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Diffstat (limited to 'libs/zlib/src/zlib.h')
| -rw-r--r-- | libs/zlib/src/zlib.h | 3870 |
1 files changed, 1935 insertions, 1935 deletions
diff --git a/libs/zlib/src/zlib.h b/libs/zlib/src/zlib.h index 4916b4d4b9..e9104e9239 100644 --- a/libs/zlib/src/zlib.h +++ b/libs/zlib/src/zlib.h @@ -1,1935 +1,1935 @@ -/* zlib.h -- interface of the 'zlib' general purpose compression library - version 1.2.12, March 11th, 2022 - - Copyright (C) 1995-2022 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://tools.ietf.org/html/rfc1950 - (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). -*/ - -#ifndef ZLIB_H -#define ZLIB_H - -#include "zconf.h" - -#ifdef __cplusplus -extern "C" { -#endif - -#define ZLIB_VERSION "1.2.12" -#define ZLIB_VERNUM 0x12c0 -#define ZLIB_VER_MAJOR 1 -#define ZLIB_VER_MINOR 2 -#define ZLIB_VER_REVISION 12 -#define ZLIB_VER_SUBREVISION 0 - -/* - The 'zlib' compression library provides in-memory compression and - decompression functions, including integrity checks of the uncompressed data. - This version of the library supports only one compression method (deflation) - but other algorithms 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, - 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 and raw deflate 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 the 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 { - z_const Bytef *next_in; /* next input byte */ - uInt avail_in; /* number of bytes available at next_in */ - uLong total_in; /* total number of input bytes read so far */ - - Bytef *next_out; /* next output byte will go here */ - uInt avail_out; /* remaining free space at next_out */ - uLong total_out; /* total number of bytes output so far */ - - z_const 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: binary or text - for deflate, or the decoding state for inflate */ - uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */ - uLong reserved; /* reserved for future use */ -} z_stream; - -typedef z_stream FAR *z_streamp; - -/* - gzip header information passed to and from zlib routines. See RFC 1952 - for more details on the meanings of these fields. -*/ -typedef struct gz_header_s { - int text; /* true if compressed data believed to be text */ - uLong time; /* modification time */ - int xflags; /* extra flags (not used when writing a gzip file) */ - int os; /* operating system */ - Bytef *extra; /* pointer to extra field or Z_NULL if none */ - uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ - uInt extra_max; /* space at extra (only when reading header) */ - Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ - uInt name_max; /* space at name (only when reading header) */ - Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ - uInt comm_max; /* space at comment (only when reading header) */ - int hcrc; /* true if there was or will be a header crc */ - int done; /* true when done reading gzip header (not used - when writing a gzip file) */ -} gz_header; - -typedef gz_header FAR *gz_headerp; - -/* - 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. In that case, zlib is thread-safe. When zalloc and zfree are - Z_NULL on entry to the initialization function, they are set to internal - routines that use the standard library functions malloc() and free(). - - 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 by 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 -#define Z_BLOCK 5 -#define Z_TREES 6 -/* 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_FIXED 4 -#define Z_DEFAULT_STRATEGY 0 -/* compression strategy; see deflateInit2() below for details */ - -#define Z_BINARY 0 -#define Z_TEXT 1 -#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ -#define Z_UNKNOWN 2 -/* Possible values of the data_type field for deflate() */ - -#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, or - 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(). - - - Generate 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. Some output may be provided even if - flush is zero. - - 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. See deflatePending(), - which can be used if desired to determine whether or not there is more ouput - in that case. - - Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to - decide how much data to accumulate before producing output, in order to - maximize compression. - - 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. This - completes the current deflate block and follows it with an empty stored block - that is three bits plus filler bits to the next byte, followed by four bytes - (00 00 ff ff). - - If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the - output buffer, but the output is not aligned to a byte boundary. All of the - input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. - This completes the current deflate block and follows it with an empty fixed - codes block that is 10 bits long. This assures that enough bytes are output - in order for the decompressor to finish the block before the empty fixed - codes block. - - If flush is set to Z_BLOCK, a deflate block is completed and emitted, as - for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to - seven bits of the current block are held to be written as the next byte after - the next deflate block is completed. In this case, the decompressor may not - be provided enough bits at this point in order to complete decompression of - the data provided so far to the compressor. It may need to wait for the next - block to be emitted. This is for advanced applications that need to control - the emission of deflate blocks. - - 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 - 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 or Z_BUF_ERROR, 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 in the first deflate call after deflateInit if all the - compression is to be done in a single step. In order to complete in one - call, avail_out must be at least the value returned by deflateBound (see - below). Then deflate is guaranteed to return Z_STREAM_END. If not enough - output space is provided, deflate will not return Z_STREAM_END, and it must - be called again as described above. - - deflate() sets strm->adler to the Adler-32 checksum of all input read - so far (that is, total_in bytes). If a gzip stream is being generated, then - strm->adler will be the CRC-32 checksum of the input read so far. (See - deflateInit2 below.) - - deflate() may update strm->data_type if it can make a good guess about - the input data type (Z_BINARY or Z_TEXT). If 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 Z_NULL or the state was inadvertently written over - by the application), or 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. In the current version of inflate, the provided input is not - read or consumed. The allocation of a sliding window will be deferred to - the first call of inflate (if the decompression does not complete on the - first call). 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, or Z_STREAM_ERROR if the parameters are - invalid, such as a null pointer to the structure. msg is set to null if - there is no error message. inflateInit does not perform any decompression. - Actual decompression will be done by inflate(). So next_in, and avail_in, - next_out, and avail_out are unused and unchanged. The current - implementation of inflateInit() does not process any header information -- - that is deferred until inflate() is called. -*/ - - -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), then next_in and avail_in are updated - accordingly, and processing will resume at this point for the next call of - inflate(). - - - Generate 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. If the - caller of inflate() does not provide both available input and available - output space, it is possible that there will be no progress made. 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, - Z_BLOCK, or Z_TREES. 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 gets 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. - To assist in this, on return inflate() always sets 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. data_type is set as noted here every time inflate() returns for all - flush options, and so can be used to determine the amount of currently - consumed input in bits. - - The Z_TREES option behaves as Z_BLOCK does, but it also returns when the - end of each deflate block header is reached, before any actual data in that - block is decoded. This allows the caller to determine the length of the - deflate block header for later use in random access within a deflate block. - 256 is added to the value of strm->data_type when inflate() returns - immediately after reaching the end of the deflate block header. - - 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 of the uncompressed data for the - operation to complete. (The size of the uncompressed data may have been - saved by the compressor for this purpose.) The use of Z_FINISH is not - required to perform an inflation in one step. However it may be used to - inform inflate that a faster approach can be used for the single inflate() - call. Z_FINISH also informs inflate to not maintain a sliding window if the - stream completes, which reduces inflate's memory footprint. If the stream - does not complete, either because not all of the stream is provided or not - enough output space is provided, then a sliding window will be allocated and - inflate() can be called again to continue the operation as if Z_NO_FLUSH had - been used. - - 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 effects of the flush parameter in this implementation are - on the return value of inflate() as noted below, when inflate() returns early - when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of - memory for a sliding window when Z_FINISH is used. - - If a preset dictionary is needed after this call (see inflateSetDictionary - below), inflate sets strm->adler to the Adler-32 checksum of the dictionary - chosen by the compressor and returns Z_NEED_DICT; otherwise it sets - strm->adler to the Adler-32 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 Adler-32 - checksum is equal to that saved by the compressor and returns Z_STREAM_END - only if the checksum is correct. - - inflate() can decompress and check either zlib-wrapped or gzip-wrapped - deflate data. The header type is detected automatically, if requested when - initializing with inflateInit2(). Any information contained in the gzip - header is not retained unless inflateGetHeader() is used. When processing - gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output - produced so far. The CRC-32 is checked against the gzip trailer, as is the - uncompressed length, modulo 2^32. - - 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, in which case strm->msg points to a string with a more specific - error), Z_STREAM_ERROR if the stream structure was inconsistent (for example - next_in or next_out was Z_NULL, or the state was inadvertently written over - by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR - if no progress was 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 to be attempted. -*/ - - -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, or Z_STREAM_ERROR if the stream state - was inconsistent. -*/ - - - /* 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 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. - - For the current implementation of deflate(), a windowBits value of 8 (a - window size of 256 bytes) is not supported. As a result, a request for 8 - will result in 9 (a 512-byte window). In that case, providing 8 to - inflateInit2() will result in an error when the zlib header with 9 is - checked against the initialization of inflate(). The remedy is to not use 8 - with deflateInit2() with this initialization, or at least in that case use 9 - with inflateInit2(). - - 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 a 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 the appropriate value, - if the operating system was determined at compile time. If a gzip stream is - being written, strm->adler is a CRC-32 instead of an Adler-32. - - For raw deflate or gzip encoding, a request for a 256-byte window is - rejected as invalid, since only the zlib header provides a means of - transmitting the window size to the decompressor. - - 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_STRATEGY 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. - Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler - decoder for special applications. - - deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid - method), or 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. 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. When using the zlib format, this - function must be called immediately after deflateInit, deflateInit2 or - deflateReset, and before any call of deflate. When doing raw deflate, this - function must be called either before any call of deflate, or immediately - after the completion of a deflate block, i.e. after all input has been - consumed and all output has been delivered when using any of the flush - options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. 