
*/
/**
deflate compresses 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. deflate performs one or both of the
following actions:
- Compress 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 and avail_in are updated and
processing will resume at this point for the next call of deflate().
- Provide more output starting at next_out and update next_out and avail_out
accordingly. This action is forced if the parameter flush is non zero.
Forcing flush frequently degrades the compression ratio, so this parameter
should be set only when necessary (in interactive applications).
Some output may be provided even if flush is not set.
Before the call of deflate(), the application should ensure that at least
one of the actions is possible, by providing more input and/or consuming
more output, and updating avail_in or avail_out accordingly; avail_out
should never be zero before the call. The application can consume the
compressed output when it wants, for example when the output buffer is full
(avail_out == 0), or after each call of deflate(). If deflate 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.
Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
decide how much data to accumualte before producing output, in order to
maximize compression.
If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
flushed to the output buffer and the output is aligned on a byte boundary, so
that the decompressor can get all input data available so far. (In particular
avail_in is zero after the call if enough output space has been provided
before the call.) Flushing may degrade compression for some compression
algorithms and so it should be used only when necessary.
If flush is set to Z_FULL_FLUSH, all output is flushed as with
Z_SYNC_FLUSH, and the compression state is reset so that decompression can
restart from this point if previous compressed data has been damaged or if
random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
compression.
If deflate returns with avail_out == 0, this function must be called again
with the same value of the flush parameter and more output space (updated
avail_out), until the flush is complete (deflate returns with non-zero
avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
avail_out is greater than six to avoid repeated flush markers due to
avail_out == 0 on return.
If the parameter flush is set to Z_FINISH, pending input is processed,
pending output is flushed and deflate returns with Z_STREAM_END if there
was enough output space; if deflate returns with Z_OK, this function must be
called again with Z_FINISH and more output space (updated avail_out) but no
more input data, until it returns with Z_STREAM_END or an error. After
deflate has returned Z_STREAM_END, the only possible operations on the
stream are deflateReset or deflateEnd.
Z_FINISH can be used immediately after deflateInit if all the compression
is to be done in a single step. In this case, avail_out must be at least
the value returned by deflateBound (see below). If deflate does not return
Z_STREAM_END, then it must be called again as described above.
deflate() sets strm->adler to the adler32 checksum of all input read
so far (that is, total_in bytes).
deflate() may update strm->data_type if it can make a good guess about
the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
binary. This field is only for information purposes and does not affect
the compression algorithm in any manner.
deflate() returns Z_OK if some progress has been made (more input
processed or more output produced), Z_STREAM_END if all input has been
consumed and all output has been produced (only when flush is set to
Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
(for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
fatal, and deflate() can be called again with more input and more output
space to continue compressing.
@param strm Stream of data
@param flush Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
decide how much data to accumualte before producing output, in order to
maximize compression. Refer to the description above for more details.
@return deflate returns Z_OK on success. Refer to the description above for more details.
*/
ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
/**
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
pending output.
deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
stream state was inconsistent, Z_DATA_ERROR if the stream was freed
prematurely (some input or output was discarded). In the error case,
msg may be set but then points to a static string (which must not be
deallocated).
@param strm Stream of data
@return deflateEnd returns Z_OK on success. Refer to the description above for more details.
*/
ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
/*
ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
Initializes the internal stream state for decompression. The fields
next_in, avail_in, zalloc, zfree and opaque must be initialized before by
the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
value depends on the compression method), inflateInit determines the
compression method from the zlib header and allocates all data structures
accordingly; otherwise the allocation will be deferred to the first call of
inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
use default allocation functions.
inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
version assumed by the caller. msg is set to null if there is no error
message. inflateInit does not perform any decompression apart from reading
the zlib header if present: this will be done by inflate(). (So next_in and
avail_in may be modified, but next_out and avail_out are unchanged.)
*/
/**
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.
@param strm Stream of data
@param flush This parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
Z_FINISH, or Z_BLOCK. Refer to the description for more details.
@return inflate returns Z_OK on success. Refer to the description above for more details.
*/
ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
/**
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
pending output.
@param strm Stream of data
@return 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).
*/
ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
/* Advanced functions */
/*
The following functions are needed only in some special applications.
*/
/*
ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
int level,
int method,
int windowBits,
int memLevel,
int strategy));
This is another version of deflateInit with more compression options. The
fields next_in, zalloc, zfree and opaque must be initialized before by
the caller.
The method parameter is the compression method. It must be Z_DEFLATED in
this version of the library.
The windowBits parameter is the base two logarithm of the window size
(the size of the history buffer). It should be in the range 8..15 for this
version of the library. Larger values of this parameter result in better
compression at the expense of memory usage. The default value is 15 if
deflateInit is used instead.
Note: In this version of the library a windowBits value of 8 is unsupported
due to a problem with the window size being set to 256 bytes. Although a
value of 8 will be accepted by deflateInit2(), as it is being changed
internally from 8 to 9, it will not be possible to use the same value when it
comes to decompression. This is because inflateInit2() does not make the same
change internally and as a result a Z_DATA_ERROR is returned when calling
inflate(). It is therefore advised that for this version of the library
windowBits of 9 is used in place of 8.
windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
determines the window size. deflate() will then generate raw deflate data
with no zlib header or trailer, and will not compute an adler32 check value.
windowBits can also be greater than 15 for optional gzip encoding. Add
16 to windowBits to write a simple gzip header and trailer around the
compressed data instead of a zlib wrapper. The gzip header will have no
file name, no extra data, no comment, no modification time (set to zero),
no header crc, and the operating system will be set to 3 (UNIX). If a
gzip stream is being written, strm->adler is a crc32 instead of an adler32.
