/* zlib.h -- interface of the 'zlib' general purpose compression library
- version 1.0.5, Jan 3rd, 1998.
+ version 1.2.0, March 9th, 2003
- Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
+ Copyright (C) 1995-2003 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
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
+ 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 ftp://ds.internic.net/rfc/rfc1950.txt
+ 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
+#include "zconf.h"
+
#ifdef __cplusplus
extern "C" {
#endif
-#include "zconf.h"
-
-#define ZLIB_VERSION "1.0.5"
+#define ZLIB_VERSION "1.2.0"
/*
The 'zlib' compression library provides in-memory compression and
decompression functions, including integrity checks of the uncompressed
data. This version of the library supports only one compression method
- (deflation) but other algorithms may be added later and will have the same
+ (deflation) but other algorithms will be added later and will have the same
stream interface.
- For compression the application must provide the output buffer and
- may optionally provide the input buffer for optimization. For decompression,
- the application must provide the input buffer and may optionally provide
- the output buffer for optimization.
-
Compression can be done in a single step if the buffers are large
enough (for example if an input file is mmap'ed), or can be done by
repeated calls of the compression function. In the latter case, the
application must provide more input and/or consume the output
(providing more output space) before each call.
- The library does not install any signal handler. It is recommended to
- add at least a handler for SIGSEGV when decompressing; the library checks
- the consistency of the input data whenever possible but may go nuts
- for some forms of corrupted input.
+ The compressed data format used 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.
+
+ 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.
+
+ This library does not provide any functions to write gzip files in memory.
+ However such functions could be easily written using zlib's deflate function,
+ the documentation in the gzip RFC, and the examples in gzio.c.
+
+ The library does not install any signal handler. The decoder checks
+ the consistency of the compressed data, so the library should never
+ crash even in case of corrupted input.
*/
typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
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,
/* constants */
#define Z_NO_FLUSH 0
-#define Z_PARTIAL_FLUSH 1
+#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
#define Z_SYNC_FLUSH 2
#define Z_FULL_FLUSH 3
#define Z_FINISH 4
/* basic functions */
-extern const char * EXPORT zlibVersion OF((void));
+ZEXTERN const char * ZEXPORT zlibVersion OF((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.
*/
/*
-extern int EXPORT deflateInit OF((z_streamp strm, int level));
+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.
*/
-extern int EXPORT deflate OF((z_streamp strm, int flush));
+ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
/*
- Performs one or both of the following actions:
+ 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
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_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
+ 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). 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
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
+ 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 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
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.
+ 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.
*/
-extern int EXPORT deflateEnd OF((z_streamp strm));
+ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
/*
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
/*
-extern int EXPORT inflateInit OF((z_streamp strm));
+ZEXTERN int ZEXPORT inflateInit OF((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.
+ 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: this will be
- done by inflate().
+ 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.)
*/
-extern int EXPORT inflate OF((z_streamp strm, int flush));
+ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
/*
- Performs one or both of the following actions:
+ inflate decompresses as much data as possible, and stops when the input
+ buffer becomes empty or the output buffer becomes full. It may some
+ 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
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.
+ The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, or
+ Z_FINISH. Z_SYNC_FLUSH requests that inflate() flush as much output as
+ possible to the output buffer.
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
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
+ is never required, but can be used to inform inflate that a faster approach
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.
+ 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.
+
+ 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.
*/
-extern int EXPORT inflateEnd OF((z_streamp strm));
+ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
/*
All dynamically allocated data structures for this stream are freed.
This function discards any unprocessed input and does not flush any
*/
/*
-extern int EXPORT deflateInit2 OF((z_streamp strm,
- int level,
- int method,
- int windowBits,
- int memLevel,
- int strategy));
+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. (Method 9 will allow a 64K history buffer and
- partial block flushes.)
+ 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 (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.
+ 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.
+
+ 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.
The memLevel parameter specifies how much memory should be allocated
for the internal compression state. memLevel=1 uses minimum memory but
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().
+ 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 EXPORT deflateSetDictionary OF((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
+ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
+ const Bytef *dictionary,
+ uInt dictLength));
+/*
+ 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. 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
+ 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.
