alpar@9: /* zlib.h -- interface of the 'zlib' general purpose compression library alpar@9: version 1.2.5, April 19th, 2010 alpar@9: alpar@9: Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler alpar@9: alpar@9: This software is provided 'as-is', without any express or implied alpar@9: warranty. In no event will the authors be held liable for any damages alpar@9: arising from the use of this software. alpar@9: alpar@9: Permission is granted to anyone to use this software for any purpose, alpar@9: including commercial applications, and to alter it and redistribute it alpar@9: freely, subject to the following restrictions: alpar@9: alpar@9: 1. The origin of this software must not be misrepresented; you must not alpar@9: claim that you wrote the original software. If you use this software alpar@9: in a product, an acknowledgment in the product documentation would be alpar@9: appreciated but is not required. alpar@9: 2. Altered source versions must be plainly marked as such, and must not be alpar@9: misrepresented as being the original software. alpar@9: 3. This notice may not be removed or altered from any source distribution. alpar@9: alpar@9: Jean-loup Gailly Mark Adler alpar@9: jloup@gzip.org madler@alumni.caltech.edu alpar@9: alpar@9: alpar@9: The data format used by the zlib library is described by RFCs (Request for alpar@9: Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt alpar@9: (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). alpar@9: */ alpar@9: alpar@9: #ifndef ZLIB_H alpar@9: #define ZLIB_H alpar@9: alpar@9: #include "zconf.h" alpar@9: alpar@9: #ifdef __cplusplus alpar@9: extern "C" { alpar@9: #endif alpar@9: alpar@9: #define ZLIB_VERSION "1.2.5" alpar@9: #define ZLIB_VERNUM 0x1250 alpar@9: #define ZLIB_VER_MAJOR 1 alpar@9: #define ZLIB_VER_MINOR 2 alpar@9: #define ZLIB_VER_REVISION 5 alpar@9: #define ZLIB_VER_SUBREVISION 0 alpar@9: alpar@9: /* alpar@9: The 'zlib' compression library provides in-memory compression and alpar@9: decompression functions, including integrity checks of the uncompressed data. alpar@9: This version of the library supports only one compression method (deflation) alpar@9: but other algorithms will be added later and will have the same stream alpar@9: interface. alpar@9: alpar@9: Compression can be done in a single step if the buffers are large enough, alpar@9: or can be done by repeated calls of the compression function. In the latter alpar@9: case, the application must provide more input and/or consume the output alpar@9: (providing more output space) before each call. alpar@9: alpar@9: The compressed data format used by default by the in-memory functions is alpar@9: the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped alpar@9: around a deflate stream, which is itself documented in RFC 1951. alpar@9: alpar@9: The library also supports reading and writing files in gzip (.gz) format alpar@9: with an interface similar to that of stdio using the functions that start alpar@9: with "gz". The gzip format is different from the zlib format. gzip is a alpar@9: gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. alpar@9: alpar@9: This library can optionally read and write gzip streams in memory as well. alpar@9: alpar@9: The zlib format was designed to be compact and fast for use in memory alpar@9: and on communications channels. The gzip format was designed for single- alpar@9: file compression on file systems, has a larger header than zlib to maintain alpar@9: directory information, and uses a different, slower check method than zlib. alpar@9: alpar@9: The library does not install any signal handler. The decoder checks alpar@9: the consistency of the compressed data, so the library should never crash alpar@9: even in case of corrupted input. alpar@9: */ alpar@9: alpar@9: typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); alpar@9: typedef void (*free_func) OF((voidpf opaque, voidpf address)); alpar@9: alpar@9: struct internal_state; alpar@9: alpar@9: typedef struct z_stream_s { alpar@9: Bytef *next_in; /* next input byte */ alpar@9: uInt avail_in; /* number of bytes available at next_in */ alpar@9: uLong total_in; /* total nb of input bytes read so far */ alpar@9: alpar@9: Bytef *next_out; /* next output byte should be put there */ alpar@9: uInt avail_out; /* remaining free space at next_out */ alpar@9: uLong total_out; /* total nb of bytes output so far */ alpar@9: alpar@9: char *msg; /* last error message, NULL if no error */ alpar@9: struct internal_state FAR *state; /* not visible by applications */ alpar@9: alpar@9: alloc_func zalloc; /* used to allocate the internal state */ alpar@9: free_func zfree; /* used to free the internal state */ alpar@9: voidpf opaque; /* private data object passed to zalloc and zfree */ alpar@9: alpar@9: int data_type; /* best guess about the data type: binary or text */ alpar@9: uLong adler; /* adler32 value of the uncompressed data */ alpar@9: uLong reserved; /* reserved for future use */ alpar@9: } z_stream; alpar@9: alpar@9: typedef z_stream FAR *z_streamp; alpar@9: alpar@9: /* alpar@9: gzip header information passed to and from zlib routines. See RFC 1952 alpar@9: for more details on the meanings of these fields. alpar@9: */ alpar@9: typedef struct gz_header_s { alpar@9: int text; /* true if compressed data believed to be text */ alpar@9: uLong time; /* modification time */ alpar@9: int xflags; /* extra flags (not used when writing a gzip file) */ alpar@9: int os; /* operating system */ alpar@9: Bytef *extra; /* pointer to extra field or Z_NULL if none */ alpar@9: uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ alpar@9: uInt extra_max; /* space at extra (only when reading header) */ alpar@9: Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ alpar@9: uInt name_max; /* space at name (only when reading header) */ alpar@9: Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ alpar@9: uInt comm_max; /* space at comment (only when reading header) */ alpar@9: int hcrc; /* true if there was or will be a header crc */ alpar@9: int done; /* true when done reading gzip header (not used alpar@9: when writing a gzip file) */ alpar@9: } gz_header; alpar@9: alpar@9: typedef gz_header FAR *gz_headerp; alpar@9: alpar@9: /* alpar@9: The application must update next_in and avail_in when avail_in has dropped alpar@9: to zero. It must update next_out and avail_out when avail_out has dropped alpar@9: to zero. The application must initialize zalloc, zfree and opaque before alpar@9: calling the init function. All other fields are set by the compression alpar@9: library and must not be updated by the application. alpar@9: alpar@9: The opaque value provided by the application will be passed as the first alpar@9: parameter for calls of zalloc and zfree. This can be useful for custom alpar@9: memory management. The compression library attaches no meaning to the alpar@9: opaque value. alpar@9: alpar@9: zalloc must return Z_NULL if there is not enough memory for the object. alpar@9: If zlib is used in a multi-threaded application, zalloc and zfree must be alpar@9: thread safe. alpar@9: alpar@9: On 16-bit systems, the functions zalloc and zfree must be able to allocate alpar@9: exactly 65536 bytes, but will not be required to allocate more than this if alpar@9: the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers alpar@9: returned by zalloc for objects of exactly 65536 bytes *must* have their alpar@9: offset normalized to zero. The default allocation function provided by this alpar@9: library ensures this (see zutil.c). To reduce memory requirements and avoid alpar@9: any allocation of 64K objects, at the expense of compression ratio, compile alpar@9: the library with -DMAX_WBITS=14 (see zconf.h). alpar@9: alpar@9: The fields total_in and total_out can be used for statistics or progress alpar@9: reports. After compression, total_in holds the total size of the alpar@9: uncompressed data and may be saved for use in the decompressor (particularly alpar@9: if the decompressor wants to decompress everything in a single step). alpar@9: */ alpar@9: alpar@9: /* constants */ alpar@9: alpar@9: #define Z_NO_FLUSH 0 alpar@9: #define Z_PARTIAL_FLUSH 1 alpar@9: #define Z_SYNC_FLUSH 2 alpar@9: #define Z_FULL_FLUSH 3 alpar@9: #define Z_FINISH 4 alpar@9: #define Z_BLOCK 5 alpar@9: #define Z_TREES 6 alpar@9: /* Allowed flush values; see deflate() and inflate() below for details */ alpar@9: alpar@9: #define Z_OK 0 alpar@9: #define Z_STREAM_END 1 alpar@9: #define Z_NEED_DICT 2 alpar@9: #define Z_ERRNO (-1) alpar@9: #define Z_STREAM_ERROR (-2) alpar@9: #define Z_DATA_ERROR (-3) alpar@9: #define Z_MEM_ERROR (-4) alpar@9: #define Z_BUF_ERROR (-5) alpar@9: #define Z_VERSION_ERROR (-6) alpar@9: /* Return codes for the compression/decompression functions. Negative values alpar@9: * are errors, positive values are used for special but normal events. alpar@9: */ alpar@9: alpar@9: #define Z_NO_COMPRESSION 0 alpar@9: #define Z_BEST_SPEED 1 alpar@9: #define Z_BEST_COMPRESSION 9 alpar@9: #define Z_DEFAULT_COMPRESSION (-1) alpar@9: /* compression levels */ alpar@9: alpar@9: #define Z_FILTERED 1 alpar@9: #define Z_HUFFMAN_ONLY 2 alpar@9: #define Z_RLE 3 alpar@9: #define Z_FIXED 4 alpar@9: #define Z_DEFAULT_STRATEGY 0 alpar@9: /* compression strategy; see deflateInit2() below for details */ alpar@9: alpar@9: #define Z_BINARY 0 alpar@9: #define Z_TEXT 1 alpar@9: #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ alpar@9: #define Z_UNKNOWN 2 alpar@9: /* Possible values of the data_type field (though see inflate()) */ alpar@9: alpar@9: #define Z_DEFLATED 8 alpar@9: /* The deflate compression method (the only one supported in this version) */ alpar@9: alpar@9: #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ alpar@9: alpar@9: #define zlib_version zlibVersion() alpar@9: /* for compatibility with versions < 1.0.2 */ alpar@9: alpar@9: alpar@9: /* basic functions */ alpar@9: alpar@9: ZEXTERN const char * ZEXPORT zlibVersion OF((void)); alpar@9: /* The application can compare zlibVersion and ZLIB_VERSION for consistency. alpar@9: If the first character differs, the library code actually used is not alpar@9: compatible with the zlib.h header file used by the application. This check alpar@9: is automatically made by deflateInit and inflateInit. alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); alpar@9: alpar@9: Initializes the internal stream state for compression. The fields alpar@9: zalloc, zfree and opaque must be initialized before by the caller. If