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 - provided in deflateInit or deflateInit2. Thus the strings most likely to be - useful should be put at the end of the dictionary, not at the front. In - addition, the current implementation of deflate will use at most the window - size minus 262 bytes of the provided dictionary. - - Upon return of this function, strm->adler is set to the Adler-32 value - of the dictionary; the decompressor may later use this value to determine - which dictionary has been used by the compressor. (The Adler-32 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 - Adler-32 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 (e.g. dictionary being Z_NULL) or the stream state is - inconsistent (for example if deflate has already been called for this stream - or if not at a block boundary for raw deflate). deflateSetDictionary does - not perform any compression: this will be done by deflate(). -*/ - -ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm, - Bytef *dictionary, - uInt *dictLength)); -/* - Returns the sliding dictionary being maintained by deflate. dictLength is - set to the number of bytes in the dictionary, and that many bytes are copied - to dictionary. dictionary must have enough space, where 32768 bytes is - always enough. If deflateGetDictionary() is called with dictionary equal to - Z_NULL, then only the dictionary length is returned, and nothing is copied. - Similary, if dictLength is Z_NULL, then it is not set. - - deflateGetDictionary() may return a length less than the window size, even - when more than the window size in input has been provided. It may return up - to 258 bytes less in that case, due to how zlib's implementation of deflate - manages the sliding window and lookahead for matches, where matches can be - up to 258 bytes long. If the application needs the last window-size bytes of - input, then that would need to be saved by the application outside of zlib. - - deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the - stream state is inconsistent. -*/ - -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 Z_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 the internal compression state. The stream - will leave the compression level and any other attributes that may have been - set unchanged. - - deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being Z_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 approach (which is a function of the level) or the - strategy is changed, and if there have been any deflate() calls since the - state was initialized or reset, then the input available so far is - compressed with the old level and strategy using deflate(strm, Z_BLOCK). - There are three approaches for the compression levels 0, 1..3, and 4..9 - respectively. The new level and strategy will take effect at the next call - of deflate(). - - If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does - not have enough output space to complete, then the parameter change will not - take effect. In this case, deflateParams() can be called again with the - same parameters and more output space to try again. - - In order to assure a change in the parameters on the first try, the - deflate stream should be flushed using deflate() with Z_BLOCK or other flush - request until strm.avail_out is not zero, before calling deflateParams(). - Then no more input data should be provided before the deflateParams() call. - If this is done, the old level and strategy will be applied to the data - compressed before deflateParams(), and the new level and strategy will be - applied to the the data compressed after deflateParams(). - - deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream - state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if - there was not enough output space to complete the compression of the - available input data before a change in the strategy or approach. Note that - in the case of a Z_BUF_ERROR, the parameters are not changed. A return - value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be - retried with more output space. -*/ - -ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, - int good_length, - int max_lazy, - int nice_length, - int max_chain)); -/* - Fine tune deflate's internal compression parameters. This should only be - used by someone who understands the algorithm used by zlib's deflate for - searching for the best matching string, and even then only by the most - fanatic optimizer trying to squeeze out the last compressed bit for their - specific input data. Read the deflate.c source code for the meaning of the - max_lazy, good_length, nice_length, and max_chain parameters. - - deflateTune() can be called after deflateInit() or deflateInit2(), and - returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. - */ - -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(), and after deflateSetHeader(), if used. This would be used - to allocate an output buffer for deflation in a single pass, and so would be - called before deflate(). If that first deflate() call is provided the - sourceLen input bytes, an output buffer allocated to the size returned by - deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed - to return Z_STREAM_END. Note that it is possible for the compressed size to - be larger than the value returned by deflateBound() if flush options other - than Z_FINISH or Z_NO_FLUSH are used. -*/ - -ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, - unsigned *pending, - int *bits)); -/* - deflatePending() returns the number of bytes and bits of output that have - been generated, but not yet provided in the available output. The bytes not - provided would be due to the available output space having being consumed. - The number of bits of output not provided are between 0 and 7, where they - await more bits to join them in order to fill out a full byte. If pending - or bits are Z_NULL, then those values are not set. - - deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent. - */ - -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, Z_BUF_ERROR if there was not enough - room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the - source stream state was inconsistent. -*/ - -ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, - gz_headerp head)); -/* - deflateSetHeader() provides gzip header information for when a gzip - stream is requested by deflateInit2(). deflateSetHeader() may be called - after deflateInit2() or deflateReset() and before the first call of - deflate(). The text, time, os, extra field, name, and comment information - in the provided gz_header structure are written to the gzip header (xflag is - ignored -- the extra flags are set according to the compression level). The - caller must assure that, if not Z_NULL, name and comment are terminated with - a zero byte, and that if extra is not Z_NULL, that extra_len bytes are - available there. If hcrc is true, a gzip header crc is included. Note that - the current versions of the command-line version of gzip (up through version - 1.3.x) do not support header crc's, and will report that it is a "multi-part - gzip file" and give up. - - If deflateSetHeader is not used, the default gzip header has text false, - the time set to zero, and os set to 255, with no extra, name, or comment - fields. The gzip header is returned to the default state by deflateReset(). - - deflateSetHeader 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 zero to request that inflate use the window size in - the zlib header of the compressed stream. - - 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 Adler-32 or a CRC-32 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 - CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see - below), inflate() will *not* automatically decode concatenated gzip members. - inflate() will return Z_STREAM_END at the end of the gzip member. The state - would need to be reset to continue decoding a subsequent gzip member. This - *must* be done if there is more data after a gzip member, in order for the - decompression to be compliant with the gzip standard (RFC 1952). - - inflateInit2 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, or Z_STREAM_ERROR if the parameters are - invalid, such as a null pointer to the structure. msg is set to null if - there is no error message. inflateInit2 does not perform any decompression - apart from possibly reading the zlib header if present: actual decompression - will be done by inflate(). (So next_in and avail_in may be modified, but - next_out and avail_out are unused and unchanged.) The current implementation - of inflateInit2() does not process any header information -- that is - deferred until inflate() is called. -*/ - -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 that call returned Z_NEED_DICT. The dictionary chosen by the compressor - can be determined from the Adler-32 value returned by that call of inflate. - The compressor and decompressor must use exactly the same dictionary (see - deflateSetDictionary). For raw inflate, this function can be called at any - time to set the dictionary. If the provided dictionary is smaller than the - window and there is already data in the window, then the provided dictionary - will amend what's there. The application must insure that the dictionary - that was used for compression is provided. - - inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a - parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is - inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the - expected one (incorrect Adler-32 value). inflateSetDictionary does not - perform any decompression: this will be done by subsequent calls of - inflate(). -*/ - -ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, - Bytef *dictionary, - uInt *dictLength)); -/* - Returns the sliding dictionary being maintained by inflate. dictLength is - set to the number of bytes in the dictionary, and that many bytes are copied - to dictionary. dictionary must have enough space, where 32768 bytes is - always enough. If inflateGetDictionary() is called with dictionary equal to - Z_NULL, then only the dictionary length is returned, and nothing is copied. - Similary, if dictLength is Z_NULL, then it is not set. - - inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the - stream state is inconsistent. -*/ - -ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); -/* - Skips invalid compressed data until a possible full flush point (see above - for the description of deflate with Z_FULL_FLUSH) can be found, or until all - available input is skipped. No output is provided. - - inflateSync searches for a 00 00 FF FF pattern in the compressed data. - All full flush points have this pattern, but not all occurrences of this - pattern are full flush points. - - inflateSync returns Z_OK if a possible 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 Z_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 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 Z_NULL). -*/ - -ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, - int windowBits)); -/* - This function is the same as inflateReset, but it also permits changing - the wrap and window size requests. The windowBits parameter is interpreted - the same as it is for inflateInit2. If the window size is changed, then the - memory allocated for the window is freed, and the window will be reallocated - by inflate() if needed. - - inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being Z_NULL), or if - the windowBits parameter is invalid. -*/ - -ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, - int bits, - int value)); -/* - This function inserts bits in the inflate input stream. The intent is - that this function is used to start inflating at a bit position in the - middle of a byte. The provided bits will be used before any bytes are used - from next_in. This function should only be used with raw inflate, and - should be used before the first inflate() call after inflateInit2() or - inflateReset(). bits must be less than or equal to 16, and that many of the - least significant bits of value will be inserted in the input. - - If bits is negative, then the input stream bit buffer is emptied. Then - inflatePrime() can be called again to put bits in the buffer. This is used - to clear out bits leftover after feeding inflate a block description prior - to feeding inflate codes. - - inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent. -*/ - -ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); -/* - This function returns two values, one in the lower 16 bits of the return - value, and the other in the remaining upper bits, obtained by shifting the - return value down 16 bits. If the upper value is -1 and the lower value is - zero, then inflate() is currently decoding information outside of a block. - If the upper value is -1 and the lower value is non-zero, then inflate is in - the middle of a stored block, with the lower value equaling the number of - bytes from the input remaining to copy. If the upper value is not -1, then - it is the number of bits back from the current bit position in the input of - the code (literal or length/distance pair) currently being processed. In - that case the lower value is the number of bytes already emitted for that - code. - - A code is being processed if inflate is waiting for more input to complete - decoding of the code, or if it has completed decoding but is waiting for - more output space to write the literal or match data. - - inflateMark() is used to mark locations in the input data for random - access, which may be at bit positions, and to note those cases where the - output of a code may span boundaries of random access blocks. The current - location in the input stream can be determined from avail_in and data_type - as noted in the description for the Z_BLOCK flush parameter for inflate. - - inflateMark returns the value noted above, or -65536 if the provided - source stream state was inconsistent. -*/ - -ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, - gz_headerp head)); -/* - inflateGetHeader() requests that gzip header information be stored in the - provided gz_header structure. inflateGetHeader() may be called after - inflateInit2() or inflateReset(), and before the first call of inflate(). - As inflate() processes the gzip stream, head->done is zero until the header - is completed, at which time head->done