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