dbf-halloween2015

annotate libs/zlib/inflate.h @ 3:c37fe5d8a4ed

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windows port
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 01 Nov 2015 06:04:28 +0200
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nuclear@1 1 /* inflate.h -- internal inflate state definition
nuclear@1 2 * Copyright (C) 1995-2004 Mark Adler
nuclear@1 3 * For conditions of distribution and use, see copyright notice in zlib.h
nuclear@1 4 */
nuclear@1 5
nuclear@1 6 /* WARNING: this file should *not* be used by applications. It is
nuclear@1 7 part of the implementation of the compression library and is
nuclear@1 8 subject to change. Applications should only use zlib.h.
nuclear@1 9 */
nuclear@1 10
nuclear@1 11 /* define NO_GZIP when compiling if you want to disable gzip header and
nuclear@1 12 trailer decoding by inflate(). NO_GZIP would be used to avoid linking in
nuclear@1 13 the crc code when it is not needed. For shared libraries, gzip decoding
nuclear@1 14 should be left enabled. */
nuclear@1 15 #ifndef NO_GZIP
nuclear@1 16 # define GUNZIP
nuclear@1 17 #endif
nuclear@1 18
nuclear@1 19 /* Possible inflate modes between inflate() calls */
nuclear@1 20 typedef enum {
nuclear@1 21 HEAD, /* i: waiting for magic header */
nuclear@1 22 FLAGS, /* i: waiting for method and flags (gzip) */
nuclear@1 23 TIME, /* i: waiting for modification time (gzip) */
nuclear@1 24 OS, /* i: waiting for extra flags and operating system (gzip) */
nuclear@1 25 EXLEN, /* i: waiting for extra length (gzip) */
nuclear@1 26 EXTRA, /* i: waiting for extra bytes (gzip) */
nuclear@1 27 NAME, /* i: waiting for end of file name (gzip) */
nuclear@1 28 COMMENT, /* i: waiting for end of comment (gzip) */
nuclear@1 29 HCRC, /* i: waiting for header crc (gzip) */
nuclear@1 30 DICTID, /* i: waiting for dictionary check value */
nuclear@1 31 DICT, /* waiting for inflateSetDictionary() call */
nuclear@1 32 TYPE, /* i: waiting for type bits, including last-flag bit */
nuclear@1 33 TYPEDO, /* i: same, but skip check to exit inflate on new block */
nuclear@1 34 STORED, /* i: waiting for stored size (length and complement) */
nuclear@1 35 COPY, /* i/o: waiting for input or output to copy stored block */
nuclear@1 36 TABLE, /* i: waiting for dynamic block table lengths */
nuclear@1 37 LENLENS, /* i: waiting for code length code lengths */
nuclear@1 38 CODELENS, /* i: waiting for length/lit and distance code lengths */
nuclear@1 39 LEN, /* i: waiting for length/lit code */
nuclear@1 40 LENEXT, /* i: waiting for length extra bits */
nuclear@1 41 DIST, /* i: waiting for distance code */
nuclear@1 42 DISTEXT, /* i: waiting for distance extra bits */
nuclear@1 43 MATCH, /* o: waiting for output space to copy string */
nuclear@1 44 LIT, /* o: waiting for output space to write literal */
nuclear@1 45 CHECK, /* i: waiting for 32-bit check value */
nuclear@1 46 LENGTH, /* i: waiting for 32-bit length (gzip) */
nuclear@1 47 DONE, /* finished check, done -- remain here until reset */
nuclear@1 48 BAD, /* got a data error -- remain here until reset */
nuclear@1 49 MEM, /* got an inflate() memory error -- remain here until reset */
nuclear@1 50 SYNC /* looking for synchronization bytes to restart inflate() */
nuclear@1 51 } inflate_mode;
nuclear@1 52
nuclear@1 53 /*
nuclear@1 54 State transitions between above modes -
nuclear@1 55
nuclear@1 56 (most modes can go to the BAD or MEM mode -- not shown for clarity)
nuclear@1 57
nuclear@1 58 Process header:
nuclear@1 59 HEAD -> (gzip) or (zlib)
nuclear@1 60 (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
nuclear@1 61 NAME -> COMMENT -> HCRC -> TYPE
nuclear@1 62 (zlib) -> DICTID or TYPE
nuclear@1 63 DICTID -> DICT -> TYPE
nuclear@1 64 Read deflate blocks:
nuclear@1 65 TYPE -> STORED or TABLE or LEN or CHECK
nuclear@1 66 STORED -> COPY -> TYPE
nuclear@1 67 TABLE -> LENLENS -> CODELENS -> LEN
nuclear@1 68 Read deflate codes:
nuclear@1 69 LEN -> LENEXT or LIT or TYPE
nuclear@1 70 LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
nuclear@1 71 LIT -> LEN
nuclear@1 72 Process trailer:
nuclear@1 73 CHECK -> LENGTH -> DONE
nuclear@1 74 */
nuclear@1 75
nuclear@1 76 /* state maintained between inflate() calls. Approximately 7K bytes. */
nuclear@1 77 struct inflate_state {
nuclear@1 78 inflate_mode mode; /* current inflate mode */
nuclear@1 79 int last; /* true if processing last block */
nuclear@1 80 int wrap; /* bit 0 true for zlib, bit 1 true for gzip */
nuclear@1 81 int havedict; /* true if dictionary provided */
nuclear@1 82 int flags; /* gzip header method and flags (0 if zlib) */
nuclear@1 83 unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */
nuclear@1 84 unsigned long check; /* protected copy of check value */
nuclear@1 85 unsigned long total; /* protected copy of output count */
nuclear@1 86 gz_headerp head; /* where to save gzip header information */
nuclear@1 87 /* sliding window */
nuclear@1 88 unsigned wbits; /* log base 2 of requested window size */
nuclear@1 89 unsigned wsize; /* window size or zero if not using window */
nuclear@1 90 unsigned whave; /* valid bytes in the window */
nuclear@1 91 unsigned write; /* window write index */
nuclear@1 92 unsigned char FAR *window; /* allocated sliding window, if needed */
nuclear@1 93 /* bit accumulator */
nuclear@1 94 unsigned long hold; /* input bit accumulator */
nuclear@1 95 unsigned bits; /* number of bits in "in" */
nuclear@1 96 /* for string and stored block copying */
nuclear@1 97 unsigned length; /* literal or length of data to copy */
nuclear@1 98 unsigned offset; /* distance back to copy string from */
nuclear@1 99 /* for table and code decoding */
nuclear@1 100 unsigned extra; /* extra bits needed */
nuclear@1 101 /* fixed and dynamic code tables */
nuclear@1 102 code const FAR *lencode; /* starting table for length/literal codes */
nuclear@1 103 code const FAR *distcode; /* starting table for distance codes */
nuclear@1 104 unsigned lenbits; /* index bits for lencode */
nuclear@1 105 unsigned distbits; /* index bits for distcode */
nuclear@1 106 /* dynamic table building */
nuclear@1 107 unsigned ncode; /* number of code length code lengths */
nuclear@1 108 unsigned nlen; /* number of length code lengths */
nuclear@1 109 unsigned ndist; /* number of distance code lengths */
nuclear@1 110 unsigned have; /* number of code lengths in lens[] */
nuclear@1 111 code FAR *next; /* next available space in codes[] */
nuclear@1 112 unsigned short lens[320]; /* temporary storage for code lengths */
nuclear@1 113 unsigned short work[288]; /* work area for code table building */
nuclear@1 114 code codes[ENOUGH]; /* space for code tables */
nuclear@1 115 };