diff options
Diffstat (limited to 'lib/libz/zlib.h')
| -rw-r--r-- | lib/libz/zlib.h | 502 |
1 files changed, 305 insertions, 197 deletions
diff --git a/lib/libz/zlib.h b/lib/libz/zlib.h index 337fe9f..06f988c 100644 --- a/lib/libz/zlib.h +++ b/lib/libz/zlib.h @@ -1,7 +1,7 @@ /* zlib.h -- interface of the 'zlib' general purpose compression library - version 1.0.4, Jul 24th, 1996. + version 1.1.1, Feb 27th, 1998 - Copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler + Copyright (C) 1995-1998 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 @@ -20,7 +20,7 @@ 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 @@ -37,30 +37,27 @@ extern "C" { #include "zconf.h" -#define ZLIB_VERSION "1.0.4" +#define ZLIB_VERSION "1.1.1" /* 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 library also supports reading and writing files in gzip (.gz) format + with an interface similar to that of stdio. + + 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)); @@ -104,6 +101,9 @@ typedef z_stream FAR *z_streamp; 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, @@ -123,7 +123,7 @@ typedef z_stream FAR *z_streamp; /* 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 @@ -168,7 +168,7 @@ typedef z_stream FAR *z_streamp; /* basic functions */ -extern const char * EXPORT zlibVersion OF((void)); +extern 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. @@ -176,7 +176,7 @@ extern const char * EXPORT zlibVersion OF((void)); */ /* -extern int EXPORT deflateInit OF((z_streamp strm, int level)); +extern 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. @@ -198,9 +198,15 @@ extern int EXPORT deflateInit OF((z_streamp strm, int level)); */ -extern int EXPORT deflate OF((z_streamp strm, int flush)); +extern 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 @@ -222,24 +228,23 @@ extern int EXPORT deflate OF((z_streamp strm, int flush)); 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). 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 @@ -254,6 +259,9 @@ extern int EXPORT deflate OF((z_streamp strm, int flush)); 0.1% larger than avail_in plus 12 bytes. If deflate does not return Z_STREAM_END, then it must be called again as described above. + deflate() 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 @@ -267,7 +275,7 @@ extern int EXPORT deflate OF((z_streamp strm, int flush)); */ -extern int EXPORT deflateEnd OF((z_streamp strm)); +extern 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 @@ -282,24 +290,35 @@ extern int EXPORT deflateEnd OF((z_streamp strm)); /* -extern int EXPORT inflateInit OF((z_streamp strm)); +extern 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)); +extern 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 @@ -320,9 +339,9 @@ extern int EXPORT inflate OF((z_streamp strm, int flush)); 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 + If the parameter flush is set to Z_SYNC_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 + not specified for values of the flush parameter other than Z_SYNC_FLUSH and Z_FINISH, but the current implementation actually flushes as much output as possible anyway. @@ -337,22 +356,30 @@ extern int EXPORT inflate OF((z_streamp strm, int flush)); is never required, but can be used to inform inflate that a faster routine may be used for the single inflate() call. - inflate() returns Z_OK if some progress has been made (more input - processed or more output produced), Z_STREAM_END if the end of the - compressed data has been reached and all uncompressed output has been - produced, Z_NEED_DICT if a preset dictionary is needed at this point (see - inflateSetDictionary below), Z_DATA_ERROR if the input data was corrupted, - Z_STREAM_ERROR if the stream structure was inconsistent (for example if - next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, - Z_BUF_ERROR if no progress is possible or if there was not enough room in - the output buffer when Z_FINISH is used. In the Z_DATA_ERROR case, the - application may then call inflateSync to look for a good compression block. - In the Z_NEED_DICT case, strm->adler is set to the Adler32 value of the - dictionary chosen by the compressor. + If a preset dictionary is needed at this point (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() 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 + adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent + (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not + enough memory, Z_BUF_ERROR if no progress is possible or if there was not + enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR + case, the application may then call inflateSync to look for a good + compression block. */ -extern int EXPORT inflateEnd OF((z_streamp strm)); +extern 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 @@ -370,26 +397,25 @@ extern int EXPORT inflateEnd OF((z_streamp strm)); */ /* -extern int EXPORT deflateInit2 OF((z_streamp strm, - int level, - int method, - int windowBits, - int memLevel, - int strategy)); +extern 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. The memLevel parameter specifies how much memory should be allocated for the internal compression state. memLevel=1 uses minimum memory but @@ -408,42 +434,35 @@ extern int EXPORT deflateInit2 OF((z_streamp strm, 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 +extern 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 or deflateInit2, before any call of + deflate. The compressor and decompressor must use exactly the same dictionary (see inflateSetDictionary). + The dictionary should consist of strings (byte sequences) that are likely to be encountered later in the data to be compressed, with the most commonly used strings preferably put towards the end of the dictionary. Using a - dictionary is most useful when the data to be compressed is short and - can be predicted with good accuracy; the data can then be compressed better - than with the default empty dictionary. In this version of the library, - only the last 32K bytes of the dictionary are used. + 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 @@ -451,21 +470,16 @@ extern int EXPORT deflateSetDictionary OF((z_streamp strm, actually used by the