is set to one. If a zlib stream is - being decoded, then head->done is set to -1 to indicate that there will be - no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be - used to force inflate() to return immediately after header processing is - complete and before any actual data is decompressed. - - The text, time, xflags, and os fields are filled in with the gzip header - contents. hcrc is set to true if there is a header CRC. (The header CRC - was valid if done is set to one.) If extra is not Z_NULL, then extra_max - contains the maximum number of bytes to write to extra. Once done is true, - extra_len contains the actual extra field length, and extra contains the - extra field, or that field truncated if extra_max is less than extra_len. - If name is not Z_NULL, then up to name_max characters are written there, - terminated with a zero unless the length is greater than name_max. If - comment is not Z_NULL, then up to comm_max characters are written there, - terminated with a zero unless the length is greater than comm_max. When any - of extra, name, or comment are not Z_NULL and the respective field is not - present in the header, then that field is set to Z_NULL to signal its - absence. This allows the use of deflateSetHeader() with the returned - structure to duplicate the header. However if those fields are set to - allocated memory, then the application will need to save those pointers - elsewhere so that they can be eventually freed. - - If inflateGetHeader is not used, then the header information is simply - discarded. The header is always checked for validity, including the header - CRC if present. inflateReset() will reset the process to discard the header - information. The application would need to call inflateGetHeader() again to - retrieve the header from the next gzip stream. - - inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent. -*/ - -/* -ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp 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 parameters 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 *, - z_const unsigned char FAR * FAR *)); -typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); - -ZEXTERN int ZEXPORT inflateBack OF((z_streamp 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 potentially 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. inflate() can be faster on modern CPUs when used with large - buffers. inflateBack() 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 default - behavior of inflate(), which expects a zlib 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_in 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_streamp 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: ZLIB_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) - */ - -#ifndef Z_SOLO - - /* 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 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 data. compress() is equivalent to compress2() with a level - parameter of Z_DEFAULT_COMPRESSION. - - 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 data. - - 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 uncompressed data. - - 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. In - the case where there is not enough room, uncompress() will fill the output - buffer with the uncompressed data up to that point. -*/ - -ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen, - const Bytef *source, uLong *sourceLen)); -/* - Same as uncompress, except that sourceLen is a pointer, where the - length of the source is *sourceLen. On return, *sourceLen is the number of - source bytes consumed. -*/ - - /* gzip file access functions */ - -/* - This library 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. -*/ - -typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ - -/* -ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); - - Open the gzip (.gz) file at path for reading and decompressing, or - compressing and 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", - 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression - as in "wb9F". (See the description of deflateInit2 for more information - about the strategy parameter.) 'T' will request transparent writing or - appending with no compression and not using the gzip format. - - "a" can be used instead of "w" to request that the gzip stream that will - be written be appended to the file. "+" will result in an error, since - reading and writing to the same gzip file is not supported. The addition of - "x" when writing will create the file exclusively, which fails if the file - already exists. On systems that support it, the addition of "e" when - reading or writing will set the flag to close the file on an execve() call. - - These functions, as well as gzip, will read and decode a sequence of gzip - streams in a file. The append function of gzopen() can be used to create - such a file. (Also see gzflush() for another way to do this.) When - appending, gzopen does not test whether the file begins with a gzip stream, - nor does it look for the end of the gzip streams to begin appending. gzopen - will simply append a gzip stream to the existing file. - - 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. When - reading, this will be detected automatically by looking for the magic two- - byte gzip header. - - gzopen returns NULL if the file could not be opened, if there was - insufficient memory to allocate the gzFile state, or if an invalid mode was - specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). - errno can be checked to determine if the reason gzopen failed was that the - file could not be opened. -*/ - -ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); -/* - Associate a gzFile with the file descriptor fd. File descriptors are - obtained from calls like open, dup, creat, pipe or fileno (if 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 fd = dup(fd_keep); gz = gzdopen(fd, - mode);. The duplicated descriptor should be saved to avoid a leak, since - gzdopen does not close fd if it fails. If you are using fileno() to get the - file descriptor from a FILE *, then you will have to use dup() to avoid - double-close()ing the file descriptor. Both gzclose() and fclose() will - close the associated file descriptor, so they need to have different file - descriptors. - - gzdopen returns NULL if there was insufficient memory to allocate the - gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not - provided, or '+' was provided), or if fd is -1. The file descriptor is not - used until the next gz* read, write, seek, or close operation, so gzdopen - will not detect if fd is invalid (unless fd is -1). -*/ - -ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); -/* - Set the internal buffer size used by this library's functions for file to - size. The default buffer size is 8192 bytes. This function must be called - after gzopen() or gzdopen(), and before any other calls that read or write - the file. The buffer memory allocation is always deferred to the first read - or write. Three times that size in buffer space is allocated. A larger - buffer size of, for example, 64K or 128K bytes will noticeably increase the - speed of decompression (reading). - - The new buffer size also affects the maximum length for gzprintf(). - - gzbuffer() returns 0 on success, or -1 on failure, such as being called - too late. -*/ - -ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); -/* - Dynamically update the compression level and strategy for file. See the - description of deflateInit2 for the meaning of these parameters. Previously - provided data is flushed before applying the parameter changes. - - gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not - opened for writing, Z_ERRNO if there is an error writing the flushed data, - or Z_MEM_ERROR if there is a memory allocation error. -*/ - -ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); -/* - Read and decompress up to len uncompressed bytes from file into buf. If - the input file is not in gzip format, gzread copies the given number of - bytes into the buffer directly from the file. - - After reaching the end of a gzip stream in the input, gzread will continue - to read, looking for another gzip stream. Any number of gzip streams may be - concatenated in the input file, and will all be decompressed by gzread(). - If something other than a gzip stream is encountered after a gzip stream, - that remaining trailing garbage is ignored (and no error is returned). - - gzread can be used to read a gzip file that is being concurrently written. - Upon reaching the end of the input, gzread will return with the available - data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then - gzclearerr can be used to clear the end of file indicator in order to permit - gzread to be tried again. Z_OK indicates that a gzip stream was completed - on the last gzread. Z_BUF_ERROR indicates that the input file ended in the - middle of a gzip stream. Note that gzread does not return -1 in the event - of an incomplete gzip stream. This error is deferred until gzclose(), which - will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip - stream. Alternatively, gzerror can be used before gzclose to detect this - case. - - gzread returns the number of uncompressed bytes actually read, less than - len for end of file, or -1 for error. If len is too large to fit in an int, - then nothing is read, -1 is returned, and the error state is set to - Z_STREAM_ERROR. -*/ - -ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems, - gzFile file)); -/* - Read and decompress up to nitems items of size size from file into buf, - otherwise operating as gzread() does. This duplicates the interface of - stdio's fread(), with size_t request and return types. If the library - defines size_t, then z_size_t is identical to size_t. If not, then z_size_t - is an unsigned integer type that can contain a pointer. - - gzfread() returns the number of full items read of size size, or zero if - the end of the file was reached and a full item could not be read, or if - there was an error. gzerror() must be consulted if zero is returned in - order to determine if there was an error. If the multiplication of size and - nitems overflows, i.e. the product does not fit in a z_size_t, then nothing - is read, zero is returned, and the error state is set to Z_STREAM_ERROR. - - In the event that the end of file is reached and only a partial item is - available at the end, i.e. the remaining uncompressed data length is not a - multiple of size, then the final partial item is nevetheless read into buf - and the end-of-file flag is set. The length of the partial item read is not - provided, but could be inferred from the result of gztell(). This behavior - is the same as the behavior of fread() implementations in common libraries, - but it prevents the direct use of gzfread() to read a concurrently written - file, reseting and retrying on end-of-file, when size is not 1. -*/ - -ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len)); -/* - Compress and write the len uncompressed bytes at buf to file. gzwrite - returns the number of uncompressed bytes written or 0 in case of error. -*/ - -ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size, - z_size_t nitems, gzFile file)); -/* - Compress and write nitems items of size size from buf to file, duplicating - the interface of stdio's fwrite(), with size_t request and return types. If - the library defines size_t, then z_size_t is identical to size_t. If not, - then z_size_t is an unsigned integer type that can contain a pointer. - - gzfwrite() returns the number of full items written of size size, or zero - if there was an error. If the multiplication of size and nitems overflows, - i.e. the product does not fit in a z_size_t, then nothing is written, zero - is returned, and the error state is set to Z_STREAM_ERROR. -*/ - -ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); -/* - Convert, format, compress, and write the arguments (...) to file under - control of the string format, as in fprintf. gzprintf returns the number of - uncompressed bytes actually written, or a negative zlib error code in case - of error. The number of uncompressed bytes written is limited to 8191, or - one less than the buffer size given to gzbuffer(). The caller should assure - that this limit is not exceeded. If it is exceeded, then gzprintf() will - 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. - This can be determined using zlibCompileFlags(). -*/ - -ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); -/* - Compress and write the given null-terminated string s to 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)); -/* - Read and decompress bytes from file into buf, until len-1 characters are - read, or until a newline character is read and transferred to buf, or an - end-of-file condition is encountered. If any characters are read or if len - is one, the string is terminated with a null character. If no characters - are read due to an end-of-file or len is less than one, then the buffer is - left untouched. - - gzgets returns buf which is a null-terminated string, or it returns NULL - for end-of-file or in case of error. If there was an error, the contents at - buf are indeterminate. -*/ - -ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); -/* - Compress and write c, converted to an unsigned char, into file. gzputc - returns the value that was written, or -1 in case of error. -*/ - -ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); -/* - Read and decompress one byte from file. gzgetc returns this byte or -1 - in case of end of file or error. This is implemented as a macro for speed. - As such, it does not do all of the checking the other functions do. I.e. - it does not check to see if file is NULL, nor whether the structure file - points to