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Diffstat (limited to 'sys/lib/libz/zlib.h')
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diff --git a/sys/lib/libz/zlib.h b/sys/lib/libz/zlib.h new file mode 100644 index 00000000000..337fe9fe8a3 --- /dev/null +++ b/sys/lib/libz/zlib.h @@ -0,0 +1,780 @@ +/* zlib.h -- interface of the 'zlib' general purpose compression library + version 1.0.4, Jul 24th, 1996. + + Copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. + + Jean-loup Gailly Mark Adler + gzip@prep.ai.mit.edu madler@alumni.caltech.edu + + + The data format used by the zlib library is described by RFCs (Request for + Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt + (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). +*/ + +#ifndef _ZLIB_H +#define _ZLIB_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include "zconf.h" + +#define ZLIB_VERSION "1.0.4" + +/* + 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 + 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. +*/ + +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. + 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 +#define Z_SYNC_FLUSH 2 +#define Z_FULL_FLUSH 3 +#define Z_FINISH 4 +/* Allowed flush values; see deflate() below for details */ + +#define Z_OK 0 +#define Z_STREAM_END 1 +#define Z_NEED_DICT 2 +#define Z_ERRNO (-1) +#define Z_STREAM_ERROR (-2) +#define Z_DATA_ERROR (-3) +#define Z_MEM_ERROR (-4) +#define Z_BUF_ERROR (-5) +#define Z_VERSION_ERROR (-6) +/* Return codes for the compression/decompression functions. Negative + * values are errors, positive values are used for special but normal events. + */ + +#define Z_NO_COMPRESSION 0 +#define Z_BEST_SPEED 1 +#define Z_BEST_COMPRESSION 9 +#define Z_DEFAULT_COMPRESSION (-1) +/* compression levels */ + +#define Z_FILTERED 1 +#define Z_HUFFMAN_ONLY 2 +#define Z_DEFAULT_STRATEGY 0 +/* compression strategy; see deflateInit2() below for details */ + +#define Z_BINARY 0 +#define Z_ASCII 1 +#define Z_UNKNOWN 2 +/* Possible values of the data_type field */ + +#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 */ + +extern const char * EXPORT 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. + */ + +/* +extern int EXPORT 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(). +*/ + + +extern int EXPORT deflate OF((z_streamp strm, int flush)); +/* + Performs one or both of the following actions: + + - Compress more input starting at next_in and update next_in and avail_in + accordingly. If not all input can be processed (because there is not + enough room in the output buffer), next_in and avail_in are updated and + processing will resume at this point for the next call of deflate(). + + - Provide more output starting at next_out and update next_out and avail_out + accordingly. This action is forced if the parameter flush is non zero. + Forcing flush frequently degrades the compression ratio, so this parameter + should be set only when necessary (in interactive applications). + Some output may be provided even if flush is not set. + + Before the call of deflate(), the application should ensure that at least + one of the actions is possible, by providing more input and/or consuming + more output, and updating avail_in or avail_out accordingly; avail_out + should never be zero before the call. The application can consume the + compressed output when it wants, for example when the output buffer is full + (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK + and with zero avail_out, it must be called again after making room in the + output buffer because there might be more output pending. + + If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression + block is terminated and flushed to the output buffer so that the + decompressor can get all input data available so far. For method 9, a future + variant on method 8, the current block will be flushed but not terminated. + Z_SYNC_FLUSH has the same effect as partial flush except that the compressed + output is byte aligned (the compressor can clear its internal bit buffer) + and the current block is always terminated; this can be useful if the + compressor has to be restarted from scratch after an interruption (in which + case the internal state of the compressor may be lost). + If flush is set to Z_FULL_FLUSH, the compression block is terminated, a + special marker is output and the compression dictionary is discarded; this + is useful to allow the decompressor to synchronize if one compressed block + has been damaged (see inflateSync below). Flushing degrades compression and + so should be used only when necessary. Using Z_FULL_FLUSH too often can + seriously degrade the compression. If deflate returns with avail_out == 0, + this function must be called again with the same value of the flush + parameter and more output space (updated avail_out), until the flush is + complete (deflate returns with non-zero avail_out). + + If the parameter flush is set to Z_FINISH, pending input is processed, + pending output is flushed and deflate returns with Z_STREAM_END if there + was enough output space; if deflate returns with Z_OK, this function must be + called again with Z_FINISH and more output space (updated avail_out) but no + more input data, until it returns with Z_STREAM_END or an error. After + deflate has returned Z_STREAM_END, the only possible operations on the + stream are deflateReset or deflateEnd. + + Z_FINISH can be used immediately after deflateInit if all the compression + is to be done in a single step. In this case, avail_out must be at least + 0.1% larger than avail_in plus 12 bytes. If deflate does not return + Z_STREAM_END, then it must be called again as described above. + + deflate() may update data_type if it can make a good guess about + the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered + binary. This field is only for information purposes and does not affect + the compression algorithm in any manner. + + deflate() returns Z_OK if some progress has been made (more input + processed or more output produced), Z_STREAM_END if all input has been + consumed and all output has been produced (only when flush is set to + Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example + if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible. +*/ + + +extern int EXPORT 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). +*/ + + +/* +extern int EXPORT 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. + + inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not + enough memory, Z_VERSION_ERROR if the zlib library version is incompatible + with the version assumed by the caller. msg is set to null if there is no + error message. inflateInit does not perform any decompression: this will be + done by inflate(). +*/ + + +extern int EXPORT inflate OF((z_streamp strm, int flush)); +/* + Performs one or both of the following actions: + + - Decompress more input starting at next_in and update next_in and avail_in + accordingly. If not all input can be processed (because there is not + enough room in the output buffer), next_in is updated and processing + will resume at this point for the next call of inflate(). + + - Provide more output starting at next_out and update next_out and avail_out + accordingly. inflate() provides as much output as possible, until there + is no more input data or no more space in the output buffer (see below + about the flush parameter). + + Before the call of inflate(), the application should ensure that at least + one of the actions is possible, by providing more input and/or consuming + more output, and updating the next_* and avail_* values accordingly. + The application can consume the uncompressed output when it wants, for + example when the output buffer is full (avail_out == 0), or after each + call of inflate(). If inflate returns Z_OK and with zero avail_out, it + must be called again after making room in the output buffer because there + might be more output pending. + + If the parameter flush is set to Z_PARTIAL_FLUSH, inflate flushes as much + output as possible to the output buffer. The flushing behavior of inflate is + not specified for values of the flush parameter other than Z_PARTIAL_FLUSH + and Z_FINISH, but the current implementation actually flushes as much output + as possible anyway. + + inflate() should normally be called until it returns Z_STREAM_END or an + error. However if all decompression is to be performed in a single step + (a single call of inflate), the parameter flush should be set to + Z_FINISH. In this case all pending input is processed and all pending + output is flushed; avail_out must be large enough to hold all the + uncompressed data. (The size of the uncompressed data may have been saved + by the compressor for this purpose.) The next operation on this stream must + be inflateEnd to deallocate the decompression state. The use of Z_FINISH + is never required, but can be used to inform inflate that a faster routine + may be used for the single inflate() call. + + inflate() returns Z_OK if some progress has been made (more input + processed or more output produced), Z_STREAM_END if the end of the + compressed data has been reached and all uncompressed output has been + produced, Z_NEED_DICT if a preset dictionary is needed at this point (see + inflateSetDictionary below), Z_DATA_ERROR if the input data was corrupted, + Z_STREAM_ERROR if the stream structure was inconsistent (for example if + next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, + Z_BUF_ERROR if no progress is possible or if there was not enough room in + the output buffer when Z_FINISH is used. In the Z_DATA_ERROR case, the + application may then call inflateSync to look for a good compression block. + In the Z_NEED_DICT case, strm->adler is set to the Adler32 value of the + dictionary chosen by the compressor. +*/ + + +extern int EXPORT 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. +*/ + +/* +extern int EXPORT 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.) + + The windowBits parameter is the base two logarithm of the window size + (the size of the history buffer). It should be in the range 8..15 for this + version of the library (the value 16 will be allowed for method 9). Larger + values of this parameter result in better compression at the expense of + memory usage. The default value is 15 if deflateInit is used instead. + + The memLevel parameter specifies how much memory should be allocated + for the internal compression state. memLevel=1 uses minimum memory but + is slow and reduces compression ratio; memLevel=9 uses maximum memory + for optimal speed. The default value is 8. See zconf.h for total memory + usage as a function of windowBits and memLevel. + + The strategy parameter is used to tune the compression algorithm. Use the + value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a + filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no + string match). Filtered data consists mostly of small values with a + somewhat random distribution. In this case, the compression algorithm is + tuned to compress them better. The effect of Z_FILTERED is to force more + Huffman coding and less string matching; it is somewhat intermediate + between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects + the compression ratio but not the correctness of the compressed output even + if it is not set appropriately. + + If next_in is not null, the library will use this buffer to hold also + some history information; the buffer must either hold the entire input + data, or have at least 1<<(windowBits+1) bytes and be writable. If next_in + is null, the library will allocate its own history buffer (and leave next_in + null). next_out need not be provided here but must be provided by the + application for the next call of deflate(). + + If the history buffer is provided by the application, next_in must + must never be changed by the application since the compressor maintains + information inside this buffer from call to call; the application + must provide more input only by increasing avail_in. next_in is always + reset by the library in this case. + + deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was + not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as + an invalid method). msg is set to null if there is no error message. + deflateInit2 does not perform any compression: this will be done by + deflate(). +*/ + +extern int 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 + dictionary (see inflateSetDictionary). + The dictionary should consist of strings (byte sequences) that are likely + to be encountered later in the data to be compressed, with the most commonly + used strings preferably put towards the end of the dictionary. Using a + dictionary is most useful when the data to be compressed is short and + can be predicted with good accuracy; the data can then be compressed better + than with the default empty dictionary. In this version of the