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Diffstat (limited to 'src/zlib/zlib.h')
| -rw-r--r-- | src/zlib/zlib.h | 1200 |
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diff --git a/src/zlib/zlib.h b/src/zlib/zlib.h new file mode 100644 index 000000000..e067b127b --- /dev/null +++ b/src/zlib/zlib.h @@ -0,0 +1,1200 @@ +/* zlib.h -- interface of the 'zlib' general purpose compression library
+ version 1.2.2, October 3rd, 2004
+
+ Copyright (C) 1995-2004 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
+
+#include "zconf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZLIB_VERSION "1.2.2"
+#define ZLIB_VERNUM 0x1220
+
+/*
+ The 'zlib' compression library provides in-memory compression and
+ decompression functions, including integrity checks of the uncompressed
+ data. This version of the library supports only one compression method
+ (deflation) but other algorithms will be added later and will have the same
+ stream interface.
+
+ Compression can be done in a single step if the buffers are large
+ enough (for example if an input file is mmap'ed), or can be done by
+ repeated calls of the compression function. In the latter case, the
+ application must provide more input and/or consume the output
+ (providing more output space) before each call.
+
+ The compressed data format used by default by the in-memory functions is
+ the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
+ around a deflate stream, which is itself documented in RFC 1951.
+
+ The library also supports reading and writing files in gzip (.gz) format
+ with an interface similar to that of stdio using the functions that start
+ with "gz". The gzip format is different from the zlib format. gzip is a
+ gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
+
+ This library can optionally read and write gzip streams in memory as well.
+
+ The zlib format was designed to be compact and fast for use in memory
+ and on communications channels. The gzip format was designed for single-
+ file compression on file systems, has a larger header than zlib to maintain
+ directory information, and uses a different, slower check method than zlib.
+
+ The library does not install any signal handler. The decoder checks
+ the consistency of the compressed data, so the library should never
+ crash even in case of corrupted input.
+*/
+
+typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
+typedef void (*free_func) OF((voidpf opaque, voidpf address));
+
+struct internal_state;
+
+typedef struct z_stream_s {
+ Bytef *next_in; /* next input byte */
+ uInt avail_in; /* number of bytes available at next_in */
+ uLong total_in; /* total nb of input bytes read so far */
+
+ Bytef *next_out; /* next output byte should be put there */
+ uInt avail_out; /* remaining free space at next_out */
+ uLong total_out; /* total nb of bytes output so far */
+
+ char *msg; /* last error message, NULL if no error */
+ struct internal_state FAR *state; /* not visible by applications */
+
+ alloc_func zalloc; /* used to allocate the internal state */
+ free_func zfree; /* used to free the internal state */
+ voidpf opaque; /* private data object passed to zalloc and zfree */
+
+ int data_type; /* best guess about the data type: ascii or binary */
+ uLong adler; /* adler32 value of the uncompressed data */
+ uLong reserved; /* reserved for future use */
+} z_stream;
+
+typedef z_stream FAR *z_streamp;
+
+/*
+ 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 */
+
+#define Z_NO_FLUSH 0
+#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
+#define Z_SYNC_FLUSH 2
+#define Z_FULL_FLUSH 3
+#define Z_FINISH 4
+#define Z_BLOCK 5
+/* Allowed flush values; see deflate() and inflate() below for details */
+
+#define Z_OK 0
+#define Z_STREAM_END 1
+#define Z_NEED_DICT 2
+#define Z_ERRNO (-1)
+#define Z_STREAM_ERROR (-2)
+#define Z_DATA_ERROR (-3)
+#define Z_MEM_ERROR (-4)
+#define Z_BUF_ERROR (-5)
+#define Z_VERSION_ERROR (-6)
+/* Return codes for the compression/decompression functions. Negative
+ * values are errors, positive values are used for special but normal events.