+
+ 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
+ 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.)
+ actually used by the compressor.) If a raw deflate was requested, then the
+ adler32 value is not computed and strm->adler is not set.
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().
+ 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().
*/
-extern int EXPORT deflateCopy OF((z_streamp dest,
- z_streamp source));
+ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
+ z_streamp source));
/*
- Sets the destination stream as a complete copy of the source stream. If
- the source stream is using an application-supplied history buffer, a new
- buffer is allocated for the destination stream. The compressed output
- buffer is always application-supplied. It's the responsibility of the
- application to provide the correct values of next_out and avail_out for the
- next call of deflate.
+ 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
destination.
*/
-extern int EXPORT deflateReset OF((z_streamp strm));
+ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
/*
This function is equivalent to deflateEnd followed by deflateInit,
but does not free and reallocate all the internal compression state.
stream state was inconsistent (such as zalloc or state being NULL).
*/
-extern int EXPORT deflateParams OF((z_streamp strm, int level, int strategy));
+ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
+ int level,
+ int strategy));
/*
- Dynamically update the compression level and compression strategy.
- 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().
+ 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
if strm->avail_out was zero.
*/
+ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
+ uLong sourceLen));
+/*
+ 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().
+*/
+
/*
-extern int EXPORT inflateInit2 OF((z_streamp strm,
- int windowBits));
+ZEXTERN int ZEXPORT inflateInit2 OF((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.
+ 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 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().
+ this version of the library. 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.
+
+ 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.
+
+ 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 negative
+ memLevel). 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.)
*/
-extern int EXPORT inflateSetDictionary OF((z_streamp strm,
- const Bytef *dictionary,
- uInt dictLength));
+ZEXTERN int ZEXPORT inflateSetDictionary OF((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
+ Initializes the decompression dictionary 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
+ expected one (incorrect adler32 value). inflateSetDictionary does not
perform any decompression: this will be done by subsequent calls of
inflate().
*/
-extern int EXPORT inflateSync OF((z_streamp strm));
+ZEXTERN int ZEXPORT inflateSync OF((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.
+ 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.
- 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,
+ 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
until success or end of the input data.
*/
-extern int EXPORT inflateReset OF((z_streamp strm));
+ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
+ z_streamp source));
+/*
+ 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.
+
+ 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 inflateReset OF((z_streamp strm));
/*
This function is equivalent to inflateEnd followed by inflateInit,
but does not free and reallocate all the internal decompression state.
stream state was inconsistent (such as zalloc or state being NULL).
*/
+/*
+ZEXTERN int ZEXPORT inflateBackInit OF((z_stream FAR *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.
+
+ 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.
+*/
+
+typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
+typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
+
+ZEXTERN int ZEXPORT inflateBack OF((z_stream FAR *strm,
+ in_func in, void FAR *in_desc,
+ out_func out, void FAR *out_desc));
+/*
+ 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 optinally 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.
+*/
+
+ZEXTERN int ZEXPORT inflateBackEnd(z_stream FAR *strm);
+/*
+ All memory allocated by inflateBackInit() is freed.
+
+ inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
+ state was inconsistent.
+*/
+
/* 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,
+ 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.
*/
-extern int EXPORT compress OF((Bytef *dest, uLongf *destLen,
- const Bytef *source, uLong sourceLen));
+ZEXTERN int ZEXPORT compress OF((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
+ 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.
buffer.
*/
-extern int EXPORT uncompress OF((Bytef *dest, uLongf *destLen,
- const Bytef *source, uLong sourceLen));
+ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
+ const Bytef *source, uLong sourceLen,
+ int level));
+/*
+ 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.
+
+ 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 uLong ZEXPORT compressBound OF((uLong sourceLen));
+/*
+ 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.
+*/
+
+ZEXTERN int ZEXPORT uncompress OF((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
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.
+ buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
*/
typedef voidp gzFile;
-extern gzFile EXPORT gzopen OF((const char *path, const char *mode));
+ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
/*
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.
+ ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
+ Huffman only compression as in "wb1h". (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.
+
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).