The memLevel parameter specifies how much memory should be allocated
for the internal compression state. memLevel=1 uses minimum memory but
is slow and reduces compression ratio; memLevel=9 uses maximum memory
for optimal speed. The default value is 8. See zconf.h for total memory
usage as a function of windowBits and memLevel.
The strategy parameter is used to tune the compression algorithm. Use the
value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
string match), or Z_RLE to limit match distances to one (run-length
encoding). Filtered data consists mostly of small values with a somewhat
random distribution. In this case, the compression algorithm is tuned to
compress them better. The effect of Z_FILTERED is to force more Huffman
coding and less string matching; it is somewhat intermediate between
Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
parameter only affects the compression ratio but not the correctness of the
compressed output even if it is not set appropriately. Z_FIXED prevents the
use of dynamic Huffman codes, allowing for a simpler decoder for special
applications.
deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
method). msg is set to null if there is no error message. deflateInit2 does
not perform any compression: this will be done by deflate().
*/
/**
Initializes the compression dictionary from the given byte sequence
without producing any compressed output. This function must be called
immediately after deflateInit, deflateInit2 or deflateReset, before any
call of deflate. The compressor and decompressor must use exactly the same
dictionary (see inflateSetDictionary).
The dictionary should consist of strings (byte sequences) that are likely
to be encountered later in the data to be compressed, with the most commonly
used strings preferably put towards the end of the dictionary. Using a
dictionary is most useful when the data to be compressed is short and can be
predicted with good accuracy; the data can then be compressed better than
with the default empty dictionary.
Depending on the size of the compression data structures selected by
deflateInit or deflateInit2, a part of the dictionary may in effect be
discarded, for example if the dictionary is larger than the window size in
deflate or deflate2. Thus the strings most likely to be useful should be
put at the end of the dictionary, not at the front. In addition, the
current implementation of deflate will use at most the window size minus
262 bytes of the provided dictionary.
Upon return of this function, strm->adler is set to the adler32 value
of the dictionary; the decompressor may later use this value to determine
which dictionary has been used by the compressor. (The adler32 value
applies to the whole dictionary even if only a subset of the dictionary is
actually used by the compressor.) If a raw deflate was requested, then the
adler32 value is not computed and strm->adler is not set.
@param strm Stream of data
@param dictionary Pointer to the dictionary. Refer to the description above for more details.
@param dictLength Dictionay Length
@return deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
parameter is invalid (such as NULL dictionary) or the stream state is
inconsistent (for example if deflate has already been called for this stream
or if the compression method is bsort). deflateSetDictionary does not
perform any compression: this will be done by deflate().
*/
ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
const Bytef *dictionary,
uInt dictLength));
/**
Sets the destination stream as a complete copy of the source stream.
This function can be useful when several compression strategies will be
tried, for example when there are several ways of pre-processing the input
data with a filter. The streams that will be discarded should then be freed
by calling deflateEnd. Note that deflateCopy duplicates the internal
compression state which can be quite large, so this strategy is slow and
can consume lots of memory.
@param dest destination stream
@param souce source stream of data
@return deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
(such as zalloc being NULL). msg is left unchanged in both source and
destination.
*/
ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
z_streamp source));
/**
This function is equivalent to deflateEnd followed by deflateInit,
but does not free and reallocate all the internal compression state.
The stream will keep the same compression level and any other attributes
that may have been set by deflateInit2.
@param strm stream of data
@return deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent (such as zalloc or state being NULL).
*/
ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
/**
Dynamically update the compression level and compression strategy. The
interpretation of level and strategy is as in deflateInit2. This can be
used to switch between compression and straight copy of the input data, or
to switch to a different kind of input data requiring a different
strategy. If the compression level is changed, the input available so far
is compressed with the old level (and may be flushed); the new level will
take effect only at the next call of deflate().
Before the call of deflateParams, the stream state must be set as for
a call of deflate(), since the currently available input may have to
be compressed and flushed. In particular, strm->avail_out must be non-zero.
@param strm stream of data
@param level compression level
@param strategy compression algorithm
@return deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
if strm->avail_out was zero.
*/
ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
int level,
int strategy));
/**
Fine tune deflate's internal compression parameters. This should only be
used by someone who understands the algorithm used by zlib's deflate for
searching for the best matching string, and even then only by the most
fanatic optimizer trying to squeeze out the last compressed bit for their
specific input data. Read the deflate.c source code for the meaning of the
max_lazy, good_length, nice_length, and max_chain parameters.
deflateTune() can be called after deflateInit() or deflateInit2()
@param strm stream of data
@param good_length reduce lazy search above this match length
@param max_lazy do not perform lazy search above this match length
@param nice_length quit search above this match length
@param max_chain
@return deflateTune returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
*/
ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
int good_length,
int max_lazy,
int nice_length,
int max_chain));
/**
deflateBound() returns an upper bound on the compressed size after
deflation of sourceLen bytes. It must be called after deflateInit()
or deflateInit2(). This would be used to allocate an output buffer
for deflation in a single pass, and so would be called before deflate().
@param strm stream of data
@param sourceLen source length
@return deflateBound returns an upper bound on the compressed size after
deflation of sourceLen bytes.
*/
ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
uLong sourceLen));
/**
deflatePrime() inserts bits in the deflate output stream. The intent
is that this function is used to start off the deflate output with the
bits leftover from a previous deflate stream when appending to it. As such,
this function can only be used for raw deflate, and must be used before the
first deflate() call after a deflateInit2() or deflateReset(). bits must be
less than or equal to 16, and that many of the least significant bits of
value will be inserted in the output.