has been clobbered or not. -*/ - -ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); -/* - Push c back onto the stream for file to be read as the first character on - the next read. At least one character of push-back is always allowed. - gzungetc() returns the character pushed, or -1 on failure. gzungetc() will - fail if c is -1, and may fail if a character has been pushed but not read - yet. If gzungetc is used immediately after gzopen or gzdopen, at least the - output buffer size of pushed characters is allowed. (See gzbuffer above.) - The pushed character will be discarded if the stream is repositioned with - gzseek() or gzrewind(). -*/ - -ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); -/* - Flush all pending output to file. The parameter flush is as in the - deflate() function. The return value is the zlib error number (see function - gzerror below). gzflush is only permitted when writing. - - If the flush parameter is Z_FINISH, the remaining data is written and the - gzip stream is completed in the output. If gzwrite() is called again, a new - gzip stream will be started in the output. gzread() is able to read such - concatenated gzip streams. - - gzflush should be called only when strictly necessary because it will - degrade compression if called too often. -*/ - -/* -ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, - z_off_t offset, int whence)); - - Set the starting position to offset relative to whence for the next gzread - or gzwrite on 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)); -/* - Rewind 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)); - - Return the starting position for the next gzread or gzwrite on file. - This position represents a number of bytes in the uncompressed data stream, - and is zero when starting, even if appending or reading a gzip stream from - the middle of a file using gzdopen(). - - gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) -*/ - -/* -ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); - - Return the current compressed (actual) read or write offset of file. This - offset includes the count of bytes that precede the gzip stream, for example - when appending or when using gzdopen() for reading. When reading, the - offset does not include as yet unused buffered input. This information can - be used for a progress indicator. On error, gzoffset() returns -1. -*/ - -ZEXTERN int ZEXPORT gzeof OF((gzFile file)); -/* - Return true (1) if the end-of-file indicator for file has been set while - reading, false (0) otherwise. Note that the end-of-file indicator is set - only if the read tried to go past the end of the input, but came up short. - Therefore, just like feof(), gzeof() may return false even if there is no - more data to read, in the event that the last read request was for the exact - number of bytes remaining in the input file. This will happen if the input - file size is an exact multiple of the buffer size. - - If gzeof() returns true, then the read functions will return no more data, - unless the end-of-file indicator is reset by gzclearerr() and the input file - has grown since the previous end of file was detected. -*/ - -ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); -/* - Return true (1) if file is being copied directly while reading, or false - (0) if file is a gzip stream being decompressed. - - If the input file is empty, gzdirect() will return true, since the input - does not contain a gzip stream. - - If gzdirect() is used immediately after gzopen() or gzdopen() it will - cause buffers to be allocated to allow reading the file to determine if it - is a gzip file. Therefore if gzbuffer() is used, it should be called before - gzdirect(). - - When writing, gzdirect() returns true (1) if transparent writing was - requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: - gzdirect() is not needed when writing. Transparent writing must be - explicitly requested, so the application already knows the answer. When - linking statically, using gzdirect() will include all of the zlib code for - gzip file reading and decompression, which may not be desired.) -*/ - -ZEXTERN int ZEXPORT gzclose OF((gzFile file)); -/* - Flush all pending output for file, if necessary, close file and - deallocate the (de)compression state. Note that once file is closed, you - cannot call gzerror with file, since its structures have been deallocated. - gzclose must not be called more than once on the same file, just as free - must not be called more than once on the same allocation. - - gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a - file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the - last read ended in the middle of a gzip stream, or Z_OK on success. -*/ - -ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); -ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); -/* - Same as gzclose(), but gzclose_r() is only for use when reading, and - gzclose_w() is only for use when writing or appending. The advantage to - using these instead of gzclose() is that they avoid linking in zlib - compression or decompression code that is not used when only reading or only - writing respectively. If gzclose() is used, then both compression and - decompression code will be included the application when linking to a static - zlib library. -*/ - -ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); -/* - Return the error message for the last error which occurred on 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. - - The application must not modify the returned string. Future calls to - this function may invalidate the previously returned string. If file is - closed, then the string previously returned by gzerror will no longer be - available. - - gzerror() should be used to distinguish errors from end-of-file for those - functions above that do not distinguish those cases in their return values. -*/ - -ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); -/* - Clear 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. -*/ - -#endif /* !Z_SOLO */ - - /* 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. An Adler-32 value is in the range of a 32-bit - unsigned integer. If buf is Z_NULL, this function returns the required - initial value for the checksum. - - An Adler-32 checksum is almost as reliable as a CRC-32 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 adler32_z OF((uLong adler, const Bytef *buf, - z_size_t len)); -/* - Same as adler32(), but with a size_t length. -*/ - -/* -ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, - z_off_t len2)); - - Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 - and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for - each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of - seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note - that the z_off_t type (like off_t) is a signed integer. If len2 is - negative, the result has no meaning or utility. -*/ - -ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); -/* - Update a running CRC-32 with the bytes buf[0..len-1] and return the - updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer. - If buf is Z_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(); -*/ - -ZEXTERN uLong ZEXPORT crc32_z OF((uLong crc, const Bytef *buf, - z_size_t len)); -/* - Same as crc32(), but with a size_t length. -*/ - -/* -ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); - - Combine two CRC-32 check values into one. For two sequences of bytes, - seq1 and seq2 with lengths len1 and len2, CRC-32 check values were - calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 - check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and - len2. -*/ - -/* -ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2)); - - Return the operator corresponding to length len2, to be used with - crc32_combine_op(). -*/ - -ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, uLong op)); -/* - Give the same result as crc32_combine(), using op in place of len2. op is - is generated from len2 by crc32_combine_gen(). This will be faster than - crc32_combine() if the generated op is used more than once. -*/ - - - /* 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_streamp strm, int windowBits, - unsigned char FAR *window, - const char *version, - int stream_size)); -#ifdef Z_PREFIX_SET -# define z_deflateInit(strm, level) \ - deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) -# define z_inflateInit(strm) \ - inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) -# define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ - deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ - (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) -# define z_inflateInit2(strm, windowBits) \ - inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ - (int)sizeof(z_stream)) -# define z_inflateBackInit(strm, windowBits, window) \ - inflateBackInit_((strm), (windowBits), (window), \ - ZLIB_VERSION, (int)sizeof(z_stream)) -#else -# 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)) -#endif - -#ifndef Z_SOLO - -/* gzgetc() macro and its supporting function and exposed data structure. Note - * that the real internal state is much larger than the exposed structure. - * This abbreviated structure exposes just enough for the gzgetc() macro. The - * user should not mess with these exposed elements, since their names or - * behavior could change in the future, perhaps even capriciously. They can - * only be used by the gzgetc() macro. You have been warned. - */ -struct gzFile_s { - unsigned have; - unsigned char *next; - z_off64_t pos; -}; -ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ -#ifdef Z_PREFIX_SET -# undef z_gzgetc -# define z_gzgetc(g) \ - ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) -#else -# define gzgetc(g) \ - ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) -#endif - -/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or - * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if - * both are true, the application gets the *64 functions, and the regular - * functions are changed to 64 bits) -- in case these are set on systems - * without large file support, _LFS64_LARGEFILE must also be true - */ -#ifdef Z_LARGE64 - ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); - ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); - ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); - ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); - ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); - ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); - ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off64_t)); -#endif - -#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) -# ifdef Z_PREFIX_SET -# define z_gzopen z_gzopen64 -# define z_gzseek z_gzseek64 -# define z_gztell z_gztell64 -# define z_gzoffset z_gzoffset64 -# define z_adler32_combine z_adler32_combine64 -# define z_crc32_combine z_crc32_combine64 -# define z_crc32_combine_gen z_crc32_combine_gen64 -# else -# define gzopen gzopen64 -# define gzseek gzseek64 -# define gztell gztell64 -# define gzoffset gzoffset64 -# define adler32_combine adler32_combine64 -# define crc32_combine crc32_combine64 -# define crc32_combine_gen crc32_combine_gen64 -# endif -# ifndef Z_LARGE64 - ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); - ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); - ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); - ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); - ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); - ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); - ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off_t)); -# endif -#else - ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); - ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); - ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); - ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); - ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); - ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); - ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); -#endif - -#else /* Z_SOLO */ - - ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); - ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); - ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); - -#endif /* !Z_SOLO */ - -/* undocumented functions */ -ZEXTERN const char * ZEXPORT zError OF((int)); -ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); -ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); -ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); -ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int)); -ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF ((z_streamp)); -ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); -ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); -#if defined(_WIN32) && !defined(Z_SOLO) -ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, - const char *mode)); -#endif -#if defined(STDC) || defined(Z_HAVE_STDARG_H) -# ifndef Z_SOLO -ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, - const char *format, - va_list va)); -# endif -#endif - -#ifdef __cplusplus -} -#endif - -#endif /* ZLIB_H */ +/* zlib.h -- interface of the 'zlib' general purpose compression library
+ version 1.2.13, October 13th, 2022
+
+ Copyright (C) 1995-2022 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://tools.ietf.org/html/rfc1950
+ (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
+*/
+
+#ifndef ZLIB_H
+#define ZLIB_H
+
+#include "zconf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZLIB_VERSION "1.2.13"
+#define ZLIB_VERNUM 0x12d0
+#define ZLIB_VER_MAJOR 1
+#define ZLIB_VER_MINOR 2
+#define ZLIB_VER_REVISION 13
+#define ZLIB_VER_SUBREVISION 0
+
+/*
+ The 'zlib' compression library provides in-memory compression and
+ decompression functions, including integrity checks of the uncompressed data.
