williamr@4: /** williamr@4: @file williamr@4: @publishedAll williamr@4: @released williamr@4: */ williamr@4: williamr@4: /* zlib.h -- interface of the 'zlib' general purpose compression library williamr@4: version 1.2.3, July 18th, 2005 williamr@4: williamr@4: Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler williamr@4: williamr@4: This software is provided 'as-is', without any express or implied williamr@4: warranty. In no event will the authors be held liable for any damages williamr@4: arising from the use of this software. williamr@4: williamr@4: Permission is granted to anyone to use this software for any purpose, williamr@4: including commercial applications, and to alter it and redistribute it williamr@4: freely, subject to the following restrictions: williamr@4: williamr@4: 1. The origin of this software must not be misrepresented; you must not williamr@4: claim that you wrote the original software. If you use this software williamr@4: in a product, an acknowledgment in the product documentation would be williamr@4: appreciated but is not required. williamr@4: 2. Altered source versions must be plainly marked as such, and must not be williamr@4: misrepresented as being the original software. williamr@4: 3. This notice may not be removed or altered from any source distribution. williamr@4: williamr@4: Jean-loup Gailly Mark Adler williamr@4: jloup@gzip.org madler@alumni.caltech.edu williamr@4: williamr@4: williamr@4: The data format used by the zlib library is described by RFCs (Request for williamr@4: Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt williamr@4: (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). williamr@4: */ williamr@4: williamr@4: williamr@4: #ifndef _ZLIB_H williamr@4: #define _ZLIB_H williamr@4: williamr@4: #if (defined(__TOOLS2__) || defined(__TOOLS__)) williamr@4: // A tools build picks up the zconf.h file from the user include path williamr@4: #include "zconf.h" williamr@4: #else williamr@4: // Any other build picks up zconf.h from stdapis system include directory williamr@4: #include williamr@4: #endif williamr@4: williamr@4: #ifdef __cplusplus williamr@4: extern "C" { williamr@4: #endif williamr@4: williamr@4: /** Zlib version */ williamr@4: #define ZLIB_VERSION "1.2.3" williamr@4: /** Zlib version Number */ williamr@4: #define ZLIB_VERNUM 0x1230 williamr@4: williamr@4: /** williamr@4: The 'zlib' compression library provides in-memory compression and williamr@4: decompression functions, including integrity checks of the uncompressed williamr@4: data. This version of the library supports only one compression method williamr@4: (deflation) but other algorithms will be added later and will have the same williamr@4: stream interface. williamr@4: williamr@4: Compression can be done in a single step if the buffers are large williamr@4: enough (for example if an input file is mmap'ed), or can be done by williamr@4: repeated calls of the compression function. In the latter case, the williamr@4: application must provide more input and/or consume the output williamr@4: (providing more output space) before each call. williamr@4: williamr@4: The compressed data format used by default by the in-memory functions is williamr@4: the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped williamr@4: around a deflate stream, which is itself documented in RFC 1951. williamr@4: williamr@4: The library also supports reading and writing files in gzip (.gz) format williamr@4: with an interface similar to that of stdio using the functions that start williamr@4: with "gz". The gzip format is different from the zlib format. gzip is a williamr@4: gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. williamr@4: williamr@4: This library can optionally read and write gzip streams in memory as well. williamr@4: williamr@4: The zlib format was designed to be compact and fast for use in memory williamr@4: and on communications channels. The gzip format was designed for single- williamr@4: file compression on file systems, has a larger header than zlib to maintain williamr@4: directory information, and uses a different, slower check method than zlib. williamr@4: williamr@4: The library does not install any signal handler. The decoder checks williamr@4: the consistency of the compressed data, so the library should never williamr@4: crash even in case of corrupted input. williamr@4: */ williamr@4: williamr@4: /** Function pointer - used to allocate the internal state */ williamr@4: typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); williamr@4: /** Function pointer - used to free the internal state */ williamr@4: typedef void (*free_func) OF((voidpf opaque, voidpf address)); williamr@4: williamr@4: struct internal_state; williamr@4: williamr@4: /** williamr@4: Encapsulates a zip stream williamr@4: */ williamr@4: typedef struct z_stream_s { williamr@4: /** Next input byte */ williamr@4: Bytef *next_in; williamr@4: /** Number of bytes available at next_in */ williamr@4: uInt avail_in; williamr@4: /** Total nb of input bytes read so far */ williamr@4: uLong total_in; williamr@4: williamr@4: /** Next output byte should be put there */ williamr@4: Bytef *next_out; williamr@4: /** Remaining free space at next_out */ williamr@4: uInt avail_out; williamr@4: /** Total nb of bytes output so far */ williamr@4: uLong total_out; williamr@4: williamr@4: /** Last error message, NULL if no error */ williamr@4: char *msg; williamr@4: /** Not visible by applications */ williamr@4: struct internal_state FAR *state; williamr@4: williamr@4: /** Used to allocate the internal state */ williamr@4: alloc_func zalloc; williamr@4: /** Used to free the internal state */ williamr@4: free_func zfree; williamr@4: /** Private data object passed to zalloc and zfree */ williamr@4: voidpf opaque; williamr@4: williamr@4: /** Best guess about the data type: binary or text */ williamr@4: int data_type; williamr@4: /** Adler32 value of the uncompressed data */ williamr@4: uLong adler; williamr@4: /** Reserved for future use */ williamr@4: uLong reserved; williamr@4: } z_stream; williamr@4: williamr@4: /** typedef z_stream* as z_streamp. Refer to z_stream_s for more details */ williamr@4: typedef z_stream FAR *z_streamp; williamr@4: williamr@4: /** williamr@4: gzip header information passed to and from zlib routines. See RFC 1952 williamr@4: for more details on the meanings of these fields. williamr@4: */ williamr@4: typedef struct gz_header_s { williamr@4: /** True if compressed data believed to be text */ williamr@4: int text; williamr@4: /** Modification time */ williamr@4: uLong time; williamr@4: /** Extra flags (not used when writing a gzip file) */ williamr@4: int xflags; williamr@4: /** Operating system */ williamr@4: int os; williamr@4: /** Pointer to extra field or Z_NULL if none */ williamr@4: Bytef *extra; williamr@4: /** Extra field length (valid if extra != Z_NULL) */ williamr@4: uInt extra_len; williamr@4: /** Space at extra (only when reading header) */ williamr@4: uInt extra_max; williamr@4: /** Pointer to zero-terminated file name or Z_NULL */ williamr@4: Bytef *name; williamr@4: /** Space at name (only when reading header) */ williamr@4: uInt name_max; williamr@4: /** Pointer to zero-terminated comment or Z_NULL */ williamr@4: Bytef *comment; williamr@4: /** Space at comment (only when reading header) */ williamr@4: uInt comm_max; williamr@4: /** True if there was or will be a header crc */ williamr@4: int hcrc; williamr@4: /** True when done reading gzip header (not used when writing a gzip file) */ williamr@4: int done; williamr@4: } gz_header; williamr@4: williamr@4: /** gz_headerp is typedef gz_header* */ williamr@4: typedef gz_header FAR *gz_headerp; williamr@4: williamr@4: /* williamr@4: The application must update next_in and avail_in when avail_in has williamr@4: dropped to zero. It must update next_out and avail_out when avail_out williamr@4: has dropped to zero. The application must initialize zalloc, zfree and williamr@4: opaque before calling the init function. All other fields are set by the williamr@4: compression library and must not be updated by the application. williamr@4: williamr@4: The opaque value provided by the application will be passed as the first williamr@4: parameter for calls of zalloc and zfree. This can be useful for custom williamr@4: memory management. The compression library attaches no meaning to the williamr@4: opaque value. williamr@4: williamr@4: zalloc must return Z_NULL if there is not enough memory for the object. williamr@4: If zlib is used in a multi-threaded application, zalloc and zfree must be williamr@4: thread safe. williamr@4: williamr@4: On 16-bit systems, the functions zalloc and zfree must be able to allocate williamr@4: exactly 65536 bytes, but will not be required to allocate more than this williamr@4: if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, williamr@4: pointers returned by zalloc for objects of exactly 65536 bytes *must* williamr@4: have their offset normalized to zero. The default allocation function williamr@4: provided by this library ensures this (see zutil.c). To reduce memory williamr@4: requirements and avoid any allocation of 64K objects, at the expense of williamr@4: compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). williamr@4: williamr@4: The fields total_in and total_out can be used for statistics or williamr@4: progress reports. After compression, total_in holds the total size of williamr@4: the uncompressed data and may be saved for use in the decompressor williamr@4: (particularly if the decompressor wants to decompress everything in williamr@4: a single step). williamr@4: */ williamr@4: williamr@4: /* constants */ williamr@4: williamr@4: /** Allowed flush values; see deflate() and inflate() below for details */ williamr@4: #define Z_NO_FLUSH 0 williamr@4: /** Allowed flush values; see deflate() and inflate() below for details. This constant will be removed, use Z_SYNC_FLUSH instead*/ williamr@4: #define Z_PARTIAL_FLUSH 1 williamr@4: /** Allowed flush values; see deflate() and inflate() below for details */ williamr@4: #define Z_SYNC_FLUSH 2 williamr@4: /** Allowed flush values; see deflate() and inflate() below for details */ williamr@4: #define Z_FULL_FLUSH 3 williamr@4: /** Allowed flush values; see deflate() and inflate() below for details */ williamr@4: #define Z_FINISH 4 williamr@4: /** Allowed flush values; see deflate() and inflate() below for details */ williamr@4: #define Z_BLOCK 5 williamr@4: williamr@4: williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_OK 0 williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_STREAM_END 1 williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_NEED_DICT 2 williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_ERRNO (-1) williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_STREAM_ERROR (-2) williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_DATA_ERROR (-3) williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_MEM_ERROR (-4) williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_BUF_ERROR (-5) williamr@4: /** Return codes for the compression/decompression functions. Negative williamr@4: values are errors, positive values are used for special but normal events. */ williamr@4: #define Z_VERSION_ERROR (-6) williamr@4: williamr@4: williamr@4: /** Compression level as no compression */ williamr@4: #define Z_NO_COMPRESSION 0 williamr@4: /** Compression level for best speed */ williamr@4: #define Z_BEST_SPEED 1 williamr@4: /** Compression level for best compression */ williamr@4: #define Z_BEST_COMPRESSION 9 williamr@4: /** Compression level for default compression */ williamr@4: #define Z_DEFAULT_COMPRESSION (-1) williamr@4: williamr@4: williamr@4: /** Compression strategy; see deflateInit2() below for details */ williamr@4: #define Z_FILTERED 1 williamr@4: /** Compression strategy; see deflateInit2() below for details */ williamr@4: #define Z_HUFFMAN_ONLY 2 williamr@4: /** Compression strategy; see deflateInit2() below for details */ williamr@4: #define Z_RLE 3 williamr@4: /** Compression strategy; see deflateInit2() below for details */ williamr@4: #define Z_FIXED 4 williamr@4: /** Compression strategy; see deflateInit2() below for details */ williamr@4: #define Z_DEFAULT_STRATEGY 0 williamr@4: williamr@4: williamr@4: /** Possible values of the data_type field (though see inflate()) */ williamr@4: #define Z_BINARY 0 williamr@4: /** Possible values of the data_type field (though see inflate()) */ williamr@4: #define Z_TEXT 1 williamr@4: /** Possible values of the data_type field (though see inflate()). It is used for compatibility with 1.2.2 and earlier */ williamr@4: #define Z_ASCII Z_TEXT williamr@4: /** Possible values of the data_type field (though see inflate()) */ williamr@4: #define Z_UNKNOWN 2 williamr@4: williamr@4: williamr@4: /** The deflate compression method (the only one supported in this version) */ williamr@4: #define Z_DEFLATED 8 williamr@4: williamr@4: /** For initializing zalloc, zfree, opaque */ williamr@4: #define Z_NULL 0 williamr@4: williamr@4: /** For compatibility with versions < 1.0.2 */ williamr@4: #define zlib_version zlibVersion() williamr@4: williamr@4: williamr@4: /* basic functions */ williamr@4: williamr@4: /** The application can compare zlibVersion and ZLIB_VERSION for consistency. williamr@4: If the first character differs, the library code actually used is williamr@4: not compatible with the zlib.h header file used by the application. williamr@4: This check is automatically made by deflateInit and inflateInit. williamr@4: @return returns zlib version williamr@4: */ williamr@4: ZEXTERN const char * ZEXPORT zlibVersion OF((void)); williamr@4: williamr@4: /* williamr@4: ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); williamr@4: williamr@4: Initializes the internal stream state for compression. The fields williamr@4: zalloc, zfree and opaque must be initialized before by the caller. williamr@4: If zalloc and zfree are set to Z_NULL, deflateInit updates them to williamr@4: use default allocation functions. williamr@4: williamr@4: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: williamr@4: 1 gives best speed, 9 gives best compression, 0 gives no compression at williamr@4: all (the input data is simply copied a block at a time). williamr@4: Z_DEFAULT_COMPRESSION requests a default compromise between speed and williamr@4: compression (currently equivalent to level 6). williamr@4: williamr@4: deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not williamr@4: enough memory, Z_STREAM_ERROR if level is not a valid compression level, williamr@4: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible williamr@4: with the version assumed by the caller (ZLIB_VERSION). williamr@4: msg is set to null if there is no error message. deflateInit does not williamr@4: perform any compression: this will be done by deflate(). williamr@4: */ williamr@4: williamr@4: /** williamr@4: deflate compresses as much data as possible, and stops when the input williamr@4: buffer becomes empty or the output buffer becomes full. It may introduce some williamr@4: output latency (reading input without producing any output) except when williamr@4: forced to flush. williamr@4: williamr@4: The detailed semantics are as follows. deflate performs one or both of the williamr@4: following actions: williamr@4: williamr@4: - Compress more input starting at next_in and update next_in and avail_in williamr@4: accordingly. If not all input can be processed (because there is not williamr@4: enough room in the output buffer), next_in and avail_in are updated and williamr@4: processing will resume at this point for the next call of deflate(). williamr@4: williamr@4: - Provide more output starting at next_out and update next_out and avail_out williamr@4: accordingly. This action is forced if the parameter flush is non zero. williamr@4: Forcing flush frequently degrades the compression ratio, so this parameter williamr@4: should be set only when necessary (in interactive applications). williamr@4: Some output may be provided even if flush is not set. williamr@4: williamr@4: Before the call of deflate(), the application should ensure that at least williamr@4: one of the actions is possible, by providing more input and/or consuming williamr@4: more output, and updating avail_in or avail_out accordingly; avail_out williamr@4: should never be zero before the call. The application can consume the williamr@4: compressed output when it wants, for example when the output buffer is full williamr@4: (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK williamr@4: and with zero avail_out, it must be called again after making room in the williamr@4: output buffer because there might be more output pending. williamr@4: williamr@4: Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to williamr@4: decide how much data to accumualte before producing output, in order to williamr@4: maximize compression. williamr@4: williamr@4: If the parameter flush is set to Z_SYNC_FLUSH, all pending output is williamr@4: flushed to the output buffer and the output is aligned on a byte boundary, so williamr@4: that the decompressor can get all input data available so far. (In particular williamr@4: avail_in is zero after the call if enough output space has been provided williamr@4: before the call.) Flushing may degrade compression for some compression williamr@4: algorithms and so it should be used only when necessary. williamr@4: williamr@4: If flush is set to Z_FULL_FLUSH, all output is flushed as with williamr@4: Z_SYNC_FLUSH, and the compression state is reset so that decompression can williamr@4: restart from this point if previous compressed data has been damaged or if williamr@4: random access is desired. Using Z_FULL_FLUSH too often can seriously degrade williamr@4: compression. williamr@4: williamr@4: If deflate returns with avail_out == 0, this function must be called again williamr@4: with the same value of the flush parameter and more output space (updated williamr@4: avail_out), until the flush is complete (deflate returns with non-zero williamr@4: avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that williamr@4: avail_out is greater than six to avoid repeated flush markers due to williamr@4: avail_out == 0 on return. williamr@4: williamr@4: If the parameter flush is set to Z_FINISH, pending input is processed, williamr@4: pending output is flushed and deflate returns with Z_STREAM_END if there williamr@4: was enough output space; if deflate returns with Z_OK, this function must be williamr@4: called again with Z_FINISH and more output space (updated avail_out) but no williamr@4: more input data, until it returns with Z_STREAM_END or an error. After williamr@4: deflate has returned Z_STREAM_END, the only possible operations on the williamr@4: stream are deflateReset or deflateEnd. williamr@4: williamr@4: Z_FINISH can be used immediately after deflateInit if all the compression williamr@4: is to be done in a single step. In this case, avail_out must be at least williamr@4: the value returned by deflateBound (see below). If deflate does not return williamr@4: Z_STREAM_END, then it must be called again as described above. williamr@4: williamr@4: deflate() sets strm->adler to the adler32 checksum of all input read williamr@4: so far (that is, total_in bytes). williamr@4: williamr@4: deflate() may update strm->data_type if it can make a good guess about williamr@4: the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered williamr@4: binary. This field is only for information purposes and does not affect williamr@4: the compression algorithm in any manner. williamr@4: williamr@4: deflate() returns Z_OK if some progress has been made (more input williamr@4: processed or more output produced), Z_STREAM_END if all input has been williamr@4: consumed and all output has been produced (only when flush is set to williamr@4: Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example williamr@4: if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible williamr@4: (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not williamr@4: fatal, and deflate() can be called again with more input and more output williamr@4: space to continue compressing. williamr@4: williamr@4: @param strm Stream of data williamr@4: @param flush Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to williamr@4: decide how much data to accumualte before producing output, in order to williamr@4: maximize compression. Refer to the description above for more details. williamr@4: @return deflate returns Z_OK on success. Refer to the description above for more details. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); williamr@4: williamr@4: /** williamr@4: All dynamically allocated data structures for this stream are freed. williamr@4: This function discards any unprocessed input and does not flush any williamr@4: pending output. williamr@4: williamr@4: deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the williamr@4: stream state was inconsistent, Z_DATA_ERROR if the stream was freed williamr@4: prematurely (some input or output was discarded). In the error case, williamr@4: msg may be set but then points to a static string (which must not be williamr@4: deallocated). williamr@4: williamr@4: @param strm Stream of data williamr@4: @return deflateEnd returns Z_OK on success. Refer to the description above for more details. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); williamr@4: williamr@4: /* williamr@4: ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); williamr@4: williamr@4: Initializes the internal stream state for decompression. The fields williamr@4: next_in, avail_in, zalloc, zfree and opaque must be initialized before by williamr@4: the caller. If next_in is not Z_NULL and avail_in is large enough (the exact williamr@4: value depends on the compression method), inflateInit determines the williamr@4: compression method from the zlib header and allocates all data structures williamr@4: accordingly; otherwise the allocation will be deferred to the first call of williamr@4: inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to williamr@4: use default allocation functions. williamr@4: williamr@4: inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the williamr@4: version assumed by the caller. msg is set to null if there is no error williamr@4: message. inflateInit does not perform any decompression apart from reading williamr@4: the zlib header if present: this will be done by inflate(). (So next_in and williamr@4: avail_in may be modified, but next_out and avail_out are unchanged.) williamr@4: */ williamr@4: williamr@4: /** williamr@4: inflate decompresses as much data as possible, and stops when the input williamr@4: buffer becomes empty or the output buffer becomes full. It may introduce williamr@4: some output latency (reading input without producing any output) except when williamr@4: forced to flush. williamr@4: williamr@4: The detailed semantics are as follows. inflate performs one or both of the williamr@4: following actions: williamr@4: williamr@4: - Decompress more input starting at next_in and update next_in and avail_in williamr@4: accordingly. If not all input can be processed (because there is not williamr@4: enough room in the output buffer), next_in is updated and processing williamr@4: will resume at this point for the next call of inflate(). williamr@4: williamr@4: - Provide more output starting at next_out and update next_out and avail_out williamr@4: accordingly. inflate() provides as much output as possible, until there williamr@4: is no more input data or no more space in the output buffer (see below williamr@4: about the flush parameter). williamr@4: williamr@4: Before the call of inflate(), the application should ensure that at least williamr@4: one of the actions is possible, by providing more input and/or consuming williamr@4: more output, and updating the next_* and avail_* values accordingly. williamr@4: The application can consume the uncompressed output when it wants, for williamr@4: example when the output buffer is full (avail_out == 0), or after each williamr@4: call of inflate(). If inflate returns Z_OK and with zero avail_out, it williamr@4: must be called again after making room in the output buffer because there williamr@4: might be more output pending. williamr@4: williamr@4: The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, williamr@4: Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much williamr@4: output as possible to the output buffer. Z_BLOCK requests that inflate() stop williamr@4: if and when it gets to the next deflate block boundary. When decoding the williamr@4: zlib or gzip format, this will cause inflate() to return immediately after williamr@4: the header and before the first block. When doing a raw inflate, inflate() williamr@4: will go ahead and process the first block, and will return when it gets to williamr@4: the end of that block, or when it runs out of data. williamr@4: williamr@4: The Z_BLOCK option assists in appending to or combining deflate streams. williamr@4: Also to assist in this, on return inflate() will set strm->data_type to the williamr@4: number of unused bits in the last byte taken from strm->next_in, plus 64 williamr@4: if inflate() is currently decoding the last block in the deflate stream, williamr@4: plus 128 if inflate() returned immediately after decoding an end-of-block williamr@4: code or decoding the complete header up to just before the first byte of the williamr@4: deflate stream. The end-of-block will not be indicated until all of the williamr@4: uncompressed data from that block has been written to strm->next_out. The williamr@4: number of unused bits may in general be greater than seven, except when williamr@4: bit 7 of data_type is set, in which case the number of unused bits will be williamr@4: less than eight. williamr@4: williamr@4: inflate() should normally be called until it returns Z_STREAM_END or an williamr@4: error. However if all decompression is to be performed in a single step williamr@4: (a single call of inflate), the parameter flush should be set to williamr@4: Z_FINISH. In this case all pending input is processed and all pending williamr@4: output is flushed; avail_out must be large enough to hold all the williamr@4: uncompressed data. (The size of the uncompressed data may have been saved williamr@4: by the compressor for this purpose.) The next operation on this stream must williamr@4: be inflateEnd to deallocate the decompression state. The use of Z_FINISH williamr@4: is never required, but can be used to inform inflate that a faster approach williamr@4: may be used for the single inflate() call. williamr@4: williamr@4: In this implementation, inflate() always flushes as much output as williamr@4: possible to the output buffer, and always uses the faster approach on the williamr@4: first call. So the only effect of the flush parameter in this implementation williamr@4: is on the return value of inflate(), as noted below, or when it returns early williamr@4: because Z_BLOCK is used. williamr@4: williamr@4: If a preset dictionary is needed after this call (see inflateSetDictionary williamr@4: below), inflate sets strm->adler to the adler32 checksum of the dictionary williamr@4: chosen by the compressor and returns Z_NEED_DICT; otherwise it sets williamr@4: strm->adler to the adler32 checksum of all output produced so far (that is, williamr@4: total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described williamr@4: below. At the end of the stream, inflate() checks that its computed adler32 williamr@4: checksum is equal to that saved by the compressor and returns Z_STREAM_END williamr@4: only if the checksum is correct. williamr@4: williamr@4: inflate() will decompress and check either zlib-wrapped or gzip-wrapped williamr@4: deflate data. The header type is detected automatically. Any information williamr@4: contained in the gzip header is not retained, so applications that need that williamr@4: information should instead use raw inflate, see inflateInit2() below, or williamr@4: inflateBack() and perform their own processing of the gzip header and williamr@4: trailer. williamr@4: williamr@4: inflate() returns Z_OK if some progress has been made (more input processed williamr@4: or more output produced), Z_STREAM_END if the end of the compressed data has williamr@4: been reached and all uncompressed output has been produced, Z_NEED_DICT if a williamr@4: preset dictionary is needed at this point, Z_DATA_ERROR if the input data was williamr@4: corrupted (input stream not conforming to the zlib format or incorrect check williamr@4: value), Z_STREAM_ERROR if the stream structure was inconsistent (for example williamr@4: if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, williamr@4: Z_BUF_ERROR if no progress is possible or if there was not enough room in the williamr@4: output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and williamr@4: inflate() can be called again with more input and more output space to williamr@4: continue decompressing. If Z_DATA_ERROR is returned, the application may then williamr@4: call inflateSync() to look for a good compression block if a partial recovery williamr@4: of the data is desired. williamr@4: williamr@4: @param strm Stream of data williamr@4: @param flush This parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, williamr@4: Z_FINISH, or Z_BLOCK. Refer to the description for more details. williamr@4: @return inflate returns Z_OK on success. Refer to the description above for more details. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); williamr@4: williamr@4: /** williamr@4: All dynamically allocated data structures for this stream are freed. williamr@4: This function discards any unprocessed input and does not flush any williamr@4: pending output. williamr@4: williamr@4: @param strm Stream of data williamr@4: @return inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state williamr@4: was inconsistent. In the error case, msg may be set but then points to a williamr@4: static string (which must not be deallocated). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); williamr@4: williamr@4: /* Advanced functions */ williamr@4: williamr@4: /* williamr@4: The following functions are needed only in some special applications. williamr@4: */ williamr@4: williamr@4: /* williamr@4: ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, williamr@4: int level, williamr@4: int method, williamr@4: int windowBits, williamr@4: int memLevel, williamr@4: int strategy)); williamr@4: williamr@4: This is another version of deflateInit with more compression options. The williamr@4: fields next_in, zalloc, zfree and opaque must be initialized before by williamr@4: the caller. williamr@4: williamr@4: The method parameter is the compression method. It must be Z_DEFLATED in williamr@4: this version of the library. williamr@4: williamr@4: The windowBits parameter is the base two logarithm of the window size williamr@4: (the size of the history buffer). It should be in the range 8..15 for this williamr@4: version of the library. Larger values of this parameter result in better williamr@4: compression at the expense of memory usage. The default value is 15 if williamr@4: deflateInit is used instead. williamr@4: williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported williamr@4: due to a problem with the window size being set to 256 bytes. Although a williamr@4: value of 8 will be accepted by deflateInit2(), as it is being changed williamr@4: internally from 8 to 9, it will not be possible to use the same value when it williamr@4: comes to decompression. This is because inflateInit2() does not make the same williamr@4: change internally and as a result a Z_DATA_ERROR is returned when calling williamr@4: inflate(). It is therefore advised that for this version of the library williamr@4: windowBits of 9 is used in place of 8. williamr@4: williamr@4: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits williamr@4: determines the window size. deflate() will then generate raw deflate data williamr@4: with no zlib header or trailer, and will not compute an adler32 check value. williamr@4: williamr@4: windowBits can also be greater than 15 for optional gzip encoding. Add williamr@4: 16 to windowBits to write a simple gzip header and trailer around the williamr@4: compressed data instead of a zlib wrapper. The gzip header will have no williamr@4: file name, no extra data, no comment, no modification time (set to zero), williamr@4: no header crc, and the operating system will be set to 3 (UNIX). If a williamr@4: gzip stream is being written, strm->adler is a crc32 instead of an adler32. williamr@4: williamr@4: The memLevel parameter specifies how much memory should be allocated williamr@4: for the internal compression state. memLevel=1 uses minimum memory but williamr@4: is slow and reduces compression ratio; memLevel=9 uses maximum memory williamr@4: for optimal speed. The default value is 8. See zconf.h for total memory williamr@4: usage as a function of windowBits and memLevel. williamr@4: williamr@4: The strategy parameter is used to tune the compression algorithm. Use the williamr@4: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a williamr@4: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no williamr@4: string match), or Z_RLE to limit match distances to one (run-length williamr@4: encoding). Filtered data consists mostly of small values with a somewhat williamr@4: random distribution. In this case, the compression algorithm is tuned to williamr@4: compress them better. The effect of Z_FILTERED is to force more Huffman williamr@4: coding and less string matching; it is somewhat intermediate between williamr@4: Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as williamr@4: Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy williamr@4: parameter only affects the compression ratio but not the correctness of the williamr@4: compressed output even if it is not set appropriately. Z_FIXED prevents the williamr@4: use of dynamic Huffman codes, allowing for a simpler decoder for special williamr@4: applications. williamr@4: williamr@4: deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid williamr@4: method). msg is set to null if there is no error message. deflateInit2 does williamr@4: not perform any compression: this will be done by deflate(). williamr@4: */ williamr@4: williamr@4: /** williamr@4: Initializes the compression dictionary from the given byte sequence williamr@4: without producing any compressed output. This function must be called williamr@4: immediately after deflateInit, deflateInit2 or deflateReset, before any williamr@4: call of deflate. The compressor and decompressor must use exactly the same williamr@4: dictionary (see inflateSetDictionary). williamr@4: williamr@4: The dictionary should consist of strings (byte sequences) that are likely williamr@4: to be encountered later in the data to be compressed, with the most commonly williamr@4: used strings preferably put towards the end of the dictionary. Using a williamr@4: dictionary is most useful when the data to be compressed is short and can be williamr@4: predicted with good accuracy; the data can then be compressed better than williamr@4: with the default empty dictionary. williamr@4: williamr@4: Depending on the size of the compression data structures selected by williamr@4: deflateInit or deflateInit2, a part of the dictionary may in effect be williamr@4: discarded, for example if the dictionary is larger than the window size in williamr@4: deflate or deflate2. Thus the strings most likely to be useful should be williamr@4: put at the end of the dictionary, not at the front. In addition, the williamr@4: current implementation of deflate will use at most the window size minus williamr@4: 262 bytes of the provided dictionary. williamr@4: williamr@4: Upon return of this function, strm->adler is set to the adler32 value williamr@4: of the dictionary; the decompressor may later use this value to determine williamr@4: which dictionary has been used by the compressor. (The adler32 value williamr@4: applies to the whole dictionary even if only a subset of the dictionary is williamr@4: actually used by the compressor.) If a raw deflate was requested, then the williamr@4: adler32 value is not computed and strm->adler is not set. williamr@4: williamr@4: @param strm Stream of data williamr@4: @param dictionary Pointer to the dictionary. Refer to the description above for more details. williamr@4: @param dictLength Dictionay Length williamr@4: @return deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a williamr@4: parameter is invalid (such as NULL dictionary) or the stream state is williamr@4: inconsistent (for example if deflate has already been called for this stream williamr@4: or if the compression method is bsort). deflateSetDictionary does not williamr@4: perform any compression: this will be done by deflate(). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, williamr@4: const Bytef *dictionary, williamr@4: uInt dictLength)); williamr@4: williamr@4: /** williamr@4: Sets the destination stream as a complete copy of the source stream. williamr@4: williamr@4: This function can be useful when several compression strategies will be williamr@4: tried, for example when there are several ways of pre-processing the input williamr@4: data with a filter. The streams that will be discarded should then be freed williamr@4: by calling deflateEnd. Note that deflateCopy duplicates the internal williamr@4: compression state which can be quite large, so this strategy is slow and williamr@4: can consume lots of memory. williamr@4: williamr@4: @param dest destination stream williamr@4: @param souce source stream of data williamr@4: @return deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not williamr@4: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent williamr@4: (such as zalloc being NULL). msg is left unchanged in both source and williamr@4: destination. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, williamr@4: z_streamp source)); williamr@4: williamr@4: /** williamr@4: This function is equivalent to deflateEnd followed by deflateInit, williamr@4: but does not free and reallocate all the internal compression state. williamr@4: The stream will keep the same compression level and any other attributes williamr@4: that may have been set by deflateInit2. williamr@4: williamr@4: @param strm stream of data williamr@4: @return deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent (such as zalloc or state being NULL). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); williamr@4: williamr@4: /** williamr@4: Dynamically update the compression level and compression strategy. The williamr@4: interpretation of level and strategy is as in deflateInit2. This can be williamr@4: used to switch between compression and straight copy of the input data, or williamr@4: to switch to a different kind of input data requiring a different williamr@4: strategy. If the compression level is changed, the input available so far williamr@4: is compressed with the old level (and may be flushed); the new level will williamr@4: take effect only at the next call of deflate(). williamr@4: williamr@4: Before the call of deflateParams, the stream state must be set as for williamr@4: a call of deflate(), since the currently available input may have to williamr@4: be compressed and flushed. In particular, strm->avail_out must be non-zero. williamr@4: williamr@4: @param strm stream of data williamr@4: @param level compression level williamr@4: @param strategy compression algorithm williamr@4: @return deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR williamr@4: if strm->avail_out was zero. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, williamr@4: int level, williamr@4: int strategy)); williamr@4: williamr@4: /** williamr@4: Fine tune deflate's internal compression parameters. This should only be williamr@4: used by someone who understands the algorithm used by zlib's deflate for williamr@4: searching for the best matching string, and even then only by the most williamr@4: fanatic optimizer trying to squeeze out the last compressed bit for their williamr@4: specific input data. Read the deflate.c source code for the meaning of the williamr@4: max_lazy, good_length, nice_length, and max_chain parameters. williamr@4: williamr@4: deflateTune() can be called after deflateInit() or deflateInit2() williamr@4: williamr@4: @param strm stream of data williamr@4: @param good_length reduce lazy search above this match length williamr@4: @param max_lazy do not perform lazy search above this match length williamr@4: @param nice_length quit search above this match length williamr@4: @param max_chain williamr@4: @return deflateTune returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, williamr@4: int good_length, williamr@4: int max_lazy, williamr@4: int nice_length, williamr@4: int max_chain)); williamr@4: williamr@4: /** williamr@4: deflateBound() returns an upper bound on the compressed size after williamr@4: deflation of sourceLen bytes. It must be called after deflateInit() williamr@4: or deflateInit2(). This would be used to allocate an output buffer williamr@4: for deflation in a single pass, and so would be called before deflate(). williamr@4: williamr@4: @param strm stream of data williamr@4: @param sourceLen source length williamr@4: @return deflateBound returns an upper bound on the compressed size after williamr@4: deflation of sourceLen bytes. williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, williamr@4: uLong sourceLen)); williamr@4: williamr@4: /** williamr@4: deflatePrime() inserts bits in the deflate output stream. The intent williamr@4: is that this function is used to start off the deflate output with the williamr@4: bits leftover from a previous deflate stream when appending to it. As such, williamr@4: this function can only be used for raw deflate, and must be used before the williamr@4: first deflate() call after a deflateInit2() or deflateReset(). bits must be williamr@4: less than or equal to 16, and that many of the least significant bits of williamr@4: value will be inserted in the output. williamr@4: williamr@4: @param strm stream of data williamr@4: @param bits bits must be less than or equal to 16, and that many of the least williamr@4: significant bits of value will be inserted in the output. williamr@4: @param value represents value of the bits to be inserted williamr@4: @return deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, williamr@4: int bits, williamr@4: int value)); williamr@4: williamr@4: /** williamr@4: deflateSetHeader() provides gzip header information for when a gzip williamr@4: stream is requested by deflateInit2(). deflateSetHeader() may be called williamr@4: after deflateInit2() or deflateReset() and before the first call of williamr@4: deflate(). The text, time, os, extra field, name, and comment information williamr@4: in the provided gz_header structure are written to the gzip header (xflag is williamr@4: ignored -- the extra flags are set according to the compression level). The williamr@4: caller must assure that, if not Z_NULL, name and comment are terminated with williamr@4: a zero byte, and that if extra is not Z_NULL, that extra_len bytes are williamr@4: available there. If hcrc is true, a gzip header crc is included. Note that williamr@4: the current versions of the command-line version of gzip (up through version williamr@4: 1.3.x) do not support header crc's, and will report that it is a "multi-part williamr@4: gzip file" and give up. williamr@4: williamr@4: If deflateSetHeader is not used, the default gzip header has text false, williamr@4: the time set to zero, and os set to 3, with no extra, name, or comment williamr@4: fields. The gzip header is returned to the default state by deflateReset(). williamr@4: williamr@4: @param strm stream of data williamr@4: @param head gzip header williamr@4: @return deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, williamr@4: gz_headerp head)); williamr@4: williamr@4: /* williamr@4: ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, williamr@4: int windowBits)); williamr@4: williamr@4: This is another version of inflateInit with an extra parameter. The williamr@4: fields next_in, avail_in, zalloc, zfree and opaque must be initialized williamr@4: before by the caller. williamr@4: williamr@4: The windowBits parameter is the base two logarithm of the maximum window williamr@4: size (the size of the history buffer). It should be in the range 8..15 for williamr@4: this version of the library. The default value is 15 if inflateInit is used williamr@4: instead. windowBits must be greater than or equal to the windowBits value williamr@4: provided to deflateInit2() while compressing, or it must be equal to 15 if williamr@4: deflateInit2() was not used. If a compressed stream with a larger window williamr@4: size is given as input, inflate() will return with the error code williamr@4: Z_DATA_ERROR instead of trying to allocate a larger window. williamr@4: williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported williamr@4: due to a problem with the window size being set to 256 bytes. Although a williamr@4: value of 8 will be accepted by deflateInit2(), as it is being changed williamr@4: internally from 8 to 9, it will not be possible to use the same value when it williamr@4: comes to decompression. This is because inflateInit2() does not make the same williamr@4: change internally and as a result a Z_DATA_ERROR is returned when calling williamr@4: inflate(). It is therefore advised that for this version of the library williamr@4: windowBits of 9 is used in place of 8. williamr@4: williamr@4: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits williamr@4: determines the window size. inflate() will then process raw deflate data, williamr@4: not looking for a zlib or gzip header, not generating a check value, and not williamr@4: looking for any check values for comparison at the end of the stream. This williamr@4: is for use with other formats that use the deflate compressed data format williamr@4: such as zip. Those formats provide their own check values. If a custom williamr@4: format is developed using the raw deflate format for compressed data, it is williamr@4: recommended that a check value such as an adler32 or a crc32 be applied to williamr@4: the uncompressed data as is done in the zlib, gzip, and zip formats. For williamr@4: most applications, the zlib format should be used as is. Note that comments williamr@4: above on the use in deflateInit2() applies to the magnitude of windowBits. williamr@4: williamr@4: windowBits can also be greater than 15 for optional gzip decoding. Add williamr@4: 32 to windowBits to enable zlib and gzip decoding with automatic header williamr@4: detection, or add 16 to decode only the gzip format (the zlib format will williamr@4: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is williamr@4: a crc32 instead of an adler32. williamr@4: williamr@4: inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg williamr@4: is set to null if there is no error message. inflateInit2 does not perform williamr@4: any decompression apart from reading the zlib header if present: this will williamr@4: be done by inflate(). (So next_in and avail_in may be modified, but next_out williamr@4: and avail_out are unchanged.) williamr@4: */ williamr@4: williamr@4: /** williamr@4: Initializes the decompression dictionary from the given uncompressed byte williamr@4: sequence. This function must be called immediately after a call of inflate, williamr@4: if that call returned Z_NEED_DICT. The dictionary chosen by the compressor williamr@4: can be determined from the adler32 value returned by that call of inflate. williamr@4: The compressor and decompressor must use exactly the same dictionary (see williamr@4: deflateSetDictionary). For raw inflate, this function can be called williamr@4: immediately after inflateInit2() or inflateReset() and before any call of williamr@4: inflate() to set the dictionary. The application must insure that the williamr@4: dictionary that was used for compression is provided. williamr@4: williamr@4: inflateSetDictionary does not perform any decompression: this will be done williamr@4: by subsequent calls of inflate(). williamr@4: williamr@4: @param strm stream of data williamr@4: @param dictionary Pointer to dictionary williamr@4: @param dictLength Dictionary Length williamr@4: @return inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a williamr@4: parameter is invalid (such as NULL dictionary) or the stream state is williamr@4: inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the williamr@4: expected one (incorrect adler32 value). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, williamr@4: const Bytef *dictionary, williamr@4: uInt dictLength)); williamr@4: williamr@4: /** williamr@4: Skips invalid compressed data until a full flush point (see above the williamr@4: description of deflate with Z_FULL_FLUSH) can be found, or until all williamr@4: available input is skipped. No output is provided. williamr@4: williamr@4: @param strm Stream of data williamr@4: @return inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR williamr@4: if no more input was provided, Z_DATA_ERROR if no flush point has been found, williamr@4: or Z_STREAM_ERROR if the stream structure was inconsistent. In the success williamr@4: case, the application may save the current current value of total_in which williamr@4: indicates where valid compressed data was found. In the error case, the williamr@4: application may repeatedly call inflateSync, providing more input each time, williamr@4: until success or end of the input data. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); williamr@4: williamr@4: /** williamr@4: Sets the destination stream as a complete copy of the source stream. williamr@4: williamr@4: This function can be useful when randomly accessing a large stream. The williamr@4: first pass through the stream can periodically record the inflate state, williamr@4: allowing restarting inflate at those points when randomly accessing the williamr@4: stream. williamr@4: williamr@4: @param dest destination stream williamr@4: @param source source stream of data williamr@4: @return inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not williamr@4: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent williamr@4: (such as zalloc being NULL). msg is left unchanged in both source and williamr@4: destination. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, williamr@4: z_streamp source)); williamr@4: williamr@4: /** williamr@4: This function is equivalent to inflateEnd followed by inflateInit, williamr@4: but does not free and reallocate all the internal decompression state. williamr@4: The stream will keep attributes that may have been set by inflateInit2. williamr@4: williamr@4: @param strm Stream of data williamr@4: @return inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent (such as zalloc or state being NULL). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); williamr@4: williamr@4: /** williamr@4: This function inserts bits in the inflate input stream. The intent is williamr@4: that this function is used to start inflating at a bit position in the williamr@4: middle of a byte. The provided bits will be used before any bytes are used williamr@4: from next_in. This function should only be used with raw inflate, and williamr@4: should be used before the first inflate() call after inflateInit2() or williamr@4: inflateReset(). bits must be less than or equal to 16, and that many of the williamr@4: least significant bits of value will be inserted in the input. williamr@4: williamr@4: @param strm stream of data williamr@4: @param bits bits must be less than or equal to 16, and that many of the williamr@4: least significant bits of value will be inserted in the input. williamr@4: @param value @param value represents value of the bits to be inserted williamr@4: @return inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, williamr@4: int bits, williamr@4: int value)); williamr@4: williamr@4: /** williamr@4: inflateGetHeader() requests that gzip header information be stored in the williamr@4: provided gz_header structure. inflateGetHeader() may be called after williamr@4: inflateInit2() or inflateReset(), and before the first call of inflate(). williamr@4: As inflate() processes the gzip stream, head->done is zero until the header williamr@4: is completed, at which time head->done is set to one. If a zlib stream is williamr@4: being decoded, then head->done is set to -1 to indicate that there will be williamr@4: no gzip header information forthcoming. Note that Z_BLOCK can be used to williamr@4: force inflate() to return immediately after header processing is complete williamr@4: and before any actual data is decompressed. williamr@4: williamr@4: The text, time, xflags, and os fields are filled in with the gzip header williamr@4: contents. hcrc is set to true if there is a header CRC. (The header CRC williamr@4: was valid if done is set to one.) If extra is not Z_NULL, then extra_max williamr@4: contains the maximum number of bytes to write to extra. Once done is true, williamr@4: extra_len contains the actual extra field length, and extra contains the williamr@4: extra field, or that field truncated if extra_max is less than extra_len. williamr@4: If name is not Z_NULL, then up to name_max characters are written there, williamr@4: terminated with a zero unless the length is greater than name_max. If williamr@4: comment is not Z_NULL, then up to comm_max characters are written there, williamr@4: terminated with a zero unless the length is greater than comm_max. When williamr@4: any of extra, name, or comment are not Z_NULL and the respective field is williamr@4: not present in the header, then that field is set to Z_NULL to signal its williamr@4: absence. This allows the use of deflateSetHeader() with the returned williamr@4: structure to duplicate the header. However if those fields are set to williamr@4: allocated memory, then the application will need to save those pointers williamr@4: elsewhere so that they can be eventually freed. williamr@4: williamr@4: If inflateGetHeader is not used, then the header information is simply williamr@4: discarded. The header is always checked for validity, including the header williamr@4: CRC if present. inflateReset() will reset the process to discard the header williamr@4: information. The application would need to call inflateGetHeader() again to williamr@4: retrieve the header from the next gzip stream. williamr@4: williamr@4: @param stream of data williamr@4: @param head gzip header williamr@4: @return inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source williamr@4: stream state was inconsistent. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, williamr@4: gz_headerp head)); williamr@4: williamr@4: /* williamr@4: ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, williamr@4: unsigned char FAR *window)); williamr@4: williamr@4: Initialize the internal stream state for decompression using inflateBack() williamr@4: calls. The fields zalloc, zfree and opaque in strm must be initialized williamr@4: before the call. If zalloc and zfree are Z_NULL, then the default library- williamr@4: derived memory allocation routines are used. windowBits is the base two williamr@4: logarithm of the window size, in the range 8..15. window is a caller williamr@4: supplied buffer of that size. Except for special applications where it is williamr@4: assured that deflate was used with small window sizes, windowBits must be 15 williamr@4: and a 32K byte window must be supplied to be able to decompress general williamr@4: deflate streams. williamr@4: williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported williamr@4: due to a problem with the window size being set to 256 bytes. Although a williamr@4: value of 8 will be accepted by deflateInit2(), as it is being changed williamr@4: internally from 8 to 9, it will not be possible to use the same value when it williamr@4: comes to decompression. This is because inflateInit2() does not make the same williamr@4: change internally and as a result a Z_DATA_ERROR is returned when calling williamr@4: inflate(). It is therefore advised that for this version of the library williamr@4: windowBits of 9 is used in place of 8. williamr@4: williamr@4: See inflateBack() for the usage of these routines. williamr@4: williamr@4: inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of williamr@4: the paramaters are invalid, Z_MEM_ERROR if the internal state could not williamr@4: be allocated, or Z_VERSION_ERROR if the version of the library does not williamr@4: match the version of the header file. williamr@4: */ williamr@4: williamr@4: /** Input function pointer defined to be used in inflateBack */ williamr@4: typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); williamr@4: /** Output function pointer defined to be used in inflateBack */ williamr@4: typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); williamr@4: williamr@4: williamr@4: /** williamr@4: inflateBack() does a raw inflate with a single call using a call-back williamr@4: interface for input and output. This is more efficient than inflate() for williamr@4: file i/o applications in that it avoids copying between the output and the williamr@4: sliding window by simply making the window itself the output buffer. This williamr@4: function trusts the application to not change the output buffer passed by williamr@4: the output function, at least until inflateBack() returns. williamr@4: williamr@4: inflateBackInit() must be called first to allocate the internal state williamr@4: and to initialize the state with the user-provided window buffer. williamr@4: inflateBack() may then be used multiple times to inflate a complete, raw williamr@4: deflate stream with each call. inflateBackEnd() is then called to free williamr@4: the allocated state. williamr@4: williamr@4: A raw deflate stream is one with no zlib or gzip header or trailer. williamr@4: This routine would normally be used in a utility that reads zip or gzip williamr@4: files and writes out uncompressed files. The utility would decode the williamr@4: header and process the trailer on its own, hence this routine expects williamr@4: only the raw deflate stream to decompress. This is different from the williamr@4: normal behavior of inflate(), which expects either a zlib or gzip header and williamr@4: trailer around the deflate stream. williamr@4: williamr@4: inflateBack() uses two subroutines supplied by the caller that are then williamr@4: called by inflateBack() for input and output. inflateBack() calls those williamr@4: routines until it reads a complete deflate stream and writes out all of the williamr@4: uncompressed data, or until it encounters an error. The function's williamr@4: parameters and return types are defined above in the in_func and out_func williamr@4: typedefs. inflateBack() will call in(in_desc, &buf) which should return the williamr@4: number of bytes of provided input, and a pointer to that input in buf. If williamr@4: there is no input available, in() must return zero--buf is ignored in that williamr@4: case--and inflateBack() will return a buffer error. inflateBack() will call williamr@4: out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() williamr@4: should return zero on success, or non-zero on failure. If out() returns williamr@4: non-zero, inflateBack() will return with an error. Neither in() nor out() williamr@4: are permitted to change the contents of the window provided to williamr@4: inflateBackInit(), which is also the buffer that out() uses to write from. williamr@4: The length written by out() will be at most the window size. Any non-zero williamr@4: amount of input may be provided by in(). williamr@4: williamr@4: For convenience, inflateBack() can be provided input on the first call by williamr@4: setting strm->next_in and strm->avail_in. If that input is exhausted, then williamr@4: in() will be called. Therefore strm->next_in must be initialized before williamr@4: calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called williamr@4: immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in williamr@4: must also be initialized, and then if strm->avail_in is not zero, input will williamr@4: initially be taken from strm->next_in[0 .. strm->avail_in - 1]. williamr@4: williamr@4: The in_desc and out_desc parameters of inflateBack() is passed as the williamr@4: first parameter of in() and out() respectively when they are called. These williamr@4: descriptors can be optionally used to pass any information that the caller- williamr@4: supplied in() and out() functions need to do their job. williamr@4: williamr@4: On return, inflateBack() will set strm->next_in and strm->avail_in to williamr@4: pass back any unused input that was provided by the last in() call. The williamr@4: return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR williamr@4: if in() or out() returned an error, Z_DATA_ERROR if there was a format williamr@4: error in the deflate stream (in which case strm->msg is set to indicate the williamr@4: nature of the error), or Z_STREAM_ERROR if the stream was not properly williamr@4: initialized. In the case of Z_BUF_ERROR, an input or output error can be williamr@4: distinguished using strm->next_in which will be Z_NULL only if in() returned williamr@4: an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to williamr@4: out() returning non-zero. (in() will always be called before out(), so williamr@4: strm->next_in is assured to be defined if out() returns non-zero.) Note williamr@4: that inflateBack() cannot return Z_OK. williamr@4: williamr@4: @param strm stream of data williamr@4: @param in input function pointer williamr@4: @param in_desc input parameters for in_func williamr@4: @param out output function pointer williamr@4: @param out_desc output parameters for out_func williamr@4: @return Refer to the above description for detailed explanation williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, williamr@4: in_func in, void FAR *in_desc, williamr@4: out_func out, void FAR *out_desc)); williamr@4: williamr@4: /** williamr@4: All memory allocated by inflateBackInit() is freed. williamr@4: williamr@4: @param strm stream of data williamr@4: @return inflateBackEnd returns Z_OK on success, or Z_STREAM_ERROR if the stream williamr@4: state was inconsistent. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); williamr@4: williamr@4: /** williamr@4: Return flags indicating compile-time options. williamr@4: williamr@4: Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: williamr@4: 1.0: size of uInt williamr@4: 3.2: size of uLong williamr@4: 5.4: size of voidpf (pointer) williamr@4: 7.6: size of z_off_t williamr@4: williamr@4: Compiler, assembler, and debug options: williamr@4: 8: DEBUG williamr@4: 9: ASMV or ASMINF -- use ASM code williamr@4: 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention williamr@4: 11: 0 (reserved) williamr@4: williamr@4: One-time table building (smaller code, but not thread-safe if true): williamr@4: 12: BUILDFIXED -- build static block decoding tables when needed williamr@4: 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed williamr@4: 14,15: 0 (reserved) williamr@4: williamr@4: Library content (indicates missing functionality): williamr@4: 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking williamr@4: deflate code when not needed) williamr@4: 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect williamr@4: and decode gzip streams (to avoid linking crc code) williamr@4: 18-19: 0 (reserved) williamr@4: williamr@4: Operation variations (changes in library functionality): williamr@4: 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate williamr@4: 21: FASTEST -- deflate algorithm with only one, lowest compression level williamr@4: 22,23: 0 (reserved) williamr@4: williamr@4: The sprintf variant used by gzprintf (zero is best): williamr@4: 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format williamr@4: 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! williamr@4: 26: 0 = returns value, 1 = void -- 1 means inferred string length returned williamr@4: williamr@4: Remainder: williamr@4: 27-31: 0 (reserved) williamr@4: williamr@4: @return Refer to the above description for detailed explanation williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); williamr@4: williamr@4: /* utility functions */ williamr@4: williamr@4: /* williamr@4: The following utility functions are implemented on top of the williamr@4: basic stream-oriented functions. To simplify the interface, some williamr@4: default options are assumed (compression level and memory usage, williamr@4: standard memory allocation functions). The source code of these williamr@4: utility functions can easily be modified if you need special options. williamr@4: */ williamr@4: williamr@4: /** williamr@4: Compresses the source buffer into the destination buffer. sourceLen is williamr@4: the byte length of the source buffer. Upon entry, destLen is the total williamr@4: size of the destination buffer, which must be at least the value returned williamr@4: by compressBound(sourceLen). Upon exit, destLen is the actual size of the williamr@4: compressed buffer. williamr@4: This function can be used to compress a whole file at once if the williamr@4: input file is mmap'ed. williamr@4: williamr@4: @param dest destination buffer williamr@4: @param destLen byte length of destination buffer williamr@4: @param source source buffer williamr@4: @param sourceLen byte length of source buffer williamr@4: @return compress returns Z_OK if success, Z_MEM_ERROR if there was not williamr@4: enough memory, Z_BUF_ERROR if there was not enough room in the output williamr@4: buffer. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, williamr@4: const Bytef *source, uLong sourceLen)); williamr@4: williamr@4: /** williamr@4: Compresses the source buffer into the destination buffer. The level williamr@4: parameter has the same meaning as in deflateInit. sourceLen is the byte williamr@4: length of the source buffer. Upon entry, destLen is the total size of the williamr@4: destination buffer, which must be at least the value returned by williamr@4: compressBound(sourceLen). Upon exit, destLen is the actual size of the williamr@4: compressed buffer. williamr@4: williamr@4: @param dest destination buffer williamr@4: @param destLen byte length of destination buffer williamr@4: @param source source buffer williamr@4: @param sourceLen byte length of source buffer williamr@4: @param level Compression level williamr@4: @return compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_BUF_ERROR if there was not enough room in the output buffer, williamr@4: Z_STREAM_ERROR if the level parameter is invalid. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, williamr@4: const Bytef *source, uLong sourceLen, williamr@4: int level)); williamr@4: williamr@4: /** williamr@4: compressBound() returns an upper bound on the compressed size after williamr@4: compress() or compress2() on sourceLen bytes. It would be used before williamr@4: a compress() or compress2() call to allocate the destination buffer. williamr@4: williamr@4: @param source buffer length williamr@4: @return compressBound returns an upper bound on the compressed size after williamr@4: compress() or compress2() on sourceLen bytes. williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); williamr@4: williamr@4: /** williamr@4: Decompresses the source buffer into the destination buffer. sourceLen is williamr@4: the byte length of the source buffer. Upon entry, destLen is the total williamr@4: size of the destination buffer, which must be large enough to hold the williamr@4: entire uncompressed data. (The size of the uncompressed data must have williamr@4: been saved previously by the compressor and transmitted to the decompressor williamr@4: by some mechanism outside the scope of this compression library.) williamr@4: Upon exit, destLen is the actual size of the compressed buffer. williamr@4: This function can be used to decompress a whole file at once if the williamr@4: input file is mmap'ed. williamr@4: williamr@4: @param dest destination buffer williamr@4: @param destLen byte length of destination buffer williamr@4: @param source source buffer williamr@4: @param sourceLen byte length of source buffer williamr@4: @return uncompress returns Z_OK if success, Z_MEM_ERROR if there was not williamr@4: enough memory, Z_BUF_ERROR if there was not enough room in the output williamr@4: buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, williamr@4: const Bytef *source, uLong sourceLen)); williamr@4: williamr@4: #ifndef SYMBIAN_EZLIB_EXCLUDE_GZ_FUNCTIONS williamr@4: /** gzfile is typedef to voidp i.e. void pointer(void*) */ williamr@4: typedef voidp gzFile; williamr@4: williamr@4: /** williamr@4: Opens a gzip (.gz) file for reading or writing. The mode parameter williamr@4: is as in fopen ("rb" or "wb") but can also include a compression level williamr@4: ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for williamr@4: Huffman only compression as in "wb1h", or 'R' for run-length encoding williamr@4: as in "wb1R". (See the description of deflateInit2 for more information williamr@4: about the strategy parameter.) williamr@4: williamr@4: gzopen can be used to read a file which is not in gzip format; in this williamr@4: case gzread will directly read from the file without decompression. williamr@4: williamr@4: @param path location of the file williamr@4: @param mode refer to above description williamr@4: @return gzopen returns NULL if the file could not be opened or if there was williamr@4: insufficient memory to allocate the (de)compression state; errno williamr@4: can be checked to distinguish the two cases (if errno is zero, the williamr@4: zlib error is Z_MEM_ERROR). williamr@4: */ williamr@4: ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); williamr@4: williamr@4: /** williamr@4: gzdopen() associates a gzFile with the file descriptor fd. File williamr@4: descriptors are obtained from calls like open, dup, creat, pipe or williamr@4: fileno (in the file has been previously opened with fopen). williamr@4: The mode parameter is as in gzopen. williamr@4: The next call of gzclose on the returned gzFile will also close the williamr@4: file descriptor fd, just like fclose(fdopen(fd), mode) closes the file williamr@4: descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). williamr@4: williamr@4: @param fd file descriptor williamr@4: @param mode The mode parameter is as in gzopen williamr@4: @return gzdopen returns NULL if there was insufficient memory to allocate williamr@4: the (de)compression state. williamr@4: */ williamr@4: ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); williamr@4: williamr@4: /** williamr@4: Dynamically update the compression level or strategy. See the description williamr@4: of deflateInit2 for the meaning of these parameters. williamr@4: williamr@4: @param file gzip file williamr@4: @param level compression level williamr@4: @param strategy compression algorithm williamr@4: @return gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not williamr@4: opened for writing. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); williamr@4: williamr@4: /** williamr@4: Reads the given number of uncompressed bytes from the compressed file. williamr@4: If the input file was not in gzip format, gzread copies the given number williamr@4: of bytes into the buffer. williamr@4: williamr@4: @param file gzip file williamr@4: @param buf buffer to store the copied data from the gzip file williamr@4: @param len length of the data to be copied williamr@4: @return gzread returns the number of uncompressed bytes actually read (0 for williamr@4: end of file, -1 for error). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); williamr@4: williamr@4: /** williamr@4: Writes the given number of uncompressed bytes into the compressed file. williamr@4: gzwrite returns the number of uncompressed bytes actually written williamr@4: (0 in case of error). williamr@4: williamr@4: @param file gzip file williamr@4: @param buf buffer containing data to be written to the gzip file williamr@4: @param len length of the data williamr@4: @return gzwrite returns the number of uncompressed bytes actually written williamr@4: (0 in case of error) williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzwrite OF((gzFile file, williamr@4: voidpc buf, unsigned len)); williamr@4: williamr@4: /** williamr@4: Converts, formats, and writes the args to the compressed file under williamr@4: control of the format string, as in fprintf. gzprintf returns the number of williamr@4: uncompressed bytes actually written (0 in case of error). The number of williamr@4: uncompressed bytes written is limited to 4095. The caller should assure that williamr@4: this limit is not exceeded. If it is exceeded, then gzprintf() will return williamr@4: return an error (0) with nothing written. In this case, there may also be a williamr@4: buffer overflow with unpredictable consequences, which is possible only if williamr@4: zlib was compiled with the insecure functions sprintf() or vsprintf() williamr@4: because the secure snprintf() or vsnprintf() functions were not available. williamr@4: williamr@4: @param file gzip file williamr@4: @param format format string williamr@4: @return refer to the description above williamr@4: */ williamr@4: ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); williamr@4: williamr@4: /** williamr@4: Writes the given null-terminated string to the compressed file, excluding williamr@4: the terminating null character. williamr@4: williamr@4: @param file gzip file williamr@4: @param s null-terminated string williamr@4: @return gzputs returns the number of characters written, or -1 in case of error. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); williamr@4: williamr@4: /** williamr@4: Reads bytes from the compressed file until len-1 characters are read, or williamr@4: a newline character is read and transferred to buf, or an end-of-file williamr@4: condition is encountered. The string is then terminated with a null williamr@4: character. williamr@4: williamr@4: @param file gzip file williamr@4: @param buf buffer to store the copied data from the gzip file williamr@4: @param len number of characters to be read (len-1) williamr@4: @return gzgets returns buf, or Z_NULL in case of error. williamr@4: */ williamr@4: ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); williamr@4: williamr@4: /** williamr@4: Writes c, converted to an unsigned char, into the compressed file. williamr@4: gzputc returns the value that was written, or -1 in case of error. williamr@4: williamr@4: @param file gzip file williamr@4: @param c character williamr@4: @return gzputc returns the value that was written, or -1 in case of error. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); williamr@4: williamr@4: /** williamr@4: Reads one byte from the compressed file. gzgetc returns this byte williamr@4: or -1 in case of end of file or error. williamr@4: williamr@4: @param file gzip file williamr@4: @return gzgetc returns this byte or -1 in case of end of file or error. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); williamr@4: williamr@4: /** williamr@4: Push one character back onto the stream to be read again later. williamr@4: Only one character of push-back is allowed. gzungetc() returns the williamr@4: character pushed, or -1 on failure. gzungetc() will fail if a williamr@4: character has been pushed but not read yet, or if c is -1. The pushed williamr@4: character will be discarded if the stream is repositioned with gzseek() williamr@4: or gzrewind(). williamr@4: williamr@4: @param c character williamr@4: @param file gzip file williamr@4: @return gzungetc returns the character pushed, or -1 on failure. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); williamr@4: williamr@4: /** williamr@4: Flushes all pending output into the compressed file. The parameter williamr@4: flush is as in the deflate() function. The return value is the zlib williamr@4: error number (see function gzerror below). gzflush returns Z_OK if williamr@4: the flush parameter is Z_FINISH and all output could be flushed. williamr@4: gzflush should be called only when strictly necessary because it can williamr@4: degrade compression. williamr@4: williamr@4: @param file gzip file williamr@4: @param flush parameter flush is as in the deflate() function williamr@4: @return gzflush returns Z_OK if the flush parameter is Z_FINISH and all output could be flushed. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); williamr@4: williamr@4: /** williamr@4: Sets the starting position for the next gzread or gzwrite on the williamr@4: given compressed file. The offset represents a number of bytes in the williamr@4: uncompressed data stream. The whence parameter is defined as in lseek(2); williamr@4: the value SEEK_END is not supported. williamr@4: If the file is opened for reading, this function is emulated but can be williamr@4: extremely slow. If the file is opened for writing, only forward seeks are williamr@4: supported; gzseek then compresses a sequence of zeroes up to the new williamr@4: starting position. williamr@4: williamr@4: @param file gzip file williamr@4: @param offset represents a number of bytes in the uncompressed data stream williamr@4: @param whence defined as in lseek(2); the value SEEK_END is not supported. williamr@4: @return gzseek returns the resulting offset location as measured in bytes from williamr@4: the beginning of the uncompressed stream, or -1 in case of error, in williamr@4: particular if the file is opened for writing and the new starting position williamr@4: would be before the current position. williamr@4: */ williamr@4: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, williamr@4: z_off_t offset, int whence)); williamr@4: williamr@4: /** williamr@4: Rewinds the given file. This function is supported only for reading. williamr@4: williamr@4: gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) williamr@4: williamr@4: @param file gzip file williamr@4: @return refer to gzseek() return value & description williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); williamr@4: williamr@4: /** williamr@4: Returns the starting position for the next gzread or gzwrite on the williamr@4: given compressed file. This position represents a number of bytes in the williamr@4: uncompressed data stream. williamr@4: williamr@4: gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) williamr@4: williamr@4: @param file gzip file williamr@4: @return gztell returns the starting position for the next gzread or gzwrite on the williamr@4: given compressed file williamr@4: */ williamr@4: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); williamr@4: williamr@4: /** williamr@4: Returns 1 when EOF has previously been detected reading the given williamr@4: input stream, otherwise zero. williamr@4: williamr@4: @param file gzip file williamr@4: @return gzeof returns 1 when EOF has previously been detected reading the given williamr@4: input stream, otherwise zero. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzeof OF((gzFile file)); williamr@4: williamr@4: /** williamr@4: Returns 1 if file is being read directly without decompression, otherwise williamr@4: zero. williamr@4: williamr@4: @param file gzip file williamr@4: @return gzdirect returns 1 if file is being read directly without decompression, otherwise zero. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); williamr@4: williamr@4: /** williamr@4: Flushes all pending output if necessary, closes the compressed file williamr@4: and deallocates all the (de)compression state. The return value is the zlib williamr@4: error number (see function gzerror below). williamr@4: williamr@4: @param file gzip file williamr@4: @return gzclose returns the zlib error number (see function gzerror below). williamr@4: */ williamr@4: ZEXTERN int ZEXPORT gzclose OF((gzFile file)); williamr@4: williamr@4: /** williamr@4: Returns the error message for the last error which occurred on the williamr@4: given compressed file. errnum is set to zlib error number. If an williamr@4: error occurred in the file system and not in the compression library, williamr@4: errnum is set to Z_ERRNO and the application may consult errno williamr@4: to get the exact error code. williamr@4: williamr@4: @param file gzip file williamr@4: @param errnum error number williamr@4: @return gzerror returns the error message for the last error which occurred on the williamr@4: given compressed file. williamr@4: */ williamr@4: ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); williamr@4: williamr@4: /** williamr@4: Clears the error and end-of-file flags for file. This is analogous to the williamr@4: clearerr() function in stdio. This is useful for continuing to read a gzip williamr@4: file that is being written concurrently. williamr@4: williamr@4: @param file gzip file williamr@4: */ williamr@4: ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); williamr@4: williamr@4: #endif //SYMBIAN_EZLIB_EXCLUDE_GZ_FUNCTIONS williamr@4: williamr@4: /* checksum functions */ williamr@4: williamr@4: /* williamr@4: These functions are not related to compression but are exported williamr@4: anyway because they might be useful in applications using the williamr@4: compression library. williamr@4: */ williamr@4: williamr@4: /** williamr@4: Update a running Adler-32 checksum with the bytes buf[0..len-1] and williamr@4: return the updated checksum. If buf is NULL, this function returns williamr@4: the required initial value for the checksum. williamr@4: An Adler-32 checksum is almost as reliable as a CRC32 but can be computed williamr@4: much faster. Usage example: williamr@4: williamr@4: uLong adler = adler32(0L, Z_NULL, 0); williamr@4: williamr@4: while (read_buffer(buffer, length) != EOF) { williamr@4: adler = adler32(adler, buffer, length); williamr@4: } williamr@4: if (adler != original_adler) error(); williamr@4: williamr@4: @param adler Adler-32 checksum williamr@4: @param buf pointer to buffer williamr@4: @param len length of buffer williamr@4: @return If buf is NULL, this function returns williamr@4: the required initial value for the checksum. williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); williamr@4: williamr@4: /** williamr@4: Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 williamr@4: and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for williamr@4: each, adler1 and adler2. williamr@4: williamr@4: @param adler1 Adler-32 checksum williamr@4: @param adler2 Adler-32 checksum williamr@4: @param len2 length williamr@4: @return adler32_combine returns the Adler-32 checksum of williamr@4: seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, williamr@4: z_off_t len2)); williamr@4: williamr@4: /** williamr@4: Update a running CRC-32 with the bytes buf[0..len-1] and return the williamr@4: updated CRC-32. If buf is NULL, this function returns the required initial williamr@4: value for the for the crc. Pre- and post-conditioning (one's complement) is williamr@4: performed within this function so it shouldn't be done by the application. williamr@4: Usage example: williamr@4: williamr@4: uLong crc = crc32(0L, Z_NULL, 0); williamr@4: williamr@4: while (read_buffer(buffer, length) != EOF) { williamr@4: crc = crc32(crc, buffer, length); williamr@4: } williamr@4: if (crc != original_crc) error(); williamr@4: williamr@4: @param crc CRC-32 check value williamr@4: @param buf pointer to buffer williamr@4: @param len length of buffer williamr@4: @return If buf is NULL, this function returns the required initial williamr@4: value for the for the crc. williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); williamr@4: williamr@4: /** williamr@4: Combine two CRC-32 check values into one. For two sequences of bytes, williamr@4: seq1 and seq2 with lengths len1 and len2, CRC-32 check values were williamr@4: calculated for each, crc1 and crc2. williamr@4: williamr@4: @param crc1 CRC-32 check value williamr@4: @param crc2 CRC-32 check value williamr@4: @param len2 length williamr@4: @return crc32_combine returns the CRC-32 check value of seq1 and seq2 williamr@4: concatenated, requiring only crc1, crc2, and len2. williamr@4: */ williamr@4: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); williamr@4: williamr@4: williamr@4: williamr@4: /* various hacks, don't look :) */ williamr@4: williamr@4: /* deflateInit and inflateInit are macros to allow checking the zlib version williamr@4: * and the compiler's view of z_stream: williamr@4: */ williamr@4: /** williamr@4: Initializes the internal stream state for compression. The fields williamr@4: zalloc, zfree and opaque must be initialized before by the caller. williamr@4: If zalloc and zfree are set to Z_NULL, deflateInit updates them to williamr@4: use default allocation functions. williamr@4: williamr@4: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: williamr@4: 1 gives best speed, 9 gives best compression, 0 gives no compression at williamr@4: all (the input data is simply copied a block at a time). williamr@4: Z_DEFAULT_COMPRESSION requests a default compromise between speed and williamr@4: compression (currently equivalent to level 6). williamr@4: williamr@4: deflateInit does not perform any compression: this will be done by deflate(). williamr@4: williamr@4: @param strm stream of data williamr@4: @param level compression level williamr@4: @param version version of library williamr@4: @param stream_size stream size williamr@4: @return deflateInit_ returns Z_OK if success, Z_MEM_ERROR if there was not williamr@4: enough memory, Z_STREAM_ERROR if level is not a valid compression level, williamr@4: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible williamr@4: with the version assumed by the caller (ZLIB_VERSION). williamr@4: msg is set to null if there is no error message. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, williamr@4: const char *version, int stream_size)); williamr@4: williamr@4: /** williamr@4: Initializes the internal stream state for decompression. The fields williamr@4: next_in, avail_in, zalloc, zfree and opaque must be initialized before by williamr@4: the caller. If next_in is not Z_NULL and avail_in is large enough (the exact williamr@4: value depends on the compression method), inflateInit determines the williamr@4: compression method from the zlib header and allocates all data structures williamr@4: accordingly; otherwise the allocation will be deferred to the first call of williamr@4: inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to williamr@4: use default allocation functions. williamr@4: williamr@4: inflateInit does not perform any decompression apart from reading williamr@4: the zlib header if present: this will be done by inflate(). (So next_in and williamr@4: avail_in may be modified, but next_out and avail_out are unchanged.) williamr@4: williamr@4: @param strm stream of data williamr@4: @param version version of library williamr@4: @param stream_size stream size williamr@4: @return inflateInit_ returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the williamr@4: version assumed by the caller. msg is set to null if there is no error williamr@4: message. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, williamr@4: const char *version, int stream_size)); williamr@4: williamr@4: /** williamr@4: This is another version of deflateInit with more compression options. The williamr@4: fields next_in, zalloc, zfree and opaque must be initialized before by williamr@4: the caller. williamr@4: williamr@4: The method parameter is the compression method. It must be Z_DEFLATED in williamr@4: this version of the library. williamr@4: williamr@4: The windowBits parameter is the base two logarithm of the window size williamr@4: (the size of the history buffer). It should be in the range 8..15 for this williamr@4: version of the library. Larger values of this parameter result in better williamr@4: compression at the expense of memory usage. The default value is 15 if williamr@4: deflateInit is used instead. williamr@4: williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported williamr@4: due to a problem with the window size being set to 256 bytes. Although a williamr@4: value of 8 will be accepted by deflateInit2(), as it is being changed williamr@4: internally from 8 to 9, it will not be possible to use the same value when it williamr@4: comes to decompression. This is because inflateInit2() does not make the same williamr@4: change internally and as a result a Z_DATA_ERROR is returned when calling williamr@4: inflate(). It is therefore advised that for this version of the library williamr@4: windowBits of 9 is used in place of 8. williamr@4: williamr@4: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits williamr@4: determines the window size. deflate() will then generate raw deflate data williamr@4: with no zlib header or trailer, and will not compute an adler32 check value. williamr@4: williamr@4: windowBits can also be greater than 15 for optional gzip encoding. Add williamr@4: 16 to windowBits to write a simple gzip header and trailer around the williamr@4: compressed data instead of a zlib wrapper. The gzip header will have no williamr@4: file name, no extra data, no comment, no modification time (set to zero), williamr@4: no header crc, and the operating system will be set to 3 (UNIX). If a williamr@4: gzip stream is being written, strm->adler is a crc32 instead of an adler32. williamr@4: williamr@4: The memLevel parameter specifies how much memory should be allocated williamr@4: for the internal compression state. memLevel=1 uses minimum memory but williamr@4: is slow and reduces compression ratio; memLevel=9 uses maximum memory williamr@4: for optimal speed. The default value is 8. See zconf.h for total memory williamr@4: usage as a function of windowBits and memLevel. williamr@4: williamr@4: The strategy parameter is used to tune the compression algorithm. Use the williamr@4: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a williamr@4: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no williamr@4: string match), or Z_RLE to limit match distances to one (run-length williamr@4: encoding). Filtered data consists mostly of small values with a somewhat williamr@4: random distribution. In this case, the compression algorithm is tuned to williamr@4: compress them better. The effect of Z_FILTERED is to force more Huffman williamr@4: coding and less string matching; it is somewhat intermediate between williamr@4: Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as williamr@4: Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy williamr@4: parameter only affects the compression ratio but not the correctness of the williamr@4: compressed output even if it is not set appropriately. Z_FIXED prevents the williamr@4: use of dynamic Huffman codes, allowing for a simpler decoder for special williamr@4: applications. williamr@4: deflateInit2 does not perform any compression: this will be done by deflate(). williamr@4: williamr@4: @param strm stream of data williamr@4: @param level compression level williamr@4: @param method compression method williamr@4: @param windowBits refer to above note & description for window bits value williamr@4: @param memLevel memory level (i.e. how much memory should be allocated). refer to above description for more detail williamr@4: @param strategy compression algorithm williamr@4: @param version version of library williamr@4: @param stream_size size of stream williamr@4: @return deflateInit2_ returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid williamr@4: method). msg is set to null if there is no error message. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, williamr@4: int windowBits, int memLevel, williamr@4: int strategy, const char *version, williamr@4: int stream_size)); williamr@4: williamr@4: /** williamr@4: This is another version of inflateInit with an extra parameter. The williamr@4: fields next_in, avail_in, zalloc, zfree and opaque must be initialized williamr@4: before by the caller. williamr@4: williamr@4: The windowBits parameter is the base two logarithm of the maximum window williamr@4: size (the size of the history buffer). It should be in the range 8..15 for williamr@4: this version of the library. The default value is 15 if inflateInit is used williamr@4: instead. windowBits must be greater than or equal to the windowBits value williamr@4: provided to deflateInit2() while compressing, or it must be equal to 15 if williamr@4: deflateInit2() was not used. If a compressed stream with a larger window williamr@4: size is given as input, inflate() will return with the error code williamr@4: Z_DATA_ERROR instead of trying to allocate a larger window. williamr@4: williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported williamr@4: due to a problem with the window size being set to 256 bytes. Although a williamr@4: value of 8 will be accepted by deflateInit2(), as it is being changed williamr@4: internally from 8 to 9, it will not be possible to use the same value when it williamr@4: comes to decompression. This is because inflateInit2() does not make the same williamr@4: change internally and as a result a Z_DATA_ERROR is returned when calling williamr@4: inflate(). It is therefore advised that for this version of the library williamr@4: windowBits of 9 is used in place of 8. williamr@4: williamr@4: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits williamr@4: determines the window size. inflate() will then process raw deflate data, williamr@4: not looking for a zlib or gzip header, not generating a check value, and not williamr@4: looking for any check values for comparison at the end of the stream. This williamr@4: is for use with other formats that use the deflate compressed data format williamr@4: such as zip. Those formats provide their own check values. If a custom williamr@4: format is developed using the raw deflate format for compressed data, it is williamr@4: recommended that a check value such as an adler32 or a crc32 be applied to williamr@4: the uncompressed data as is done in the zlib, gzip, and zip formats. For williamr@4: most applications, the zlib format should be used as is. Note that comments williamr@4: above on the use in deflateInit2() applies to the magnitude of windowBits. williamr@4: williamr@4: windowBits can also be greater than 15 for optional gzip decoding. Add williamr@4: 32 to windowBits to enable zlib and gzip decoding with automatic header williamr@4: detection, or add 16 to decode only the gzip format (the zlib format will williamr@4: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is williamr@4: a crc32 instead of an adler32. williamr@4: williamr@4: @param strm stream of data williamr@4: @param windowBits refer to above note & description for window bits value williamr@4: @param version version of library williamr@4: @param stream_size size of stream williamr@4: @return inflateInit2_ returns Z_OK if success, Z_MEM_ERROR if there was not enough williamr@4: memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg williamr@4: is set to null if there is no error message. inflateInit2 does not perform williamr@4: any decompression apart from reading the zlib header if present: this will williamr@4: be done by inflate(). (So next_in and avail_in may be modified, but next_out williamr@4: and avail_out are unchanged.) williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, williamr@4: const char *version, int stream_size)); williamr@4: williamr@4: /** williamr@4: Initialize the internal stream state for decompression using inflateBack() williamr@4: calls. The fields zalloc, zfree and opaque in strm must be initialized williamr@4: before the call. If zalloc and zfree are Z_NULL, then the default library- williamr@4: derived memory allocation routines are used. windowBits is the base two williamr@4: logarithm of the window size, in the range 8..15. window is a caller williamr@4: supplied buffer of that size. Except for special applications where it is williamr@4: assured that deflate was used with small window sizes, windowBits must be 15 williamr@4: and a 32K byte window must be supplied to be able to decompress general williamr@4: deflate streams. williamr@4: williamr@4: Note: In this version of the library a windowBits value of 8 is unsupported williamr@4: due to a problem with the window size being set to 256 bytes. Although a williamr@4: value of 8 will be accepted by deflateInit2(), as it is being changed williamr@4: internally from 8 to 9, it will not be possible to use the same value when it williamr@4: comes to decompression. This is because inflateInit2() does not make the same williamr@4: change internally and as a result a Z_DATA_ERROR is returned when calling williamr@4: inflate(). It is therefore advised that for this version of the library williamr@4: windowBits of 9 is used in place of 8. williamr@4: williamr@4: See inflateBack() for the usage of these routines. williamr@4: williamr@4: @param strm stream of data williamr@4: @param windowBits refer to above note for window bits value williamr@4: @param window window is a caller supplied buffer of that size williamr@4: @param version version of library williamr@4: @param stream_size size of stream williamr@4: @return inflateBackInit_ returns Z_OK on success, Z_STREAM_ERROR if any of williamr@4: the paramaters are invalid, Z_MEM_ERROR if the internal state could not williamr@4: be allocated, or Z_VERSION_ERROR if the version of the library does not williamr@4: match the version of the header file. williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, williamr@4: unsigned char FAR *window, williamr@4: const char *version, williamr@4: int stream_size)); williamr@4: williamr@4: /** williamr@4: Macro deflateInit defined for deflateInit_() williamr@4: @param strm stream of data williamr@4: @param level compression level williamr@4: */ williamr@4: #define deflateInit(strm, level) \ williamr@4: deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) williamr@4: /** williamr@4: Macro inflateInit defined for inflateInit_() williamr@4: @param strm stream of data williamr@4: */ williamr@4: #define inflateInit(strm) \ williamr@4: inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) williamr@4: /** williamr@4: Macro deflateInit2 defined for deflateInit2_() williamr@4: @param strm stream of data williamr@4: @param level compression level williamr@4: @param method compression method williamr@4: @param windowBits refer to the note for window bits value in deflateInit2_() williamr@4: @param memLevel memory level (i.e. how much memory should be allocated). refer to above description for more detail williamr@4: @param strategy compression algorithm williamr@4: */ williamr@4: #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ williamr@4: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ williamr@4: (strategy), ZLIB_VERSION, sizeof(z_stream)) williamr@4: /** williamr@4: Macro inflateInit2 defined for inflateInit2_() williamr@4: @param strm stream of data williamr@4: @param windowBits refer to the note for window bits value in inflateInit2_() williamr@4: */ williamr@4: #define inflateInit2(strm, windowBits) \ williamr@4: inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) williamr@4: /** williamr@4: Macro inflateBackInit defined for inflateBackInit_() williamr@4: @param strm stream of data williamr@4: @param windowBits refer to the note for window bits value in inflateBackInit_() williamr@4: @param window window is a caller supplied buffer of that size williamr@4: */ williamr@4: #define inflateBackInit(strm, windowBits, window) \ williamr@4: inflateBackInit_((strm), (windowBits), (window), \ williamr@4: ZLIB_VERSION, sizeof(z_stream)) williamr@4: williamr@4: williamr@4: #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) williamr@4: /** Hack for buggy compilers */ williamr@4: struct internal_state {int dummy;}; williamr@4: #endif williamr@4: williamr@4: /** williamr@4: Returns the string representing the error code williamr@4: williamr@4: @param int error code williamr@4: @return zError returns string representing the error code williamr@4: */ williamr@4: ZEXTERN const char * ZEXPORT zError OF((int)); williamr@4: /** williamr@4: Checks whether inflate is currently at the end of a block generated by Z_SYNC_FLUSH or Z_FULL_FLUSH williamr@4: williamr@4: @param z stream of data williamr@4: @return inflateSyncPoint returns true(1) if inflate is currently at the end of a block. Otherwise false(0) williamr@4: */ williamr@4: ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z)); williamr@4: /** williamr@4: Initialize the tables before allowing more than one thread to use crc32() williamr@4: williamr@4: @return get_crc_table returns pointer to the crc table after initialisation williamr@4: */ williamr@4: ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); williamr@4: williamr@4: #ifdef __cplusplus williamr@4: } williamr@4: #endif williamr@4: williamr@4: #endif /* _ZLIB_H */