@param strm stream of data
@param bits bits must be less than or equal to 16, and that many of the least
significant bits of value will be inserted in the output.
@param value represents value of the bits to be inserted
@return deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent.
*/
ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
int bits,
int value));
/**
deflateSetHeader() provides gzip header information for when a gzip
stream is requested by deflateInit2(). deflateSetHeader() may be called
after deflateInit2() or deflateReset() and before the first call of
deflate(). The text, time, os, extra field, name, and comment information
in the provided gz_header structure are written to the gzip header (xflag is
ignored -- the extra flags are set according to the compression level). The
caller must assure that, if not Z_NULL, name and comment are terminated with
a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
available there. If hcrc is true, a gzip header crc is included. Note that
the current versions of the command-line version of gzip (up through version
1.3.x) do not support header crc's, and will report that it is a "multi-part
gzip file" and give up.
If deflateSetHeader is not used, the default gzip header has text false,
the time set to zero, and os set to 3, with no extra, name, or comment
fields. The gzip header is returned to the default state by deflateReset().
@param strm stream of data
@param head gzip header
@return deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent.
*/
ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
gz_headerp head));
/*
ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
int windowBits));
This is another version of inflateInit with an extra parameter. The
fields next_in, avail_in, zalloc, zfree and opaque 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 default value is 15 if inflateInit is used
instead. windowBits must be greater than or equal to the windowBits value
provided to deflateInit2() while compressing, or it must be equal to 15 if
deflateInit2() was not used. 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.
Note: In this version of the library a windowBits value of 8 is unsupported
due to a problem with the window size being set to 256 bytes. Although a
value of 8 will be accepted by deflateInit2(), as it is being changed
internally from 8 to 9, it will not be possible to use the same value when it
comes to decompression. This is because inflateInit2() does not make the same
change internally and as a result a Z_DATA_ERROR is returned when calling
inflate(). It is therefore advised that for this version of the library
windowBits of 9 is used in place of 8.
windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
determines the window size. inflate() will then process raw deflate data,
not looking for a zlib or gzip header, not generating a check value, and not
looking for any check values for comparison at the end of the stream. This
is for use with other formats that use the deflate compressed data format
such as zip. Those formats provide their own check values. If a custom
format is developed using the raw deflate format for compressed data, it is
recommended that a check value such as an adler32 or a crc32 be applied to
the uncompressed data as is done in the zlib, gzip, and zip formats. For
most applications, the zlib format should be used as is. Note that comments
above on the use in deflateInit2() applies to the magnitude of windowBits.
windowBits can also be greater than 15 for optional gzip decoding. Add
32 to windowBits to enable zlib and gzip decoding with automatic header
detection, or add 16 to decode only the gzip format (the zlib format will
return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is
a crc32 instead of an adler32.
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 a null strm). msg
is set to null if there is no error message. inflateInit2 does not perform
any decompression apart from reading the zlib header if present: this will
be done by inflate(). (So next_in and avail_in may be modified, but next_out
and avail_out are unchanged.)
*/
/**
Initializes the decompression dictionary from the given uncompressed byte
sequence. This function must be called immediately after a call of inflate,
if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
can be determined from the adler32 value returned by that call of inflate.
The compressor and decompressor must use exactly the same dictionary (see
deflateSetDictionary). For raw inflate, this function can be called
immediately after inflateInit2() or inflateReset() and before any call of
inflate() to set the dictionary. The application must insure that the
dictionary that was used for compression is provided.
inflateSetDictionary does not perform any decompression: this will be done
by subsequent calls of inflate().
@param strm stream of data
@param dictionary Pointer to dictionary
@param dictLength Dictionary Length
@return inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
parameter is invalid (such as NULL dictionary) or the stream state is
inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
expected one (incorrect adler32 value).
*/
ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
const Bytef *dictionary,
uInt dictLength));
/**
Skips invalid compressed data until a full flush point (see above the
description of deflate with Z_FULL_FLUSH) can be found, or until all
available input is skipped. No output is provided.
@param strm Stream of data
@return inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
if no more input was provided, Z_DATA_ERROR if no flush point 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.
*/
ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
/**
Sets the destination stream as a complete copy of the source stream.
This function can be useful when randomly accessing a large stream. The
first pass through the stream can periodically record the inflate state,
allowing restarting inflate at those points when randomly accessing the
stream.
@param dest destination stream
@param source source stream of data
@return inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
(such as zalloc being NULL). msg is left unchanged in both source and
destination.
*/
ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
z_streamp source));
/**
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.
@param strm Stream of data
@return inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent (such as zalloc or state being NULL).
*/
ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
/**
This function inserts bits in the inflate input stream. The intent is
that this function is used to start inflating at a bit position in the
middle of a byte. The provided bits will be used before any bytes are used
from next_in. This function should only be used with raw inflate, and
should be used before the first inflate() call after inflateInit2() or
inflateReset(). bits must be less than or equal to 16, and that many of the
least significant bits of value will be inserted in the input.
@param strm stream of data
@param bits bits must be less than or equal to 16, and that many of the
least significant bits of value will be inserted in the input.
@param value @param value represents value of the bits to be inserted
@return inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent.
*/
ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
int bits,
int value));
/**
inflateGetHeader() requests that gzip header information be stored in the
provided gz_header structure. inflateGetHeader() may be called after
inflateInit2() or inflateReset(), and before the first call of inflate().