+ This version of the library supports only one compression method (deflation)
+ but other algorithms 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,
+ 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 and raw deflate 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 the 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 {
+ z_const Bytef *next_in; /* next input byte */
+ uInt avail_in; /* number of bytes available at next_in */
+ uLong total_in; /* total number of input bytes read so far */
+
+ Bytef *next_out; /* next output byte will go here */
+ uInt avail_out; /* remaining free space at next_out */
+ uLong total_out; /* total number of bytes output so far */
+
+ z_const 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: binary or text
+ for deflate, or the decoding state for inflate */
+ uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */
+ uLong reserved; /* reserved for future use */
+} z_stream;
+
+typedef z_stream FAR *z_streamp;
+
+/*
+ gzip header information passed to and from zlib routines. See RFC 1952
+ for more details on the meanings of these fields.
+*/
+typedef struct gz_header_s {
+ int text; /* true if compressed data believed to be text */
+ uLong time; /* modification time */
+ int xflags; /* extra flags (not used when writing a gzip file) */
+ int os; /* operating system */
+ Bytef *extra; /* pointer to extra field or Z_NULL if none */
+ uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
+ uInt extra_max; /* space at extra (only when reading header) */
+ Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
+ uInt name_max; /* space at name (only when reading header) */
+ Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
+ uInt comm_max; /* space at comment (only when reading header) */
+ int hcrc; /* true if there was or will be a header crc */
+ int done; /* true when done reading gzip header (not used
+ when writing a gzip file) */
+} gz_header;
+
+typedef gz_header FAR *gz_headerp;
+
+/*
+ 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. In that case, zlib is thread-safe. When zalloc and zfree are
+ Z_NULL on entry to the initialization function, they are set to internal
+ routines that use the standard library functions malloc() and free().
+
+ 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 by 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
+#define Z_BLOCK 5
+#define Z_TREES 6
+/* 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_FIXED 4
+#define Z_DEFAULT_STRATEGY 0
+/* compression strategy; see deflateInit2() below for details */
+
+#define Z_BINARY 0
+#define Z_TEXT 1
+#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
+#define Z_UNKNOWN 2
+/* Possible values of the data_type field for deflate() */
+
+#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, or
+ 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().
+
+ - Generate 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. Some output may be provided even if
+ flush is zero.
+
+ 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. See deflatePending(),
+ which can be used if desired to determine whether or not there is more output
+ in that case.
+
+ Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
+ decide how much data to accumulate before producing output, in order to
+ maximize compression.
+
+ 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. This
+ completes the current deflate block and follows it with an empty stored block
+ that is three bits plus filler bits to the next byte, followed by four bytes
+ (00 00 ff ff).
+
+ If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
+ output buffer, but the output is not aligned to a byte boundary. All of the
+ input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
+ This completes the current deflate block and follows it with an empty fixed
+ codes block that is 10 bits long. This assures that enough bytes are output
+ in order for the decompressor to finish the block before the empty fixed
+ codes block.
+
+ If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
+ for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
+ seven bits of the current block are held to be written as the next byte after
+ the next deflate block is completed. In this case, the decompressor may not
+ be provided enough bits at this point in order to complete decompression of
+ the data provided so far to the compressor. It may need to wait for the next
+ block to be emitted. This is for advanced applications that need to control
+ the emission of deflate blocks.
+
+ 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
+ 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 or Z_BUF_ERROR, 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 in the first deflate call after deflateInit if all the
+ compression is to be done in a single step. In order to complete in one
+ call, avail_out must be at least the value returned by deflateBound (see
+ below). Then deflate is guaranteed to return Z_STREAM_END. If not enough
+ output space is provided, deflate will not return Z_STREAM_END, and it must
+ be called again as described above.
+
+ deflate() sets strm->adler to the Adler-32 checksum of all input read
+ so far (that is, total_in bytes). If a gzip stream is being generated, then
+ strm->adler will be the CRC-32 checksum of the input read so far. (See
+ deflateInit2 below.)
+
+ deflate() may update strm->data_type if it can make a good guess about
+ the input data type (Z_BINARY or Z_TEXT). If 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 Z_NULL or the state was inadvertently written over
+ by the application), or 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. In the current version of inflate, the provided input is not
+ read or consumed. The allocation of a sliding window will be deferred to
+ the first call of inflate (if the decompression does not complete on the
+ first call). 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, or Z_STREAM_ERROR if the parameters are
+ invalid, such as a null pointer to the structure. msg is set to null if
+ there is no error message. inflateInit does not perform any decompression.
+ Actual decompression will be done by inflate(). So next_in, and avail_in,
+ next_out, and avail_out are unused and unchanged. The current
+ implementation of inflateInit() does not process any header information --
+ that is deferred until inflate() is called.
+*/
+
+
+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), then next_in and avail_in are updated
+ accordingly, and processing will resume at this point for the next call of
+ inflate().
+
+ - Generate 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. If the
+ caller of inflate() does not provide both available input and available
+ output space, it is possible that there will be no progress made. 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,
+ Z_BLOCK, or Z_TREES. 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 gets 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.
+ To assist in this, on return inflate() always sets 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. data_type is set as noted here every time inflate() returns for all
+ flush options, and so can be used to determine the amount of currently
+ consumed input in bits.
+
+ The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
+ end of each deflate block header is reached, before any actual data in that
+ block is decoded. This allows the caller to determine the length of the
+ deflate block header for later use in random access within a deflate block.
+ 256 is added to the value of strm->data_type when inflate() returns
+ immediately after reaching the end of the deflate block header.
+
+ 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 of the uncompressed data for the
+ operation to complete. (The size of the uncompressed data may have been
+ saved by the compressor for this purpose.) The use of Z_FINISH is not
+ required to perform an inflation in one step. However it may be used to
+ inform inflate that a faster approach can be used for the single inflate()
+ call. Z_FINISH also informs inflate to not maintain a sliding window if the
+ stream completes, which reduces inflate's memory footprint. If the stream
+ does not complete, either because not all of the stream is provided or not
+ enough output space is provided, then a sliding window will be allocated and
+ inflate() can be called again to continue the operation as if Z_NO_FLUSH had
+ been used.
+
+ 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 effects of the flush parameter in this implementation are
+ on the return value of inflate() as noted below, when inflate() returns early
+ when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
+ memory for a sliding window when Z_FINISH is used.
+
+ If a preset dictionary is needed after this call (see inflateSetDictionary
+ below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
+ chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+ strm->adler to the Adler-32 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 Adler-32
+ checksum is equal to that saved by the compressor and returns Z_STREAM_END
+ only if the checksum is correct.
+
+ inflate() can decompress and check either zlib-wrapped or gzip-wrapped
+ deflate data. The header type is detected automatically, if requested when
+ initializing with inflateInit2(). Any information contained in the gzip
+ header is not retained unless inflateGetHeader() is used. When processing
+ gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
+ produced so far. The CRC-32 is checked against the gzip trailer, as is the
+ uncompressed length, modulo 2^32.
+
+ 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, in which case strm->msg points to a string with a more specific
+ error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+ next_in or next_out was Z_NULL, or the state was inadvertently written over
+ by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
+ if no progress was 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 to be attempted.
+*/
+
+
+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, or Z_STREAM_ERROR if the stream state
+ was inconsistent.
+*/
+
+
+ /* 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 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.
+
+ For the current implementation of deflate(), a windowBits value of 8 (a
+ window size of 256 bytes) is not supported. As a result, a request for 8
+ will result in 9 (a 512-byte window). In that case, providing 8 to
+ inflateInit2() will result in an error when the zlib header with 9 is
+ checked against the initialization of inflate(). The remedy is to not use 8
+ with deflateInit2() with this initialization, or at least in that case use 9
+ with inflateInit2().
+
+ 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 a 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 the appropriate value,
+ if the operating system was determined at compile time. If a gzip stream is
+ being written, strm->adler is a CRC-32 instead of an Adler-32.
+
+ For raw deflate or gzip encoding, a request for a 256-byte window is
+ rejected as invalid, since only the zlib header provides a means of
+ transmitting the window size to the decompressor.
+
+ 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_STRATEGY 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.
+ Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
+ decoder for special applications.
+
+ deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+ memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
+ method), or 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. 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. When using the zlib format, this
+ function must be called immediately after deflateInit, deflateInit2 or
+ deflateReset, and before any call of deflate. When doing raw deflate, this
+ function must be called either before any call of deflate, or immediately
+ after the completion of a deflate block, i.e. after all input has been
+ consumed and all output has been delivered when using any of the flush
+ options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. 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
+ provided in deflateInit or deflateInit2. Thus the strings most likely to be
+ useful should be put at the end of the dictionary, not at the front. In
+ addition, the current implementation of deflate will use at most the window
+ size minus 262 bytes of the provided dictionary.
+
+ Upon return of this function, strm->adler is set to the Adler-32 value
+ of the dictionary; the decompressor may later use this value to determine
+ which dictionary has been used by the compressor. (The Adler-32 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
+ Adler-32 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 (e.g. dictionary being Z_NULL) or the stream state is
+ inconsistent (for example if deflate has already been called for this stream
+ or if not at a block boundary for raw deflate). deflateSetDictionary does
+ not perform any compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
+ Bytef *dictionary,
+ uInt *dictLength));
+/*
+ Returns the sliding dictionary being maintained by deflate. dictLength is
+ set to the number of bytes in the dictionary, and that many bytes are copied
+ to dictionary. dictionary must have enough space, where 32768 bytes is
+ always enough. If deflateGetDictionary() is called with dictionary equal to
+ Z_NULL, then only the dictionary length is returned, and nothing is copied.
+ Similarly, if dictLength is Z_NULL, then it is not set.
+
+ deflateGetDictionary() may return a length less than the window size, even
+ when more than the window size in input has been provided. It may return up
+ to 258 bytes less in that case, due to how zlib's implementation of deflate
+ manages the sliding window and lookahead for matches, where matches can be
+ up to 258 bytes long. If the application needs the last window-size bytes of
+ input, then that would need to be saved by the application outside of zlib.
