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