| Geant4 Cross Reference |
1 /* inflate.h -- internal inflate state definit 1
2 * Copyright (C) 1995-2019 Mark Adler
3 * For conditions of distribution and use, see
4 */
5
6 /* WARNING: this file should *not* be used by
7 part of the implementation of the compressi
8 subject to change. Applications should only
9 */
10
11 /* define NO_GZIP when compiling if you want t
12 trailer decoding by inflate(). NO_GZIP wou
13 the crc code when it is not needed. For sh
14 should be left enabled. */
15 #ifndef NO_GZIP
16 # define GUNZIP
17 #endif
18
19 /* Possible inflate modes between inflate() ca
20 typedef enum {
21 HEAD = 16180, /* i: waiting for magic he
22 FLAGS, /* i: waiting for method and f
23 TIME, /* i: waiting for modification
24 OS, /* i: waiting for extra flags
25 EXLEN, /* i: waiting for extra length
26 EXTRA, /* i: waiting for extra bytes
27 NAME, /* i: waiting for end of file
28 COMMENT, /* i: waiting for end of comme
29 HCRC, /* i: waiting for header crc (
30 DICTID, /* i: waiting for dictionary c
31 DICT, /* waiting for inflateSetDicti
32 TYPE, /* i: waiting for type bit
33 TYPEDO, /* i: same, but skip check
34 STORED, /* i: waiting for stored s
35 COPY_, /* i/o: same as COPY below
36 COPY, /* i/o: waiting for input
37 TABLE, /* i: waiting for dynamic
38 LENLENS, /* i: waiting for code len
39 CODELENS, /* i: waiting for length/l
40 LEN_, /* i: same as LEN belo
41 LEN, /* i: waiting for leng
42 LENEXT, /* i: waiting for leng
43 DIST, /* i: waiting for dist
44 DISTEXT, /* i: waiting for dist
45 MATCH, /* o: waiting for outp
46 LIT, /* o: waiting for outp
47 CHECK, /* i: waiting for 32-bit check
48 LENGTH, /* i: waiting for 32-bit lengt
49 DONE, /* finished check, done -- rem
50 BAD, /* got a data error -- remain
51 MEM, /* got an inflate() memory err
52 SYNC /* looking for synchronization
53 } inflate_mode;
54
55 /*
56 State transitions between above modes -
57
58 (most modes can go to BAD or MEM on error
59
60 Process header:
61 HEAD -> (gzip) or (zlib) or (raw)
62 (gzip) -> FLAGS -> TIME -> OS -> EXLEN
63 HCRC -> TYPE
64 (zlib) -> DICTID or TYPE
65 DICTID -> DICT -> TYPE
66 (raw) -> TYPEDO
67 Read deflate blocks:
68 TYPE -> TYPEDO -> STORED or TABLE
69 STORED -> COPY_ -> COPY -> TYPE
70 TABLE -> LENLENS -> CODELENS -> LE
71 LEN_ -> LEN
72 Read deflate codes in fixed or dynamic blo
73 LEN -> LENEXT or LIT or TYPE
74 LENEXT -> DIST -> DISTEXT -> M
75 LIT -> LEN
76 Process trailer:
77 CHECK -> LENGTH -> DONE
78 */
79
80 /* State maintained between inflate() calls --
81 including the allocated sliding window, whi
82 struct inflate_state {
83 z_streamp strm; /* pointer bac
84 inflate_mode mode; /* current inf
85 int last; /* true if pro
86 int wrap; /* bit 0 true
87 bit 2 true
88 int havedict; /* true if dic
89 int flags; /* gzip header
90 -1 if raw o
91 unsigned dmax; /* zlib header
92 unsigned long check; /* protected c
93 unsigned long total; /* protected c
94 gz_headerp head; /* where to sa
95 /* sliding window */
96 unsigned wbits; /* log base 2
97 unsigned wsize; /* window size
98 unsigned whave; /* valid bytes
99 unsigned wnext; /* window writ
100 unsigned char FAR *window; /* allocated s
101 /* bit accumulator */
102 unsigned long hold; /* input bit a
103 unsigned bits; /* number of b
104 /* for string and stored block copying
105 unsigned length; /* literal or
106 unsigned offset; /* distance ba
107 /* for table and code decoding */
108 unsigned extra; /* extra bits
109 /* fixed and dynamic code tables */
110 code const FAR *lencode; /* starting ta
111 code const FAR *distcode; /* starting ta
112 unsigned lenbits; /* index bits
113 unsigned distbits; /* index bits
114 /* dynamic table building */
115 unsigned ncode; /* number of c
116 unsigned nlen; /* number of l
117 unsigned ndist; /* number of d
118 unsigned have; /* number of c
119 code FAR *next; /* next availa
120 unsigned short lens[320]; /* temporary s
121 unsigned short work[288]; /* work area f
122 code codes[ENOUGH]; /* space for c
123 int sane; /* if false, a
124 int back; /* bits back o
125 unsigned was; /* initial len
126 };
127