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author | Mark Adler <madler@alumni.caltech.edu> | 2011-09-09 23:21:47 -0700 |
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committer | Mark Adler <madler@alumni.caltech.edu> | 2011-09-09 23:21:47 -0700 |
commit | 7c2a874e50b871d04fbd19501f7b42cff55e5abc (patch) | |
tree | 1879cd29182ababb17cde77cee5ce74505db4006 /inflate.h | |
parent | a383133c4e7b93113cee912f213cf9502d785fa7 (diff) | |
download | zlib-7c2a874e50b871d04fbd19501f7b42cff55e5abc.tar.gz zlib-7c2a874e50b871d04fbd19501f7b42cff55e5abc.tar.bz2 zlib-7c2a874e50b871d04fbd19501f7b42cff55e5abc.zip |
zlib 1.2.0v1.2.0
Diffstat (limited to 'inflate.h')
-rw-r--r-- | inflate.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/inflate.h b/inflate.h new file mode 100644 index 0000000..5bcc82b --- /dev/null +++ b/inflate.h | |||
@@ -0,0 +1,115 @@ | |||
1 | /* inflate.h -- internal inflate state definition | ||
2 | * Copyright (C) 1995-2003 Mark Adler | ||
3 | * For conditions of distribution and use, see copyright notice in zlib.h | ||
4 | */ | ||
5 | |||
6 | /* WARNING: this file should *not* be used by applications. It is | ||
7 | part of the implementation of the compression library and is | ||
8 | subject to change. Applications should only use zlib.h. | ||
9 | */ | ||
10 | |||
11 | /* define NO_GUNZIP when compiling if you want to disable gzip header and | ||
12 | trailer decoding by inflate(). NO_GUNZIP would be used to avoid linking in | ||
13 | the crc code when it is not needed. For shared libraries, gzip decoding | ||
14 | should be left enabled. */ | ||
15 | #ifndef NO_GUNZIP | ||
16 | # define GUNZIP | ||
17 | #endif | ||
18 | |||
19 | /* Possible inflate modes between inflate() calls */ | ||
20 | typedef enum { | ||
21 | HEAD, /* i: waiting for magic header */ | ||
22 | #ifdef GUNZIP | ||
23 | FLAGS, /* i: waiting for method and flags (gzip) */ | ||
24 | TIME, /* i: waiting for modification time (gzip) */ | ||
25 | OS, /* i: waiting for extra flags and operating system (gzip) */ | ||
26 | EXLEN, /* i: waiting for extra length (gzip) */ | ||
27 | EXTRA, /* i: waiting for extra bytes (gzip) */ | ||
28 | NAME, /* i: waiting for end of file name (gzip) */ | ||
29 | COMMENT, /* i: waiting for end of comment (gzip) */ | ||
30 | HCRC, /* i: waiting for header crc (gzip) */ | ||
31 | #endif | ||
32 | DICTID, /* i: waiting for dictionary check value */ | ||
33 | DICT, /* waiting for inflateSetDictionary() call */ | ||
34 | TYPE, /* i: waiting for type bits, including last-flag bit */ | ||
35 | STORED, /* i: waiting for stored size (length and complement) */ | ||
36 | COPY, /* i/o: waiting for input or output to copy stored block */ | ||
37 | TABLE, /* i: waiting for dynamic block table lengths */ | ||
38 | LENLENS, /* i: waiting for code length code lengths */ | ||
39 | CODELENS, /* i: waiting for length/lit and distance code lengths */ | ||
40 | LEN, /* i: waiting for length/lit code */ | ||
41 | LENEXT, /* i: waiting for length extra bits */ | ||
42 | DIST, /* i: waiting for distance code */ | ||
43 | DISTEXT, /* i: waiting for distance extra bits */ | ||
44 | MATCH, /* o: waiting for output space to copy string */ | ||
45 | LIT, /* o: waiting for output space to write literal */ | ||
46 | CHECK, /* i: waiting for 32-bit check value */ | ||
47 | #ifdef GUNZIP | ||
