/* zlib.h -- interface of the 'zlib' general purpose compression library Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. Jean-loup Gailly Mark Adler jloup@gzip.org madler@alumni.caltech.edu The data format used by the zlib library is described by RFCs (Request for Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). */ #ifndef _ZLIB_H #define _ZLIB_H #include struct internal_state; typedef struct z_stream_s { const Byte *next_in; uInt avail_in; uLong total_in; Byte *next_out; uInt avail_out; uLong total_out; char *msg; struct internal_state *state; void *workspace; int data_type; uLong adler; uLong reserved; } z_stream; typedef z_stream *z_streamp; #define Z_NO_FLUSH 0 #define Z_PARTIAL_FLUSH 1 #define Z_PACKET_FLUSH 2 #define Z_SYNC_FLUSH 3 #define Z_FULL_FLUSH 4 #define Z_FINISH 5 #define Z_BLOCK 6 #define Z_OK 0 #define Z_STREAM_END 1 #define Z_NEED_DICT 2 #define Z_ERRNO (-1) #define Z_STREAM_ERROR (-2) #define Z_DATA_ERROR (-3) #define Z_MEM_ERROR (-4) #define Z_BUF_ERROR (-5) #define Z_VERSION_ERROR (-6) #define Z_NO_COMPRESSION 0 #define Z_BEST_SPEED 1 #define Z_BEST_COMPRESSION 9 #define Z_DEFAULT_COMPRESSION (-1) #define Z_FILTERED 1 #define Z_HUFFMAN_ONLY 2 #define Z_DEFAULT_STRATEGY 0 #define Z_BINARY 0 #define Z_ASCII 1 #define Z_UNKNOWN 2 #define Z_DEFLATED 8 extern int zlib_deflate_workspacesize (int windowBits, int memLevel); extern int zlib_deflate (z_streamp strm, int flush); extern int zlib_deflateEnd (z_streamp strm); extern int zlib_inflate_workspacesize (void); extern int zlib_inflate (z_streamp strm, int flush); /* inflate decompresses as much data as possible, and stops when the input buffer becomes empty or the output buffer becomes full. It may introduce some output latency (reading input without producing any output) except when forced to flush. The detailed semantics are as follows. inflate performs one or both of the following actions: - Decompress more input starting at next_in and update next_in and avail_in accordingly. If not all input can be processed (because there is not enough room in the output buffer), next_in is updated and processing will resume at this point for the next call of inflate(). - Provide more output starting at next_out and update next_out and avail_out accordingly. inflate() provides as much output as possible, until there is no more input data or no more space in the output buffer (see below about the flush parameter). Before the call of inflate(), the application should ensure that at least one of the actions is possible, by providing more input and/or consuming more output, and updating the next_* and avail_* values accordingly. The application can consume the uncompressed output when it wants, for example when the output buffer is full (avail_out == 0), or after each call of inflate(). If inflate returns Z_OK and with zero avail_out, it must be called again after making room in the output buffer because there might be more output pending. The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much output as possible to the output buffer. Z_BLOCK requests that inflate() stop if and when it gets to the next deflate block boundary. When decoding the zlib or gzip format, this will cause inflate() to return immediately after the header and before the first block. When doing a raw inflate, inflate() will go ahead and process the first block, and will return when it gets to the end of that block, or when it runs out of data. The Z_BLOCK option assists in appending to or combining deflate streams. Also to assist in this, on return inflate() will set strm->data_type to the number of unused bits in the last byte taken from strm->next_in, plus 64 if inflate() is currently decoding the last block in the deflate stream, plus 128 if inflate() returned immediately after decoding an end-of-block code or decoding the complete header up to just before the first byte of the deflate stream. The end-of-block will not be indicated until all of the uncompressed data from that block has been written to strm->next_out. The number of unused bits may in general be greater than seven, except when bit 7 of data_type is set, in which case the number of unused bits will be less than eight. inflate() should normally be called until it returns Z_STREAM_END or an error. However if all decompression is to be performed in a single step (a single call of inflate), the parameter flush should be set to Z_FINISH. In this case all pending input is processed and all pending output is flushed; avail_out must be large enough to hold all the uncompressed data. (The size of the uncompressed data may have been saved by the compressor for this purpose.) The next operation on this stream must be inflateEnd to deallocate the decompression state. The use of Z_FINISH is never required, but can be used to inform inflate that a faster approach may be used for the single inflate() call. In this implementation, inflate() always flushes as much output as possible to the output buffer, and always uses the faster approach on the first call. So the only effect of the flush parameter in this implementation is on the return value of inflate(), as noted below, or when it returns early because Z_BLOCK is used. If a preset dictionary is needed after this call (see inflateSetDictionary below), inflate sets strm->adler to the adler32 checksum of the dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise it sets strm->adler to the adler32 checksum of all output produced so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described below. At the end of the stream, inflate() checks that its computed adler32 checksum is equal to that saved by the compressor and returns Z_STREAM_END only if the checksum is correct. inflate() will decompress and check either zlib-wrapped or gzip-wrapped deflate data. The header type is detected automatically. Any information contained in the gzip header is not retained, so applications that need that information should instead use raw inflate, see inflateInit2() below, or inflateBack() and perform their own processing of the gzip header and trailer. inflate() returns Z_OK if some progress has been made (more input processed or more output produced), Z_STREAM_END if the end of the compressed data has been reached and all uncompressed output has been produced, Z_NEED_DICT if a preset dictionary is needed at this point, Z_DATA_ERROR if the input data was corrupted (input stream not conforming to the zlib format or incorrect check value), Z_STREAM_ERROR if the stream structure was inconsistent (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no progress is possible or if there was not enough room in the output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and inflate() can be called again with more input and more output space to continue decompressing. If Z_DATA_ERROR is returned, the application may then call inflateSync() to look for a good compression block if a partial recovery of the data is desired. */ extern int zlib_inflateEnd (z_streamp strm); #if 0 extern int zlib_deflateSetDictionary (z_streamp strm, const Byte *dictionary, uInt dictLength); #endif #if 0 extern int zlib_deflateCopy (z_streamp dest, z_streamp source); #endif extern int zlib_deflateReset (z_streamp strm); static inline unsigned long deflateBound(unsigned long s) { return s + ((s + 7) >> 3) + ((s + 63) >> 6) + 11; } #if 0 extern int zlib_deflateParams (z_streamp strm, int level, int strategy); #endif extern int zlib_inflateSetDictionary (z_streamp strm, const Byte *dictionary, uInt dictLength); #if 0 extern int zlib_inflateSync (z_streamp strm); #endif extern int zlib_inflateReset (z_streamp strm); extern int zlib_inflateIncomp (z_stream *strm); #define zlib_deflateInit(strm, level) \ zlib_deflateInit2((strm), (level), Z_DEFLATED, MAX_WBITS, \ DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY) #define zlib_inflateInit(strm) \ zlib_inflateInit2((strm), DEF_WBITS) extern int zlib_deflateInit2(z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy); extern int zlib_inflateInit2(z_streamp strm, int windowBits); #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) struct internal_state {int dummy;}; #endif extern int zlib_inflate_blob(void *dst, unsigned dst_sz, const void *src, unsigned src_sz); #endif