/* zlibdll.h -- interface of the 'zlib' general purpose compression library
version 1.0.4, Jul 24th, 1996.
Copyright (C) 1995-1996 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
gzip@prep.ai.mit.edu 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 ftp://ds.internic.net/rfc/rfc1950.txt
(zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
*/
/* Modifications:
* conversion to C++; to handle IStream objects; to be a DLL
* Copyright (C) 1998 Autodesk, Inc.
*
* Written by Pete Samson, Kinetix
*/
#ifndef _ZLIBDLL_H
#define _ZLIBDLL_H
#define ZLIB_VERSION "1.0.4"
#define USE_ISTREAMS
#define Z_NO_FLUSH 0
#define Z_PARTIAL_FLUSH 1
#define Z_SYNC_FLUSH 2
#define Z_FULL_FLUSH 3
#define Z_FINISH 4
/* Allowed flush values; see deflate() below for details */
#define Z_OK 0
#define Z_STREAM_END 1
#define Z_NEED_DICT 2
#define Z_ERRNO (-1)
#define Z_STREAM_ERROR (-2)
#define Z_DATA_ERROR (-3)
#define Z_MEM_ERROR (-4)
#define Z_BUF_ERROR (-5)
#define Z_VERSION_ERROR (-6)
/* Return codes for the compression/decompression functions. Negative
* values are errors, positive values are used for special but normal events.
*/
#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
#define Z_NO_COMPRESSION 0
#define Z_BEST_SPEED 1
#define Z_BEST_COMPRESSION 9
#define Z_DEFAULT_COMPRESSION (-1)
/* compression levels */
#define Z_FILTERED 1
#define Z_HUFFMAN_ONLY 2
#define Z_DEFAULT_STRATEGY 0
/* compression strategy; see deflateInit2() below for details */
typedef unsigned char Byte; /* 8 bits */
typedef unsigned int uInt; /* 16 bits or more */
typedef unsigned long uLong; /* 32 bits or more */
typedef void *voidpf;
typedef void *voidp;
typedef voidpf (*alloc_func) (voidpf opaque, uInt items, uInt size);
typedef void (*free_func) (voidpf opaque, voidpf address);
typedef Byte Bytef;
typedef char charf;
typedef int intf;
typedef uInt uIntf;
typedef uLong uLongf;
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 *state; /* not visible by applications */
alloc_func zalloc; /* used to allocate the internal state */
free_func zfree; /* used to free the internal state */
voidpf opaque; /* private data object passed to zalloc and zfree */
int data_type; /* best guess about the data type: ascii or binary */
uLong adler; /* adler32 value of the uncompressed data */
uLong reserved; /* reserved for future use */
} z_stream;
typedef z_stream *z_streamp;
typedef wchar_t WCHAR;
/* basic functions */
extern const char * zlibVersion(void);
/* 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.
*/
/*
extern int deflateInit(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().
*/
extern int deflate(z_streamp strm, int flush);
/*
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.
If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression
block is terminated and flushed to the output buffer so that the
decompressor can get all input data available so far. For method 9, a future
variant on method 8, the current block will be flushed but not terminated.
Z_SYNC_FLUSH has the same effect as partial flush except that the compressed
output is byte aligned (the compressor can clear its internal bit buffer)
and the current block is always terminated; this can be useful if the
compressor has to be restarted from scratch after an interruption (in which
case the internal state of the compressor may be lost).
If flush is set to Z_FULL_FLUSH, the compression block is terminated, a
special marker is output and the compression dictionary is discarded; this
is useful to allow the decompressor to synchronize if one compressed block
has been damaged (see inflateSync below). Flushing degrades compression and
so should be used only when necessary. Using Z_FULL_FLUSH too often can
seriously degrade the 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).
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
0.1% larger than avail_in plus 12 bytes. If deflate does not return
Z_STREAM_END, then it must be called again as described above.
deflate() may update data_type if it can make a good guess about
the input data type (Z_ASCII or Z_BINARY). 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.
*/
extern int deflateEnd(z_streamp strm);
/*
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
pending output.
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).
*/
extern int inflateInit(z_streamp strm);
/*
Initializes the internal stream state for decompression. The fields
zalloc, zfree and opaque must be initialized before by the caller. 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: this will be
done by inflate().
*/
extern int inflate(z_streamp 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() 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.
If the parameter flush is set to Z_PARTIAL_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
and Z_FINISH, but the current implementation actually flushes as much output
as possible anyway.
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_NEED_DICT if a preset dictionary is needed at this point (see
inflateSetDictionary below), 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.
In the Z_NEED_DICT case, strm->adler is set to the Adler32 value of the
dictionary chosen by the compressor.