library, + only the last 32K bytes of the dictionary are used. + Upon return of this function, strm->adler is set to the Adler32 value + of the dictionary; the decompressor may later use this value to determine + which dictionary has been used by the compressor. (The Adler32 value + applies to the whole dictionary even if only a subset of the dictionary is + actually used by the compressor.) + + deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a + parameter is invalid (such as NULL dictionary) or the stream state + is inconsistent (for example if deflate has already been called for this + stream). deflateSetDictionary does not perform any compression: this will + be done by deflate(). +*/ + +extern int EXPORT 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. + + 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. +*/ + +extern int EXPORT 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). +*/ + +extern int EXPORT 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(). + + 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. +*/ + +/* +extern int EXPORT 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. + + The windowBits parameter is the base two logarithm of the maximum window + size (the size of the history buffer). It should be in the range 8..15 for + this version of the library (the value 16 will be allowed soon). The + default value is 15 if inflateInit is used instead. If a compressed stream + with a larger window size is given as input, inflate() will return with + the error code Z_DATA_ERROR instead of trying to allocate a larger window. + + If next_out is not null, the library will use this buffer for the history + buffer; the buffer must either be large enough to hold the entire output + data, or have at least 1<<windowBits bytes. If next_out is null, the + library will allocate its own buffer (and leave next_out null). next_in + need not be provided here but must be provided by the application for the + next call of inflate(). + + If the history buffer is provided by the application, next_out must + never be changed by the application since the decompressor maintains + history information inside this buffer from call to call; the application + can only reset next_out to the beginning of the history buffer when + avail_out is zero and all output has been consumed. + + inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was + not enough memory, Z_STREAM_ERROR if a parameter is invalid (such as + windowBits < 8). msg is set to null if there is no error message. + inflateInit2 does not perform any decompression: this will be done by + inflate(). +*/ + +extern int EXPORT 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 + dictionary (see deflateSetDictionary). + + inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a + parameter is invalid (such as NULL dictionary) or the stream state is + inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the + expected one (incorrect Adler32 value). inflateSetDictionary does not + perform any decompression: this will be done by subsequent calls of + inflate(). +*/ + +extern int EXPORT 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. + + inflateSync returns Z_OK if the special marker has been found, Z_BUF_ERROR + if no more input was provided, Z_DATA_ERROR if no marker has been found, + or Z_STREAM_ERROR if the stream structure was inconsistent. In the success + case, the application may save the current current value of total_in which + indicates where valid compressed data was found. In the error case, the + application may repeatedly call inflateSync, providing more input each time, + until success or end of the input data. +*/ + +extern int EXPORT 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). +*/ + + + /* utility functions */ + +/* + The following utility functions are implemented on top of the + basic stream-oriented functions. To simplify the interface, some + default options are assumed (compression level, window size, + standard memory allocation functions). The source code of these + utility functions can easily be modified if you need special options. +*/ + +extern int EXPORT compress OF((Bytef *dest, uLongf *destLen, + const Bytef *source, uLong sourceLen)); +/* + Compresses the source buffer into the destination buffer. sourceLen is + the byte length of the source buffer. Upon entry, destLen is the total + size of the destination buffer, which must be at least 0.1% larger than + sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the + compressed buffer. + This function can be used to compress a whole file at once if the + input file is mmap'ed. + compress returns Z_OK if success, Z_MEM_ERROR if there was not + enough memory, Z_BUF_ERROR if there was not enough room in the output + buffer. +*/ + +extern int EXPORT 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. +*/ + + +typedef voidp gzFile; + +extern gzFile EXPORT 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. + gzopen returns NULL if the file could not be opened or if there was + insufficient memory to allocate the (de)compression state; errno + can be checked to distinguish the two cases (if errno is zero, the + zlib error is Z_MEM_ERROR). +*/ + +extern gzFile EXPORT 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. +*/ + +extern int EXPORT 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). */ + +extern int EXPORT 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)); +/* + 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. +*/ + +extern int EXPORT 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)); +/* + Returns the error message for the last error which occurred on the + given compressed file. errnum is set to zlib error number. If an + error occurred in the file system and not in the compression library, + errnum is set to Z_ERRNO and the application may consult errno + to get the exact error code. +*/ + + /* checksum functions */ + +/* + These functions are not related to compression but are exported + anyway because they might be useful in applications using the + compression library. +*/ + +extern uLong EXPORT 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(); +*/ + +extern uLong EXPORT 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: + */ +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)); +#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)) + +#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() */ + +#ifdef __cplusplus +} +#endif + +#endif /* _ZLIB_H */ |