As inflate() processes the gzip stream, head->done is zero until the header
is completed, at which time head->done is set to one. If a zlib stream is
being decoded, then head->done is set to -1 to indicate that there will be
no gzip header information forthcoming. Note that Z_BLOCK can be used to
force inflate() to return immediately after header processing is complete
and before any actual data is decompressed.
The text, time, xflags, and os fields are filled in with the gzip header
contents. hcrc is set to true if there is a header CRC. (The header CRC
was valid if done is set to one.) If extra is not Z_NULL, then extra_max
contains the maximum number of bytes to write to extra. Once done is true,
extra_len contains the actual extra field length, and extra contains the
extra field, or that field truncated if extra_max is less than extra_len.
If name is not Z_NULL, then up to name_max characters are written there,
terminated with a zero unless the length is greater than name_max. If
comment is not Z_NULL, then up to comm_max characters are written there,
terminated with a zero unless the length is greater than comm_max. When
any of extra, name, or comment are not Z_NULL and the respective field is
not present in the header, then that field is set to Z_NULL to signal its
absence. This allows the use of deflateSetHeader() with the returned
structure to duplicate the header. However if those fields are set to
allocated memory, then the application will need to save those pointers
elsewhere so that they can be eventually freed.
If inflateGetHeader is not used, then the header information is simply
discarded. The header is always checked for validity, including the header
CRC if present. inflateReset() will reset the process to discard the header
information. The application would need to call inflateGetHeader() again to
retrieve the header from the next gzip stream.
@param stream of data
@param head gzip header
@return inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
stream state was inconsistent.
*/
ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
gz_headerp head));
/*
ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
unsigned char FAR *window));
Initialize the internal stream state for decompression using inflateBack()
calls. The fields zalloc, zfree and opaque in strm must be initialized
before the call. If zalloc and zfree are Z_NULL, then the default library-
derived memory allocation routines are used. windowBits is the base two
logarithm of the window size, in the range 8..15. window is a caller
supplied buffer of that size. Except for special applications where it is
assured that deflate was used with small window sizes, windowBits must be 15
and a 32K byte window must be supplied to be able to decompress general
deflate streams.
Note: In this version of the library a windowBits value of 8 is unsupported
due to a problem with the window size being set to 256 bytes. Although a
value of 8 will be accepted by deflateInit2(), as it is being changed
internally from 8 to 9, it will not be possible to use the same value when it
comes to decompression. This is because inflateInit2() does not make the same
change internally and as a result a Z_DATA_ERROR is returned when calling
inflate(). It is therefore advised that for this version of the library
windowBits of 9 is used in place of 8.
See inflateBack() for the usage of these routines.
inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
the paramaters are invalid, Z_MEM_ERROR if the internal state could not
be allocated, or Z_VERSION_ERROR if the version of the library does not
match the version of the header file.
*/
/** Input function pointer defined to be used in inflateBack */
typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
/** Output function pointer defined to be used in inflateBack */
typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
/**
inflateBack() does a raw inflate with a single call using a call-back
interface for input and output. This is more efficient than inflate() for
file i/o applications in that it avoids copying between the output and the
sliding window by simply making the window itself the output buffer. This
function trusts the application to not change the output buffer passed by
the output function, at least until inflateBack() returns.
inflateBackInit() must be called first to allocate the internal state
and to initialize the state with the user-provided window buffer.
inflateBack() may then be used multiple times to inflate a complete, raw
deflate stream with each call. inflateBackEnd() is then called to free
the allocated state.
A raw deflate stream is one with no zlib or gzip header or trailer.
This routine would normally be used in a utility that reads zip or gzip
files and writes out uncompressed files. The utility would decode the
header and process the trailer on its own, hence this routine expects
only the raw deflate stream to decompress. This is different from the
normal behavior of inflate(), which expects either a zlib or gzip header and
trailer around the deflate stream.
inflateBack() uses two subroutines supplied by the caller that are then
called by inflateBack() for input and output. inflateBack() calls those
routines until it reads a complete deflate stream and writes out all of the
uncompressed data, or until it encounters an error. The function's
parameters and return types are defined above in the in_func and out_func
typedefs. inflateBack() will call in(in_desc, &buf) which should return the
number of bytes of provided input, and a pointer to that input in buf. If
there is no input available, in() must return zero--buf is ignored in that
case--and inflateBack() will return a buffer error. inflateBack() will call
out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
should return zero on success, or non-zero on failure. If out() returns
non-zero, inflateBack() will return with an error. Neither in() nor out()
are permitted to change the contents of the window provided to
inflateBackInit(), which is also the buffer that out() uses to write from.
The length written by out() will be at most the window size. Any non-zero
amount of input may be provided by in().
For convenience, inflateBack() can be provided input on the first call by
setting strm->next_in and strm->avail_in. If that input is exhausted, then
in() will be called. Therefore strm->next_in must be initialized before
calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
must also be initialized, and then if strm->avail_in is not zero, input will
initially be taken from strm->next_in[0 .. strm->avail_in - 1].
The in_desc and out_desc parameters of inflateBack() is passed as the
first parameter of in() and out() respectively when they are called. These
descriptors can be optionally used to pass any information that the caller-
supplied in() and out() functions need to do their job.
On return, inflateBack() will set strm->next_in and strm->avail_in to
pass back any unused input that was provided by the last in() call. The
return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
if in() or out() returned an error, Z_DATA_ERROR if there was a format
error in the deflate stream (in which case strm->msg is set to indicate the
nature of the error), or Z_STREAM_ERROR if the stream was not properly
initialized. In the case of Z_BUF_ERROR, an input or output error can be
distinguished using strm->next_in which will be Z_NULL only if in() returned
an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
out() returning non-zero. (in() will always be called before out(), so
strm->next_in is assured to be defined if out() returns non-zero.) Note
that inflateBack() cannot return Z_OK.