alpar@9: zalloc and zfree are set to Z_NULL, deflateInit updates them to use default alpar@9: allocation functions. alpar@9: alpar@9: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: alpar@9: 1 gives best speed, 9 gives best compression, 0 gives no compression at all alpar@9: (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION alpar@9: requests a default compromise between speed and compression (currently alpar@9: equivalent to level 6). alpar@9: alpar@9: deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough alpar@9: memory, Z_STREAM_ERROR if level is not a valid compression level, or alpar@9: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible alpar@9: with the version assumed by the caller (ZLIB_VERSION). msg is set to null alpar@9: if there is no error message. deflateInit does not perform any compression: alpar@9: this will be done by deflate(). alpar@9: */ alpar@9: alpar@9: alpar@9: ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); alpar@9: /* alpar@9: deflate compresses as much data as possible, and stops when the input alpar@9: buffer becomes empty or the output buffer becomes full. It may introduce alpar@9: some output latency (reading input without producing any output) except when alpar@9: forced to flush. alpar@9: alpar@9: The detailed semantics are as follows. deflate performs one or both of the alpar@9: following actions: alpar@9: alpar@9: - Compress more input starting at next_in and update next_in and avail_in alpar@9: accordingly. If not all input can be processed (because there is not alpar@9: enough room in the output buffer), next_in and avail_in are updated and alpar@9: processing will resume at this point for the next call of deflate(). alpar@9: alpar@9: - Provide more output starting at next_out and update next_out and avail_out alpar@9: accordingly. This action is forced if the parameter flush is non zero. alpar@9: Forcing flush frequently degrades the compression ratio, so this parameter alpar@9: should be set only when necessary (in interactive applications). Some alpar@9: output may be provided even if flush is not set. alpar@9: alpar@9: Before the call of deflate(), the application should ensure that at least alpar@9: one of the actions is possible, by providing more input and/or consuming more alpar@9: output, and updating avail_in or avail_out accordingly; avail_out should alpar@9: never be zero before the call. The application can consume the compressed alpar@9: output when it wants, for example when the output buffer is full (avail_out alpar@9: == 0), or after each call of deflate(). If deflate returns Z_OK and with alpar@9: zero avail_out, it must be called again after making room in the output alpar@9: buffer because there might be more output pending. alpar@9: alpar@9: Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to alpar@9: decide how much data to accumulate before producing output, in order to alpar@9: maximize compression. alpar@9: alpar@9: If the parameter flush is set to Z_SYNC_FLUSH, all pending output is alpar@9: flushed to the output buffer and the output is aligned on a byte boundary, so alpar@9: that the decompressor can get all input data available so far. (In alpar@9: particular avail_in is zero after the call if enough output space has been alpar@9: provided before the call.) Flushing may degrade compression for some alpar@9: compression algorithms and so it should be used only when necessary. This alpar@9: completes the current deflate block and follows it with an empty stored block alpar@9: that is three bits plus filler bits to the next byte, followed by four bytes alpar@9: (00 00 ff ff). alpar@9: alpar@9: If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the alpar@9: output buffer, but the output is not aligned to a byte boundary. All of the alpar@9: input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. alpar@9: This completes the current deflate block and follows it with an empty fixed alpar@9: codes block that is 10 bits long. This assures that enough bytes are output alpar@9: in order for the decompressor to finish the block before the empty fixed code alpar@9: block. alpar@9: alpar@9: If flush is set to Z_BLOCK, a deflate block is completed and emitted, as alpar@9: for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to alpar@9: seven bits of the current block are held to be written as the next byte after alpar@9: the next deflate block is completed. In this case, the decompressor may not alpar@9: be provided enough bits at this point in order to complete decompression of alpar@9: the data provided so far to the compressor. It may need to wait for the next alpar@9: block to be emitted. This is for advanced applications that need to control alpar@9: the emission of deflate blocks. alpar@9: alpar@9: If flush is set to Z_FULL_FLUSH, all output is flushed as with alpar@9: Z_SYNC_FLUSH, and the compression state is reset so that decompression can alpar@9: restart from this point if previous compressed data has been damaged or if alpar@9: random access is desired. Using Z_FULL_FLUSH too often can seriously degrade alpar@9: compression. alpar@9: alpar@9: If deflate returns with avail_out == 0, this function must be called again alpar@9: with the same value of the flush parameter and more output space (updated alpar@9: avail_out), until the flush is complete (deflate returns with non-zero alpar@9: avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that alpar@9: avail_out is greater than six to avoid repeated flush markers due to alpar@9: avail_out == 0 on return. alpar@9: alpar@9: If the parameter flush is set to Z_FINISH, pending input is processed, alpar@9: pending output is flushed and deflate returns with Z_STREAM_END if there was alpar@9: enough output space; if deflate returns with Z_OK, this function must be alpar@9: called again with Z_FINISH and more output space (updated avail_out) but no alpar@9: more input data, until it returns with Z_STREAM_END or an error. After alpar@9: deflate has returned Z_STREAM_END, the only possible operations on the stream alpar@9: are deflateReset or deflateEnd. alpar@9: alpar@9: Z_FINISH can be used immediately after deflateInit if all the compression alpar@9: is to be done in a single step. In this case, avail_out must be at least the alpar@9: value returned by deflateBound (see below). If deflate does not return alpar@9: Z_STREAM_END, then it must be called again as described above. alpar@9: alpar@9: deflate() sets strm->adler to the adler32 checksum of all input read alpar@9: so far (that is, total_in bytes). alpar@9: alpar@9: deflate() may update strm->data_type if it can make a good guess about alpar@9: the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered alpar@9: binary. This field is only for information purposes and does not affect the alpar@9: compression algorithm in any manner. alpar@9: alpar@9: deflate() returns Z_OK if some progress has been made (more input alpar@9: processed or more output produced), Z_STREAM_END if all input has been alpar@9: consumed and all output has been produced (only when flush is set to alpar@9: Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example alpar@9: if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible alpar@9: (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not alpar@9: fatal, and deflate() can be called again with more input and more output alpar@9: space to continue compressing. alpar@9: */ alpar@9: alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); alpar@9: /* alpar@9: All dynamically allocated data structures for this stream are freed. alpar@9: This function discards any unprocessed input and does not flush any pending alpar@9: output. alpar@9: alpar@9: deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the alpar@9: stream state was inconsistent, Z_DATA_ERROR if the stream was freed alpar@9: prematurely (some input or output was discarded). In the error case, msg alpar@9: may be set but then points to a static string (which must not be alpar@9: deallocated). alpar@9: */ alpar@9: alpar@9: alpar@9: /* alpar@9: ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); alpar@9: alpar@9: Initializes the internal stream state for decompression. The fields alpar@9: next_in, avail_in, zalloc, zfree and opaque must be initialized before by alpar@9: the caller. If next_in is not Z_NULL and avail_in is large enough (the alpar@9: exact value depends on the compression method), inflateInit determines the alpar@9: compression method from the zlib header and allocates all data structures alpar@9: accordingly; otherwise the allocation will be deferred to the first call of alpar@9: inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to alpar@9: use default allocation functions. alpar@9: alpar@9: inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough alpar@9: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the alpar@9: version assumed by the caller, or Z_STREAM_ERROR if the parameters are alpar@9: invalid, such as a null pointer to the structure. msg is set to null if alpar@9: there is no error message. inflateInit does not perform any decompression alpar@9: apart from possibly reading the zlib header if present: actual decompression alpar@9: will be done by inflate(). (So next_in and avail_in may be modified, but alpar@9: next_out and avail_out are unused and unchanged.) The current implementation alpar@9: of inflateInit() does not process any header information -- that is deferred alpar@9: until inflate() is called. alpar@9: */ alpar@9: alpar@9: alpar@9: ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); alpar@9: /* alpar@9: inflate decompresses as much data as possible, and stops when the input alpar@9: buffer becomes empty or the output buffer becomes full. It may introduce alpar@9: some output latency (reading input without producing any output) except when alpar@9: forced to flush. alpar@9: alpar@9: The detailed semantics are as follows. inflate performs one or both of the alpar@9: following actions: alpar@9: alpar@9: - Decompress more input starting at next_in and update next_in and avail_in alpar@9: accordingly. If not all input can be processed (because there is not alpar@9: enough room in the output buffer), next_in is updated and processing will alpar@9: resume at this point for the next call of inflate(). alpar@9: alpar@9: - Provide more output starting at next_out and update next_out and avail_out alpar@9: accordingly. inflate() provides as much output as possible, until there