cannam@130: /* zlib.h -- interface of the 'zlib' general purpose compression library cannam@130: version 1.2.8, April 28th, 2013 cannam@130: cannam@130: Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler cannam@130: cannam@130: This software is provided 'as-is', without any express or implied cannam@130: warranty. In no event will the authors be held liable for any damages cannam@130: arising from the use of this software. cannam@130: cannam@130: Permission is granted to anyone to use this software for any purpose, cannam@130: including commercial applications, and to alter it and redistribute it cannam@130: freely, subject to the following restrictions: cannam@130: cannam@130: 1. The origin of this software must not be misrepresented; you must not cannam@130: claim that you wrote the original software. If you use this software cannam@130: in a product, an acknowledgment in the product documentation would be cannam@130: appreciated but is not required. cannam@130: 2. Altered source versions must be plainly marked as such, and must not be cannam@130: misrepresented as being the original software. cannam@130: 3. This notice may not be removed or altered from any source distribution. cannam@130: cannam@130: Jean-loup Gailly Mark Adler cannam@130: jloup@gzip.org madler@alumni.caltech.edu cannam@130: cannam@130: cannam@130: The data format used by the zlib library is described by RFCs (Request for cannam@130: Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 cannam@130: (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). cannam@130: */ cannam@130: cannam@130: #ifndef ZLIB_H cannam@130: #define ZLIB_H cannam@130: cannam@130: #include "zconf.h" cannam@130: cannam@130: #ifdef __cplusplus cannam@130: extern "C" { cannam@130: #endif cannam@130: cannam@130: #define ZLIB_VERSION "1.2.8" cannam@130: #define ZLIB_VERNUM 0x1280 cannam@130: #define ZLIB_VER_MAJOR 1 cannam@130: #define ZLIB_VER_MINOR 2 cannam@130: #define ZLIB_VER_REVISION 8 cannam@130: #define ZLIB_VER_SUBREVISION 0 cannam@130: cannam@130: /* cannam@130: The 'zlib' compression library provides in-memory compression and cannam@130: decompression functions, including integrity checks of the uncompressed data. cannam@130: This version of the library supports only one compression method (deflation) cannam@130: but other algorithms will be added later and will have the same stream cannam@130: interface. cannam@130: cannam@130: Compression can be done in a single step if the buffers are large enough, cannam@130: or can be done by repeated calls of the compression function. In the latter cannam@130: case, the application must provide more input and/or consume the output cannam@130: (providing more output space) before each call. cannam@130: cannam@130: The compressed data format used by default by the in-memory functions is cannam@130: the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped cannam@130: around a deflate stream, which is itself documented in RFC 1951. cannam@130: cannam@130: The library also supports reading and writing files in gzip (.gz) format cannam@130: with an interface similar to that of stdio using the functions that start cannam@130: with "gz". The gzip format is different from the zlib format. gzip is a cannam@130: gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. cannam@130: cannam@130: This library can optionally read and write gzip streams in memory as well. cannam@130: cannam@130: The zlib format was designed to be compact and fast for use in memory cannam@130: and on communications channels. The gzip format was designed for single- cannam@130: file compression on file systems, has a larger header than zlib to maintain cannam@130: directory information, and uses a different, slower check method than zlib. cannam@130: cannam@130: The library does not install any signal handler. The decoder checks cannam@130: the consistency of the compressed data, so the library should never crash cannam@130: even in case of corrupted input. cannam@130: */ cannam@130: cannam@130: typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); cannam@130: typedef void (*free_func) OF((voidpf opaque, voidpf address)); cannam@130: cannam@130: struct internal_state; cannam@130: cannam@130: typedef struct z_stream_s { cannam@130: z_const Bytef *next_in; /* next input byte */ cannam@130: uInt avail_in; /* number of bytes available at next_in */ cannam@130: uLong total_in; /* total number of input bytes read so far */ cannam@130: cannam@130: Bytef *next_out; /* next output byte should be put there */ cannam@130: uInt avail_out; /* remaining free space at next_out */ cannam@130: uLong total_out; /* total number of bytes output so far */ cannam@130: cannam@130: z_const char *msg; /* last error message, NULL if no error */ cannam@130: struct internal_state FAR *state; /* not visible by applications */ cannam@130: cannam@130: alloc_func zalloc; /* used to allocate the internal state */ cannam@130: free_func zfree; /* used to free the internal state */ cannam@130: voidpf opaque; /* private data object passed to zalloc and zfree */ cannam@130: cannam@130: int data_type; /* best guess about the data type: binary or text */ cannam@130: uLong adler; /* adler32 value of the uncompressed data */ cannam@130: uLong reserved; /* reserved for future use */ cannam@130: } z_stream; cannam@130: cannam@130: typedef z_stream FAR *z_streamp; cannam@130: cannam@130: /* cannam@130: gzip header information passed to and from zlib routines. See RFC 1952 cannam@130: for more details on the meanings of these fields. cannam@130: */ cannam@130: typedef struct gz_header_s { cannam@130: int text; /* true if compressed data believed to be text */ cannam@130: uLong time; /* modification time */ cannam@130: int xflags; /* extra flags (not used when writing a gzip file) */ cannam@130: int os; /* operating system */ cannam@130: Bytef *extra; /* pointer to extra field or Z_NULL if none */ cannam@130: uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ cannam@130: uInt extra_max; /* space at extra (only when reading header) */ cannam@130: Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ cannam@130: uInt name_max; /* space at name (only when reading header) */ cannam@130: Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ cannam@130: uInt comm_max; /* space at comment (only when reading header) */ cannam@130: int hcrc; /* true if there was or will be a header crc */ cannam@130: int done; /* true when done reading gzip header (not used cannam@130: when writing a gzip file) */ cannam@130: } gz_header; cannam@130: cannam@130: typedef gz_header FAR *gz_headerp; cannam@130: cannam@130: /* cannam@130: The application must update next_in and avail_in when avail_in has dropped cannam@130: to zero. It must update next_out and avail_out when avail_out has dropped cannam@130: to zero. The application must initialize zalloc, zfree and opaque before cannam@130: calling the init function. All other fields are set by the compression cannam@130: library and must not be updated by the application. cannam@130: cannam@130: The opaque value provided by the application will be passed as the first cannam@130: parameter for calls of zalloc and zfree. This can be useful for custom cannam@130: memory management. The compression library attaches no meaning to the cannam@130: opaque value. cannam@130: cannam@130: zalloc must return Z_NULL if there is not enough memory for the object. cannam@130: If zlib is used in a multi-threaded application, zalloc and zfree must be cannam@130: thread safe. cannam@130: cannam@130: On 16-bit systems, the functions zalloc and zfree must be able to allocate cannam@130: exactly 65536 bytes, but will not be required to allocate more than this if cannam@130: the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers cannam@130: returned by zalloc for objects of exactly 65536 bytes *must* have their cannam@130: offset normalized to zero. The default allocation function provided by this cannam@130: library ensures this (see zutil.c). To reduce memory requirements and avoid cannam@130: any allocation of 64K objects, at the expense of compression ratio, compile cannam@130: the library with -DMAX_WBITS=14 (see zconf.h). cannam@130: cannam@130: The fields total_in and total_out can be used for statistics or progress cannam@130: reports. After compression, total_in holds the total size of the cannam@130: uncompressed data and may be saved for use in the decompressor (particularly cannam@130: if the decompressor wants to decompress everything in a single step). cannam@130: */ cannam@130: cannam@130: /* constants */ cannam@130: cannam@130: #define Z_NO_FLUSH 0 cannam@130: #define Z_PARTIAL_FLUSH 1 cannam@130: #define Z_SYNC_FLUSH 2 cannam@130: #define Z_FULL_FLUSH 3 cannam@130: #define Z_FINISH 4 cannam@130: #define Z_BLOCK 5 cannam@130: #define Z_TREES 6 cannam@130: /* Allowed flush values; see deflate() and inflate() below for details */ cannam@130: cannam@130: #define Z_OK 0 cannam@130: #define Z_STREAM_END 1 cannam@130: #define Z_NEED_DICT 2 cannam@130: #define Z_ERRNO (-1) cannam@130: #define Z_STREAM_ERROR (-2) cannam@130: #define Z_DATA_ERROR (-3) cannam@130: #define Z_MEM_ERROR (-4) cannam@130: #define Z_BUF_ERROR (-5) cannam@130: #define Z_VERSION_ERROR (-6) cannam@130: /* Return codes for the compression/decompression functions. Negative values cannam@130: * are errors, positive values are used for special but normal events. cannam@130: */ cannam@130: cannam@130: #define Z_NO_COMPRESSION 0 cannam@130: #define Z_BEST_SPEED 1 cannam@130: #define Z_BEST_COMPRESSION 9 cannam@130: #define Z_DEFAULT_COMPRESSION (-1) cannam@130: /* compression levels */ cannam@130: cannam@130: #define Z_FILTERED 1 cannam@130: #define Z_HUFFMAN_ONLY 2 cannam@130: #define Z_RLE 3 cannam@130: #define Z_FIXED 4 cannam@130: #define Z_DEFAULT_STRATEGY 0 cannam@130: /* compression strategy; see deflateInit2() below for details */ cannam@130: cannam@130: #define Z_BINARY 0 cannam@130: #define Z_TEXT 1 cannam@130: #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ cannam@130: #define Z_UNKNOWN 2 cannam@130: /* Possible values of the data_type field (though see inflate()) */ cannam@130: cannam@130: #define Z_DEFLATED 8 cannam@130: /* The deflate compression method (the only one supported in this version) */ cannam@130: cannam@130: #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ cannam@130: cannam@130: #define zlib_version zlibVersion() cannam@130: /* for compatibility with versions < 1.0.2 */ cannam@130: cannam@130: cannam@130: /* basic functions */ cannam@130: cannam@130: ZEXTERN const char * ZEXPORT zlibVersion OF((void)); cannam@130: /* The application can compare zlibVersion and ZLIB_VERSION for consistency. cannam@130: If the first character differs, the library code actually used is not cannam@130: compatible with the zlib.h header file used by the application. This check cannam@130: is automatically made by deflateInit and inflateInit. cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); cannam@130: cannam@130: Initializes the internal stream state for compression. The fields cannam@130: zalloc, zfree and opaque must be initialized before by the caller. If cannam@130: zalloc and zfree are set to Z_NULL, deflateInit updates them to use default cannam@130: allocation functions. cannam@130: cannam@130: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: cannam@130: 1 gives best speed, 9 gives best compression, 0 gives no compression at all cannam@130: (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION cannam@130: requests a default compromise between speed and compression (currently cannam@130: equivalent to level 6). cannam@130: cannam@130: deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough cannam@130: memory, Z_STREAM_ERROR if level is not a valid compression level, or cannam@130: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible cannam@130: with the version assumed by the caller (ZLIB_VERSION). msg is set to null cannam@130: if there is no error message. deflateInit does not perform any compression: cannam@130: this will be done by deflate(). cannam@130: */ cannam@130: cannam@130: cannam@130: ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); cannam@130: /* cannam@130: deflate compresses as much data as possible, and stops when the input cannam@130: buffer becomes empty or the output buffer becomes full. It may introduce cannam@130: some output latency (reading input without producing any output) except when cannam@130: forced to flush. cannam@130: cannam@130: The detailed semantics are as follows. deflate performs one or both of the cannam@130: following actions: cannam@130: cannam@130: - Compress more input starting at next_in and update next_in and avail_in cannam@130: accordingly. If not all input can be processed (because there is not cannam@130: enough room in the output buffer), next_in and avail_in are updated and cannam@130: processing will resume at this point for the next call of deflate(). cannam@130: cannam@130: - Provide more output starting at next_out and update next_out and avail_out cannam@130: accordingly. This action is forced if the parameter flush is non zero. cannam@130: Forcing flush frequently degrades the compression ratio, so this parameter cannam@130: should be set only when necessary (in interactive applications). Some cannam@130: output may be provided even if flush is not set. cannam@130: cannam@130: Before the call of deflate(), the application should ensure that at least cannam@130: one of the actions is possible, by providing more input and/or consuming more cannam@130: output, and updating avail_in or avail_out accordingly; avail_out should cannam@130: never be zero before the call. The application can consume the compressed cannam@130: output when it wants, for example when the output buffer is full (avail_out cannam@130: == 0), or after each call of deflate(). If deflate returns Z_OK and with cannam@130: zero avail_out, it must be called again after making room in the output cannam@130: buffer because there might be more output pending. cannam@130: cannam@130: Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to cannam@130: decide how much data to accumulate before producing output, in order to cannam@130: maximize compression. cannam@130: cannam@130: If the parameter flush is set to Z_SYNC_FLUSH, all pending output is cannam@130: flushed to the output buffer and the output is aligned on a byte boundary, so cannam@130: that the decompressor can get all input data available so far. (In cannam@130: particular avail_in is zero after the call if enough output space has been cannam@130: provided before the call.) Flushing may degrade compression for some cannam@130: compression algorithms and so it should be used only when necessary. This cannam@130: completes the current deflate block and follows it with an empty stored block cannam@130: that is three bits plus filler bits to the next byte, followed by four bytes cannam@130: (00 00 ff ff). cannam@130: cannam@130: If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the cannam@130: output buffer, but the output is not aligned to a byte boundary. All of the cannam@130: input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. cannam@130: This completes the current deflate block and follows it with an empty fixed cannam@130: codes block that is 10 bits long. This assures that enough bytes are output cannam@130: in order for the decompressor to finish the block before the empty fixed code cannam@130: block. cannam@130: cannam@130: If flush is set to Z_BLOCK, a deflate block is completed and emitted, as cannam@130: for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to cannam@130: seven bits of the current block are held to be written as the next byte after cannam@130: the next deflate block is completed. In this case, the decompressor may not cannam@130: be provided enough bits at this point in order to complete decompression of cannam@130: the data provided so far to the compressor. It may need to wait for the next cannam@130: block to be emitted. This is for advanced applications that need to control cannam@130: the emission of deflate blocks. cannam@130: cannam@130: If flush is set to Z_FULL_FLUSH, all output is flushed as with cannam@130: Z_SYNC_FLUSH, and the compression state is reset so that decompression can cannam@130: restart from this point if previous compressed data has been damaged or if cannam@130: random access is desired. Using Z_FULL_FLUSH too often can seriously degrade cannam@130: compression. cannam@130: cannam@130: If deflate returns with avail_out == 0, this function must be called again cannam@130: with the same value of the flush parameter and more output space (updated cannam@130: avail_out), until the flush is complete (deflate returns with non-zero cannam@130: avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that cannam@130: avail_out is greater than six to avoid repeated flush markers due to cannam@130: avail_out == 0 on return. cannam@130: cannam@130: If the parameter flush is set to Z_FINISH, pending input is processed, cannam@130: pending output is flushed and deflate returns with Z_STREAM_END if there was cannam@130: enough output space; if deflate returns with Z_OK, this function must be cannam@130: called again with Z_FINISH and more output space (updated avail_out) but no cannam@130: more input data, until it returns with Z_STREAM_END or an error. After cannam@130: deflate has returned Z_STREAM_END, the only possible operations on the stream cannam@130: are deflateReset or deflateEnd. cannam@130: cannam@130: Z_FINISH can be used immediately after deflateInit if all the compression cannam@130: is to be done in a single step. In this case, avail_out must be at least the cannam@130: value returned by deflateBound (see below). Then deflate is guaranteed to cannam@130: return Z_STREAM_END. If not enough output space is provided, deflate will cannam@130: not return Z_STREAM_END, and it must be called again as described above. cannam@130: cannam@130: deflate() sets strm->adler to the adler32 checksum of all input read cannam@130: so far (that is, total_in bytes). cannam@130: cannam@130: deflate() may update strm->data_type if it can make a good guess about cannam@130: the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered cannam@130: binary. This field is only for information purposes and does not affect the cannam@130: compression algorithm in any manner. cannam@130: cannam@130: deflate() returns Z_OK if some progress has been made (more input cannam@130: processed or more output produced), Z_STREAM_END if all input has been cannam@130: consumed and all output has been produced (only when flush is set to cannam@130: Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example cannam@130: if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible cannam@130: (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not cannam@130: fatal, and deflate() can be called again with more input and more output cannam@130: space to continue compressing. cannam@130: */ cannam@130: cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); cannam@130: /* cannam@130: All dynamically allocated data structures for this stream are freed. cannam@130: This function discards any unprocessed input and does not flush any pending cannam@130: output. cannam@130: cannam@130: deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the cannam@130: stream state was inconsistent, Z_DATA_ERROR if the stream was freed cannam@130: prematurely (some input or output was discarded). In the error case, msg cannam@130: may be set but then points to a static string (which must not be cannam@130: deallocated). cannam@130: */ cannam@130: cannam@130: cannam@130: /* cannam@130: ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); cannam@130: cannam@130: Initializes the internal stream state for decompression. The fields cannam@130: next_in, avail_in, zalloc, zfree and opaque must be initialized before by cannam@130: the caller. If next_in is not Z_NULL and avail_in is large enough (the cannam@130: exact value depends on the compression method), inflateInit determines the cannam@130: compression method from the zlib header and allocates all data structures cannam@130: accordingly; otherwise the allocation will be deferred to the first call of cannam@130: inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to cannam@130: use default allocation functions. cannam@130: cannam@130: inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough cannam@130: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the cannam@130: version assumed by the caller, or Z_STREAM_ERROR if the parameters are cannam@130: invalid, such as a null pointer to the structure. msg is set to null if cannam@130: there is no error message. inflateInit does not perform any decompression cannam@130: apart from possibly reading the zlib header if present: actual decompression cannam@130: will be done by inflate(). (So next_in and avail_in may be modified, but cannam@130: next_out and avail_out are unused and unchanged.) The current implementation cannam@130: of inflateInit() does not process any header information -- that is deferred cannam@130: until inflate() is called. cannam@130: */ cannam@130: cannam@130: cannam@130: ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); cannam@130: /* cannam@130: inflate decompresses as much data as possible, and stops when the input cannam@130: buffer becomes empty or the output buffer becomes full. It may introduce cannam@130: some output latency (reading input without producing any output) except when cannam@130: forced to flush. cannam@130: cannam@130: The detailed semantics are as follows. inflate performs one or both of the cannam@130: following actions: cannam@130: cannam@130: - Decompress more input starting at next_in and update next_in and avail_in cannam@130: accordingly. If not all input can be processed (because there is not cannam@130: enough room in the output buffer), next_in is updated and processing will cannam@130: resume at this point for the next call of inflate(). cannam@130: cannam@130: - Provide more output starting at next_out and update next_out and avail_out cannam@130: accordingly. inflate() provides as much output as possible, until there is cannam@130: no more input data or no more space in the output buffer (see below about cannam@130: the flush parameter). cannam@130: cannam@130: Before the call of inflate(), the application should ensure that at least cannam@130: one of the actions is possible, by providing more input and/or consuming more cannam@130: output, and updating the next_* and avail_* values accordingly. The cannam@130: application can consume the uncompressed output when it wants, for example cannam@130: when the output buffer is full (avail_out == 0), or after each call of cannam@130: inflate(). If inflate returns Z_OK and with zero avail_out, it must be cannam@130: called again after making room in the output buffer because there might be cannam@130: more output pending. cannam@130: cannam@130: The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, cannam@130: Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much cannam@130: output as possible to the output buffer. Z_BLOCK requests that inflate() cannam@130: stop if and when it gets to the next deflate block boundary. When decoding cannam@130: the zlib or gzip format, this will cause inflate() to return immediately cannam@130: after the header and before the first block. When doing a raw inflate, cannam@130: inflate() will go ahead and process the first block, and will return when it cannam@130: gets to the end of that block, or when it runs out of data. cannam@130: cannam@130: The Z_BLOCK option assists in appending to or combining deflate streams. cannam@130: Also to assist in this, on return inflate() will set strm->data_type to the cannam@130: number of unused bits in the last byte taken from strm->next_in, plus 64 if cannam@130: inflate() is currently decoding the last block in the deflate stream, plus cannam@130: 128 if inflate() returned immediately after decoding an end-of-block code or cannam@130: decoding the complete header up to just before the first byte of the deflate cannam@130: stream. The end-of-block will not be indicated until all of the uncompressed cannam@130: data from that block