nuclear@26: /* inflate.h -- internal inflate state definition nuclear@26: * Copyright (C) 1995-2004 Mark Adler nuclear@26: * For conditions of distribution and use, see copyright notice in zlib.h nuclear@26: */ nuclear@26: nuclear@26: /* WARNING: this file should *not* be used by applications. It is nuclear@26: part of the implementation of the compression library and is nuclear@26: subject to change. Applications should only use zlib.h. nuclear@26: */ nuclear@26: nuclear@26: /* define NO_GZIP when compiling if you want to disable gzip header and nuclear@26: trailer decoding by inflate(). NO_GZIP would be used to avoid linking in nuclear@26: the crc code when it is not needed. For shared libraries, gzip decoding nuclear@26: should be left enabled. */ nuclear@26: #ifndef NO_GZIP nuclear@26: # define GUNZIP nuclear@26: #endif nuclear@26: nuclear@26: /* Possible inflate modes between inflate() calls */ nuclear@26: typedef enum { nuclear@26: HEAD, /* i: waiting for magic header */ nuclear@26: FLAGS, /* i: waiting for method and flags (gzip) */ nuclear@26: TIME, /* i: waiting for modification time (gzip) */ nuclear@26: OS, /* i: waiting for extra flags and operating system (gzip) */ nuclear@26: EXLEN, /* i: waiting for extra length (gzip) */ nuclear@26: EXTRA, /* i: waiting for extra bytes (gzip) */ nuclear@26: NAME, /* i: waiting for end of file name (gzip) */ nuclear@26: COMMENT, /* i: waiting for end of comment (gzip) */ nuclear@26: HCRC, /* i: waiting for header crc (gzip) */ nuclear@26: DICTID, /* i: waiting for dictionary check value */ nuclear@26: DICT, /* waiting for inflateSetDictionary() call */ nuclear@26: TYPE, /* i: waiting for type bits, including last-flag bit */ nuclear@26: TYPEDO, /* i: same, but skip check to exit inflate on new block */ nuclear@26: STORED, /* i: waiting for stored size (length and complement) */ nuclear@26: COPY, /* i/o: waiting for input or output to copy stored block */ nuclear@26: TABLE, /* i: waiting for dynamic block table lengths */ nuclear@26: LENLENS, /* i: waiting for code length code lengths */ nuclear@26: CODELENS, /* i: waiting for length/lit and distance code lengths */ nuclear@26: LEN, /* i: waiting for length/lit code */ nuclear@26: LENEXT, /* i: waiting for length extra bits */ nuclear@26: DIST, /* i: waiting for distance code */ nuclear@26: DISTEXT, /* i: waiting for distance extra bits */ nuclear@26: MATCH, /* o: waiting for output space to copy string */ nuclear@26: LIT, /* o: waiting for output space to write literal */ nuclear@26: CHECK, /* i: waiting for 32-bit check value */ nuclear@26: LENGTH, /* i: waiting for 32-bit length (gzip) */ nuclear@26: DONE, /* finished check, done -- remain here until reset */ nuclear@26: BAD, /* got a data error -- remain here until reset */ nuclear@26: MEM, /* got an inflate() memory error -- remain here until reset */ nuclear@26: SYNC /* looking for synchronization bytes to restart inflate() */ nuclear@26: } inflate_mode; nuclear@26: nuclear@26: /* nuclear@26: State transitions between above modes - nuclear@26: nuclear@26: (most modes can go to the BAD or MEM mode -- not shown for clarity) nuclear@26: nuclear@26: Process header: nuclear@26: HEAD -> (gzip) or (zlib) nuclear@26: (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME nuclear@26: NAME -> COMMENT -> HCRC -> TYPE nuclear@26: (zlib) -> DICTID or TYPE nuclear@26: DICTID -> DICT -> TYPE nuclear@26: Read deflate blocks: nuclear@26: TYPE -> STORED or TABLE or LEN or CHECK nuclear@26: STORED -> COPY -> TYPE nuclear@26: TABLE -> LENLENS -> CODELENS -> LEN nuclear@26: Read deflate codes: nuclear@26: LEN -> LENEXT or LIT or TYPE nuclear@26: LENEXT -> DIST -> DISTEXT -> MATCH -> LEN nuclear@26: LIT -> LEN nuclear@26: Process trailer: nuclear@26: CHECK -> LENGTH -> DONE nuclear@26: */ nuclear@26: nuclear@26: /* state maintained between inflate() calls. Approximately 7K bytes. */ nuclear@26: struct inflate_state { nuclear@26: inflate_mode mode; /* current inflate mode */ nuclear@26: int last; /* true if processing last block */ nuclear@26: int wrap; /* bit 0 true for zlib, bit 1 true for gzip */ nuclear@26: int havedict; /* true if dictionary provided */ nuclear@26: int flags; /* gzip header method and flags (0 if zlib) */ nuclear@26: unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */ nuclear@26: unsigned long check; /* protected copy of check value */ nuclear@26: unsigned long total; /* protected copy of output count */ nuclear@26: gz_headerp head; /* where to save gzip header information */ nuclear@26: /* sliding window */ nuclear@26: unsigned wbits; /* log base 2 of requested window size */ nuclear@26: unsigned wsize; /* window size or zero if not using window */ nuclear@26: unsigned whave; /* valid bytes in the window */ nuclear@26: unsigned write; /* window write index */ nuclear@26: unsigned char FAR *window; /* allocated sliding window, if needed */ nuclear@26: /* bit accumulator */ nuclear@26: unsigned long hold; /* input bit accumulator */ nuclear@26: unsigned bits; /* number of bits in "in" */ nuclear@26: /* for string and stored block copying */ nuclear@26: unsigned length; /* literal or length of data to copy */ nuclear@26: unsigned offset; /* distance back to copy string from */ nuclear@26: /* for table and code decoding */ nuclear@26: unsigned extra; /* extra bits needed */ nuclear@26: /* fixed and dynamic code tables */ nuclear@26: code const FAR *lencode; /* starting table for length/literal codes */ nuclear@26: code const FAR *distcode; /* starting table for distance codes */ nuclear@26: unsigned lenbits; /* index bits for lencode */ nuclear@26: unsigned distbits; /* index bits for distcode */ nuclear@26: /* dynamic table building */ nuclear@26: unsigned ncode; /* number of code length code lengths */ nuclear@26: unsigned nlen; /* number of length code lengths */ nuclear@26: unsigned ndist; /* number of distance code lengths */ nuclear@26: unsigned have; /* number of code lengths in lens[] */ nuclear@26: code FAR *next; /* next available space in codes[] */ nuclear@26: unsigned short lens[320]; /* temporary storage for code lengths */ nuclear@26: unsigned short work[288]; /* work area for code table building */ nuclear@26: code codes[ENOUGH]; /* space for code tables */ nuclear@26: };