is alpar@9: no more input data or no more space in the output buffer (see below about alpar@9: the flush parameter). alpar@9: alpar@9: Before the call of inflate(), the application should ensure that at least alpar@9: one of the actions is possible, by providing more input and/or consuming more alpar@9: output, and updating the next_* and avail_* values accordingly. The alpar@9: application can consume the uncompressed output when it wants, for example alpar@9: when the output buffer is full (avail_out == 0), or after each call of alpar@9: inflate(). If inflate returns Z_OK and with zero avail_out, it must be alpar@9: called again after making room in the output buffer because there might be alpar@9: more output pending. alpar@9: alpar@9: The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, alpar@9: Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much alpar@9: output as possible to the output buffer. Z_BLOCK requests that inflate() alpar@9: stop if and when it gets to the next deflate block boundary. When decoding alpar@9: the zlib or gzip format, this will cause inflate() to return immediately alpar@9: after the header and before the first block. When doing a raw inflate, alpar@9: inflate() will go ahead and process the first block, and will return when it alpar@9: gets to the end of that block, or when it runs out of data. alpar@9: alpar@9: The Z_BLOCK option assists in appending to or combining deflate streams. alpar@9: Also to assist in this, on return inflate() will set strm->data_type to the alpar@9: number of unused bits in the last byte taken from strm->next_in, plus 64 if alpar@9: inflate() is currently decoding the last block in the deflate stream, plus alpar@9: 128 if inflate() returned immediately after decoding an end-of-block code or alpar@9: decoding the complete header up to just before the first byte of the deflate alpar@9: stream. The end-of-block will not be indicated until all of the uncompressed alpar@9: data from that block has been written to strm->next_out. The number of alpar@9: unused bits may in general be greater than seven, except when bit 7 of alpar@9: data_type is set, in which case the number of unused bits will be less than alpar@9: eight. data_type is set as noted here every time inflate() returns for all alpar@9: flush options, and so can be used to determine the amount of currently alpar@9: consumed input in bits. alpar@9: alpar@9: The Z_TREES option behaves as Z_BLOCK does, but it also returns when the alpar@9: end of each deflate block header is reached, before any actual data in that alpar@9: block is decoded. This allows the caller to determine the length of the alpar@9: deflate block header for later use in random access within a deflate block. alpar@9: 256 is added to the value of strm->data_type when inflate() returns alpar@9: immediately after reaching the end of the deflate block header. alpar@9: alpar@9: inflate() should normally be called until it returns Z_STREAM_END or an alpar@9: error. However if all decompression is to be performed in a single step (a alpar@9: single call of inflate), the parameter flush should be set to Z_FINISH. In alpar@9: this case all pending input is processed and all pending output is flushed; alpar@9: avail_out must be large enough to hold all the uncompressed data. (The size alpar@9: of the uncompressed data may have been saved by the compressor for this alpar@9: purpose.) The next operation on this stream must be inflateEnd to deallocate alpar@9: the decompression state. The use of Z_FINISH is never required, but can be alpar@9: used to inform inflate that a faster approach may be used for the single alpar@9: inflate() call. alpar@9: alpar@9: In this implementation, inflate() always flushes as much output as alpar@9: possible to the output buffer, and always uses the faster approach on the alpar@9: first call. So the only effect of the flush parameter in this implementation alpar@9: is on the return value of inflate(), as noted below, or when it returns early alpar@9: because Z_BLOCK or Z_TREES is used. alpar@9: alpar@9: If a preset dictionary is needed after this call (see inflateSetDictionary alpar@9: below), inflate sets strm->adler to the adler32 checksum of the dictionary alpar@9: chosen by the compressor and returns Z_NEED_DICT; otherwise it sets alpar@9: strm->adler to the adler32 checksum of all output produced so far (that is, alpar@9: total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described alpar@9: below. At the end of the stream, inflate() checks that its computed adler32 alpar@9: checksum is equal to that saved by the compressor and returns Z_STREAM_END alpar@9: only if the checksum is correct. alpar@9: alpar@9: inflate() can decompress and check either zlib-wrapped or gzip-wrapped alpar@9: deflate data. The header type is detected automatically, if requested when alpar@9: initializing with inflateInit2(). Any information contained in the gzip alpar@9: header is not retained, so applications that need that information should alpar@9: instead use raw inflate, see inflateInit2() below, or inflateBack() and alpar@9: perform their own processing of the gzip header and trailer. alpar@9: alpar@9: inflate() returns Z_OK if some progress has been made (more input processed alpar@9: or more output produced), Z_STREAM_END if the end of the compressed data has alpar@9: been reached and all uncompressed output has been produced, Z_NEED_DICT if a alpar@9: preset dictionary is needed at this point, Z_DATA_ERROR if the input data was alpar@9: corrupted (input stream not conforming to the zlib format or incorrect check alpar@9: value), Z_STREAM_ERROR if the stream structure was inconsistent (for example alpar@9: next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, alpar@9: Z_BUF_ERROR if no progress is possible or if there was not enough room in the alpar@9: output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and alpar@9: inflate() can be called again with more input and more output space to alpar@9: continue decompressing. If Z_DATA_ERROR is returned, the application may alpar@9: then call inflateSync() to look for a good compression block if a partial alpar@9: recovery of the data is desired. alpar@9: */ alpar@9: alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); alpar@9: /* alpar@9: All dynamically allocated data structures for this stream are freed. alpar@9: This function discards any unprocessed input and does not flush any pending alpar@9: output. alpar@9: alpar@9: inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state alpar@9: was inconsistent. In the error case, msg may be set but then points to a alpar@9: static string (which must not be deallocated). alpar@9: */ alpar@9: alpar@9: alpar@9: /* Advanced functions */ alpar@9: alpar@9: /* alpar@9: The following functions are needed only in some special applications. alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, alpar@9: int level, alpar@9: int method, alpar@9: int windowBits, alpar@9: int memLevel, alpar@9: int strategy)); alpar@9: alpar@9: This is another version of deflateInit with more compression options. The alpar@9: fields next_in, zalloc, zfree and opaque must be initialized before by the alpar@9: caller. alpar@9: alpar@9: The method parameter is the compression method. It must be Z_DEFLATED in alpar@9: this version of the library. alpar@9: alpar@9: The windowBits parameter is the base two logarithm of the window size alpar@9: (the size of the history buffer). It should be in the range 8..15 for this alpar@9: version of the library. Larger values of this parameter result in better alpar@9: compression at the expense of memory usage. The default value is 15 if alpar@9: deflateInit is used instead. alpar@9: alpar@9: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits alpar@9: determines the window size. deflate() will then generate raw deflate data alpar@9: with no zlib header or trailer, and will not compute an adler32 check value. alpar@9: alpar@9: windowBits can also be greater than 15 for optional gzip encoding. Add alpar@9: 16 to windowBits to write a simple gzip header and trailer around the alpar@9: compressed data instead of a zlib wrapper. The gzip header will have no alpar@9: file name, no extra data, no comment, no modification time (set to zero), no alpar@9: header crc, and the operating system will be set to 255 (unknown). If a alpar@9: gzip stream is being written, strm->adler is a crc32 instead of an adler32. alpar@9: alpar@9: The memLevel parameter specifies how much memory should be allocated alpar@9: for the internal compression state. memLevel=1 uses minimum memory but is alpar@9: slow and reduces compression ratio; memLevel=9 uses maximum memory for alpar@9: optimal speed. The default value is 8. See zconf.h for total memory usage alpar@9: as a function of windowBits and memLevel. alpar@9: alpar@9: The strategy parameter is used to tune the compression algorithm. Use the alpar@9: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a alpar@9: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no alpar@9: string match), or Z_RLE to limit match distances to one (run-length alpar@9: encoding). Filtered data consists mostly of small values with a somewhat alpar@9: random distribution. In this case, the compression algorithm is tuned to alpar@9: compress them better. The effect of Z_FILTERED is to force more Huffman alpar@9: coding and less string matching; it is somewhat intermediate between alpar@9: Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as alpar@9: fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The alpar@9: strategy parameter only affects the compression ratio but not the alpar@9: correctness of the compressed output even if it is not set appropriately. alpar@9: Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler alpar@9: decoder for special applications. alpar@9: alpar@9: deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough alpar@9: memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid alpar@9: method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is alpar@9: incompatible with the version assumed by the caller (ZLIB_VERSION). msg is alpar@9: set to null if there is no error message. deflateInit2 does not perform any alpar@9: compression: this will be done by deflate(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, alpar@9: const Bytef *dictionary, alpar@9: uInt dictLength)); alpar@9: /* alpar@9: Initializes the compression dictionary from the given