@param strm stream of data
@param in input function pointer
@param in_desc input parameters for in_func
@param out output function pointer
@param out_desc output parameters for out_func
@return Refer to the above description for detailed explanation
*/
ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
in_func in, void FAR *in_desc,
out_func out, void FAR *out_desc));
/**
All memory allocated by inflateBackInit() is freed.
@param strm stream of data
@return inflateBackEnd returns Z_OK on success, or Z_STREAM_ERROR if the stream
state was inconsistent.
*/
ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
/**
Return flags indicating compile-time options.
Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
1.0: size of uInt
3.2: size of uLong
5.4: size of voidpf (pointer)
7.6: size of z_off_t
Compiler, assembler, and debug options:
8: DEBUG
9: ASMV or ASMINF -- use ASM code
10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
11: 0 (reserved)
One-time table building (smaller code, but not thread-safe if true):
12: BUILDFIXED -- build static block decoding tables when needed
13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
14,15: 0 (reserved)
Library content (indicates missing functionality):
16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
deflate code when not needed)
17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
and decode gzip streams (to avoid linking crc code)
18-19: 0 (reserved)
Operation variations (changes in library functionality):
20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
21: FASTEST -- deflate algorithm with only one, lowest compression level
22,23: 0 (reserved)
The sprintf variant used by gzprintf (zero is best):
24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
26: 0 = returns value, 1 = void -- 1 means inferred string length returned
Remainder:
27-31: 0 (reserved)
@return Refer to the above description for detailed explanation
*/
ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
/* 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.
*/
/**
Compresses the source buffer into the destination buffer. sourceLen is
the byte length of the source buffer. Upon entry, destLen is the total
size of the destination buffer, which must be at least the value returned
by compressBound(sourceLen). Upon exit, destLen is the actual size of the
compressed buffer.
This function can be used to compress a whole file at once if the
input file is mmap'ed.
@param dest destination buffer
@param destLen byte length of destination buffer
@param source source buffer
@param sourceLen byte length of source buffer
@return compress returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory, Z_BUF_ERROR if there was not enough room in the output
buffer.
*/
ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen));
/**
Compresses the source buffer into the destination buffer. The level
parameter has the same meaning as in deflateInit. sourceLen is the byte
length of the source buffer. Upon entry, destLen is the total size of the
destination buffer, which must be at least the value returned by
compressBound(sourceLen). Upon exit, destLen is the actual size of the
compressed buffer.
@param dest destination buffer
@param destLen byte length of destination buffer
@param source source buffer
@param sourceLen byte length of source buffer
@param level Compression level
@return compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
memory, Z_BUF_ERROR if there was not enough room in the output buffer,
Z_STREAM_ERROR if the level parameter is invalid.
*/
ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen,
int level));
/**
compressBound() returns an upper bound on the compressed size after
compress() or compress2() on sourceLen bytes. It would be used before
a compress() or compress2() call to allocate the destination buffer.
@param source buffer length
@return compressBound returns an upper bound on the compressed size after
compress() or compress2() on sourceLen bytes.
*/
ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
/**
Decompresses the source buffer into the destination buffer. sourceLen is
the byte length of the source buffer. Upon entry, destLen is the total
size of the destination buffer, which must be large enough to hold the
entire uncompressed data. (The size of the uncompressed data must have
been saved previously by the compressor and transmitted to the decompressor
by some mechanism outside the scope of this compression library.)
Upon exit, destLen is the actual size of the compressed buffer.
This function can be used to decompress a whole file at once if the
input file is mmap'ed.
@param dest destination buffer
@param destLen byte length of destination buffer
@param source source buffer
@param sourceLen byte length of source buffer
@return uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory, Z_BUF_ERROR if there was not enough room in the output
buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
*/
ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen));
#ifndef SYMBIAN_EZLIB_EXCLUDE_GZ_FUNCTIONS
/** gzfile is typedef to voidp i.e. void pointer(void*) */
typedef voidp gzFile;
/**
Opens a gzip (.gz) file for reading or writing. The mode parameter
is as in fopen ("rb" or "wb") but can also include a compression level
("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
Huffman only compression as in "wb1h", or 'R' for run-length encoding
as in "wb1R". (See the description of deflateInit2 for more information
about the strategy parameter.)
gzopen can be used to read a file which is not in gzip format; in this
case gzread will directly read from the file without decompression.
@param path location of the file
@param mode refer to above description
@return gzopen returns NULL if the file could not be opened or if there was
insufficient memory to allocate the (de)compression state; errno
can be checked to distinguish the two cases (if errno is zero, the
zlib error is Z_MEM_ERROR).
*/
ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
/**
gzdopen() associates a gzFile with the file descriptor fd. File
descriptors are obtained from calls like open, dup, creat, pipe or
fileno (in the file has been previously opened with fopen).
The mode parameter is as in gzopen.
The next call of gzclose on the returned gzFile will also close the
file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
@param fd file descriptor
@param mode The mode parameter is as in gzopen
@return gzdopen returns NULL if there was insufficient memory to allocate
the (de)compression state.
*/
ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
/**
Dynamically update the compression level or strategy. See the description
of deflateInit2 for the meaning of these parameters.
@param file gzip file
@param level compression level
@param strategy compression algorithm
@return gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
opened for writing.
*/
ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
/**
Reads the given number of uncompressed bytes from the compressed file.
If the input file was not in gzip format, gzread copies the given number
of bytes into the buffer.