+
+ deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+ stream state is inconsistent.
+*/
+
+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 Z_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 the internal compression state. The stream
+ will leave the compression level and any other attributes that may have been
+ set unchanged.
+
+ deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent (such as zalloc or state being Z_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 approach (which is a function of the level) or the
+ strategy is changed, and if there have been any deflate() calls since the
+ state was initialized or reset, then the input available so far is
+ compressed with the old level and strategy using deflate(strm, Z_BLOCK).
+ There are three approaches for the compression levels 0, 1..3, and 4..9
+ respectively. The new level and strategy will take effect at the next call
+ of deflate().
+
+ If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
+ not have enough output space to complete, then the parameter change will not
+ take effect. In this case, deflateParams() can be called again with the
+ same parameters and more output space to try again.
+
+ In order to assure a change in the parameters on the first try, the
+ deflate stream should be flushed using deflate() with Z_BLOCK or other flush
+ request until strm.avail_out is not zero, before calling deflateParams().
+ Then no more input data should be provided before the deflateParams() call.
+ If this is done, the old level and strategy will be applied to the data
+ compressed before deflateParams(), and the new level and strategy will be
+ applied to the the data compressed after deflateParams().
+
+ deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
+ state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
+ there was not enough output space to complete the compression of the
+ available input data before a change in the strategy or approach. Note that
+ in the case of a Z_BUF_ERROR, the parameters are not changed. A return
+ value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
+ retried with more output space.
+*/
+
+ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
+ int good_length,
+ int max_lazy,
+ int nice_length,
+ int max_chain));
+/*
+ Fine tune deflate's internal compression parameters. This should only be
+ used by someone who understands the algorithm used by zlib's deflate for
+ searching for the best matching string, and even then only by the most
+ fanatic optimizer trying to squeeze out the last compressed bit for their
+ specific input data. Read the deflate.c source code for the meaning of the
+ max_lazy, good_length, nice_length, and max_chain parameters.
+
+ deflateTune() can be called after deflateInit() or deflateInit2(), and
+ returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
+ */
+
+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(), and after deflateSetHeader(), if used. This would be used
+ to allocate an output buffer for deflation in a single pass, and so would be
+ called before deflate(). If that first deflate() call is provided the
+ sourceLen input bytes, an output buffer allocated to the size returned by
+ deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
+ to return Z_STREAM_END. Note that it is possible for the compressed size to
+ be larger than the value returned by deflateBound() if flush options other
+ than Z_FINISH or Z_NO_FLUSH are used.
+*/
+
+ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
+ unsigned *pending,
+ int *bits));
+/*
+ deflatePending() returns the number of bytes and bits of output that have
+ been generated, but not yet provided in the available output. The bytes not
+ provided would be due to the available output space having being consumed.
+ The number of bits of output not provided are between 0 and 7, where they
+ await more bits to join them in order to fill out a full byte. If pending
+ or bits are Z_NULL, then those values are not set.
+
+ deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+ */
+
+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, Z_BUF_ERROR if there was not enough
+ room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
+ source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
+ gz_headerp head));
+/*
+ deflateSetHeader() provides gzip header information for when a gzip
+ stream is requested by deflateInit2(). deflateSetHeader() may be called
+ after deflateInit2() or deflateReset() and before the first call of
+ deflate(). The text, time, os, extra field, name, and comment information
+ in the provided gz_header structure are written to the gzip header (xflag is
+ ignored -- the extra flags are set according to the compression level). The
+ caller must assure that, if not Z_NULL, name and comment are terminated with
+ a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
+ available there. If hcrc is true, a gzip header crc is included. Note that
+ the current versions of the command-line version of gzip (up through version
+ 1.3.x) do not support header crc's, and will report that it is a "multi-part
+ gzip file" and give up.
+
+ If deflateSetHeader is not used, the default gzip header has text false,
+ the time set to zero, and os set to 255, with no extra, name, or comment
+ fields. The gzip header is returned to the default state by deflateReset().
+
+ deflateSetHeader 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 zero to request that inflate use the window size in
+ the zlib header of the compressed stream.
+
+ 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 Adler-32 or a CRC-32 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
+ CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see
+ below), inflate() will *not* automatically decode concatenated gzip members.
+ inflate() will return Z_STREAM_END at the end of the gzip member. The state
+ would need to be reset to continue decoding a subsequent gzip member. This
+ *must* be done if there is more data after a gzip member, in order for the
+ decompression to be compliant with the gzip standard (RFC 1952).
+
+ inflateInit2 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, or Z_STREAM_ERROR if the parameters are
+ invalid, such as a null pointer to the structure. msg is set to null if
+ there is no error message. inflateInit2 does not perform any decompression
+ apart from possibly reading the zlib header if present: actual decompression
+ will be done by inflate(). (So next_in and avail_in may be modified, but
+ next_out and avail_out are unused and unchanged.) The current implementation
+ of inflateInit2() does not process any header information -- that is
+ deferred until inflate() is called.
+*/
+
+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 that call returned Z_NEED_DICT. The dictionary chosen by the compressor
+ can be determined from the Adler-32 value returned by that call of inflate.
+ The compressor and decompressor must use exactly the same dictionary (see
+ deflateSetDictionary). For raw inflate, this function can be called at any
+ time to set the dictionary. If the provided dictionary is smaller than the
+ window and there is already data in the window, then the provided dictionary
+ will amend what's there. The application must insure that the dictionary
+ that was used for compression is provided.
+
+ inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
+ parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
+ inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
+ expected one (incorrect Adler-32 value). inflateSetDictionary does not
+ perform any decompression: this will be done by subsequent calls of
+ inflate().
+*/
+
+ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
+ Bytef *dictionary,
+ uInt *dictLength));
+/*
+ Returns the sliding dictionary being maintained by inflate. dictLength is
+ set to the number of bytes in the dictionary, and that many bytes are copied
+ to dictionary. dictionary must have enough space, where 32768 bytes is
+ always enough. If inflateGetDictionary() is called with dictionary equal to
+ Z_NULL, then only the dictionary length is returned, and nothing is copied.
+ Similarly, if dictLength is Z_NULL, then it is not set.
+
+ inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+ stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
+/*
+ Skips invalid compressed data until a possible full flush point (see above
+ for the description of deflate with Z_FULL_FLUSH) can be found, or until all
+ available input is skipped. No output is provided.
+
+ inflateSync searches for a 00 00 FF FF pattern in the compressed data.
+ All full flush points have this pattern, but not all occurrences of this
+ pattern are full flush points.
+
+ inflateSync returns Z_OK if a possible 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 Z_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 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 Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
+ int windowBits));
+/*
+ This function is the same as inflateReset, but it also permits changing
+ the wrap and window size requests. The windowBits parameter is interpreted
+ the same as it is for inflateInit2. If the window size is changed, then the
+ memory allocated for the window is freed, and the window will be reallocated
+ by inflate() if needed.
+
+ inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent (such as zalloc or state being Z_NULL), or if
+ the windowBits parameter is invalid.
+*/
+
+ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
+ int bits,
+ int value));
+/*
+ This function inserts bits in the inflate input stream. The intent is
+ that this function is used to start inflating at a bit position in the
+ middle of a byte. The provided bits will be used before any bytes are used
+ from next_in. This function should only be used with raw inflate, and
+ should be used before the first inflate() call after inflateInit2() or
+ inflateReset(). bits must be less than or equal to 16, and that many of the
+ least significant bits of value will be inserted in the input.
+
+ If bits is negative, then the input stream bit buffer is emptied. Then
+ inflatePrime() can be called again to put bits in the buffer. This is used
+ to clear out bits leftover after feeding inflate a block description prior
+ to feeding inflate codes.
+
+ inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+*/
+
+ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
+/*
+ This function returns two values, one in the lower 16 bits of the return
+ value, and the other in the remaining upper bits, obtained by shifting the
+ return value down 16 bits. If the upper value is -1 and the lower value is
+ zero, then inflate() is currently decoding information outside of a block.
+ If the upper value is -1 and the lower value is non-zero, then inflate is in
+ the middle of a stored block, with the lower value equaling the number of
+ bytes from the input remaining to copy. If the upper value is not -1, then
+ it is the number of bits back from the current bit position in the input of
+ the code (literal or length/distance pair) currently being processed. In
+ that case the lower value is the number of bytes already emitted for that
+ code.
+
+ A code is being processed if inflate is waiting for more input to complete
+ decoding of the code, or if it has completed decoding but is waiting for
+ more output space to write the literal or match data.
+
+ inflateMark() is used to mark locations in the input data for random
+ access, which may be at bit positions, and to note those cases where the
+ output of a code may span boundaries of random access blocks. The current
+ location in the input stream can be determined from avail_in and data_type
+ as noted in the description for the Z_BLOCK flush parameter for inflate.
+
+ inflateMark returns the value noted above, or -65536 if the provided
+ source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
+ gz_headerp head));
+/*
+ inflateGetHeader() requests that gzip header information be stored in the
+ provided gz_header structure. inflateGetHeader() may be called after
+ inflateInit2() or inflateReset(), and before the first call of inflate().
+ As inflate() processes the gzip stream, head->done is zero until the header
+ is completed, at which time head->done is set to one. If a zlib stream is
+ being decoded, then head->done is set to -1 to indicate that there will be
+ no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
+ used to force inflate() to return immediately after header processing is
+ complete and before any actual data is decompressed.
