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