@param file gzip file
@param buf buffer to store the copied data from the gzip file
@param len length of the data to be copied
@return gzread returns the number of uncompressed bytes actually read (0 for
end of file, -1 for error).
*/
ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
/**
Writes the given number of uncompressed bytes into the compressed file.
gzwrite returns the number of uncompressed bytes actually written
(0 in case of error).
@param file gzip file
@param buf buffer containing data to be written to the gzip file
@param len length of the data
@return gzwrite returns the number of uncompressed bytes actually written
(0 in case of error)
*/
ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
voidpc buf, unsigned len));
/**
Converts, formats, and writes the args to the compressed file under
control of the format string, as in fprintf. gzprintf returns the number of
uncompressed bytes actually written (0 in case of error). The number of
uncompressed bytes written is limited to 4095. The caller should assure that
this limit is not exceeded. If it is exceeded, then gzprintf() will return
return an error (0) with nothing written. In this case, there may also be a
buffer overflow with unpredictable consequences, which is possible only if
zlib was compiled with the insecure functions sprintf() or vsprintf()
because the secure snprintf() or vsnprintf() functions were not available.
@param file gzip file
@param format format string
@return refer to the description above
*/
ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
/**
Writes the given null-terminated string to the compressed file, excluding
the terminating null character.
@param file gzip file
@param s null-terminated string
@return gzputs returns the number of characters written, or -1 in case of error.
*/
ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
/**
Reads bytes from the compressed file until len-1 characters are read, or
a newline character is read and transferred to buf, or an end-of-file
condition is encountered. The string is then terminated with a null
character.
@param file gzip file
@param buf buffer to store the copied data from the gzip file
@param len number of characters to be read (len-1)
@return gzgets returns buf, or Z_NULL in case of error.
*/
ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
/**
Writes c, converted to an unsigned char, into the compressed file.
gzputc returns the value that was written, or -1 in case of error.
@param file gzip file
@param c character
@return gzputc returns the value that was written, or -1 in case of error.
*/
ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
/**
Reads one byte from the compressed file. gzgetc returns this byte
or -1 in case of end of file or error.
@param file gzip file
@return gzgetc returns this byte or -1 in case of end of file or error.
*/
ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
/**
Push one character back onto the stream to be read again later.
Only one character of push-back is allowed. gzungetc() returns the
character pushed, or -1 on failure. gzungetc() will fail if a
character has been pushed but not read yet, or if c is -1. The pushed
character will be discarded if the stream is repositioned with gzseek()
or gzrewind().
@param c character
@param file gzip file
@return gzungetc returns the character pushed, or -1 on failure.
*/
ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
/**
Flushes all pending output into the compressed file. The parameter
flush is as in the deflate() function. The return value is the zlib
error number (see function gzerror below). gzflush returns Z_OK if
the flush parameter is Z_FINISH and all output could be flushed.
gzflush should be called only when strictly necessary because it can
degrade compression.
@param file gzip file
@param flush parameter flush is as in the deflate() function
@return gzflush returns Z_OK if the flush parameter is Z_FINISH and all output could be flushed.
*/
ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
/**
Sets the starting position for the next gzread or gzwrite on the
given compressed file. The offset represents a number of bytes in the
uncompressed data stream. The whence parameter is defined as in lseek(2);
the value SEEK_END is not supported.
If the file is opened for reading, this function is emulated but can be
extremely slow. If the file is opened for writing, only forward seeks are
supported; gzseek then compresses a sequence of zeroes up to the new
starting position.
@param file gzip file
@param offset represents a number of bytes in the uncompressed data stream
@param whence defined as in lseek(2); the value SEEK_END is not supported.
@return gzseek returns the resulting offset location as measured in bytes from
the beginning of the uncompressed stream, or -1 in case of error, in
particular if the file is opened for writing and the new starting position
would be before the current position.
*/
ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
z_off_t offset, int whence));
/**
Rewinds the given file. This function is supported only for reading.
gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
@param file gzip file
@return refer to gzseek() return value & description
*/
ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
/**
Returns the starting position for the next gzread or gzwrite on the
given compressed file. This position represents a number of bytes in the
uncompressed data stream.
gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
@param file gzip file
@return gztell returns the starting position for the next gzread or gzwrite on the
given compressed file
*/
ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
/**
Returns 1 when EOF has previously been detected reading the given
input stream, otherwise zero.
@param file gzip file
@return gzeof returns 1 when EOF has previously been detected reading the given
input stream, otherwise zero.
*/
ZEXTERN int ZEXPORT gzeof OF((gzFile file));
/**
Returns 1 if file is being read directly without decompression, otherwise
zero.
@param file gzip file
@return gzdirect returns 1 if file is being read directly without decompression, otherwise zero.
*/
ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
/**
Flushes all pending output if necessary, closes the compressed file
and deallocates all the (de)compression state. The return value is the zlib
error number (see function gzerror below).
@param file gzip file
@return gzclose returns the zlib error number (see function gzerror below).
*/
ZEXTERN int ZEXPORT gzclose OF((gzFile file));
/**
Returns the error message for the last error which occurred on the
given compressed file. errnum is set to zlib error number. If an
error occurred in the file system and not in the compression library,
errnum is set to Z_ERRNO and the application may consult errno
to get the exact error code.
@param file gzip file
@param errnum error number
@return gzerror returns the error message for the last error which occurred on the
given compressed file.
*/
ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
/**
Clears the error and end-of-file flags for file. This is analogous to the
clearerr() function in stdio. This is useful for continuing to read a gzip
file that is being written concurrently.