+
+ The text, time, xflags, and os fields are filled in with the gzip header
+ contents. hcrc is set to true if there is a header CRC. (The header CRC
+ was valid if done is set to one.) If extra is not Z_NULL, then extra_max
+ contains the maximum number of bytes to write to extra. Once done is true,
+ extra_len contains the actual extra field length, and extra contains the
+ extra field, or that field truncated if extra_max is less than extra_len.
+ If name is not Z_NULL, then up to name_max characters are written there,
+ terminated with a zero unless the length is greater than name_max. If
+ comment is not Z_NULL, then up to comm_max characters are written there,
+ terminated with a zero unless the length is greater than comm_max. When any
+ of extra, name, or comment are not Z_NULL and the respective field is not
+ present in the header, then that field is set to Z_NULL to signal its
+ absence. This allows the use of deflateSetHeader() with the returned
+ structure to duplicate the header. However if those fields are set to
+ allocated memory, then the application will need to save those pointers
+ elsewhere so that they can be eventually freed.
+
+ If inflateGetHeader is not used, then the header information is simply
+ discarded. The header is always checked for validity, including the header
+ CRC if present. inflateReset() will reset the process to discard the header
+ information. The application would need to call inflateGetHeader() again to
+ retrieve the header from the next gzip stream.
+
+ inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+ stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp 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 parameters 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 *,
+ z_const unsigned char FAR * FAR *));
+typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
+
+ZEXTERN int ZEXPORT inflateBack OF((z_streamp 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 potentially 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. inflate() can be faster on modern CPUs when used with large
+ buffers. inflateBack() 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 default
+ behavior of inflate(), which expects a zlib 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_in 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_streamp 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: ZLIB_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)
+ */
+
+#ifndef Z_SOLO
+
+ /* 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 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 data. compress() is equivalent to compress2() with a level
+ parameter of Z_DEFAULT_COMPRESSION.
+
+ 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 data.
+
+ 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 uncompressed data.
+
+ 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. In
+ the case where there is not enough room, uncompress() will fill the output
+ buffer with the uncompressed data up to that point.
+*/
+
+ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen,
+ const Bytef *source, uLong *sourceLen));
+/*
+ Same as uncompress, except that sourceLen is a pointer, where the
+ length of the source is *sourceLen. On return, *sourceLen is the number of
+ source bytes consumed.
+*/
+
+ /* gzip file access functions */
+
+/*
+ This library 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.
+*/
+
+typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
+
+/*
+ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
+
+ Open the gzip (.gz) file at path for reading and decompressing, or
+ compressing and 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",
+ 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression
+ as in "wb9F". (See the description of deflateInit2 for more information
+ about the strategy parameter.) 'T' will request transparent writing or
+ appending with no compression and not using the gzip format.
+
+ "a" can be used instead of "w" to request that the gzip stream that will
+ be written be appended to the file. "+" will result in an error, since
+ reading and writing to the same gzip file is not supported. The addition of
+ "x" when writing will create the file exclusively, which fails if the file
+ already exists. On systems that support it, the addition of "e" when
+ reading or writing will set the flag to close the file on an execve() call.
+
+ These functions, as well as gzip, will read and decode a sequence of gzip
+ streams in a file. The append function of gzopen() can be used to create
+ such a file. (Also see gzflush() for another way to do this.) When
+ appending, gzopen does not test whether the file begins with a gzip stream,
+ nor does it look for the end of the gzip streams to begin appending. gzopen
+ will simply append a gzip stream to the existing file.
+
+ 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. When
+ reading, this will be detected automatically by looking for the magic two-
+ byte gzip header.
+
+ gzopen returns NULL if the file could not be opened, if there was
+ insufficient memory to allocate the gzFile state, or if an invalid mode was
+ specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
+ errno can be checked to determine if the reason gzopen failed was that the
+ file could not be opened.
+*/
+
+ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
+/*
+ Associate a gzFile with the file descriptor fd. File descriptors are
+ obtained from calls like open, dup, creat, pipe or fileno (if 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 fd = dup(fd_keep); gz = gzdopen(fd,
+ mode);. The duplicated descriptor should be saved to avoid a leak, since
+ gzdopen does not close fd if it fails. If you are using fileno() to get the
+ file descriptor from a FILE *, then you will have to use dup() to avoid
+ double-close()ing the file descriptor. Both gzclose() and fclose() will
+ close the associated file descriptor, so they need to have different file
+ descriptors.
+
+ gzdopen returns NULL if there was insufficient memory to allocate the
+ gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
+ provided, or '+' was provided), or if fd is -1. The file descriptor is not
+ used until the next gz* read, write, seek, or close operation, so gzdopen
+ will not detect if fd is invalid (unless fd is -1).
+*/
+
+ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
+/*
+ Set the internal buffer size used by this library's functions for file to
+ size. The default buffer size is 8192 bytes. This function must be called
+ after gzopen() or gzdopen(), and before any other calls that read or write
+ the file. The buffer memory allocation is always deferred to the first read
+ or write. Three times that size in buffer space is allocated. A larger
+ buffer size of, for example, 64K or 128K bytes will noticeably increase the
+ speed of decompression (reading).
+
+ The new buffer size also affects the maximum length for gzprintf().
+
+ gzbuffer() returns 0 on success, or -1 on failure, such as being called
+ too late.
+*/
+
+ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
+/*
+ Dynamically update the compression level and strategy for file. See the
+ description of deflateInit2 for the meaning of these parameters. Previously
+ provided data is flushed before applying the parameter changes.
+
+ gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
+ opened for writing, Z_ERRNO if there is an error writing the flushed data,
+ or Z_MEM_ERROR if there is a memory allocation error.
+*/
+
+ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
+/*
+ Read and decompress up to len uncompressed bytes from file into buf. If
+ the input file is not in gzip format, gzread copies the given number of
+ bytes into the buffer directly from the file.
+
+ After reaching the end of a gzip stream in the input, gzread will continue
+ to read, looking for another gzip stream. Any number of gzip streams may be
+ concatenated in the input file, and will all be decompressed by gzread().
+ If something other than a gzip stream is encountered after a gzip stream,
+ that remaining trailing garbage is ignored (and no error is returned).
+
+ gzread can be used to read a gzip file that is being concurrently written.
+ Upon reaching the end of the input, gzread will return with the available
+ data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
+ gzclearerr can be used to clear the end of file indicator in order to permit
+ gzread to be tried again. Z_OK indicates that a gzip stream was completed
+ on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
+ middle of a gzip stream. Note that gzread does not return -1 in the event
+ of an incomplete gzip stream. This error is deferred until gzclose(), which
+ will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
+ stream. Alternatively, gzerror can be used before gzclose to detect this
+ case.
+
+ gzread returns the number of uncompressed bytes actually read, less than
+ len for end of file, or -1 for error. If len is too large to fit in an int,
+ then nothing is read, -1 is returned, and the error state is set to
+ Z_STREAM_ERROR.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
+ gzFile file));
+/*
+ Read and decompress up to nitems items of size size from file into buf,
+ otherwise operating as gzread() does. This duplicates the interface of
+ stdio's fread(), with size_t request and return types. If the library
+ defines size_t, then z_size_t is identical to size_t. If not, then z_size_t
+ is an unsigned integer type that can contain a pointer.
+
+ gzfread() returns the number of full items read of size size, or zero if
+ the end of the file was reached and a full item could not be read, or if
+ there was an error. gzerror() must be consulted if zero is returned in
+ order to determine if there was an error. If the multiplication of size and
+ nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
+ is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+ In the event that the end of file is reached and only a partial item is
+ available at the end, i.e. the remaining uncompressed data length is not a
+ multiple of size, then the final partial item is nevertheless read into buf
+ and the end-of-file flag is set. The length of the partial item read is not
+ provided, but could be inferred from the result of gztell(). This behavior
+ is the same as the behavior of fread() implementations in common libraries,
+ but it prevents the direct use of gzfread() to read a concurrently written
+ file, resetting and retrying on end-of-file, when size is not 1.
+*/
+
+ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len));
+/*
+ Compress and write the len uncompressed bytes at buf to file. gzwrite
+ returns the number of uncompressed bytes written or 0 in case of error.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
+ z_size_t nitems, gzFile file));
+/*
+ Compress and write nitems items of size size from buf to file, duplicating
+ the interface of stdio's fwrite(), with size_t request and return types. If
+ the library defines size_t, then z_size_t is identical to size_t. If not,
+ then z_size_t is an unsigned integer type that can contain a pointer.
+
+ gzfwrite() returns the number of full items written of size size, or zero
+ if there was an error. If the multiplication of size and nitems overflows,
+ i.e. the product does not fit in a z_size_t, then nothing is written, zero
+ is returned, and the error state is set to Z_STREAM_ERROR.
+*/
+
+ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
+/*
+ Convert, format, compress, and write the arguments (...) to file under
+ control of the string format, as in fprintf. gzprintf returns the number of
+ uncompressed bytes actually written, or a negative zlib error code in case
+ of error. The number of uncompressed bytes written is limited to 8191, or
+ one less than the buffer size given to gzbuffer(). The caller should assure
+ that this limit is not exceeded. If it is exceeded, then gzprintf() will
+ 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.
+ This can be determined using zlibCompileFlags().
+*/
+
+ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
+/*
+ Compress and write the given null-terminated string s to 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));
+/*
+ Read and decompress bytes from file into buf, until len-1 characters are
+ read, or until a newline character is read and transferred to buf, or an
+ end-of-file condition is encountered. If any characters are read or if len
+ is one, the string is terminated with a null character. If no characters
+ are read due to an end-of-file or len is less than one, then the buffer is
+ left untouched.
+
+ gzgets returns buf which is a null-terminated string, or it returns NULL
+ for end-of-file or in case of error. If there was an error, the contents at
+ buf are indeterminate.