byte sequence alpar@9: without producing any compressed output. This function must be called alpar@9: immediately after deflateInit, deflateInit2 or deflateReset, before any call alpar@9: of deflate. The compressor and decompressor must use exactly the same alpar@9: dictionary (see inflateSetDictionary). alpar@9: alpar@9: The dictionary should consist of strings (byte sequences) that are likely alpar@9: to be encountered later in the data to be compressed, with the most commonly alpar@9: used strings preferably put towards the end of the dictionary. Using a alpar@9: dictionary is most useful when the data to be compressed is short and can be alpar@9: predicted with good accuracy; the data can then be compressed better than alpar@9: with the default empty dictionary. alpar@9: alpar@9: Depending on the size of the compression data structures selected by alpar@9: deflateInit or deflateInit2, a part of the dictionary may in effect be alpar@9: discarded, for example if the dictionary is larger than the window size alpar@9: provided in deflateInit or deflateInit2. Thus the strings most likely to be alpar@9: useful should be put at the end of the dictionary, not at the front. In alpar@9: addition, the current implementation of deflate will use at most the window alpar@9: size minus 262 bytes of the provided dictionary. alpar@9: alpar@9: Upon return of this function, strm->adler is set to the adler32 value alpar@9: of the dictionary; the decompressor may later use this value to determine alpar@9: which dictionary has been used by the compressor. (The adler32 value alpar@9: applies to the whole dictionary even if only a subset of the dictionary is alpar@9: actually used by the compressor.) If a raw deflate was requested, then the alpar@9: adler32 value is not computed and strm->adler is not set. alpar@9: alpar@9: deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a alpar@9: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is alpar@9: inconsistent (for example if deflate has already been called for this stream alpar@9: or if the compression method is bsort). deflateSetDictionary does not alpar@9: perform any compression: this will be done by deflate(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, alpar@9: z_streamp source)); alpar@9: /* alpar@9: Sets the destination stream as a complete copy of the source stream. alpar@9: alpar@9: This function can be useful when several compression strategies will be alpar@9: tried, for example when there are several ways of pre-processing the input alpar@9: data with a filter. The streams that will be discarded should then be freed alpar@9: by calling deflateEnd. Note that deflateCopy duplicates the internal alpar@9: compression state which can be quite large, so this strategy is slow and can alpar@9: consume lots of memory. alpar@9: alpar@9: deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not alpar@9: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent alpar@9: (such as zalloc being Z_NULL). msg is left unchanged in both source and alpar@9: destination. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); alpar@9: /* alpar@9: This function is equivalent to deflateEnd followed by deflateInit, alpar@9: but does not free and reallocate all the internal compression state. The alpar@9: stream will keep the same compression level and any other attributes that alpar@9: may have been set by deflateInit2. alpar@9: alpar@9: deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent (such as zalloc or state being Z_NULL). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, alpar@9: int level, alpar@9: int strategy)); alpar@9: /* alpar@9: Dynamically update the compression level and compression strategy. The alpar@9: interpretation of level and strategy is as in deflateInit2. This can be alpar@9: used to switch between compression and straight copy of the input data, or alpar@9: to switch to a different kind of input data requiring a different strategy. alpar@9: If the compression level is changed, the input available so far is alpar@9: compressed with the old level (and may be flushed); the new level will take alpar@9: effect only at the next call of deflate(). alpar@9: alpar@9: Before the call of deflateParams, the stream state must be set as for alpar@9: a call of deflate(), since the currently available input may have to be alpar@9: compressed and flushed. In particular, strm->avail_out must be non-zero. alpar@9: alpar@9: deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if alpar@9: strm->avail_out was zero. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, alpar@9: int good_length, alpar@9: int max_lazy, alpar@9: int nice_length, alpar@9: int max_chain)); alpar@9: /* alpar@9: Fine tune deflate's internal compression parameters. This should only be alpar@9: used by someone who understands the algorithm used by zlib's deflate for alpar@9: searching for the best matching string, and even then only by the most alpar@9: fanatic optimizer trying to squeeze out the last compressed bit for their alpar@9: specific input data. Read the deflate.c source code for the meaning of the alpar@9: max_lazy, good_length, nice_length, and max_chain parameters. alpar@9: alpar@9: deflateTune() can be called after deflateInit() or deflateInit2(), and alpar@9: returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. alpar@9: */ alpar@9: alpar@9: ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, alpar@9: uLong sourceLen)); alpar@9: /* alpar@9: deflateBound() returns an upper bound on the compressed size after alpar@9: deflation of sourceLen bytes. It must be called after deflateInit() or alpar@9: deflateInit2(), and after deflateSetHeader(), if used. This would be used alpar@9: to allocate an output buffer for deflation in a single pass, and so would be alpar@9: called before deflate(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, alpar@9: int bits, alpar@9: int value)); alpar@9: /* alpar@9: deflatePrime() inserts bits in the deflate output stream. The intent alpar@9: is that this function is used to start off the deflate output with the bits alpar@9: leftover from a previous deflate stream when appending to it. As such, this alpar@9: function can only be used for raw deflate, and must be used before the first alpar@9: deflate() call after a deflateInit2() or deflateReset(). bits must be less alpar@9: than or equal to 16, and that many of the least significant bits of value alpar@9: will be inserted in the output. alpar@9: alpar@9: deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, alpar@9: gz_headerp head)); alpar@9: /* alpar@9: deflateSetHeader() provides gzip header information for when a gzip alpar@9: stream is requested by deflateInit2(). deflateSetHeader() may be called alpar@9: after deflateInit2() or deflateReset() and before the first call of alpar@9: deflate(). The text, time, os, extra field, name, and comment information alpar@9: in the provided gz_header structure are written to the gzip header (xflag is alpar@9: ignored -- the extra flags are set according to the compression level). The alpar@9: caller must assure that, if not Z_NULL, name and comment are terminated with alpar@9: a zero byte, and that if extra is not Z_NULL, that extra_len bytes are alpar@9: available there. If hcrc is true, a gzip header crc is included. Note that alpar@9: the current versions of the command-line version of gzip (up through version alpar@9: 1.3.x) do not support header crc's, and will report that it is a "multi-part alpar@9: gzip file" and give up. alpar@9: alpar@9: If deflateSetHeader is not used, the default gzip header has text false, alpar@9: the time set to zero, and os set to 255, with no extra, name, or comment alpar@9: fields. The gzip header is returned to the default state by deflateReset(). alpar@9: alpar@9: deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent. alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, alpar@9: int windowBits)); alpar@9: alpar@9: This is another version of inflateInit with an extra parameter. The alpar@9: fields next_in, avail_in, zalloc, zfree and opaque must be initialized alpar@9: before by the caller. alpar@9: alpar@9: The windowBits parameter is the base two logarithm of the maximum window alpar@9: size (the size of the history buffer). It should be in the range 8..15 for alpar@9: this version of the library. The default value is 15 if inflateInit is used alpar@9: instead. windowBits must be greater than or equal to the windowBits value alpar@9: provided to deflateInit2() while compressing, or it must be equal to 15 if alpar@9: deflateInit2() was not used. If a compressed stream with a larger window alpar@9: size is given as input, inflate() will return with the error code alpar@9: Z_DATA_ERROR instead of trying to allocate a larger window. alpar@9: alpar@9: windowBits can also be zero to request that inflate use the window size in alpar@9: the zlib header of the compressed stream. alpar@9: alpar@9: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits alpar@9: determines the window size. inflate() will then process raw deflate data, alpar@9: not looking for a zlib or gzip header, not generating a check value, and not alpar@9: looking for any check values for comparison at the end of the stream. This alpar@9: is for use with other formats that use the deflate compressed data format alpar@9: such as zip. Those formats provide their own check values. If a custom alpar@9: format is developed using the raw deflate format for compressed data, it is alpar@9: recommended that a check value such as an adler32 or a crc32 be applied to alpar@9: the uncompressed data as is done in the zlib, gzip, and zip formats. For alpar@9: most applications, the zlib format should be used as is. Note that comments alpar@9: above on the use in deflateInit2() applies to the magnitude of windowBits. alpar@9: alpar@9: windowBits can also be greater than 15 for optional gzip decoding. Add alpar@9: 32 to windowBits to enable zlib and gzip decoding with automatic header alpar@9: detection, or add 16 to decode only the gzip format (the zlib format will alpar@9: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a alpar@9: crc32 instead of an adler32. alpar@9: alpar@9: inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough alpar@9: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the alpar@9: version assumed by the caller, or Z_STREAM_ERROR if the parameters are alpar@9: invalid, such as a null pointer to the structure. msg is set to null if alpar@9: there is no error message. inflateInit2 does not perform any decompression alpar@9: apart from possibly reading the zlib header if present: actual decompression alpar@9: will be done by inflate(). (So next_in and avail_in may be modified, but alpar@9: next_out and avail_out are unused and unchanged.) The current implementation alpar@9: of inflateInit2() does not process any header information -- that is alpar@9: deferred until inflate() is called. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, alpar@9: const Bytef *dictionary, alpar@9: uInt dictLength)); alpar@9: /* alpar@9: Initializes the decompression dictionary from the given uncompressed byte alpar@9: sequence. This function must be called immediately after a call of inflate, alpar@9: if that call returned Z_NEED_DICT. The dictionary chosen by the compressor alpar@9: can be determined from the adler32 value returned by that call of inflate. alpar@9: The compressor and decompressor must use exactly the same dictionary (see alpar@9: deflateSetDictionary). For raw inflate, this function can be called alpar@9: immediately after inflateInit2() or inflateReset() and before any call of alpar@9: inflate() to set the dictionary. The application must insure that the alpar@9: dictionary that was used for compression is provided. alpar@9: alpar@9: inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a alpar@9: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is alpar@9: inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the alpar@9: expected one (incorrect adler32 value). inflateSetDictionary does not alpar@9: perform any decompression: this will be done by subsequent calls of alpar@9: inflate(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); alpar@9: /* alpar@9: Skips invalid compressed data until a full flush point (see above the alpar@9: description of deflate with Z_FULL_FLUSH) can be found, or until all alpar@9: available input is skipped. No output is provided. alpar@9: alpar@9: inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR alpar@9: if no more input was provided, Z_DATA_ERROR if no flush point has been alpar@9: found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the alpar@9: success case, the application may save the current current value of total_in alpar@9: which indicates where valid compressed data was found. In the error case, alpar@9: the application may repeatedly call inflateSync, providing more input each alpar@9: time, until success or end of the input data. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, alpar@9: z_streamp source)); alpar@9: /* alpar@9: Sets the destination stream as a complete copy of the source stream. alpar@9: alpar@9: This function can be useful when randomly accessing a large stream. The alpar@9: first pass through the stream can periodically record the inflate state, alpar@9: allowing restarting inflate at those points when randomly accessing the alpar@9: stream. alpar@9: alpar@9: inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not alpar@9: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent alpar@9: (such as zalloc being Z_NULL). msg is left unchanged in both source and alpar@9: destination. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); alpar@9: /* alpar@9: This function is equivalent to inflateEnd followed by inflateInit, alpar@9: but does not free and reallocate all the internal decompression state. The alpar@9: stream will keep attributes that may have been set by inflateInit2. alpar@9: alpar@9: inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent (such as zalloc or state being Z_NULL). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, alpar@9: int windowBits)); alpar@9: /* alpar@9: This function is the same as inflateReset, but it also permits changing alpar@9: the wrap and window size requests. The windowBits parameter is interpreted alpar@9: the same as it is for inflateInit2. alpar@9: alpar@9: inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent (such as zalloc or state being Z_NULL), or if alpar@9: the windowBits parameter is invalid. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, alpar@9: int bits, alpar@9: int value)); alpar@9: /* alpar@9: This function inserts bits in the inflate input stream. The intent is alpar@9: that this function is used to start inflating at a bit position in the alpar@9: middle of a byte. The provided bits will be used before any bytes are used alpar@9: from next_in. This function should only be used with raw inflate, and alpar@9: should be used before the first inflate() call after inflateInit2() or alpar@9: inflateReset(). bits must be less than or equal to 16, and that many of the alpar@9: least significant bits of value will be inserted in the input. alpar@9: alpar@9: If bits is negative, then the input stream bit buffer is emptied. Then alpar@9: inflatePrime() can be called again to put bits in the buffer. This is used alpar@9: to clear out bits leftover after feeding inflate a block description prior alpar@9: to feeding inflate codes. alpar@9: alpar@9: inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent. alpar@9: */ alpar@9: alpar@9: ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); alpar@9: /* alpar@9: This function returns two values, one in the lower 16 bits of the return alpar@9: value, and the other in the remaining upper bits, obtained by shifting the alpar@9: return value down 16 bits. If the upper value is -1 and the lower value is alpar@9: zero, then inflate() is currently decoding information outside of a block. alpar@9: If the upper value is -1 and the lower value is non-zero, then inflate is in alpar@9: the middle of a stored block, with the lower value equaling the number of alpar@9: bytes from the input remaining to copy. If the upper value is not -1, then alpar@9: it is the number of bits back from the current bit position in the input of alpar@9: the code (literal or length/distance pair) currently being processed. In alpar@9: that case the lower value is the number of bytes already emitted for that alpar@9: code. alpar@9: alpar@9: A code is being processed if inflate is waiting for more input to complete alpar@9: decoding of the code, or if it has completed decoding but is waiting for alpar@9: more output space to write the literal or match data. alpar@9: alpar@9: inflateMark() is used to mark locations in the input data for random alpar@9: access, which may be at bit positions, and to note those cases where the alpar@9: output of a code may span boundaries of random access blocks. The current alpar@9: location in the input stream can be determined from avail_in and data_type alpar@9: as noted in the description for the Z_BLOCK flush parameter for inflate. alpar@9: alpar@9: inflateMark returns the value noted above or -1 << 16 if the provided alpar@9: source stream state was inconsistent. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, alpar@9: gz_headerp head)); alpar@9: /* alpar@9: inflateGetHeader() requests that gzip header information be stored in the alpar@9: provided gz_header structure. inflateGetHeader() may be called after alpar@9: inflateInit2() or inflateReset(), and before the first call of inflate(). alpar@9: As inflate() processes the gzip stream, head->done is zero until the header alpar@9: is completed, at which time head->done is set to one. If a zlib stream is alpar@9: being decoded, then head->done is set to -1 to indicate that there will be alpar@9: no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be alpar@9: used to force inflate() to return immediately after header processing is alpar@9: complete and before any actual data is decompressed. alpar@9: alpar@9: The text, time, xflags, and os fields are filled in with the gzip header alpar@9: contents. hcrc is set to true if there is a header CRC. (The header CRC alpar@9: was valid if done is set to one.) If extra is not Z_NULL, then extra_max alpar@9: contains the maximum number of bytes to write to extra. Once done is true, alpar@9: extra_len contains the actual extra field length, and extra contains the alpar@9: extra field, or that field truncated if extra_max is less than extra_len. alpar@9: If name is not Z_NULL, then up to name_max characters are written there, alpar@9: terminated with a zero unless the length is greater than name_max. If alpar@9: comment is not Z_NULL, then up to comm_max characters are written there, alpar@9: terminated with a zero unless the length is greater than comm_max. When any alpar@9: of extra, name, or comment are not Z_NULL and the respective field is not alpar@9: present in the header, then that field is set to Z_NULL to signal its alpar@9: absence. This allows the use of deflateSetHeader() with the returned alpar@9: structure to duplicate the header. However if those fields are set to alpar@9: allocated memory, then the application will need to save those pointers alpar@9: elsewhere so that they can be eventually freed. alpar@9: alpar@9: If inflateGetHeader is not used, then the header information is simply alpar@9: discarded. The header is always checked for validity, including the header alpar@9: CRC if present. inflateReset() will reset the process to discard the header alpar@9: information. The application would need to call inflateGetHeader() again to alpar@9: retrieve the header from the next gzip stream. alpar@9: alpar@9: inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source alpar@9: stream state was inconsistent. alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, alpar@9: unsigned char FAR *window)); alpar@9: alpar@9: Initialize the internal stream state for decompression using inflateBack() alpar@9: calls. The fields zalloc, zfree and opaque in strm must be initialized alpar@9: before the call. If zalloc and zfree are Z_NULL, then the default library- alpar@9: derived memory allocation routines are used. windowBits is the base two alpar@9: logarithm of the window size, in the range 8..15. window is a caller alpar@9: supplied buffer of that size. Except for special applications where it is alpar@9: assured that deflate was used with small window sizes, windowBits must be 15 alpar@9: and a 32K byte window must be supplied to be able to decompress general alpar@9: deflate streams. alpar@9: alpar@9: See inflateBack() for the usage of these routines. alpar@9: alpar@9: inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of alpar@9: the paramaters are invalid, Z_MEM_ERROR if the internal state could not be alpar@9: allocated, or Z_VERSION_ERROR if the version of the library does not match alpar@9: the version of the header file. alpar@9: */ alpar@9: alpar@9: typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); alpar@9: typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, alpar@9: in_func in, void FAR *in_desc, alpar@9: out_func out, void FAR *out_desc)); alpar@9: /* alpar@9: inflateBack() does a raw inflate with a single call using a call-back alpar@9: interface for input and output. This is more efficient than inflate() for alpar@9: file i/o applications in that it avoids copying between the output and the alpar@9: sliding window by simply making the window itself the output buffer. This alpar@9: function trusts the application to not change the output buffer passed by alpar@9: the output function, at least until inflateBack() returns. alpar@9: alpar@9: inflateBackInit() must be called first to allocate the internal state alpar@9: and to initialize the state with the user-provided window buffer. alpar@9: inflateBack() may then be used multiple times to inflate a complete, raw alpar@9: deflate stream with each call. inflateBackEnd() is then called to free the alpar@9: allocated state. alpar@9: alpar@9: A raw deflate stream is one with no zlib or gzip header or trailer. alpar@9: This routine would normally be used in a utility that reads zip or gzip alpar@9: files and writes out uncompressed files. The utility would decode the alpar@9: header and process the trailer on its own, hence this routine expects only alpar@9: the raw deflate stream to decompress. This is different from the normal alpar@9: behavior of inflate(), which expects either a zlib or gzip header and alpar@9: trailer around the deflate stream. alpar@9: alpar@9: inflateBack() uses two subroutines supplied by the caller that are then alpar@9: called by inflateBack() for input and output. inflateBack() calls those alpar@9: routines until it reads a complete deflate stream and writes out all of the alpar@9: uncompressed data, or until it encounters an error. The function's alpar@9: parameters and return types are defined above in the in_func and out_func alpar@9: typedefs. inflateBack() will call in(in_desc, &buf) which should return the alpar@9: number of bytes of provided input, and a pointer to that input in buf. If alpar@9: there is no input available, in() must return zero--buf is ignored in that alpar@9: case--and inflateBack() will return a buffer error. inflateBack() will call alpar@9: out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() alpar@9: should return zero on success, or non-zero on failure. If out() returns alpar@9: non-zero, inflateBack() will return with an error. Neither in() nor out() alpar@9: are permitted to change the contents of the window provided to alpar@9: inflateBackInit(), which is also the buffer that out() uses to write from. alpar@9: The length written by out() will be at most the window size. Any non-zero alpar@9: amount of input may be provided by in(). alpar@9: alpar@9: For convenience, inflateBack() can be provided input on the first call by alpar@9: setting strm->next_in and strm->avail_in. If that input is exhausted, then alpar@9: in() will be called. Therefore strm->next_in must be initialized before alpar@9: calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called alpar@9: immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in alpar@9: must also be initialized, and then if strm->avail_in is not zero, input will alpar@9: initially be taken from strm->next_in[0 .. strm->avail_in - 1]. alpar@9: alpar@9: The in_desc and out_desc parameters of inflateBack() is passed as the alpar@9: first parameter of in() and out() respectively when they are called. These alpar@9: descriptors can be optionally used to pass any information that the caller- alpar@9: supplied in() and out() functions need to do their job. alpar@9: alpar@9: On return, inflateBack() will set strm->next_in and strm->avail_in to alpar@9: pass back any unused input that was provided by the last in() call. The alpar@9: return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR alpar@9: if in() or out() returned an error, Z_DATA_ERROR if there was a format error alpar@9: in the deflate stream (in which case strm->msg is set to indicate the nature alpar@9: of the error), or Z_STREAM_ERROR if the stream was not properly initialized. alpar@9: In the case of Z_BUF_ERROR, an input or output error can be distinguished alpar@9: using strm->next_in which will be Z_NULL only if in() returned an error. If alpar@9: strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning alpar@9: non-zero. (in() will always be called before out(), so strm->next_in is alpar@9: assured to be defined if out() returns non-zero.) Note that inflateBack() alpar@9: cannot return Z_OK. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); alpar@9: /* alpar@9: All memory allocated by inflateBackInit() is freed. alpar@9: alpar@9: inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream alpar@9: state was inconsistent. alpar@9: */ alpar@9: alpar@9: ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); alpar@9: /* Return flags indicating compile-time options. alpar@9: alpar@9: Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: alpar@9: 1.0: size of uInt alpar@9: 3.2: size of uLong alpar@9: 5.4: size of voidpf (pointer) alpar@9: 7.6: size of z_off_t alpar@9: alpar@9: Compiler, assembler, and debug options: alpar@9: 8: DEBUG alpar@9: 9: ASMV or ASMINF -- use ASM code alpar@9: 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention alpar@9: 11: 0 (reserved) alpar@9: alpar@9: One-time table building (smaller code, but not thread-safe if true): alpar@9: 12: BUILDFIXED -- build static block decoding tables when needed alpar@9: 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed alpar@9: 14,15: 0 (reserved) alpar@9: alpar@9: Library content (indicates missing functionality): alpar@9: 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking alpar@9: deflate code when not needed) alpar@9: 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect alpar@9: and decode gzip streams (to avoid linking crc code) alpar@9: 18-19: 0 (reserved) alpar@9: alpar@9: Operation variations (changes in library functionality): alpar@9: 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate alpar@9: 21: FASTEST -- deflate algorithm with only one, lowest compression level alpar@9: 22,23: 0 (reserved) alpar@9: alpar@9: The sprintf variant used by gzprintf (zero is best): alpar@9: 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format alpar@9: 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! alpar@9: 26: 0 = returns value, 1 = void -- 1 means inferred string length returned alpar@9: alpar@9: Remainder: alpar@9: 27-31: 0 (reserved) alpar@9: */ alpar@9: alpar@9: alpar@9: /* utility functions */ alpar@9: alpar@9: /* alpar@9: The following utility functions are implemented on top of the basic alpar@9: stream-oriented functions. To simplify the interface, some default options alpar@9: are assumed (compression level and memory usage, standard memory allocation alpar@9: functions). The source code of these utility functions can be modified if alpar@9: you need special options. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, alpar@9: const Bytef *source, uLong sourceLen)); alpar@9: /* alpar@9: Compresses the source buffer into the destination buffer. sourceLen is alpar@9: the byte length of the source buffer. Upon entry, destLen is the total size alpar@9: of the destination buffer, which must be at least the value returned by alpar@9: compressBound(sourceLen). Upon exit, destLen is the actual size of the alpar@9: compressed buffer. alpar@9: alpar@9: compress returns Z_OK if success, Z_MEM_ERROR if there was not alpar@9: enough memory, Z_BUF_ERROR if there was not enough room in the output alpar@9: buffer. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, alpar@9: const Bytef *source, uLong sourceLen, alpar@9: int level)); alpar@9: /* alpar@9: Compresses the source buffer into the destination buffer. The level alpar@9: parameter has the same meaning as in deflateInit. sourceLen is the byte alpar@9: length of the source buffer. Upon entry, destLen is the total size of the alpar@9: destination buffer, which must be at least the value returned by alpar@9: compressBound(sourceLen). Upon exit, destLen is the actual size of the alpar@9: compressed buffer. alpar@9: alpar@9: compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough alpar@9: memory, Z_BUF_ERROR if there was not enough room in the output buffer, alpar@9: Z_STREAM_ERROR if the level parameter is invalid. alpar@9: */ alpar@9: alpar@9: ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); alpar@9: /* alpar@9: compressBound() returns an upper bound on the compressed size after alpar@9: compress() or compress2() on sourceLen bytes. It would be used before a alpar@9: compress() or compress2() call to allocate the destination buffer. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, alpar@9: const Bytef *source, uLong sourceLen)); alpar@9: /* alpar@9: Decompresses the source buffer into the destination buffer. sourceLen is alpar@9: the byte length of the source buffer. Upon entry, destLen is the total size alpar@9: of the destination buffer, which must be large enough to hold the entire alpar@9: uncompressed data. (The size of the uncompressed data must have been saved alpar@9: previously by the compressor and transmitted to the decompressor by some alpar@9: mechanism outside the scope of this compression library.) Upon exit, destLen alpar@9: is the actual size of the uncompressed buffer. alpar@9: alpar@9: uncompress returns Z_OK if success, Z_MEM_ERROR if there was not alpar@9: enough memory, Z_BUF_ERROR if there was not enough room in the output alpar@9: buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. alpar@9: */ alpar@9: alpar@9: alpar@9: /* gzip file access functions */ alpar@9: alpar@9: /* alpar@9: This library supports reading and writing files in gzip (.gz) format with alpar@9: an interface similar to that of stdio, using the functions that start with alpar@9: "gz". The gzip format is different from the zlib format. gzip is a gzip alpar@9: wrapper, documented in RFC 1952, wrapped around a deflate stream. alpar@9: */ alpar@9: alpar@9: typedef voidp gzFile; /* opaque gzip file descriptor */ alpar@9: alpar@9: /* alpar@9: ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); alpar@9: alpar@9: Opens a gzip (.gz) file for reading or writing. The mode parameter is as alpar@9: in fopen ("rb" or "wb") but can also include a compression level ("wb9") or alpar@9: a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only alpar@9: compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' alpar@9: for fixed code compression as in "wb9F". (See the description of alpar@9: deflateInit2 for more information about the strategy parameter.) Also "a" alpar@9: can be used instead of "w" to request that the gzip stream that will be alpar@9: written be appended to the file. "+" will result in an error, since reading alpar@9: and writing to the same gzip file is not supported. alpar@9: alpar@9: gzopen can be used to read a file which is not in gzip format; in this alpar@9: case gzread will directly read from the file without decompression. alpar@9: alpar@9: gzopen returns NULL if the file could not be opened, if there was alpar@9: insufficient memory to allocate the gzFile state, or if an invalid mode was alpar@9: specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). alpar@9: errno can be checked to determine if the reason gzopen failed was that the alpar@9: file could not be opened. alpar@9: */ alpar@9: alpar@9: ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); alpar@9: /* alpar@9: gzdopen associates a gzFile with the file descriptor fd. File descriptors alpar@9: are obtained from calls like open, dup, creat, pipe or fileno (if the file alpar@9: has been previously opened with fopen). The mode parameter is as in gzopen. alpar@9: alpar@9: The next call of gzclose on the returned gzFile will also close the file alpar@9: descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor alpar@9: fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, alpar@9: mode);. The duplicated descriptor should be saved to avoid a leak, since alpar@9: gzdopen does not close fd if it fails. alpar@9: alpar@9: gzdopen returns NULL if there was insufficient memory to allocate the alpar@9: gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not alpar@9: provided, or '+' was provided), or if fd is -1. The file descriptor is not alpar@9: used until the next gz* read, write, seek, or close operation, so gzdopen alpar@9: will not detect if fd is invalid (unless fd is -1). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); alpar@9: /* alpar@9: Set the internal buffer size used by this library's functions. The alpar@9: default buffer size is 8192 bytes. This function must be called after alpar@9: gzopen() or gzdopen(), and before any other calls that read or write the alpar@9: file. The buffer memory allocation is always deferred to the first read or alpar@9: write. Two buffers are allocated, either both of the specified size when alpar@9: writing, or one of the specified size and the other twice that size when alpar@9: reading. A larger buffer size of, for example, 64K or 128K bytes will alpar@9: noticeably increase the speed of decompression (reading). alpar@9: alpar@9: The new buffer size also affects the maximum length for gzprintf(). alpar@9: alpar@9: gzbuffer() returns 0 on success, or -1 on failure, such as being called alpar@9: too late. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); alpar@9: /* alpar@9: Dynamically update the compression level or strategy. See the description alpar@9: of deflateInit2 for the meaning of these parameters. alpar@9: alpar@9: gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not alpar@9: opened for writing. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); alpar@9: /* alpar@9: Reads the given number of uncompressed bytes from the compressed file. If alpar@9: the input file was not in gzip format, gzread copies the given number of alpar@9: bytes into the buffer. alpar@9: alpar@9: After reaching the end of a gzip stream in the input, gzread will continue alpar@9: to read, looking for another gzip stream, or failing that, reading the rest alpar@9: of the input file directly without decompression. The entire input file alpar@9: will be read if gzread is called until it returns less than the requested alpar@9: len. alpar@9: alpar@9: gzread returns the number of uncompressed bytes actually read, less than alpar@9: len for end of file, or -1 for error. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzwrite OF((gzFile file, alpar@9: voidpc buf, unsigned len)); alpar@9: /* alpar@9: Writes the given number of uncompressed bytes into the compressed file. alpar@9: gzwrite returns the number of uncompressed bytes written or 0 in case of alpar@9: error. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); alpar@9: /* alpar@9: Converts, formats, and writes the arguments to the compressed file under alpar@9: control of the format string, as in fprintf. gzprintf returns the number of alpar@9: uncompressed bytes actually written, or 0 in case of error. The number of alpar@9: uncompressed bytes written is limited to 8191, or one less than the buffer alpar@9: size given to gzbuffer(). The caller should assure that this limit is not alpar@9: exceeded. If it is exceeded, then gzprintf() will return an error (0) with alpar@9: nothing written. In this case, there may also be a buffer overflow with alpar@9: unpredictable consequences, which is possible only if zlib was compiled with alpar@9: the insecure functions sprintf() or vsprintf() because the secure snprintf() alpar@9: or vsnprintf() functions were not available. This can be determined using alpar@9: zlibCompileFlags(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); alpar@9: /* alpar@9: Writes the given null-terminated string to the compressed file, excluding alpar@9: the terminating null character. alpar@9: alpar@9: gzputs returns the number of characters written, or -1 in case of error. alpar@9: */ alpar@9: alpar@9: ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); alpar@9: /* alpar@9: Reads bytes from the compressed file until len-1 characters are read, or a alpar@9: newline character is read and transferred to buf, or an end-of-file alpar@9: condition is encountered. If any characters are read or if len == 1, the alpar@9: string is terminated with a null character. If no characters are read due alpar@9: to an end-of-file or len < 1, then the buffer is left untouched. alpar@9: alpar@9: gzgets returns buf which is a null-terminated string, or it returns NULL alpar@9: for end-of-file or in case of error. If there was an error, the contents at alpar@9: buf are indeterminate. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); alpar@9: /* alpar@9: Writes c, converted to an unsigned char, into the compressed file. gzputc alpar@9: returns the value that was written, or -1 in case of error. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); alpar@9: /* alpar@9: Reads one byte from the compressed file. gzgetc returns this byte or -1 alpar@9: in case of end of file or error. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); alpar@9: /* alpar@9: Push one character back onto the stream to be read as the first character alpar@9: on the next read. At least one character of push-back is allowed. alpar@9: gzungetc() returns the character pushed, or -1 on failure. gzungetc() will alpar@9: fail if c is -1, and may fail if a character has been pushed but not read alpar@9: yet. If gzungetc is used immediately after gzopen or gzdopen, at least the alpar@9: output buffer size of pushed characters is allowed. (See gzbuffer above.) alpar@9: The pushed character will be discarded if the stream is repositioned with alpar@9: gzseek() or gzrewind(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); alpar@9: /* alpar@9: Flushes all pending output into the compressed file. The parameter flush alpar@9: is as in the deflate() function. The return value is the zlib error number alpar@9: (see function gzerror below). gzflush is only permitted when writing. alpar@9: alpar@9: If the flush parameter is Z_FINISH, the remaining data is written and the alpar@9: gzip stream is completed in the output. If gzwrite() is called again, a new alpar@9: gzip stream will be started in the output. gzread() is able to read such alpar@9: concatented gzip streams. alpar@9: alpar@9: gzflush should be called only when strictly necessary because it will alpar@9: degrade compression if called too often. alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, alpar@9: z_off_t offset, int whence)); alpar@9: alpar@9: Sets the starting position for the next gzread or gzwrite on the given alpar@9: compressed file. The offset represents a number of bytes in the alpar@9: uncompressed data stream. The whence parameter is defined as in lseek(2); alpar@9: the value SEEK_END is not supported. alpar@9: alpar@9: If the file is opened for reading, this function is emulated but can be alpar@9: extremely slow. If the file is opened for writing, only forward seeks are alpar@9: supported; gzseek then compresses a sequence of zeroes up to the new alpar@9: starting position. alpar@9: alpar@9: gzseek returns the resulting offset location as measured in bytes from alpar@9: the beginning of the uncompressed stream, or -1 in case of error, in alpar@9: particular if the file is opened for writing and the new starting position alpar@9: would be before the current position. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); alpar@9: /* alpar@9: Rewinds the given file. This function is supported only for reading. alpar@9: alpar@9: gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); alpar@9: alpar@9: Returns the starting position for the next gzread or gzwrite on the given alpar@9: compressed file. This position represents a number of bytes in the alpar@9: uncompressed data stream, and is zero when starting, even if appending or alpar@9: reading a gzip stream from the middle of a file using gzdopen(). alpar@9: alpar@9: gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); alpar@9: alpar@9: Returns the current offset in the file being read or written. This offset alpar@9: includes the count of bytes that precede the gzip stream, for example when alpar@9: appending or when using gzdopen() for reading. When reading, the offset alpar@9: does not include as yet unused buffered input. This information can be used alpar@9: for a progress indicator. On error, gzoffset() returns -1. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzeof OF((gzFile file)); alpar@9: /* alpar@9: Returns true (1) if the end-of-file indicator has been set while reading, alpar@9: false (0) otherwise. Note that the end-of-file indicator is set only if the alpar@9: read tried to go past the end of the input, but came up short. Therefore, alpar@9: just like feof(), gzeof() may return false even if there is no more data to alpar@9: read, in the event that the last read request was for the exact number of alpar@9: bytes remaining in the input file. This will happen if the input file size alpar@9: is an exact multiple of the buffer size. alpar@9: alpar@9: If gzeof() returns true, then the read functions will return no more data, alpar@9: unless the end-of-file indicator is reset by gzclearerr() and the input file alpar@9: has grown since the previous end of file was detected. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); alpar@9: /* alpar@9: Returns true (1) if file is being copied directly while reading, or false alpar@9: (0) if file is a gzip stream being decompressed. This state can change from alpar@9: false to true while reading the input file if the end of a gzip stream is alpar@9: reached, but is followed by data that is not another gzip stream. alpar@9: alpar@9: If the input file is empty, gzdirect() will return true, since the input alpar@9: does not contain a gzip stream. alpar@9: alpar@9: If gzdirect() is used immediately after gzopen() or gzdopen() it will alpar@9: cause buffers to be allocated to allow reading the file to determine if it alpar@9: is a gzip file. Therefore if gzbuffer() is used, it should be called before alpar@9: gzdirect(). alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzclose OF((gzFile file)); alpar@9: /* alpar@9: Flushes all pending output if necessary, closes the compressed file and alpar@9: deallocates the (de)compression state. Note that once file is closed, you alpar@9: cannot call gzerror with file, since its structures have been deallocated. alpar@9: gzclose must not be called more than once on the same file, just as free alpar@9: must not be called more than once on the same allocation. alpar@9: alpar@9: gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a alpar@9: file operation error, or Z_OK on success. alpar@9: */ alpar@9: alpar@9: ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); alpar@9: ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); alpar@9: /* alpar@9: Same as gzclose(), but gzclose_r() is only for use when reading, and alpar@9: gzclose_w() is only for use when writing or appending. The advantage to alpar@9: using these instead of gzclose() is that they avoid linking in zlib alpar@9: compression or decompression code that is not used when only reading or only alpar@9: writing respectively. If gzclose() is used, then both compression and alpar@9: decompression code will be included the application when linking to a static alpar@9: zlib library. alpar@9: */ alpar@9: alpar@9: ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); alpar@9: /* alpar@9: Returns the error message for the last error which occurred on the given alpar@9: compressed file. errnum is set to zlib error number. If an error occurred alpar@9: in the file system and not in the compression library, errnum is set to alpar@9: Z_ERRNO and the application may consult errno to get the exact error code. alpar@9: alpar@9: The application must not modify the returned string. Future calls to alpar@9: this function may invalidate the previously returned string. If file is alpar@9: closed, then the string previously returned by gzerror will no longer be alpar@9: available. alpar@9: alpar@9: gzerror() should be used to distinguish errors from end-of-file for those alpar@9: functions above that do not distinguish those cases in their return values. alpar@9: */ alpar@9: alpar@9: ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); alpar@9: /* alpar@9: Clears the error and end-of-file flags for file. This is analogous to the alpar@9: clearerr() function in stdio. This is useful for continuing to read a gzip alpar@9: file that is being written concurrently. alpar@9: */ alpar@9: alpar@9: alpar@9: /* checksum functions */ alpar@9: alpar@9: /* alpar@9: These functions are not related to compression but are exported alpar@9: anyway because they might be useful in applications using the compression alpar@9: library. alpar@9: */ alpar@9: alpar@9: ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); alpar@9: /* alpar@9: Update a running Adler-32 checksum with the bytes buf[0..len-1] and alpar@9: return the updated checksum. If buf is Z_NULL, this function returns the alpar@9: required initial value for the checksum. alpar@9: alpar@9: An Adler-32 checksum is almost as reliable as a CRC32 but can be computed alpar@9: much faster. alpar@9: alpar@9: Usage example: alpar@9: alpar@9: uLong adler = adler32(0L, Z_NULL, 0); alpar@9: alpar@9: while (read_buffer(buffer, length) != EOF) { alpar@9: adler = adler32(adler, buffer, length); alpar@9: } alpar@9: if (adler != original_adler) error(); alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, alpar@9: z_off_t len2)); alpar@9: alpar@9: Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 alpar@9: and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for alpar@9: each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of alpar@9: seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. alpar@9: */ alpar@9: alpar@9: ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); alpar@9: /* alpar@9: Update a running CRC-32 with the bytes buf[0..len-1] and return the alpar@9: updated CRC-32. If buf is Z_NULL, this function returns the required alpar@9: initial value for the for the crc. Pre- and post-conditioning (one's alpar@9: complement) is performed within this function so it shouldn't be done by the alpar@9: application. alpar@9: alpar@9: Usage example: alpar@9: alpar@9: uLong crc = crc32(0L, Z_NULL, 0); alpar@9: alpar@9: while (read_buffer(buffer, length) != EOF) { alpar@9: crc = crc32(crc, buffer, length); alpar@9: } alpar@9: if (crc != original_crc) error(); alpar@9: */ alpar@9: alpar@9: /* alpar@9: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); alpar@9: alpar@9: Combine two CRC-32 check values into one. For two sequences of bytes, alpar@9: seq1 and seq2 with lengths len1 and len2, CRC-32 check values were alpar@9: calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 alpar@9: check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and alpar@9: len2. alpar@9: */ alpar@9: alpar@9: alpar@9: /* various hacks, don't look :) */ alpar@9: alpar@9: /* deflateInit and inflateInit are macros to allow checking the zlib version alpar@9: * and the compiler's view of z_stream: alpar@9: */ alpar@9: ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, alpar@9: const char *version, int stream_size)); alpar@9: ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, alpar@9: const char *version, int stream_size)); alpar@9: ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, alpar@9: int windowBits, int memLevel, alpar@9: int strategy, const char *version, alpar@9: int stream_size)); alpar@9: ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, alpar@9: const char *version, int stream_size)); alpar@9: ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, alpar@9: unsigned char FAR *window, alpar@9: const char *version, alpar@9: int stream_size)); alpar@9: #define deflateInit(strm, level) \ alpar@9: deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) alpar@9: #define inflateInit(strm) \ alpar@9: inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) alpar@9: #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ alpar@9: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ alpar@9: (strategy), ZLIB_VERSION, sizeof(z_stream)) alpar@9: #define inflateInit2(strm, windowBits) \ alpar@9: inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) alpar@9: #define inflateBackInit(strm, windowBits, window) \ alpar@9: inflateBackInit_((strm), (windowBits), (window), \ alpar@9: ZLIB_VERSION, sizeof(z_stream)) alpar@9: alpar@9: /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or alpar@9: * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if alpar@9: * both are true, the application gets the *64 functions, and the regular alpar@9: * functions are changed to 64 bits) -- in case these are set on systems alpar@9: * without large file support, _LFS64_LARGEFILE must also be true alpar@9: */ alpar@9: #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 alpar@9: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); alpar@9: ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); alpar@9: ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); alpar@9: ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); alpar@9: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); alpar@9: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); alpar@9: #endif alpar@9: alpar@9: #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0 alpar@9: # define gzopen gzopen64 alpar@9: # define gzseek gzseek64 alpar@9: # define gztell gztell64 alpar@9: # define gzoffset gzoffset64 alpar@9: # define adler32_combine adler32_combine64 alpar@9: # define crc32_combine crc32_combine64 alpar@9: # ifdef _LARGEFILE64_SOURCE alpar@9: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); alpar@9: ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); alpar@9: ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); alpar@9: ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); alpar@9: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); alpar@9: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); alpar@9: # endif alpar@9: #else alpar@9: ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); alpar@9: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); alpar@9: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); alpar@9: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); alpar@9: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); alpar@9: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); alpar@9: #endif alpar@9: alpar@9: /* hack for buggy compilers */ alpar@9: #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) alpar@9: struct internal_state {int dummy;}; alpar@9: #endif alpar@9: alpar@9: /* undocumented functions */ alpar@9: ZEXTERN const char * ZEXPORT zError OF((int)); alpar@9: ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); alpar@9: ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); alpar@9: ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); alpar@9: alpar@9: #ifdef __cplusplus alpar@9: } alpar@9: #endif alpar@9: alpar@9: #endif /* ZLIB_H */