has been written to strm->next_out. The number of cannam@130: unused bits may in general be greater than seven, except when bit 7 of cannam@130: data_type is set, in which case the number of unused bits will be less than cannam@130: eight. data_type is set as noted here every time inflate() returns for all cannam@130: flush options, and so can be used to determine the amount of currently cannam@130: consumed input in bits. cannam@130: cannam@130: The Z_TREES option behaves as Z_BLOCK does, but it also returns when the cannam@130: end of each deflate block header is reached, before any actual data in that cannam@130: block is decoded. This allows the caller to determine the length of the cannam@130: deflate block header for later use in random access within a deflate block. cannam@130: 256 is added to the value of strm->data_type when inflate() returns cannam@130: immediately after reaching the end of the deflate block header. cannam@130: cannam@130: inflate() should normally be called until it returns Z_STREAM_END or an cannam@130: error. However if all decompression is to be performed in a single step (a cannam@130: single call of inflate), the parameter flush should be set to Z_FINISH. In cannam@130: this case all pending input is processed and all pending output is flushed; cannam@130: avail_out must be large enough to hold all of the uncompressed data for the cannam@130: operation to complete. (The size of the uncompressed data may have been cannam@130: saved by the compressor for this purpose.) The use of Z_FINISH is not cannam@130: required to perform an inflation in one step. However it may be used to cannam@130: inform inflate that a faster approach can be used for the single inflate() cannam@130: call. Z_FINISH also informs inflate to not maintain a sliding window if the cannam@130: stream completes, which reduces inflate's memory footprint. If the stream cannam@130: does not complete, either because not all of the stream is provided or not cannam@130: enough output space is provided, then a sliding window will be allocated and cannam@130: inflate() can be called again to continue the operation as if Z_NO_FLUSH had cannam@130: been used. cannam@130: cannam@130: In this implementation, inflate() always flushes as much output as cannam@130: possible to the output buffer, and always uses the faster approach on the cannam@130: first call. So the effects of the flush parameter in this implementation are cannam@130: on the return value of inflate() as noted below, when inflate() returns early cannam@130: when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of cannam@130: memory for a sliding window when Z_FINISH is used. cannam@130: cannam@130: If a preset dictionary is needed after this call (see inflateSetDictionary cannam@130: below), inflate sets strm->adler to the Adler-32 checksum of the dictionary cannam@130: chosen by the compressor and returns Z_NEED_DICT; otherwise it sets cannam@130: strm->adler to the Adler-32 checksum of all output produced so far (that is, cannam@130: total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described cannam@130: below. At the end of the stream, inflate() checks that its computed adler32 cannam@130: checksum is equal to that saved by the compressor and returns Z_STREAM_END cannam@130: only if the checksum is correct. cannam@130: cannam@130: inflate() can decompress and check either zlib-wrapped or gzip-wrapped cannam@130: deflate data. The header type is detected automatically, if requested when cannam@130: initializing with inflateInit2(). Any information contained in the gzip cannam@130: header is not retained, so applications that need that information should cannam@130: instead use raw inflate, see inflateInit2() below, or inflateBack() and cannam@130: perform their own processing of the gzip header and trailer. When processing cannam@130: gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output cannam@130: producted so far. The CRC-32 is checked against the gzip trailer. cannam@130: cannam@130: inflate() returns Z_OK if some progress has been made (more input processed cannam@130: or more output produced), Z_STREAM_END if the end of the compressed data has cannam@130: been reached and all uncompressed output has been produced, Z_NEED_DICT if a cannam@130: preset dictionary is needed at this point, Z_DATA_ERROR if the input data was cannam@130: corrupted (input stream not conforming to the zlib format or incorrect check cannam@130: value), Z_STREAM_ERROR if the stream structure was inconsistent (for example cannam@130: next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, cannam@130: Z_BUF_ERROR if no progress is possible or if there was not enough room in the cannam@130: output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and cannam@130: inflate() can be called again with more input and more output space to cannam@130: continue decompressing. If Z_DATA_ERROR is returned, the application may cannam@130: then call inflateSync() to look for a good compression block if a partial cannam@130: recovery of the data is desired. cannam@130: */ cannam@130: cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); cannam@130: /* cannam@130: All dynamically allocated data structures for this stream are freed. cannam@130: This function discards any unprocessed input and does not flush any pending cannam@130: output. cannam@130: cannam@130: inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state cannam@130: was inconsistent. In the error case, msg may be set but then points to a cannam@130: static string (which must not be deallocated). cannam@130: */ cannam@130: cannam@130: cannam@130: /* Advanced functions */ cannam@130: cannam@130: /* cannam@130: The following functions are needed only in some special applications. cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, cannam@130: int level, cannam@130: int method, cannam@130: int windowBits, cannam@130: int memLevel, cannam@130: int strategy)); cannam@130: cannam@130: This is another version of deflateInit with more compression options. The cannam@130: fields next_in, zalloc, zfree and opaque must be initialized before by the cannam@130: caller. cannam@130: cannam@130: The method parameter is the compression method. It must be Z_DEFLATED in cannam@130: this version of the library. cannam@130: cannam@130: The windowBits parameter is the base two logarithm of the window size cannam@130: (the size of the history buffer). It should be in the range 8..15 for this cannam@130: version of the library. Larger values of this parameter result in better cannam@130: compression at the expense of memory usage. The default value is 15 if cannam@130: deflateInit is used instead. cannam@130: cannam@130: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits cannam@130: determines the window size. deflate() will then generate raw deflate data cannam@130: with no zlib header or trailer, and will not compute an adler32 check value. cannam@130: cannam@130: windowBits can also be greater than 15 for optional gzip encoding. Add cannam@130: 16 to windowBits to write a simple gzip header and trailer around the cannam@130: compressed data instead of a zlib wrapper. The gzip header will have no cannam@130: file name, no extra data, no comment, no modification time (set to zero), no cannam@130: header crc, and the operating system will be set to 255 (unknown). If a cannam@130: gzip stream is being written, strm->adler is a crc32 instead of an adler32. cannam@130: cannam@130: The memLevel parameter specifies how much memory should be allocated cannam@130: for the internal compression state. memLevel=1 uses minimum memory but is cannam@130: slow and reduces compression ratio; memLevel=9 uses maximum memory for cannam@130: optimal speed. The default value is 8. See zconf.h for total memory usage cannam@130: as a function of windowBits and memLevel. cannam@130: cannam@130: The strategy parameter is used to tune the compression algorithm. Use the cannam@130: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a cannam@130: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no cannam@130: string match), or Z_RLE to limit match distances to one (run-length cannam@130: encoding). Filtered data consists mostly of small values with a somewhat cannam@130: random distribution. In this case, the compression algorithm is tuned to cannam@130: compress them better. The effect of Z_FILTERED is to force more Huffman cannam@130: coding and less string matching; it is somewhat intermediate between cannam@130: Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as cannam@130: fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The cannam@130: strategy parameter only affects the compression ratio but not the cannam@130: correctness of the compressed output even if it is not set appropriately. cannam@130: Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler cannam@130: decoder for special applications. cannam@130: cannam@130: deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough cannam@130: memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid cannam@130: method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is cannam@130: incompatible with the version assumed by the caller (ZLIB_VERSION). msg is cannam@130: set to null if there is no error message. deflateInit2 does not perform any cannam@130: compression: this will be done by deflate(). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, cannam@130: const Bytef *dictionary, cannam@130: uInt dictLength)); cannam@130: /* cannam@130: Initializes the compression dictionary from the given byte sequence cannam@130: without producing any compressed output. When using the zlib format, this cannam@130: function must be called immediately after deflateInit, deflateInit2 or cannam@130: deflateReset, and before any call of deflate. When doing raw deflate, this cannam@130: function must be called either before any call of deflate, or immediately cannam@130: after the completion of a deflate block, i.e. after all input has been cannam@130: consumed and all output has been delivered when using any of the flush cannam@130: options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The cannam@130: compressor and decompressor must use exactly the same dictionary (see cannam@130: inflateSetDictionary). cannam@130: cannam@130: The dictionary should consist of strings (byte sequences) that are likely cannam@130: to be encountered later in the data to be compressed, with the most commonly cannam@130: used strings preferably put towards the end of the dictionary. Using a cannam@130: dictionary is most useful when the data to be compressed is short and can be cannam@130: predicted with good accuracy; the data can then be compressed better than cannam@130: with the default empty dictionary. cannam@130: cannam@130: Depending on the size of the compression data structures selected by cannam@130: deflateInit or deflateInit2, a part of the dictionary may in effect be cannam@130: discarded, for example if the dictionary is larger than the window size cannam@130: provided in deflateInit or deflateInit2. Thus the strings most likely to be cannam@130: useful should be put at the end of the dictionary, not at the front. In cannam@130: addition, the current implementation of deflate will use at most the window cannam@130: size minus 262 bytes of the provided dictionary. cannam@130: cannam@130: Upon return of this function, strm->adler is set to the adler32 value cannam@130: of the dictionary; the decompressor may later use this value to determine cannam@130: which dictionary has been used by the compressor. (The adler32 value cannam@130: applies to the whole dictionary even if only a subset of the dictionary is cannam@130: actually used by the compressor.) If a raw deflate was requested, then the cannam@130: adler32 value is not computed and strm->adler is not set. cannam@130: cannam@130: deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a cannam@130: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is cannam@130: inconsistent (for example if deflate has already been called for this stream cannam@130: or if not at a block boundary for raw deflate). deflateSetDictionary does cannam@130: not perform any compression: this will be done by deflate(). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, cannam@130: z_streamp source)); cannam@130: /* cannam@130: Sets the destination stream as a complete copy of the source stream. cannam@130: cannam@130: This function can be useful when several compression strategies will be cannam@130: tried, for example when there are several ways of pre-processing the input cannam@130: data with a filter. The streams that will be discarded should then be freed cannam@130: by calling deflateEnd. Note that deflateCopy duplicates the internal cannam@130: compression state which can be quite large, so this strategy is slow and can cannam@130: consume lots of memory. cannam@130: cannam@130: deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not cannam@130: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent cannam@130: (such as zalloc being Z_NULL). msg is left unchanged in both source and cannam@130: destination. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); cannam@130: /* cannam@130: This function is equivalent to deflateEnd followed by deflateInit, cannam@130: but does not free and reallocate all the internal compression state. The cannam@130: stream will keep the same compression level and any other attributes that cannam@130: may have been set by deflateInit2. cannam@130: cannam@130: deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent (such as zalloc or state being Z_NULL). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, cannam@130: int level, cannam@130: int strategy)); cannam@130: /* cannam@130: Dynamically update the compression level and compression strategy. The cannam@130: interpretation of level and strategy is as in deflateInit2. This can be cannam@130: used to switch between compression and straight copy of the input data, or cannam@130: to switch to a different kind of input data requiring a different strategy. cannam@130: If the compression level is changed, the input available so far is cannam@130: compressed with the old level (and may be flushed); the new level will take cannam@130: effect only at the next call of deflate(). cannam@130: cannam@130: Before the call of deflateParams, the stream state must be set as for cannam@130: a call of deflate(), since the currently available input may have to be cannam@130: compressed and flushed. In particular, strm->avail_out must be non-zero. cannam@130: cannam@130: deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if cannam@130: strm->avail_out was zero. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, cannam@130: int good_length, cannam@130: int max_lazy, cannam@130: int nice_length, cannam@130: int max_chain)); cannam@130: /* cannam@130: Fine tune deflate's internal compression parameters. This should only be cannam@130: used by someone who understands the algorithm used by zlib's deflate for cannam@130: searching for the best matching string, and even then only by the most cannam@130: fanatic optimizer trying to squeeze out the last compressed bit for their cannam@130: specific input data. Read the deflate.c source code for the meaning of the cannam@130: max_lazy, good_length, nice_length, and max_chain parameters. cannam@130: cannam@130: deflateTune() can be called after deflateInit() or deflateInit2(), and cannam@130: returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. cannam@130: */ cannam@130: cannam@130: ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, cannam@130: uLong sourceLen)); cannam@130: /* cannam@130: deflateBound() returns an upper bound on the compressed size after cannam@130: deflation of sourceLen bytes. It must be called after deflateInit() or cannam@130: deflateInit2(), and after deflateSetHeader(), if used. This would be used cannam@130: to allocate an output buffer for deflation in a single pass, and so would be cannam@130: called before deflate(). If that first deflate() call is provided the cannam@130: sourceLen input bytes, an output buffer allocated to the size returned by cannam@130: deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed cannam@130: to return Z_STREAM_END. Note that it is possible for the compressed size to cannam@130: be larger than the value returned by deflateBound() if flush options other cannam@130: than Z_FINISH or Z_NO_FLUSH are used. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, cannam@130: unsigned *pending, cannam@130: int *bits)); cannam@130: /* cannam@130: deflatePending() returns the number of bytes and bits of output that have cannam@130: been generated, but not yet provided in the available output. The bytes not cannam@130: provided would be due to the available output space having being consumed. cannam@130: The number of bits of output not provided are between 0 and 7, where they cannam@130: await more bits to join them in order to fill out a full byte. If pending cannam@130: or bits are Z_NULL, then those values are not set. cannam@130: cannam@130: deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, cannam@130: int bits, cannam@130: int value)); cannam@130: /* cannam@130: deflatePrime() inserts bits in the deflate output stream. The intent cannam@130: is that this function is used to start off the deflate output with the bits cannam@130: leftover from a previous deflate stream when appending to it. As such, this cannam@130: function can only be used for raw deflate, and must be used before the first cannam@130: deflate() call after a deflateInit2() or deflateReset(). bits must be less cannam@130: than or equal to 16, and that many of the least significant bits of value cannam@130: will be inserted in the output. cannam@130: cannam@130: deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough cannam@130: room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the cannam@130: source stream state was inconsistent. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, cannam@130: gz_headerp head)); cannam@130: /* cannam@130: deflateSetHeader() provides gzip header information for when a gzip cannam@130: stream is requested by deflateInit2(). deflateSetHeader() may be called cannam@130: after deflateInit2() or deflateReset() and before the first call of cannam@130: deflate(). The text, time, os, extra field, name, and comment information cannam@130: in the provided gz_header structure are written to the gzip header (xflag is cannam@130: ignored -- the extra flags are set according to the compression level). The cannam@130: caller must assure that, if not Z_NULL, name and comment are terminated with cannam@130: a zero byte, and that if extra is not Z_NULL, that extra_len bytes are cannam@130: available there. If hcrc is true, a gzip header crc is included. Note that cannam@130: the current versions of the command-line version of gzip (up through version cannam@130: 1.3.x) do not support header crc's, and will report that it is a "multi-part cannam@130: gzip file" and give up. cannam@130: cannam@130: If deflateSetHeader is not used, the default gzip header has text false, cannam@130: the time set to zero, and os set to 255, with no extra, name, or comment cannam@130: fields. The gzip header is returned to the default state by deflateReset(). cannam@130: cannam@130: deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent. cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, cannam@130: int windowBits)); cannam@130: cannam@130: This is another version of inflateInit with an extra parameter. The cannam@130: fields next_in, avail_in, zalloc, zfree and opaque must be initialized cannam@130: before by the caller. cannam@130: cannam@130: The windowBits parameter is the base two logarithm of the maximum window cannam@130: size (the size of the history buffer). It should be in the range 8..15 for cannam@130: this version of the library. The default value is 15 if inflateInit is used cannam@130: instead. windowBits must be greater than or equal to the windowBits value cannam@130: provided to deflateInit2() while compressing, or it must be equal to 15 if cannam@130: deflateInit2() was not used. If a compressed stream with a larger window cannam@130: size is given as input, inflate() will return with the error code cannam@130: Z_DATA_ERROR instead of trying to allocate a larger window. cannam@130: cannam@130: windowBits can also be zero to request that inflate use the window size in cannam@130: the zlib header of the compressed stream. cannam@130: cannam@130: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits cannam@130: determines the window size. inflate() will then process raw deflate data, cannam@130: not looking for a zlib or gzip header, not generating a check value, and not cannam@130: looking for any check values for comparison at the end of the stream. This cannam@130: is for use with other formats that use the deflate compressed data format cannam@130: such as zip. Those formats provide their own check values. If a custom cannam@130: format is developed using the raw deflate format for compressed data, it is cannam@130: recommended that a check value such as an adler32 or a crc32 be applied to cannam@130: the uncompressed data as is done in the zlib, gzip, and zip formats. For cannam@130: most applications, the zlib format should be used as is. Note that comments cannam@130: above on the use in deflateInit2() applies to the magnitude of windowBits. cannam@130: cannam@130: windowBits can also be greater than 15 for optional gzip decoding. Add cannam@130: 32 to windowBits to enable zlib and gzip decoding with automatic header cannam@130: detection, or add 16 to decode only the gzip format (the zlib format will cannam@130: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a cannam@130: crc32 instead of an adler32. cannam@130: cannam@130: inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough cannam@130: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the cannam@130: version assumed by the caller, or Z_STREAM_ERROR if the parameters are cannam@130: invalid, such as a null pointer to the structure. msg is set to null if cannam@130: there is no error message. inflateInit2 does not perform any decompression cannam@130: apart from possibly reading the zlib header if present: actual decompression cannam@130: will be done by inflate(). (So next_in and avail_in may be modified, but cannam@130: next_out and avail_out are unused and unchanged.) The current implementation cannam@130: of inflateInit2() does not process any header information -- that is cannam@130: deferred until inflate() is called. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, cannam@130: const Bytef *dictionary, cannam@130: uInt dictLength)); cannam@130: /* cannam@130: Initializes the decompression dictionary from the given uncompressed byte cannam@130: sequence. This function must be called immediately after a call of inflate, cannam@130: if that call returned Z_NEED_DICT. The dictionary chosen by the compressor cannam@130: can be determined from the adler32 value returned by that call of inflate. cannam@130: The compressor and decompressor must use exactly the same dictionary (see cannam@130: deflateSetDictionary). For raw inflate, this function can be called at any cannam@130: time to set the dictionary. If the provided dictionary is smaller than the cannam@130: window and there is already data in the window, then the provided dictionary cannam@130: will amend what's there. The application must insure that the dictionary cannam@130: that was used for compression is provided. cannam@130: cannam@130: inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a cannam@130: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is cannam@130: inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the cannam@130: expected one (incorrect adler32 value). inflateSetDictionary does not cannam@130: perform any decompression: this will be done by subsequent calls of cannam@130: inflate(). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, cannam@130: Bytef *dictionary, cannam@130: uInt *dictLength)); cannam@130: /* cannam@130: Returns the sliding dictionary being maintained by inflate. dictLength is cannam@130: set to the number of bytes in the dictionary, and that many bytes are copied cannam@130: to dictionary. dictionary must have enough space, where 32768 bytes is cannam@130: always enough. If inflateGetDictionary() is called with dictionary equal to cannam@130: Z_NULL, then only the dictionary length is returned, and nothing is copied. cannam@130: Similary, if dictLength is Z_NULL, then it is not set. cannam@130: cannam@130: inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the cannam@130: stream state is inconsistent. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); cannam@130: /* cannam@130: Skips invalid compressed data until a possible full flush point (see above cannam@130: for the description of deflate with Z_FULL_FLUSH) can be found, or until all cannam@130: available input is skipped. No output is provided. cannam@130: cannam@130: inflateSync searches for a 00 00 FF FF pattern in the compressed data. cannam@130: All full flush points have this pattern, but not all occurrences of this cannam@130: pattern are full flush points. cannam@130: cannam@130: inflateSync returns Z_OK if a possible full flush point has been found, cannam@130: Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point cannam@130: has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. cannam@130: In the success case, the application may save the current current value of cannam@130: total_in which indicates where valid compressed data was found. In the cannam@130: error case, the application may repeatedly call inflateSync, providing more cannam@130: input each time, until success or end of the input data. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, cannam@130: z_streamp source)); cannam@130: /* cannam@130: Sets the destination stream as a complete copy of the source stream. cannam@130: cannam@130: This function can be useful when randomly accessing a large stream. The cannam@130: first pass through the stream can periodically record the inflate state, cannam@130: allowing restarting inflate at those points when randomly accessing the cannam@130: stream. cannam@130: cannam@130: inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not cannam@130: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent cannam@130: (such as zalloc being Z_NULL). msg is left unchanged in both source and cannam@130: destination. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); cannam@130: /* cannam@130: This function is equivalent to inflateEnd followed by inflateInit, cannam@130: but does not free and reallocate all the internal decompression state. The cannam@130: stream will keep attributes that may have been set by inflateInit2. cannam@130: cannam@130: inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent (such as zalloc or state being Z_NULL). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, cannam@130: int windowBits)); cannam@130: /* cannam@130: This function is the same as inflateReset, but it also permits changing cannam@130: the wrap and window size requests. The windowBits parameter is interpreted cannam@130: the same as it is for inflateInit2. cannam@130: cannam@130: inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent (such as zalloc or state being Z_NULL), or if cannam@130: the windowBits parameter is invalid. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, cannam@130: int bits, cannam@130: int value)); cannam@130: /* cannam@130: This function inserts bits in the inflate input stream. The intent is cannam@130: that this function is used to start inflating at a bit position in the cannam@130: middle of a byte. The provided bits will be used before any bytes are used cannam@130: from next_in. This function should only be used with raw inflate, and cannam@130: should be used before the first inflate() call after inflateInit2() or cannam@130: inflateReset(). bits must be less than or equal to 16, and that many of the cannam@130: least significant bits of value will be inserted in the input. cannam@130: cannam@130: If bits is negative, then the input stream bit buffer is emptied. Then cannam@130: inflatePrime() can be called again to put bits in the buffer. This is used cannam@130: to clear out bits leftover after feeding inflate a block description prior cannam@130: to feeding inflate codes. cannam@130: cannam@130: inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent. cannam@130: */ cannam@130: cannam@130: ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); cannam@130: /* cannam@130: This function returns two values, one in the lower 16 bits of the return cannam@130: value, and the other in the remaining upper bits, obtained by shifting the cannam@130: return value down 16 bits. If the upper value is -1 and the lower value is cannam@130: zero, then inflate() is currently decoding information outside of a block. cannam@130: If the upper value is -1 and the lower value is non-zero, then inflate is in cannam@130: the middle of a stored block, with the lower value equaling the number of cannam@130: bytes from the input remaining to copy. If the upper value is not -1, then cannam@130: it is the number of bits back from the current bit position in the input of cannam@130: the code (literal or length/distance pair) currently being processed. In cannam@130: that case the lower value is the number of bytes already emitted for that cannam@130: code. cannam@130: cannam@130: A code is being processed if inflate is waiting for more input to complete cannam@130: decoding of the code, or if it has completed decoding but is waiting for cannam@130: more output space to write the literal or match data. cannam@130: cannam@130: inflateMark() is used to mark locations in the input data for random cannam@130: access, which may be at bit positions, and to note those cases where the cannam@130: output of a code may span boundaries of random access blocks. The current cannam@130: location in the input stream can be determined from avail_in and data_type cannam@130: as noted in the description for the Z_BLOCK flush parameter for inflate. cannam@130: cannam@130: inflateMark returns the value noted above or -1 << 16 if the provided cannam@130: source stream state was inconsistent. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, cannam@130: gz_headerp head)); cannam@130: /* cannam@130: inflateGetHeader() requests that gzip header information be stored in the cannam@130: provided gz_header structure. inflateGetHeader() may be called after cannam@130: inflateInit2() or inflateReset(), and before the first call of inflate(). cannam@130: As inflate() processes the gzip stream, head->done is zero until the header cannam@130: is completed, at which time head->done is set to one. If a zlib stream is cannam@130: being decoded, then head->done is set to -1 to indicate that there will be cannam@130: no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be cannam@130: used to force inflate() to return immediately after header processing is cannam@130: complete and before any actual data is decompressed. cannam@130: cannam@130: The text, time, xflags, and os fields are filled in with the gzip header cannam@130: contents. hcrc is set to true if there is a header CRC. (The header CRC cannam@130: was valid if done is set to one.) If extra is not Z_NULL, then extra_max cannam@130: contains the maximum number of bytes to write to extra. Once done is true, cannam@130: extra_len contains the actual extra field length, and extra contains the cannam@130: extra field, or that field truncated if extra_max is less than extra_len. cannam@130: If name is not Z_NULL, then up to name_max characters are written there, cannam@130: terminated with a zero unless the length is greater than name_max. If cannam@130: comment is not Z_NULL, then up to comm_max characters are written there, cannam@130: terminated with a zero unless the length is greater than comm_max. When any cannam@130: of extra, name, or comment are not Z_NULL and the respective field is not cannam@130: present in the header, then that field is set to Z_NULL to signal its cannam@130: absence. This allows the use of deflateSetHeader() with the returned cannam@130: structure to duplicate the header. However if those fields are set to cannam@130: allocated memory, then the application will need to save those pointers cannam@130: elsewhere so that they can be eventually freed. cannam@130: cannam@130: If inflateGetHeader is not used, then the header information is simply cannam@130: discarded. The header is always checked for validity, including the header cannam@130: CRC if present. inflateReset() will reset the process to discard the header cannam@130: information. The application would need to call inflateGetHeader() again to cannam@130: retrieve the header from the next gzip stream. cannam@130: cannam@130: inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source cannam@130: stream state was inconsistent. cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, cannam@130: unsigned char FAR *window)); cannam@130: cannam@130: Initialize the internal stream state for decompression using inflateBack() cannam@130: calls. The fields zalloc, zfree and opaque in strm must be initialized cannam@130: before the call. If zalloc and zfree are Z_NULL, then the default library- cannam@130: derived memory allocation routines are used. windowBits is the base two cannam@130: logarithm of the window size, in the range 8..15. window is a caller cannam@130: supplied buffer of that size. Except for special applications where it is cannam@130: assured that deflate was used with small window sizes, windowBits must be 15 cannam@130: and a 32K byte window must be supplied to be able to decompress general cannam@130: deflate streams. cannam@130: cannam@130: See inflateBack() for the usage of these routines. cannam@130: cannam@130: inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of cannam@130: the parameters are invalid, Z_MEM_ERROR if the internal state could not be cannam@130: allocated, or Z_VERSION_ERROR if the version of the library does not match cannam@130: the version of the header file. cannam@130: */ cannam@130: cannam@130: typedef unsigned (*in_func) OF((void FAR *, cannam@130: z_const unsigned char FAR * FAR *)); cannam@130: typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, cannam@130: in_func in, void FAR *in_desc, cannam@130: out_func out, void FAR *out_desc)); cannam@130: /* cannam@130: inflateBack() does a raw inflate with a single call using a call-back cannam@130: interface for input and output. This is potentially more efficient than cannam@130: inflate() for file i/o applications, in that it avoids copying between the cannam@130: output and the sliding window by simply making the window itself the output cannam@130: buffer. inflate() can be faster on modern CPUs when used with large cannam@130: buffers. inflateBack() trusts the application to not change the output cannam@130: buffer passed by the output function, at least until inflateBack() returns. cannam@130: cannam@130: inflateBackInit() must be called first to allocate the internal state cannam@130: and to initialize the state with the user-provided window buffer. cannam@130: inflateBack() may then be used multiple times to inflate a complete, raw cannam@130: deflate stream with each call. inflateBackEnd() is then called to free the cannam@130: allocated state. cannam@130: cannam@130: A raw deflate stream is one with no zlib or gzip header or trailer. cannam@130: This routine would normally be used in a utility that reads zip or gzip cannam@130: files and writes out uncompressed files. The utility would decode the cannam@130: header and process the trailer on its own, hence this routine expects only cannam@130: the raw deflate stream to decompress. This is different from the normal cannam@130: behavior of inflate(), which expects either a zlib or gzip header and cannam@130: trailer around the deflate stream. cannam@130: cannam@130: inflateBack() uses two subroutines supplied by the caller that are then cannam@130: called by inflateBack() for input and output. inflateBack() calls those cannam@130: routines until it reads a complete deflate stream and writes out all of the cannam@130: uncompressed data, or until it