-*/
+ zlib error is Z_MEM_ERROR). */
-extern gzFile EXPORT gzdopen OF((int fd, const char *mode));
+ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
/*
gzdopen() associates a gzFile with the file descriptor fd. File
descriptors are obtained from calls like open, dup, creat, pipe or
the (de)compression state.
*/
-extern int EXPORT gzread OF((gzFile file, voidp buf, unsigned len));
+ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
+/*
+ Dynamically update the compression level or strategy. See the description
+ of deflateInit2 for the meaning of these parameters.
+ gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
+ opened for writing.
+*/
+
+ZEXTERN int ZEXPORT gzread OF((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
gzread returns the number of uncompressed bytes actually read (0 for
end of file, -1 for error). */
-extern int EXPORT gzwrite OF((gzFile file, const voidp buf, unsigned len));
+ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
+ voidpc 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 EXPORT gzflush OF((gzFile file, int flush));
+ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
+/*
+ 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, since otherwise a buffer overflow may
+ result.
+*/
+
+ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
+/*
+ Writes the given null-terminated string to the compressed file, excluding
+ the terminating null character.
+ gzputs returns the number of characters written, or -1 in case of error.
+*/
+
+ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
+/*
+ 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.
+ gzgets returns buf, or Z_NULL in case of error.
+*/
+
+ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
+/*
+ Writes c, converted to an unsigned char, into the compressed file.
+ gzputc returns the value that was written, or -1 in case of error.
+*/
+
+ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
+/*
+ Reads one byte from the compressed file. gzgetc returns this byte
+ or -1 in case of end of file or error.
+*/
+
+ZEXTERN int ZEXPORT gzflush OF((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
degrade compression.
*/
-extern int EXPORT gzclose OF((gzFile file));
+ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
+ z_off_t offset, int whence));
+/*
+ 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.
+
+ 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 int ZEXPORT gzrewind OF((gzFile file));
+/*
+ Rewinds the given file. This function is supported only for reading.
+
+ gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
+*/
+
+ZEXTERN z_off_t ZEXPORT gztell 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)
+*/
+
+ZEXTERN int ZEXPORT gzeof OF((gzFile file));
+/*
+ Returns 1 when EOF has previously been detected reading the given
+ input stream, otherwise zero.
+*/
+
+ZEXTERN int ZEXPORT gzclose 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).
*/
-extern const char * EXPORT gzerror OF((gzFile file, int *errnum));
+ZEXTERN const char * ZEXPORT gzerror OF((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
compression library.
*/
-extern uLong EXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
+ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
/*
Update a running Adler-32 checksum with the bytes buf[0..len-1] and
if (adler != original_adler) error();
*/
-extern uLong EXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
+ZEXTERN uLong ZEXPORT crc32 OF((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
/* deflateInit and inflateInit are macros to allow checking the zlib version
* and the compiler's view of z_stream:
*/
-extern int EXPORT deflateInit_ OF((z_streamp strm, int level,
- const char *version, int stream_size));
-extern int EXPORT inflateInit_ OF((z_streamp strm,
- const char *version, int stream_size));
-extern int EXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
- int windowBits, int memLevel, int strategy,
- const char *version, int stream_size));
-extern int EXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
- const char *version, int stream_size));
+ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
+ const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
+ const char *version, int stream_size));
+ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
+ int windowBits, int memLevel,
+ int strategy, const char *version,
+ int stream_size));
+ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
+ const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateBackInit_ OF((z_stream FAR *strm, int windowBits,
+ unsigned char FAR *window,
+ 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))
+ (strategy), ZLIB_VERSION, sizeof(z_stream))
#define inflateInit2(strm, windowBits) \
inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
+#define inflateBackInit(strm, windowBits, window) \
+ inflateBackInit_((strm), (windowBits), (window), \
+ ZLIB_VERSION, sizeof(z_stream))
+
#if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL)
struct internal_state {int dummy;}; /* hack for buggy compilers */
#endif
-uLongf *get_crc_table OF((void)); /* can be used by asm versions of crc32() */
+ZEXTERN const char * ZEXPORT zError OF((int err));
+ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
+ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
#ifdef __cplusplus
}
projects / zlib.git / blobdiff