+ */
+
+#define Z_NO_COMPRESSION 0
+#define Z_BEST_SPEED 1
+#define Z_BEST_COMPRESSION 9
+#define Z_DEFAULT_COMPRESSION (-1)
+/* compression levels */
+
+#define Z_FILTERED 1
+#define Z_HUFFMAN_ONLY 2
+#define Z_RLE 3
+#define Z_DEFAULT_STRATEGY 0
+/* compression strategy; see deflateInit2() below for details */
+
+#define Z_BINARY 0
+#define Z_ASCII 1
+#define Z_UNKNOWN 2
+/* Possible values of the data_type field (though see inflate()) */
+
+#define Z_DEFLATED 8
+/* The deflate compression method (the only one supported in this version) */
+
+#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
+
+#define zlib_version zlibVersion()
+/* for compatibility with versions < 1.0.2 */
+
+ /* basic functions */
+
+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.
+ This check is automatically made by deflateInit and inflateInit.
+ */
+
+/*
+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().
+*/
+
+
+ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
+/*
+ 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.
+
+ 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
+ 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 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
+ (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.
+*/
+
+
+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
+ 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).
+*/
+
+
+/*
+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.)
+*/
+
+
+ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
+/*
+ inflate decompresses as much data as possible, and stops when the input
+ buffer becomes empty or the output buffer becomes full. It may introduce
+ some output latency (reading input without producing any output) except when
+ forced to flush.
+
+ The detailed semantics are as follows. inflate performs one or both of the
+ following actions:
+
+ - Decompress more input starting at next_in and update next_in and avail_in
+ accordingly. If not all input can be processed (because there is not
+ enough room in the output buffer), next_in is updated and processing
+ will resume at this point for the next call of inflate().
+
+ - Provide more output starting at next_out and update next_out and avail_out
+ accordingly. inflate() provides as much output as possible, until there
+ is no more input data or no more space in the output buffer (see below
+ about the flush parameter).
+
+ Before the call of inflate(), the application should ensure that at least
+ one of the actions is possible, by providing more input and/or consuming
+ more output, and updating the next_* and avail_* values accordingly.
+ The application can consume the uncompressed output when it wants, for
+ example when the output buffer is full (avail_out == 0), or after each
+ call of inflate(). If inflate returns Z_OK and with zero avail_out, it
+ must be called again after making room in the output buffer because there
+ might be more output pending.
+
+ The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
+ Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
+ output as possible to the output buffer. Z_BLOCK requests that inflate() stop
+ if and when it get to the next deflate block boundary. When decoding the zlib
+ or gzip format, this will cause inflate() to return immediately after the
+ header and before the first block. When doing a raw inflate, inflate() will
+ go ahead and process the first block, and will return when it gets to the end
+ of that block, or when it runs out of data.
+
+ The Z_BLOCK option assists in appending to or combining deflate streams.
+ Also to assist in this, on return inflate() will set strm->data_type to the
+ number of unused bits in the last byte taken from strm->next_in, plus 64
+ if inflate() is currently decoding the last block in the deflate stream,
+ plus 128 if inflate() returned immediately after decoding an end-of-block
+ code or decoding the complete header up to just before the first byte of the
+ deflate stream. The end-of-block will not be indicated until all of the
+ uncompressed data from that block has been written to strm->next_out. The
+ number of unused bits may in general be greater than seven, except when
+ bit 7 of data_type is set, in which case the number of unused bits will be
+ less than eight.
+
+ inflate() should normally be called until it returns Z_STREAM_END or an
+ error. However if all decompression is to be performed in a single step
+ (a single call of inflate), the parameter flush should be set to
+ Z_FINISH. In this case all pending input is processed and all pending
+ output is flushed; avail_out must be large enough to hold all the
+ uncompressed data. (The size of the uncompressed data may have been saved
+ by the compressor for this purpose.) The next operation on this stream must
+ be inflateEnd to deallocate the decompression state. The use of Z_FINISH
+ is never required, but can be used to inform inflate that a faster approach
+ may be used for the single inflate() call.
+
+ In this implementation, inflate() always flushes as much output as
+ possible to the output buffer, and always uses the faster approach on the
+ first call. So the only effect of the flush parameter in this implementation
+ is on the return value of inflate(), as noted below, or when it returns early
+ because Z_BLOCK is used.
+
+ If a preset dictionary is needed after this call (see inflateSetDictionary
+ below), inflate sets strm->adler to the adler32 checksum of the dictionary
+ chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+ strm->adler to the adler32 checksum of all output produced so far (that is,
+ total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
+ below. At the end of the stream, inflate() checks that its computed adler32
+ checksum is equal to that saved by the compressor and returns Z_STREAM_END
+ only if the checksum is correct.