@param file gzip file
*/
ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
#endif //SYMBIAN_EZLIB_EXCLUDE_GZ_FUNCTIONS
/* checksum functions */
/*
These functions are not related to compression but are exported
anyway because they might be useful in applications using the
compression library.
*/
/**
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();
@param adler Adler-32 checksum
@param buf pointer to buffer
@param len length of buffer
@return If buf is NULL, this function returns
the required initial value for the checksum.
*/
ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
/**
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.
@param adler1 Adler-32 checksum
@param adler2 Adler-32 checksum
@param len2 length
@return adler32_combine returns the Adler-32 checksum of
seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
*/
ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
z_off_t len2));
/**
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();
@param crc CRC-32 check value
@param buf pointer to buffer
@param len length of buffer
@return If buf is NULL, this function returns the required initial
value for the for the crc.
*/
ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
/**
Combine two CRC-32 check values into one. For two sequences of bytes,
seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
calculated for each, crc1 and crc2.
@param crc1 CRC-32 check value
@param crc2 CRC-32 check value
@param len2 length
@return crc32_combine returns the CRC-32 check value of seq1 and seq2
concatenated, requiring only crc1, crc2, and len2.
*/
ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
/* various hacks, don't look :) */
/* deflateInit and inflateInit are macros to allow checking the zlib version
* and the compiler's view of z_stream:
*/
/**
Initializes the internal stream state for compression. The fields
zalloc, zfree and opaque must be initialized before by the caller.
If zalloc and zfree are set to Z_NULL, deflateInit updates them to
use default allocation functions.
The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
1 gives best speed, 9 gives best compression, 0 gives no compression at
all (the input data is simply copied a block at a time).
Z_DEFAULT_COMPRESSION requests a default compromise between speed and
compression (currently equivalent to level 6).
deflateInit does not perform any compression: this will be done by deflate().
@param strm stream of data
@param level compression level
@param version version of library
@param stream_size stream size
@return deflateInit_ returns Z_OK if success, Z_MEM_ERROR if there was not
enough memory, Z_STREAM_ERROR if level is not a valid compression level,
Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
with the version assumed by the caller (ZLIB_VERSION).
msg is set to null if there is no error message.
*/
ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
const char *version, int stream_size));
/**
Initializes the internal stream state for decompression. The fields
next_in, avail_in, zalloc, zfree and opaque must be initialized before by
the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
value depends on the compression method), inflateInit determines the
compression method from the zlib header and allocates all data structures
accordingly; otherwise the allocation will be deferred to the first call of
inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
use default allocation functions.
inflateInit does not perform any decompression apart from reading
the zlib header if present: this will be done by inflate(). (So next_in and
avail_in may be modified, but next_out and avail_out are unchanged.)
@param strm stream of data
@param version version of library
@param stream_size stream size
@return inflateInit_ returns Z_OK if success, Z_MEM_ERROR if there was not enough
memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
version assumed by the caller. msg is set to null if there is no error
message.
*/
ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
const char *version, int stream_size));
/**
This is another version of deflateInit with more compression options. The
fields next_in, zalloc, zfree and opaque must be initialized before by
the caller.
The method parameter is the compression method. It must be Z_DEFLATED in
this version of the library.
The windowBits parameter is the base two logarithm of the window size
(the size of the history buffer). It should be in the range 8..15 for this
version of the library. Larger values of this parameter result in better
compression at the expense of memory usage. The default value is 15 if
deflateInit is used instead.
Note: In this version of the library a windowBits value of 8 is unsupported
due to a problem with the window size being set to 256 bytes. Although a
value of 8 will be accepted by deflateInit2(), as it is being changed
internally from 8 to 9, it will not be possible to use the same value when it
comes to decompression. This is because inflateInit2() does not make the same
change internally and as a result a Z_DATA_ERROR is returned when calling
inflate(). It is therefore advised that for this version of the library
windowBits of 9 is used in place of 8.
windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
determines the window size. deflate() will then generate raw deflate data
with no zlib header or trailer, and will not compute an adler32 check value.
windowBits can also be greater than 15 for optional gzip encoding. Add
16 to windowBits to write a simple gzip header and trailer around the
compressed data instead of a zlib wrapper. The gzip header will have no
file name, no extra data, no comment, no modification time (set to zero),
no header crc, and the operating system will be set to 3 (UNIX). If a
gzip stream is being written, strm->adler is a crc32 instead of an adler32.
The memLevel parameter specifies how much memory should be allocated
for the internal compression state. memLevel=1 uses minimum memory but
is slow and reduces compression ratio; memLevel=9 uses maximum memory
for optimal speed. The default value is 8. See zconf.h for total memory
usage as a function of windowBits and memLevel.
The strategy parameter is used to tune the compression algorithm. Use the
value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
string match), or Z_RLE to limit match distances to one (run-length
encoding). Filtered data consists mostly of small values with a somewhat
random distribution. In this case, the compression algorithm is tuned to
compress them better. The effect of Z_FILTERED is to force more Huffman
coding and less string matching; it is somewhat intermediate between
Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
parameter only affects the compression ratio but not the correctness of the
compressed output even if it is not set appropriately. Z_FIXED prevents the
use of dynamic Huffman codes, allowing for a simpler decoder for special
applications.
deflateInit2 does not perform any compression: this will be done by deflate().
@param strm stream of data
@param level compression level
@param method compression method
@param windowBits refer to above note & description for window bits value
@param memLevel memory level (i.e. how much memory should be allocated). refer to above description for more detail
@param strategy compression algorithm
@param version version of library
@param stream_size size of stream
@return deflateInit2_ returns Z_OK if success, Z_MEM_ERROR if there was not enough
memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
method). msg is set to null if there is no error message.