compressor.) deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a - parameter is invalid (such as NULL dictionary) or the stream state - is inconsistent (for example if deflate has already been called for this - stream). deflateSetDictionary does not perform any compression: this will - be done by deflate(). + 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)); +extern 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 @@ -480,7 +494,7 @@ extern int EXPORT deflateCopy OF((z_streamp dest, destination. */ -extern int EXPORT deflateReset OF((z_streamp strm)); +extern 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. @@ -491,14 +505,15 @@ extern int EXPORT deflateReset OF((z_streamp strm)); stream state was inconsistent (such as zalloc or state being NULL). */ -extern int EXPORT deflateParams OF((z_streamp strm, int level, int strategy)); +extern 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 @@ -510,49 +525,37 @@ extern int EXPORT deflateParams OF((z_streamp strm, int level, int strategy)); */ /* -extern int EXPORT inflateInit2 OF((z_streamp strm, - int windowBits)); +extern 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. + + 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)); +extern 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 @@ -563,14 +566,14 @@ extern int EXPORT inflateSetDictionary OF((z_streamp strm, inflate(). */ -extern int EXPORT inflateSync OF((z_streamp strm)); +extern 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 @@ -578,7 +581,7 @@ extern int EXPORT inflateSync OF((z_streamp strm)); until success or end of the input data. */ -extern int EXPORT inflateReset OF((z_streamp strm)); +extern 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. @@ -594,13 +597,13 @@ extern int EXPORT inflateReset OF((z_streamp strm)); /* 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)); +extern 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 @@ -614,8 +617,23 @@ extern int EXPORT compress OF((Bytef *dest, uLongf *destLen, buffer. */ -extern int EXPORT uncompress OF((Bytef *dest, uLongf *destLen, - const Bytef *source, uLong sourceLen)); +extern 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 0.1% larger than sourceLen plus + 12 bytes. 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. +*/ + +extern 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 @@ -635,19 +653,23 @@ extern int EXPORT uncompress OF((Bytef *dest, uLongf *destLen, typedef voidp gzFile; -extern gzFile EXPORT gzopen OF((const char *path, const char *mode)); +extern 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)); +extern 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 @@ -660,7 +682,15 @@ extern gzFile EXPORT gzdopen OF((int fd, const char *mode)); the (de)compression state. */ -extern int EXPORT gzread OF((gzFile file, voidp buf, unsigned len)); +extern 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. +*/ + +extern 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 @@ -668,14 +698,49 @@ extern int EXPORT gzread OF((gzFile file, voidp buf, unsigned len)); 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)); +extern int ZEXPORT gzwrite OF((gzFile file, const voidp buf, unsigned len)); /* Writes the given number of uncompressed bytes into the compressed file. gzwrite returns the number of uncompressed bytes actually written (0 in case of error). */ -extern int EXPORT gzflush OF((gzFile file, int flush)); +extern 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). +*/ + +extern 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. +*/ + +extern 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. +*/ + +extern 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. +*/ + +extern 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. +*/ + +extern 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 @@ -685,14 +750,53 @@ extern int EXPORT gzflush OF((gzFile file, int flush)); degrade compression. */ -extern int EXPORT gzclose OF((gzFile file)); +extern 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. +*/ + +extern 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) +*/ + +extern 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) +*/ + +extern int ZEXPORT gzeof OF((gzFile file)); +/* + Returns 1 when EOF has previously been detected reading the given + input stream, otherwise zero. +*/ + +extern 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)); +extern 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 @@ -709,7 +813,7 @@ extern const char * EXPORT gzerror OF((gzFile file, int *errnum)); compression library. */ -extern uLong EXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); +extern 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 @@ -726,7 +830,7 @@ extern uLong EXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); if (adler != original_adler) error(); */ -extern uLong EXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); +extern 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 @@ -748,30 +852,34 @@ extern uLong EXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); /* 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)); +extern int ZEXPORT deflateInit_ OF((z_streamp strm, int level, + const char *version, int stream_size)); +extern int ZEXPORT inflateInit_ OF((z_streamp strm, + const char *version, int stream_size)); +extern int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, + int windowBits, int memLevel, + int strategy, const char *version, + int stream_size)); +extern int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, + const char *version, int stream_size)); #define deflateInit(strm, level) \ deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) #define inflateInit(strm) \ inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ - (strategy), ZLIB_VERSION, sizeof(z_stream)) + (strategy), ZLIB_VERSION, sizeof(z_stream)) #define inflateInit2(strm, windowBits) \ inflateInit2_((strm), (windowBits), 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() */ +extern const char * ZEXPORT zError OF((int err)); +extern int ZEXPORT inflateSyncPoint OF((z_streamp z)); +extern const uLongf * ZEXPORT get_crc_table OF((void)); #ifdef __cplusplus } |