+
+ inflate() will decompress and check either zlib-wrapped or gzip-wrapped
+ deflate data. The header type is detected automatically. Any information
+ contained in the gzip header is not retained, so applications that need that
+ information should instead use raw inflate, see inflateInit2() below, or
+ inflateBack() and perform their own processing of the gzip header and
+ trailer.
+
+ inflate() returns Z_OK if some progress has been made (more input processed
+ or more output produced), Z_STREAM_END if the end of the compressed data has
+ been reached and all uncompressed output has been produced, Z_NEED_DICT if a
+ preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
+ corrupted (input stream not conforming to the zlib format or incorrect check
+ value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+ if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
+ Z_BUF_ERROR if no progress is possible or if there was not enough room in the
+ output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
+ inflate() can be called again with more input and more output space to
+ continue decompressing. If Z_DATA_ERROR is returned, the application may then
+ call inflateSync() to look for a good compression block if a partial recovery
+ of the data is desired.
+*/
+
+
+ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
+/*
+ All dynamically allocated data structures for this stream are freed.
+ This function discards any unprocessed input and does not flush any
+ pending output.
+
+ inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
+ was inconsistent. In the error case, msg may be set but then points to a
+ static string (which must not be deallocated).
+*/
+
+ /* Advanced functions */
+
+/*
+ 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.
+
+ 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 255 (unknown). 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.
+
+ 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().
+*/
+
+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.
+
+ 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
+ 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.
+
+ 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 deflateCopy 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 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.
+
+ 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 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.
+ 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).
+*/
+
+ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
+ int level,
+ int strategy));
+/*
+ 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.
+
+ 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 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().
+*/
+
+ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
+ int bits,
+ int value));
+/*
+ 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.
+
+ deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+*/
+
+/*
+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.
+
+ 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 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.)
+*/
+
+ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
+ const Bytef *dictionary,
+ uInt dictLength));
+/*
+ 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
+ perform any decompression: this will be done by subsequent calls of
+ inflate().
+*/
+
+ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
+/*
+ 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 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 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.
+ 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).
+*/
+
+/*
+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 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.
+*/
+
+ZEXTERN int ZEXPORT inflateBackEnd OF((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.
+*/
+
+ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
+/* 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)
+ */
+
+
+ /* utility functions */
+
+/*
+ The following utility functions are implemented on top of the
+ basic stream-oriented functions. To simplify the interface, some
+ default options are assumed (compression level and memory usage,
+ standard memory allocation functions). The source code of these
+ utility functions can easily be modified if you need special options.
+*/
+
+ZEXTERN 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 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.
+ 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 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
+ 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 or incomplete.
+*/
+
+
+typedef voidp gzFile;
+
+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") 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.
+
+ 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 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
+ 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).
+ gzdopen returns NULL if there was insufficient memory to allocate
+ the (de)compression state.
+*/
+
+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
+ of bytes into the buffer.
+ gzread returns the number of uncompressed bytes actually read (0 for
+ end of file, -1 for error). */
+
+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).
+*/
+
+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. 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.
+*/
+
+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 gzungetc OF((int c, 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().
+*/
+
+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
+ 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.
+*/
+
+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).
+*/
+
+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
+ 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.
+*/
+
+ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
+/*
+ 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.
+*/
+
+ /* checksum functions */
+
+/*
+ These functions are not related to compression but are exported
+ anyway because they might be useful in applications using the
+ compression library.
+*/
+
+ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
+
+/*
+ Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+ return the updated checksum. If buf is NULL, this function returns
+ the required initial value for the checksum.
+ An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
+ much faster. Usage example:
+
+ uLong adler = adler32(0L, Z_NULL, 0);
+
+ while (read_buffer(buffer, length) != EOF) {
+ adler = adler32(adler, buffer, length);
+ }
+ if (adler != original_adler) error();
+*/
+
+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
+ 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:
+ */
+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))
+#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(ZUTIL_H) && !defined(NO_DUMMY_DECL)
+ struct internal_state {int dummy;}; /* hack for buggy compilers */
+#endif
+
+ZEXTERN const char * ZEXPORT zError OF((int));
+ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
+ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZLIB_H */
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