48 | LENGTH, /* i: waiting for 32-bit length (gzip) */ | ||
49 | #endif | ||
50 | DONE, /* finished check, done -- remain here until reset */ | ||
51 | BAD, /* got a data error -- remain here until reset */ | ||
52 | MEM, /* got an inflate() memory error -- remain here until reset */ | ||
53 | SYNC /* looking for synchronization bytes to restart inflate() */ | ||
54 | } inflate_mode; | ||
55 | |||
56 | /* | ||
57 | State transitions between above modes - | ||
58 | |||
59 | (most modes can go to the BAD or MEM mode -- not shown for clarity) | ||
60 | |||
61 | Process header: | ||
62 | HEAD -> (gzip) or (zlib) | ||
63 | (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME | ||
64 | NAME -> COMMENT -> HCRC -> TYPE | ||
65 | (zlib) -> DICTID or TYPE | ||
66 | DICTID -> DICT -> TYPE | ||
67 | Read deflate blocks: | ||
68 | TYPE -> STORED or TABLE or LEN or CHECK | ||
69 | STORED -> COPY -> TYPE | ||
70 | TABLE -> LENLENS -> CODELENS -> LEN | ||
71 | Read deflate codes: | ||
72 | LEN -> LENEXT or LIT or TYPE | ||
73 | LENEXT -> DIST -> DISTEXT -> MATCH -> LEN | ||
74 | LIT -> LEN | ||
75 | Process trailer: | ||
76 | CHECK -> LENGTH -> DONE | ||
77 | */ | ||
78 | |||
79 | /* state maintained between inflate() calls. Approximately 7K bytes. */ | ||
80 | struct inflate_state { | ||
81 | inflate_mode mode; /* current inflate mode */ | ||
82 | int last; /* true if processing last block */ | ||
83 | int wrap; /* true to process header and trailer */ | ||
84 | int havedict; /* true if dictionary provided */ | ||
85 | int flags; /* gzip header method and flags (0 if zlib) */ | ||
86 | unsigned long check; /* protected copy of check value */ | ||
87 | unsigned long total; /* protected copy of output count */ | ||
88 | /* sliding window */ | ||
89 | unsigned wbits; /* log base 2 of requested window size */ | ||
90 | unsigned wsize; /* window size or zero if not using window */ | ||
91 | unsigned write; /* window write index */ | ||
92 | unsigned char FAR *window; /* allocated sliding window, if needed */ | ||
93 | /* bit accumulator */ | ||
94 | unsigned long hold; /* input bit accumulator */ | ||
95 | unsigned bits; /* number of bits in "in" */ | ||
96 | /* for string and stored block copying */ | ||
97 | unsigned length; /* literal or length of data to copy */ | ||
98 | unsigned offset; /* distance back to copy string from */ | ||
99 | /* for table and code decoding */ | ||
100 | unsigned extra; /* extra bits needed */ | ||
101 | /* fixed and dynamic code tables */ | ||
102 | code const FAR *lencode; /* starting table for length/literal codes */ | ||
103 | code const FAR *distcode; /* starting table for distance codes */ | ||
104 | unsigned lenbits; /* index bits for lencode */ | ||
105 | unsigned distbits; /* index bits for distcode */ | ||
106 | /* dynamic table building */ | ||
107 | unsigned ncode; /* number of code length code lengths */ | ||
108 | unsigned nlen; /* number of length code lengths */ | ||
109 | unsigned ndist; /* number of distance code lengths */ | ||
110 | unsigned have; /* number of code lengths in lens[] */ | ||
111 | code FAR *next; /* next available space in codes[] */ | ||
112 | unsigned short lens[320]; /* temporary storage for code lengths */ | ||
113 | unsigned short work[288]; /* work area for code table building */ | ||
114 | code codes[ENOUGH]; /* space for code tables */ | ||
115 | }; | ||