*/
extern int inflateEnd(z_streamp strm);
/*
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
pending output.
inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
was inconsistent. In the error case, msg may be set but then points to a
static string (which must not be deallocated).
*/
/* Advanced functions */
/*
The following functions are needed only in some special applications.
*/
extern int deflateInit2(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. (Method 9 will allow a 64K history buffer and
partial block flushes.)
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 (the value 16 will be allowed for method 9). 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.
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), or Z_HUFFMAN_ONLY to force Huffman encoding only (no
string match). 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. The strategy parameter only affects
the compression ratio but not the correctness of the compressed output even
if it is not set appropriately.
If next_in is not null, the library will use this buffer to hold also
some history information; the buffer must either hold the entire input
data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in
is null, the library will allocate its own history buffer (and leave next_in
null). next_out need not be provided here but must be provided by the
application for the next call of deflate().
If the history buffer is provided by the application, next_in must
must never be changed by the application since the compressor maintains
information inside this buffer from call to call; the application
must provide more input only by increasing avail_in. next_in is always
reset by the library in this case.
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().
extern int deflateSetDictionary(z_streamp strm,
const Bytef *dictionary,
uInt dictLength);
/*
Initializes the compression dictionary (history buffer) from the given
byte sequence without producing any compressed output. This function must
be called immediately after deflateInit or deflateInit2, 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. In this version of the library,
only the last 32K bytes of the dictionary are used.
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.)
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). deflateSetDictionary does not perform any compression: this will
be done by deflate().
*/
extern int deflateReset(z_streamp strm);
/*
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.
deflateReset 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 inflateInit2(z_streamp strm,
int windowBits);
This is another version of inflateInit with more compression options. The
fields next_out, 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 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
inflate().
*/
extern int inflateSetDictionary(z_streamp strm,
const Bytef *dictionary,
uInt dictLength);
/*
Initializes the decompression dictionary (history buffer) from the given
uncompressed byte sequence. This function must be called immediately after
a call of inflate if this call returned Z_NEED_DICT. The dictionary chosen
by the compressor can be determined from the Adler32 value returned by this
call of inflate. The compressor and decompressor must use exactly the same
dictionary (see deflateSetDictionary).
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). inflateSetDictionary does not
perform any decompression: this will be done by subsequent calls of
inflate().
*/
extern int inflateSync(z_streamp 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(z_streamp 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).
*/
/* 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, window size,
standard memory allocation functions). The source code of these
utility functions can easily be modified if you need special options.
*/
extern int compress(Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen);
/*
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 0.1% larger than
sourceLen plus 12 bytes. 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.
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.
*/
extern int uncompress(Bytef *dest, uLongf *destLen,
const Bytef *source, 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.
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.
*/
typedef void *voidp;
typedef voidp gzFile;
struct IStorage;
struct IStream;
#ifdef USE_ISTREAMS
extern gzFile gzopen(IStream *, const WCHAR *ipath, const char *path, const char *mode);
#else
extern gzFile gzopen(const char *path, const char *mode);
#endif
/*
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"). 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.
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).
*/
extern int gzread(gzFile file, voidp buf, unsigned len);
/*
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.
gzread returns the number of uncompressed bytes actually read (0 for
end of file, -1 for error). */
extern int gzwrite(gzFile file, const 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).
*/
extern int gzflush(gzFile file, int flush);
/*
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.
*/
#if 0
extern int gzseek(gzFile file, long int address, uInt mode);
/*
Seeks (if read); fails (if write).
*/
#endif
extern int gzclose(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).
*/
extern const char * gzerror(gzFile file, int *errnum);
/*
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.
*/
/* checksum functions */
extern uLong crc32 (uLong crc, const Bytef *buf, uInt len);
/*
Update a running crc with the bytes buf[0..len-1] and return the updated
crc. If buf is NULL, this function returns the required initial value
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();
*/
/* various hacks, don't look :) */
/* deflateInit and inflateInit are macros to allow checking the zlib version
* and the compiler's view of z_stream:
*/
extern int deflateInit_(z_streamp strm, int level,
const char *version, int stream_size);
extern int inflateInit_(z_streamp strm,
const char *version, int stream_size);
extern int deflateInit2_(z_streamp strm, int level, int method,
int windowBits, int memLevel, int strategy,
const char *version, int stream_size);
extern int inflateInit2_(z_streamp strm, int windowBits,
const char *version, int stream_size);
#define deflateInit(strm, level) \
deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
#define inflateInit(strm) \
inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
(strategy), ZLIB_VERSION, sizeof(z_stream))
#define inflateInit2(strm, windowBits) \
inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
#endif /* _ZLIBDLL_H */