encounters an error. The function's cannam@130: parameters and return types are defined above in the in_func and out_func cannam@130: typedefs. inflateBack() will call in(in_desc, &buf) which should return the cannam@130: number of bytes of provided input, and a pointer to that input in buf. If cannam@130: there is no input available, in() must return zero--buf is ignored in that cannam@130: case--and inflateBack() will return a buffer error. inflateBack() will call cannam@130: out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() cannam@130: should return zero on success, or non-zero on failure. If out() returns cannam@130: non-zero, inflateBack() will return with an error. Neither in() nor out() cannam@130: are permitted to change the contents of the window provided to cannam@130: inflateBackInit(), which is also the buffer that out() uses to write from. cannam@130: The length written by out() will be at most the window size. Any non-zero cannam@130: amount of input may be provided by in(). cannam@130: cannam@130: For convenience, inflateBack() can be provided input on the first call by cannam@130: setting strm->next_in and strm->avail_in. If that input is exhausted, then cannam@130: in() will be called. Therefore strm->next_in must be initialized before cannam@130: calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called cannam@130: immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in cannam@130: must also be initialized, and then if strm->avail_in is not zero, input will cannam@130: initially be taken from strm->next_in[0 .. strm->avail_in - 1]. cannam@130: cannam@130: The in_desc and out_desc parameters of inflateBack() is passed as the cannam@130: first parameter of in() and out() respectively when they are called. These cannam@130: descriptors can be optionally used to pass any information that the caller- cannam@130: supplied in() and out() functions need to do their job. cannam@130: cannam@130: On return, inflateBack() will set strm->next_in and strm->avail_in to cannam@130: pass back any unused input that was provided by the last in() call. The cannam@130: return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR cannam@130: if in() or out() returned an error, Z_DATA_ERROR if there was a format error cannam@130: in the deflate stream (in which case strm->msg is set to indicate the nature cannam@130: of the error), or Z_STREAM_ERROR if the stream was not properly initialized. cannam@130: In the case of Z_BUF_ERROR, an input or output error can be distinguished cannam@130: using strm->next_in which will be Z_NULL only if in() returned an error. If cannam@130: strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning cannam@130: non-zero. (in() will always be called before out(), so strm->next_in is cannam@130: assured to be defined if out() returns non-zero.) Note that inflateBack() cannam@130: cannot return Z_OK. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); cannam@130: /* cannam@130: All memory allocated by inflateBackInit() is freed. cannam@130: cannam@130: inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream cannam@130: state was inconsistent. cannam@130: */ cannam@130: cannam@130: ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); cannam@130: /* Return flags indicating compile-time options. cannam@130: cannam@130: Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: cannam@130: 1.0: size of uInt cannam@130: 3.2: size of uLong cannam@130: 5.4: size of voidpf (pointer) cannam@130: 7.6: size of z_off_t cannam@130: cannam@130: Compiler, assembler, and debug options: cannam@130: 8: DEBUG cannam@130: 9: ASMV or ASMINF -- use ASM code cannam@130: 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention cannam@130: 11: 0 (reserved) cannam@130: cannam@130: One-time table building (smaller code, but not thread-safe if true): cannam@130: 12: BUILDFIXED -- build static block decoding tables when needed cannam@130: 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed cannam@130: 14,15: 0 (reserved) cannam@130: cannam@130: Library content (indicates missing functionality): cannam@130: 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking cannam@130: deflate code when not needed) cannam@130: 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect cannam@130: and decode gzip streams (to avoid linking crc code) cannam@130: 18-19: 0 (reserved) cannam@130: cannam@130: Operation variations (changes in library functionality): cannam@130: 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate cannam@130: 21: FASTEST -- deflate algorithm with only one, lowest compression level cannam@130: 22,23: 0 (reserved) cannam@130: cannam@130: The sprintf variant used by gzprintf (zero is best): cannam@130: 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format cannam@130: 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! cannam@130: 26: 0 = returns value, 1 = void -- 1 means inferred string length returned cannam@130: cannam@130: Remainder: cannam@130: 27-31: 0 (reserved) cannam@130: */ cannam@130: cannam@130: #ifndef Z_SOLO cannam@130: cannam@130: /* utility functions */ cannam@130: cannam@130: /* cannam@130: The following utility functions are implemented on top of the basic cannam@130: stream-oriented functions. To simplify the interface, some default options cannam@130: are assumed (compression level and memory usage, standard memory allocation cannam@130: functions). The source code of these utility functions can be modified if cannam@130: you need special options. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, cannam@130: const Bytef *source, uLong sourceLen)); cannam@130: /* cannam@130: Compresses the source buffer into the destination buffer. sourceLen is cannam@130: the byte length of the source buffer. Upon entry, destLen is the total size cannam@130: of the destination buffer, which must be at least the value returned by cannam@130: compressBound(sourceLen). Upon exit, destLen is the actual size of the cannam@130: compressed buffer. cannam@130: cannam@130: compress returns Z_OK if success, Z_MEM_ERROR if there was not cannam@130: enough memory, Z_BUF_ERROR if there was not enough room in the output cannam@130: buffer. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, cannam@130: const Bytef *source, uLong sourceLen, cannam@130: int level)); cannam@130: /* cannam@130: Compresses the source buffer into the destination buffer. The level cannam@130: parameter has the same meaning as in deflateInit. sourceLen is the byte cannam@130: length of the source buffer. Upon entry, destLen is the total size of the cannam@130: destination buffer, which must be at least the value returned by cannam@130: compressBound(sourceLen). Upon exit, destLen is the actual size of the cannam@130: compressed buffer. cannam@130: cannam@130: compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough cannam@130: memory, Z_BUF_ERROR if there was not enough room in the output buffer, cannam@130: Z_STREAM_ERROR if the level parameter is invalid. cannam@130: */ cannam@130: cannam@130: ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); cannam@130: /* cannam@130: compressBound() returns an upper bound on the compressed size after cannam@130: compress() or compress2() on sourceLen bytes. It would be used before a cannam@130: compress() or compress2() call to allocate the destination buffer. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, cannam@130: const Bytef *source, uLong sourceLen)); cannam@130: /* cannam@130: Decompresses the source buffer into the destination buffer. sourceLen is cannam@130: the byte length of the source buffer. Upon entry, destLen is the total size cannam@130: of the destination buffer, which must be large enough to hold the entire cannam@130: uncompressed data. (The size of the uncompressed data must have been saved cannam@130: previously by the compressor and transmitted to the decompressor by some cannam@130: mechanism outside the scope of this compression library.) Upon exit, destLen cannam@130: is the actual size of the uncompressed buffer. cannam@130: cannam@130: uncompress returns Z_OK if success, Z_MEM_ERROR if there was not cannam@130: enough memory, Z_BUF_ERROR if there was not enough room in the output cannam@130: buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In cannam@130: the case where there is not enough room, uncompress() will fill the output cannam@130: buffer with the uncompressed data up to that point. cannam@130: */ cannam@130: cannam@130: /* gzip file access functions */ cannam@130: cannam@130: /* cannam@130: This library supports reading and writing files in gzip (.gz) format with cannam@130: an interface similar to that of stdio, using the functions that start with cannam@130: "gz". The gzip format is different from the zlib format. gzip is a gzip cannam@130: wrapper, documented in RFC 1952, wrapped around a deflate stream. cannam@130: */ cannam@130: cannam@130: typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ cannam@130: cannam@130: /* cannam@130: ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); cannam@130: cannam@130: Opens a gzip (.gz) file for reading or writing. The mode parameter is as cannam@130: in fopen ("rb" or "wb") but can also include a compression level ("wb9") or cannam@130: a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only cannam@130: compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' cannam@130: for fixed code compression as in "wb9F". (See the description of cannam@130: deflateInit2 for more information about the strategy parameter.) 'T' will cannam@130: request transparent writing or appending with no compression and not using cannam@130: the gzip format. cannam@130: cannam@130: "a" can be used instead of "w" to request that the gzip stream that will cannam@130: be written be appended to the file. "+" will result in an error, since cannam@130: reading and writing to the same gzip file is not supported. The addition of cannam@130: "x" when writing will create the file exclusively, which fails if the file cannam@130: already exists. On systems that support it, the addition of "e" when cannam@130: reading or writing will set the flag to close the file on an execve() call. cannam@130: cannam@130: These functions, as well as gzip, will read and decode a sequence of gzip cannam@130: streams in a file. The append function of gzopen() can be used to create cannam@130: such a file. (Also see gzflush() for another way to do this.) When cannam@130: appending, gzopen does not test whether the file begins with a gzip stream, cannam@130: nor does it look for the end of the gzip streams to begin appending. gzopen cannam@130: will simply append a gzip stream to the existing file. cannam@130: cannam@130: gzopen can be used to read a file which is not in gzip format; in this cannam@130: case gzread will directly read from the file without decompression. When cannam@130: reading, this will be detected automatically by looking for the magic two- cannam@130: byte gzip header. cannam@130: cannam@130: gzopen returns NULL if the file could not be opened, if there was cannam@130: insufficient memory to allocate the gzFile state, or if an invalid mode was cannam@130: specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). cannam@130: errno can be checked to determine if the reason gzopen failed was that the cannam@130: file could not be opened. cannam@130: */ cannam@130: cannam@130: ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); cannam@130: /* cannam@130: gzdopen associates a gzFile with the file descriptor fd. File descriptors cannam@130: are obtained from calls like open, dup, creat, pipe or fileno (if the file cannam@130: has been previously opened with fopen). The mode parameter is as in gzopen. cannam@130: cannam@130: The next call of gzclose on the returned gzFile will also close the file cannam@130: descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor cannam@130: fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, cannam@130: mode);. The duplicated descriptor should be saved to avoid a leak, since cannam@130: gzdopen does not close fd if it fails. If you are using fileno() to get the cannam@130: file descriptor from a FILE *, then you will have to use dup() to avoid cannam@130: double-close()ing the file descriptor. Both gzclose() and fclose() will cannam@130: close the associated file descriptor, so they need to have different file cannam@130: descriptors. cannam@130: cannam@130: gzdopen returns NULL if there was insufficient memory to allocate the cannam@130: gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not cannam@130: provided, or '+' was provided), or if fd is -1. The file descriptor is not cannam@130: used until the next gz* read, write, seek, or close operation, so gzdopen cannam@130: will not detect if fd is invalid (unless fd is -1). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); cannam@130: /* cannam@130: Set the internal buffer size used by this library's functions. The cannam@130: default buffer size is 8192 bytes. This function must be called after cannam@130: gzopen() or gzdopen(), and before any other calls that read or write the cannam@130: file. The buffer memory allocation is always deferred to the first read or cannam@130: write. Two buffers are allocated, either both of the specified size when cannam@130: writing, or one of the specified size and the other twice that size when cannam@130: reading. A larger buffer size of, for example, 64K or 128K bytes will cannam@130: noticeably increase the speed of decompression (reading). cannam@130: cannam@130: The new buffer size also affects the maximum length for gzprintf(). cannam@130: cannam@130: gzbuffer() returns 0 on success, or -1 on failure, such as being called cannam@130: too late. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); cannam@130: /* cannam@130: Dynamically update the compression level or strategy. See the description cannam@130: of deflateInit2 for the meaning of these parameters. cannam@130: cannam@130: gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not cannam@130: opened for writing. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); cannam@130: /* cannam@130: Reads the given number of uncompressed bytes from the compressed file. If cannam@130: the input file is not in gzip format, gzread copies the given number of cannam@130: bytes into the buffer directly from the file. cannam@130: cannam@130: After reaching the end of a gzip stream in the input, gzread will continue cannam@130: to read, looking for another gzip stream. Any number of gzip streams may be cannam@130: concatenated in the input file, and will all be decompressed by gzread(). cannam@130: If something other than a gzip stream is encountered after a gzip stream, cannam@130: that remaining trailing garbage is ignored (and no error is returned). cannam@130: cannam@130: gzread can be used to read a gzip file that is being concurrently written. cannam@130: Upon reaching the end of the input, gzread will return with the available cannam@130: data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then cannam@130: gzclearerr can be used to clear the end of file indicator in order to permit cannam@130: gzread to be tried again. Z_OK indicates that a gzip stream was completed cannam@130: on the last gzread. Z_BUF_ERROR indicates that the input file ended in the cannam@130: middle of a gzip stream. Note that gzread does not return -1 in the event cannam@130: of an incomplete gzip stream. This error is deferred until gzclose(), which cannam@130: will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip cannam@130: stream. Alternatively, gzerror can be used before gzclose to detect this cannam@130: case. cannam@130: cannam@130: gzread returns the number of uncompressed bytes actually read, less than cannam@130: len for end of file, or -1 for error. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzwrite OF((gzFile file, cannam@130: voidpc buf, unsigned len)); cannam@130: /* cannam@130: Writes the given number of uncompressed bytes into the compressed file. cannam@130: gzwrite returns the number of uncompressed bytes written or 0 in case of cannam@130: error. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); cannam@130: /* cannam@130: Converts, formats, and writes the arguments to the compressed file under cannam@130: control of the format string, as in fprintf. gzprintf returns the number of cannam@130: uncompressed bytes actually written, or 0 in case of error. The number of cannam@130: uncompressed bytes written is limited to 8191, or one less than the buffer cannam@130: size given to gzbuffer(). The caller should assure that this limit is not cannam@130: exceeded. If it is exceeded, then gzprintf() will return an error (0) with cannam@130: nothing written. In this case, there may also be a buffer overflow with cannam@130: unpredictable consequences, which is possible only if zlib was compiled with cannam@130: the insecure functions sprintf() or vsprintf() because the secure snprintf() cannam@130: or vsnprintf() functions were not available. This can be determined using cannam@130: zlibCompileFlags(). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); cannam@130: /* cannam@130: Writes the given null-terminated string to the compressed file, excluding cannam@130: the terminating null character. cannam@130: cannam@130: gzputs returns the number of characters written, or -1 in case of error. cannam@130: */ cannam@130: cannam@130: ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); cannam@130: /* cannam@130: Reads bytes from the compressed file until len-1 characters are read, or a cannam@130: newline character is read and transferred to buf, or an end-of-file cannam@130: condition is encountered. If any characters are read or if len == 1, the cannam@130: string is terminated with a null character. If no characters are read due cannam@130: to an end-of-file or len < 1, then the buffer is left untouched. cannam@130: cannam@130: gzgets returns buf which is a null-terminated string, or it returns NULL cannam@130: for end-of-file or in case of error. If there was an error, the contents at cannam@130: buf are indeterminate. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); cannam@130: /* cannam@130: Writes c, converted to an unsigned char, into the compressed file. gzputc cannam@130: returns the value that was written, or -1 in case of error. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); cannam@130: /* cannam@130: Reads one byte from the compressed file. gzgetc returns this byte or -1 cannam@130: in case of end of file or error. This is implemented as a macro for speed. cannam@130: As such, it does not do all of the checking the other functions do. I.e. cannam@130: it does not check to see if file is NULL, nor whether the structure file cannam@130: points to has been clobbered or not. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); cannam@130: /* cannam@130: Push one character back onto the stream to be read as the first character cannam@130: on the next read. At least one character of push-back is allowed. cannam@130: gzungetc() returns the character pushed, or -1 on failure. gzungetc() will cannam@130: fail if c is -1, and may fail if a character has been pushed but not read cannam@130: yet. If gzungetc is used immediately after gzopen or gzdopen, at least the cannam@130: output buffer size of pushed characters is allowed. (See gzbuffer above.) cannam@130: The pushed character will be discarded if the stream is repositioned with cannam@130: gzseek() or gzrewind(). cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); cannam@130: /* cannam@130: Flushes all pending output into the compressed file. The parameter flush cannam@130: is as in the deflate() function. The return value is the zlib error number cannam@130: (see function gzerror below). gzflush is only permitted when writing. cannam@130: cannam@130: If the flush parameter is Z_FINISH, the remaining data is written and the cannam@130: gzip stream is completed in the output. If gzwrite() is called again, a new cannam@130: gzip stream will be started in the output. gzread() is able to read such cannam@130: concatented gzip streams. cannam@130: cannam@130: gzflush should be called only when strictly necessary because it will cannam@130: degrade compression if called too often. cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, cannam@130: z_off_t offset, int whence)); cannam@130: cannam@130: Sets the starting position for the next gzread or gzwrite on the given cannam@130: compressed file. The offset represents a number of bytes in the cannam@130: uncompressed data stream. The whence parameter is defined as in lseek(2); cannam@130: the value SEEK_END is not supported. cannam@130: cannam@130: If the file is opened for reading, this function is emulated but can be cannam@130: extremely slow. If the file is opened for writing, only forward seeks are cannam@130: supported; gzseek then compresses a sequence of zeroes up to the new cannam@130: starting position. cannam@130: cannam@130: gzseek returns the resulting offset location as measured in bytes from cannam@130: the beginning of the uncompressed stream, or -1 in case of error, in cannam@130: particular if the file is opened for writing and the new starting position cannam@130: would be before the current position. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); cannam@130: /* cannam@130: Rewinds the given file. This function is supported only for reading. cannam@130: cannam@130: gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); cannam@130: cannam@130: Returns the starting position for the next gzread or gzwrite on the given cannam@130: compressed file. This position represents a number of bytes in the cannam@130: uncompressed data stream, and is zero when starting, even if appending or cannam@130: reading a gzip stream from the middle of a file using gzdopen(). cannam@130: cannam@130: gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); cannam@130: cannam@130: Returns the current offset in the file being read or written. This offset cannam@130: includes the count of bytes that precede the gzip stream, for example when cannam@130: appending or when using gzdopen() for reading. When reading, the offset cannam@130: does not include as yet unused buffered input. This information can be used cannam@130: for a progress indicator. On error, gzoffset() returns -1. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzeof OF((gzFile file)); cannam@130: /* cannam@130: Returns true (1) if the end-of-file indicator has been set while reading, cannam@130: false (0) otherwise. Note that the end-of-file indicator is set only if the cannam@130: read tried to go past the end of the input, but came up short. Therefore, cannam@130: just like feof(), gzeof() may return false even if there is no more data to cannam@130: read, in the event that the last read request was for the exact number of cannam@130: bytes remaining in the input file. This will happen if the input file size cannam@130: is an exact multiple of the buffer size. cannam@130: cannam@130: If gzeof() returns true, then the read functions will return no more data, cannam@130: unless the end-of-file indicator is reset by gzclearerr() and the input file cannam@130: has grown since the previous end of file was detected. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); cannam@130: /* cannam@130: Returns true (1) if file is being copied directly while reading, or false cannam@130: (0) if file is a gzip stream being decompressed. cannam@130: cannam@130: If the input file is empty, gzdirect() will return true, since the input cannam@130: does not contain a gzip stream. cannam@130: cannam@130: If gzdirect() is used immediately after gzopen() or gzdopen() it will cannam@130: cause buffers to be allocated to allow reading the file to determine if it cannam@130: is a gzip file. Therefore if gzbuffer() is used, it should be called before cannam@130: gzdirect(). cannam@130: cannam@130: When writing, gzdirect() returns true (1) if transparent writing was cannam@130: requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: cannam@130: gzdirect() is not needed when writing. Transparent writing must be cannam@130: explicitly requested, so the application already knows the answer. When cannam@130: linking statically, using gzdirect() will include all of the zlib code for cannam@130: gzip file reading and decompression, which may not be desired.) cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzclose OF((gzFile file)); cannam@130: /* cannam@130: Flushes all pending output if necessary, closes the compressed file and cannam@130: deallocates the (de)compression state. Note that once file is closed, you cannam@130: cannot call gzerror with file, since its structures have been deallocated. cannam@130: gzclose must not be called more than once on the same file, just as free cannam@130: must not be called more than once on the same allocation. cannam@130: cannam@130: gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a cannam@130: file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the cannam@130: last read ended in the middle of a gzip stream, or Z_OK on success. cannam@130: */ cannam@130: cannam@130: ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); cannam@130: ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); cannam@130: /* cannam@130: Same as gzclose(), but gzclose_r() is only for use when reading, and cannam@130: gzclose_w() is only for use when writing or appending. The advantage to cannam@130: using these instead of gzclose() is that they avoid linking in zlib cannam@130: compression or decompression code that is not used when only reading or only cannam@130: writing respectively. If gzclose() is used, then both compression and cannam@130: decompression code will be included the application when linking to a static cannam@130: zlib library. cannam@130: */ cannam@130: cannam@130: ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); cannam@130: /* cannam@130: Returns the error message for the last error which occurred on the given cannam@130: compressed file. errnum is set to zlib error number. If an error occurred cannam@130: in the file system and not in the compression library, errnum is set to cannam@130: Z_ERRNO and the application may consult errno to get the exact error code. cannam@130: cannam@130: The application must not modify the returned string. Future calls to cannam@130: this function may invalidate the previously returned string. If file is cannam@130: closed, then the string previously returned by gzerror will no longer be cannam@130: available. cannam@130: cannam@130: gzerror() should be used to distinguish errors from end-of-file for those cannam@130: functions above that do not distinguish those cases in their return values. cannam@130: */ cannam@130: cannam@130: ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); cannam@130: /* cannam@130: Clears the error and end-of-file flags for file. This is analogous to the cannam@130: clearerr() function in stdio. This is useful for continuing to read a gzip cannam@130: file that is being written concurrently. cannam@130: */ cannam@130: cannam@130: #endif /* !Z_SOLO */ cannam@130: cannam@130: /* checksum functions */ cannam@130: cannam@130: /* cannam@130: These functions are not related to compression but are exported cannam@130: anyway because they might be useful in applications using the compression cannam@130: library. cannam@130: */ cannam@130: cannam@130: ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); cannam@130: /* cannam@130: Update a running Adler-32 checksum with the bytes buf[0..len-1] and cannam@130: return the updated checksum. If buf is Z_NULL, this function returns the cannam@130: required initial value for the checksum. cannam@130: cannam@130: An Adler-32 checksum is almost as reliable as a CRC32 but can be computed cannam@130: much faster. cannam@130: cannam@130: Usage example: cannam@130: cannam@130: uLong adler = adler32(0L, Z_NULL, 0); cannam@130: cannam@130: while (read_buffer(buffer, length) != EOF) { cannam@130: adler = adler32(adler, buffer, length); cannam@130: } cannam@130: if (adler != original_adler) error(); cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, cannam@130: z_off_t len2)); cannam@130: cannam@130: Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 cannam@130: and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for cannam@130: each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of cannam@130: seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note cannam@130: that the z_off_t type (like off_t) is a signed integer. If len2 is cannam@130: negative, the result has no meaning or utility. cannam@130: */ cannam@130: cannam@130: ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); cannam@130: /* cannam@130: Update a running CRC-32 with the bytes buf[0..len-1] and return the cannam@130: updated CRC-32. If buf is Z_NULL, this function returns the required cannam@130: initial value for the crc. Pre- and post-conditioning (one's complement) is cannam@130: performed within this function so it shouldn't be done by the application. cannam@130: cannam@130: Usage example: cannam@130: cannam@130: uLong crc = crc32(0L, Z_NULL, 0); cannam@130: cannam@130: while (read_buffer(buffer, length) != EOF) { cannam@130: crc = crc32(crc, buffer, length); cannam@130: } cannam@130: if (crc != original_crc) error(); cannam@130: */ cannam@130: cannam@130: /* cannam@130: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); cannam@130: cannam@130: Combine two CRC-32 check values into one. For two sequences of bytes, cannam@130: seq1 and seq2 with lengths len1 and len2, CRC-32 check values were cannam@130: calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 cannam@130: check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and cannam@130: len2. cannam@130: */ cannam@130: cannam@130: cannam@130: /* various hacks, don't look :) */ cannam@130: cannam@130: /* deflateInit and inflateInit are macros to allow checking the zlib version cannam@130: * and the compiler's view of z_stream: cannam@130: */ cannam@130: ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, cannam@130: const char *version, int stream_size)); cannam@130: ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, cannam@130: const char *version, int stream_size)); cannam@130: ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, cannam@130: int windowBits, int memLevel, cannam@130: int strategy, const char *version, cannam@130: int stream_size)); cannam@130: ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, cannam@130: const char *version, int stream_size)); cannam@130: ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, cannam@130: unsigned char FAR *window, cannam@130: const char *version, cannam@130: int stream_size)); cannam@130: #define deflateInit(strm, level) \ cannam@130: deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) cannam@130: #define inflateInit(strm) \ cannam@130: inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) cannam@130: #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ cannam@130: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ cannam@130: (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) cannam@130: #define inflateInit2(strm, windowBits) \ cannam@130: inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ cannam@130: (int)sizeof(z_stream)) cannam@130: #define inflateBackInit(strm, windowBits, window) \ cannam@130: inflateBackInit_((strm), (windowBits), (window), \ cannam@130: ZLIB_VERSION, (int)sizeof(z_stream)) cannam@130: cannam@130: #ifndef Z_SOLO cannam@130: cannam@130: /* gzgetc() macro and its supporting function and exposed data structure. Note cannam@130: * that the real internal state is much larger than the exposed structure. cannam@130: * This abbreviated structure exposes just enough for the gzgetc() macro. The cannam@130: * user should not mess with these exposed elements, since their names or cannam@130: * behavior could change in the future, perhaps even capriciously. They can cannam@130: * only be used by the gzgetc() macro. You have been warned. cannam@130: */ cannam@130: struct gzFile_s { cannam@130: unsigned have; cannam@130: unsigned char *next; cannam@130: z_off64_t pos; cannam@130: }; cannam@130: ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ cannam@130: #ifdef Z_PREFIX_SET cannam@130: # undef z_gzgetc cannam@130: # define z_gzgetc(g) \ cannam@130: ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) cannam@130: #else cannam@130: # define gzgetc(g) \ cannam@130: ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g)) cannam@130: #endif cannam@130: cannam@130: /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or cannam@130: * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if cannam@130: * both are true, the application gets the *64 functions, and the regular cannam@130: * functions are changed to 64 bits) -- in case these are set on systems cannam@130: * without large file support, _LFS64_LARGEFILE must also be true cannam@130: */ cannam@130: #ifdef Z_LARGE64 cannam@130: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); cannam@130: ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); cannam@130: ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); cannam@130: ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); cannam@130: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); cannam@130: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); cannam@130: #endif cannam@130: cannam@130: #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) cannam@130: # ifdef Z_PREFIX_SET cannam@130: # define z_gzopen z_gzopen64 cannam@130: # define z_gzseek z_gzseek64 cannam@130: # define z_gztell z_gztell64 cannam@130: # define z_gzoffset z_gzoffset64 cannam@130: # define z_adler32_combine z_adler32_combine64 cannam@130: # define z_crc32_combine z_crc32_combine64 cannam@130: # else cannam@130: # define gzopen gzopen64 cannam@130: # define gzseek gzseek64 cannam@130: # define gztell gztell64 cannam@130: # define gzoffset gzoffset64 cannam@130: # define adler32_combine adler32_combine64 cannam@130: # define crc32_combine crc32_combine64 cannam@130: # endif cannam@130: # ifndef Z_LARGE64 cannam@130: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); cannam@130: ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); cannam@130: ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); cannam@130: ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); cannam@130: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); cannam@130: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); cannam@130: # endif cannam@130: #else cannam@130: ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); cannam@130: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); cannam@130: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); cannam@130: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); cannam@130: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); cannam@130: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); cannam@130: #endif cannam@130: cannam@130: #else /* Z_SOLO */ cannam@130: cannam@130: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); cannam@130: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); cannam@130: cannam@130: #endif /* !Z_SOLO */ cannam@130: cannam@130: /* hack for buggy compilers */ cannam@130: #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) cannam@130: struct internal_state {int dummy;}; cannam@130: #endif cannam@130: cannam@130: /* undocumented functions */ cannam@130: ZEXTERN const char * ZEXPORT zError OF((int)); cannam@130: ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); cannam@130: ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); cannam@130: ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); cannam@130: ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); cannam@130: ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); cannam@130: #if defined(_WIN32) && !defined(Z_SOLO) cannam@130: ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, cannam@130: const char *mode)); cannam@130: #endif cannam@130: #if defined(STDC) || defined(Z_HAVE_STDARG_H) cannam@130: # ifndef Z_SOLO cannam@130: ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, cannam@130: const char *format, cannam@130: va_list va)); cannam@130: # endif cannam@130: #endif cannam@130: cannam@130: #ifdef __cplusplus cannam@130: } cannam@130: #endif cannam@130: cannam@130: #endif /* ZLIB_H */