+*/
+
+ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
+/*
+ Compress and write c, converted to an unsigned char, into file. gzputc
+ returns the value that was written, or -1 in case of error.
+*/
+
+ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
+/*
+ Read and decompress one byte from file. gzgetc returns this byte or -1
+ in case of end of file or error. This is implemented as a macro for speed.
+ As such, it does not do all of the checking the other functions do. I.e.
+ it does not check to see if file is NULL, nor whether the structure file
+ points to has been clobbered or not.
+*/
+
+ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
+/*
+ Push c back onto the stream for file to be read as the first character on
+ the next read. At least one character of push-back is always allowed.
+ gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
+ fail if c is -1, and may fail if a character has been pushed but not read
+ yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
+ output buffer size of pushed characters is allowed. (See gzbuffer above.)
+ The pushed character will be discarded if the stream is repositioned with
+ gzseek() or gzrewind().
+*/
+
+ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
+/*
+ Flush all pending output to file. The parameter flush is as in the
+ deflate() function. The return value is the zlib error number (see function
+ gzerror below). gzflush is only permitted when writing.
+
+ If the flush parameter is Z_FINISH, the remaining data is written and the
+ gzip stream is completed in the output. If gzwrite() is called again, a new
+ gzip stream will be started in the output. gzread() is able to read such
+ concatenated gzip streams.
+
+ gzflush should be called only when strictly necessary because it will
+ degrade compression if called too often.
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
+ z_off_t offset, int whence));
+
+ Set the starting position to offset relative to whence for the next gzread
+ or gzwrite on 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));
+/*
+ Rewind 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));
+
+ Return the starting position for the next gzread or gzwrite on file.
+ This position represents a number of bytes in the uncompressed data stream,
+ and is zero when starting, even if appending or reading a gzip stream from
+ the middle of a file using gzdopen().
+
+ gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
+
+ Return the current compressed (actual) read or write offset of file. This
+ offset includes the count of bytes that precede the gzip stream, for example
+ when appending or when using gzdopen() for reading. When reading, the
+ offset does not include as yet unused buffered input. This information can
+ be used for a progress indicator. On error, gzoffset() returns -1.
+*/
+
+ZEXTERN int ZEXPORT gzeof OF((gzFile file));
+/*
+ Return true (1) if the end-of-file indicator for file has been set while
+ reading, false (0) otherwise. Note that the end-of-file indicator is set
+ only if the read tried to go past the end of the input, but came up short.
+ Therefore, just like feof(), gzeof() may return false even if there is no
+ more data to read, in the event that the last read request was for the exact
+ number of bytes remaining in the input file. This will happen if the input
+ file size is an exact multiple of the buffer size.
+
+ If gzeof() returns true, then the read functions will return no more data,
+ unless the end-of-file indicator is reset by gzclearerr() and the input file
+ has grown since the previous end of file was detected.
+*/
+
+ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
+/*
+ Return true (1) if file is being copied directly while reading, or false
+ (0) if file is a gzip stream being decompressed.
+
+ If the input file is empty, gzdirect() will return true, since the input
+ does not contain a gzip stream.
+
+ If gzdirect() is used immediately after gzopen() or gzdopen() it will
+ cause buffers to be allocated to allow reading the file to determine if it
+ is a gzip file. Therefore if gzbuffer() is used, it should be called before
+ gzdirect().
+
+ When writing, gzdirect() returns true (1) if transparent writing was
+ requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
+ gzdirect() is not needed when writing. Transparent writing must be
+ explicitly requested, so the application already knows the answer. When
+ linking statically, using gzdirect() will include all of the zlib code for
+ gzip file reading and decompression, which may not be desired.)
+*/
+
+ZEXTERN int ZEXPORT gzclose OF((gzFile file));
+/*
+ Flush all pending output for file, if necessary, close file and
+ deallocate the (de)compression state. Note that once file is closed, you
+ cannot call gzerror with file, since its structures have been deallocated.
+ gzclose must not be called more than once on the same file, just as free
+ must not be called more than once on the same allocation.
+
+ gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
+ file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
+ last read ended in the middle of a gzip stream, or Z_OK on success.
+*/
+
+ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
+ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
+/*
+ Same as gzclose(), but gzclose_r() is only for use when reading, and
+ gzclose_w() is only for use when writing or appending. The advantage to
+ using these instead of gzclose() is that they avoid linking in zlib
+ compression or decompression code that is not used when only reading or only
+ writing respectively. If gzclose() is used, then both compression and
+ decompression code will be included the application when linking to a static
+ zlib library.
+*/
+
+ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
+/*
+ Return the error message for the last error which occurred on 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.
+
+ The application must not modify the returned string. Future calls to
+ this function may invalidate the previously returned string. If file is
+ closed, then the string previously returned by gzerror will no longer be
+ available.
+
+ gzerror() should be used to distinguish errors from end-of-file for those
+ functions above that do not distinguish those cases in their return values.
+*/
+
+ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
+/*
+ Clear 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.
+*/
+
+#endif /* !Z_SOLO */
+
+ /* 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. An Adler-32 value is in the range of a 32-bit
+ unsigned integer. If buf is Z_NULL, this function returns the required
+ initial value for the checksum.
+
+ An Adler-32 checksum is almost as reliable as a CRC-32 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 adler32_z OF((uLong adler, const Bytef *buf,
+ z_size_t len));
+/*
+ Same as adler32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
+ z_off_t len2));
+
+ Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
+ and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
+ each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
+ seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
+ that the z_off_t type (like off_t) is a signed integer. If len2 is
+ negative, the result has no meaning or utility.
+*/
+
+ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
+/*
+ Update a running CRC-32 with the bytes buf[0..len-1] and return the
+ updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer.
+ If buf is Z_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();
+*/
+
+ZEXTERN uLong ZEXPORT crc32_z OF((uLong crc, const Bytef *buf,
+ z_size_t len));
+/*
+ Same as crc32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
+
+ Combine two CRC-32 check values into one. For two sequences of bytes,
+ seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
+ calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
+ check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
+ len2.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2));
+
+ Return the operator corresponding to length len2, to be used with
+ crc32_combine_op().
+*/
+
+ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, uLong op));
+/*
+ Give the same result as crc32_combine(), using op in place of len2. op is
+ is generated from len2 by crc32_combine_gen(). This will be faster than
+ crc32_combine() if the generated op is used more than once.
+*/
+
+
+ /* 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_streamp strm, int windowBits,
+ unsigned char FAR *window,
+ const char *version,
+ int stream_size));
+#ifdef Z_PREFIX_SET
+# define z_deflateInit(strm, level) \
+ deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+# define z_inflateInit(strm) \
+ inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+# define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+ deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+ (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+# define z_inflateInit2(strm, windowBits) \
+ inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+ (int)sizeof(z_stream))
+# define z_inflateBackInit(strm, windowBits, window) \
+ inflateBackInit_((strm), (windowBits), (window), \
+ ZLIB_VERSION, (int)sizeof(z_stream))
+#else
+# define deflateInit(strm, level) \
+ deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+# define inflateInit(strm) \
+ inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+# define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+ deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+ (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+# define inflateInit2(strm, windowBits) \
+ inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+ (int)sizeof(z_stream))
+# define inflateBackInit(strm, windowBits, window) \
+ inflateBackInit_((strm), (windowBits), (window), \
+ ZLIB_VERSION, (int)sizeof(z_stream))
+#endif
+
+#ifndef Z_SOLO
+
+/* gzgetc() macro and its supporting function and exposed data structure. Note
+ * that the real internal state is much larger than the exposed structure.
+ * This abbreviated structure exposes just enough for the gzgetc() macro. The
+ * user should not mess with these exposed elements, since their names or
+ * behavior could change in the future, perhaps even capriciously. They can
+ * only be used by the gzgetc() macro. You have been warned.
+ */
+struct gzFile_s {
+ unsigned have;
+ unsigned char *next;
+ z_off64_t pos;
+};
+ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */
+#ifdef Z_PREFIX_SET
+# undef z_gzgetc
+# define z_gzgetc(g) \
+ ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#else
+# define gzgetc(g) \
+ ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#endif
+
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#ifdef Z_LARGE64
+ ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+ ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+ ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+ ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+ ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
+ ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
+ ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off64_t));
+#endif
+
+#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
+# ifdef Z_PREFIX_SET
+# define z_gzopen z_gzopen64
+# define z_gzseek z_gzseek64
+# define z_gztell z_gztell64
+# define z_gzoffset z_gzoffset64
+# define z_adler32_combine z_adler32_combine64
+# define z_crc32_combine z_crc32_combine64
+# define z_crc32_combine_gen z_crc32_combine_gen64
+# else
+# define gzopen gzopen64
+# define gzseek gzseek64
+# define gztell gztell64
+# define gzoffset gzoffset64
+# define adler32_combine adler32_combine64
+# define crc32_combine crc32_combine64
+# define crc32_combine_gen crc32_combine_gen64
+# endif
+# ifndef Z_LARGE64
+ ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+ ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
+ ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
+ ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
+ ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+ ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
+ ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off_t));
+# endif
+#else
+ ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
+ ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
+ ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
+ ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
+ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+ ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+ ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t));
+#endif
+
+#else /* Z_SOLO */
+
+ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+ ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+ ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t));
+
+#endif /* !Z_SOLO */
+
+/* undocumented functions */
+ZEXTERN const char * ZEXPORT zError OF((int));
+ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
+ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void));
+ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
+ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int));
+ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF((z_streamp));
+ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
+ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
+#if defined(_WIN32) && !defined(Z_SOLO)
+ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path,
+ const char *mode));
+#endif
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+# ifndef Z_SOLO
+ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file,
+ const char *format,
+ va_list va));
+# endif
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZLIB_H */
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