*/
ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
int windowBits, int memLevel,
int strategy, const char *version,
int stream_size));
/**
This is another version of inflateInit with an extra parameter. The
fields next_in, avail_in, zalloc, zfree and opaque 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 default value is 15 if inflateInit is used
instead. windowBits must be greater than or equal to the windowBits value
provided to deflateInit2() while compressing, or it must be equal to 15 if
deflateInit2() was not used. 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.
Note: In this version of the library a windowBits value of 8 is unsupported
due to a problem with the window size being set to 256 bytes. Although a
value of 8 will be accepted by deflateInit2(), as it is being changed
internally from 8 to 9, it will not be possible to use the same value when it
comes to decompression. This is because inflateInit2() does not make the same
change internally and as a result a Z_DATA_ERROR is returned when calling
inflate(). It is therefore advised that for this version of the library
windowBits of 9 is used in place of 8.
windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
determines the window size. inflate() will then process raw deflate data,
not looking for a zlib or gzip header, not generating a check value, and not
looking for any check values for comparison at the end of the stream. This
is for use with other formats that use the deflate compressed data format
such as zip. Those formats provide their own check values. If a custom
format is developed using the raw deflate format for compressed data, it is
recommended that a check value such as an adler32 or a crc32 be applied to
the uncompressed data as is done in the zlib, gzip, and zip formats. For
most applications, the zlib format should be used as is. Note that comments
above on the use in deflateInit2() applies to the magnitude of windowBits.
windowBits can also be greater than 15 for optional gzip decoding. Add
32 to windowBits to enable zlib and gzip decoding with automatic header
detection, or add 16 to decode only the gzip format (the zlib format will
return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is
a crc32 instead of an adler32.
@param strm stream of data
@param windowBits refer to above note & description for window bits value
@param version version of library
@param stream_size size of stream
@return 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 a null strm). msg
is set to null if there is no error message. inflateInit2 does not perform
any decompression apart from reading the zlib header if present: this will
be done by inflate(). (So next_in and avail_in may be modified, but next_out
and avail_out are unchanged.)
*/
ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
const char *version, int stream_size));
/**
Initialize the internal stream state for decompression using inflateBack()
calls. The fields zalloc, zfree and opaque in strm must be initialized
before the call. If zalloc and zfree are Z_NULL, then the default library-
derived memory allocation routines are used. windowBits is the base two
logarithm of the window size, in the range 8..15. window is a caller
supplied buffer of that size. Except for special applications where it is
assured that deflate was used with small window sizes, windowBits must be 15
and a 32K byte window must be supplied to be able to decompress general
deflate streams.
Note: In this version of the library a windowBits value of 8 is unsupported
due to a problem with the window size being set to 256 bytes. Although a
value of 8 will be accepted by deflateInit2(), as it is being changed
internally from 8 to 9, it will not be possible to use the same value when it
comes to decompression. This is because inflateInit2() does not make the same
change internally and as a result a Z_DATA_ERROR is returned when calling
inflate(). It is therefore advised that for this version of the library
windowBits of 9 is used in place of 8.
See inflateBack() for the usage of these routines.
@param strm stream of data
@param windowBits refer to above note for window bits value
@param window window is a caller supplied buffer of that size
@param version version of library
@param stream_size size of stream
@return inflateBackInit_ returns Z_OK on success, Z_STREAM_ERROR if any of
the paramaters are invalid, Z_MEM_ERROR if the internal state could not
be allocated, or Z_VERSION_ERROR if the version of the library does not
match the version of the header file.
*/
ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
unsigned char FAR *window,
const char *version,
int stream_size));
/**
Macro deflateInit defined for deflateInit_()
@param strm stream of data
@param level compression level
*/
#define deflateInit(strm, level) \
deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
/**
Macro inflateInit defined for inflateInit_()
@param strm stream of data
*/
#define inflateInit(strm) \
inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
/**
Macro deflateInit2 defined for deflateInit2_()
@param strm stream of data
@param level compression level
@param method compression method
@param windowBits refer to the note for window bits value in deflateInit2_()
@param memLevel memory level (i.e. how much memory should be allocated). refer to above description for more detail
@param strategy compression algorithm
*/
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
(strategy), ZLIB_VERSION, sizeof(z_stream))
/**
Macro inflateInit2 defined for inflateInit2_()
@param strm stream of data
@param windowBits refer to the note for window bits value in inflateInit2_()
*/
#define inflateInit2(strm, windowBits) \
inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
/**
Macro inflateBackInit defined for inflateBackInit_()
@param strm stream of data
@param windowBits refer to the note for window bits value in inflateBackInit_()
@param window window is a caller supplied buffer of that size
*/
#define inflateBackInit(strm, windowBits, window) \
inflateBackInit_((strm), (windowBits), (window), \
ZLIB_VERSION, sizeof(z_stream))
#if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
/** Hack for buggy compilers */
struct internal_state {int dummy;};
#endif
/**
Returns the string representing the error code
@param int error code
@return zError returns string representing the error code
*/
ZEXTERN const char * ZEXPORT zError OF((int));
/**
Checks whether inflate is currently at the end of a block generated by Z_SYNC_FLUSH or Z_FULL_FLUSH
@param z stream of data
@return inflateSyncPoint returns true(1) if inflate is currently at the end of a block. Otherwise false(0)
*/
ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
/**
Initialize the tables before allowing more than one thread to use crc32()
@return get_crc_table returns pointer to the crc table after initialisation
*/
ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
#ifdef __cplusplus
}
#endif
#endif /* _ZLIB_H */