sl@0: /* inflate.h -- internal inflate state definition sl@0: * Copyright (C) 1995-2004 Mark Adler sl@0: * For conditions of distribution and use, see copyright notice in zlib.h sl@0: */ sl@0: sl@0: /* WARNING: this file should *not* be used by applications. It is sl@0: part of the implementation of the compression library and is sl@0: subject to change. Applications should only use zlib.h. sl@0: */ sl@0: sl@0: /* define NO_GZIP when compiling if you want to disable gzip header and sl@0: trailer decoding by inflate(). NO_GZIP would be used to avoid linking in sl@0: the crc code when it is not needed. For shared libraries, gzip decoding sl@0: should be left enabled. */ sl@0: #ifndef NO_GZIP sl@0: # define GUNZIP sl@0: #endif sl@0: sl@0: /* Possible inflate modes between inflate() calls */ sl@0: typedef enum { sl@0: HEAD, /* i: waiting for magic header */ sl@0: FLAGS, /* i: waiting for method and flags (gzip) */ sl@0: TIME, /* i: waiting for modification time (gzip) */ sl@0: OS, /* i: waiting for extra flags and operating system (gzip) */ sl@0: EXLEN, /* i: waiting for extra length (gzip) */ sl@0: EXTRA, /* i: waiting for extra bytes (gzip) */ sl@0: NAME, /* i: waiting for end of file name (gzip) */ sl@0: COMMENT, /* i: waiting for end of comment (gzip) */ sl@0: HCRC, /* i: waiting for header crc (gzip) */ sl@0: DICTID, /* i: waiting for dictionary check value */ sl@0: DICT, /* waiting for inflateSetDictionary() call */ sl@0: TYPE, /* i: waiting for type bits, including last-flag bit */ sl@0: TYPEDO, /* i: same, but skip check to exit inflate on new block */ sl@0: STORED, /* i: waiting for stored size (length and complement) */ sl@0: COPY, /* i/o: waiting for input or output to copy stored block */ sl@0: TABLE, /* i: waiting for dynamic block table lengths */ sl@0: LENLENS, /* i: waiting for code length code lengths */ sl@0: CODELENS, /* i: waiting for length/lit and distance code lengths */ sl@0: LEN, /* i: waiting for length/lit code */ sl@0: LENEXT, /* i: waiting for length extra bits */ sl@0: DIST, /* i: waiting for distance code */ sl@0: DISTEXT, /* i: waiting for distance extra bits */ sl@0: MATCH, /* o: waiting for output space to copy string */ sl@0: LIT, /* o: waiting for output space to write literal */ sl@0: CHECK, /* i: waiting for 32-bit check value */ sl@0: LENGTH, /* i: waiting for 32-bit length (gzip) */ sl@0: DONE, /* finished check, done -- remain here until reset */ sl@0: BAD, /* got a data error -- remain here until reset */ sl@0: MEM, /* got an inflate() memory error -- remain here until reset */ sl@0: SYNC /* looking for synchronization bytes to restart inflate() */ sl@0: } inflate_mode; sl@0: sl@0: /* sl@0: State transitions between above modes - sl@0: sl@0: (most modes can go to the BAD or MEM mode -- not shown for clarity) sl@0: sl@0: Process header: sl@0: HEAD -> (gzip) or (zlib) sl@0: (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME sl@0: NAME -> COMMENT -> HCRC -> TYPE sl@0: (zlib) -> DICTID or TYPE sl@0: DICTID -> DICT -> TYPE sl@0: Read deflate blocks: sl@0: TYPE -> STORED or TABLE or LEN or CHECK sl@0: STORED -> COPY -> TYPE sl@0: TABLE -> LENLENS -> CODELENS -> LEN sl@0: Read deflate codes: sl@0: LEN -> LENEXT or LIT or TYPE sl@0: LENEXT -> DIST -> DISTEXT -> MATCH -> LEN sl@0: LIT -> LEN sl@0: Process trailer: sl@0: CHECK -> LENGTH -> DONE sl@0: */ sl@0: sl@0: /* state maintained between inflate() calls. Approximately 7K bytes. */ sl@0: struct inflate_state { sl@0: inflate_mode mode; /* current inflate mode */ sl@0: int last; /* true if processing last block */ sl@0: int wrap; /* bit 0 true for zlib, bit 1 true for gzip */ sl@0: int havedict; /* true if dictionary provided */ sl@0: int flags; /* gzip header method and flags (0 if zlib) */ sl@0: unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */ sl@0: unsigned long check; /* protected copy of check value */ sl@0: unsigned long total; /* protected copy of output count */ sl@0: gz_headerp head; /* where to save gzip header information */ sl@0: /* sliding window */ sl@0: unsigned wbits; /* log base 2 of requested window size */ sl@0: unsigned wsize; /* window size or zero if not using window */ sl@0: unsigned whave; /* valid bytes in the window */ sl@0: unsigned write; /* window write index */ sl@0: unsigned char FAR *window; /* allocated sliding window, if needed */ sl@0: /* bit accumulator */ sl@0: unsigned long hold; /* input bit accumulator */ sl@0: unsigned bits; /* number of bits in "in" */ sl@0: /* for string and stored block copying */ sl@0: unsigned length; /* literal or length of data to copy */ sl@0: unsigned offset; /* distance back to copy string from */ sl@0: /* for table and code decoding */ sl@0: unsigned extra; /* extra bits needed */ sl@0: /* fixed and dynamic code tables */ sl@0: code const FAR *lencode; /* starting table for length/literal codes */ sl@0: code const FAR *distcode; /* starting table for distance codes */ sl@0: unsigned lenbits; /* index bits for lencode */ sl@0: unsigned distbits; /* index bits for distcode */ sl@0: /* dynamic table building */ sl@0: unsigned ncode; /* number of code length code lengths */ sl@0: unsigned nlen; /* number of length code lengths */ sl@0: unsigned ndist; /* number of distance code lengths */ sl@0: unsigned have; /* number of code lengths in lens[] */ sl@0: code FAR *next; /* next available space in codes[] */ sl@0: unsigned short lens[320]; /* temporary storage for code lengths */ sl@0: unsigned short work[288]; /* work area for code table building */ sl@0: code codes[ENOUGH]; /* space for code tables */ sl@0: };