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inflate.h
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1 /* +---------------------------------------------------------------------------+
2  | Mobile Robot Programming Toolkit (MRPT) |
3  | http://www.mrpt.org/ |
4  | |
5  | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file |
6  | See: http://www.mrpt.org/Authors - All rights reserved. |
7  | Released under BSD License. See details in http://www.mrpt.org/License |
8  +---------------------------------------------------------------------------+ */
9 
10 /* WARNING: this file should *not* be used by applications. It is
11  part of the implementation of the compression library and is
12  subject to change. Applications should only use zlib.h.
13  */
14 
15 /* define NO_GZIP when compiling if you want to disable gzip header and
16  trailer decoding by inflate(). NO_GZIP would be used to avoid linking in
17  the crc code when it is not needed. For shared libraries, gzip decoding
18  should be left enabled. */
19 #ifndef NO_GZIP
20 # define GUNZIP
21 #endif
22 
23 /* Possible inflate modes between inflate() calls */
24 typedef enum {
25  HEAD, /* i: waiting for magic header */
26  FLAGS, /* i: waiting for method and flags (gzip) */
27  TIME, /* i: waiting for modification time (gzip) */
28  OS, /* i: waiting for extra flags and operating system (gzip) */
29  EXLEN, /* i: waiting for extra length (gzip) */
30  EXTRA, /* i: waiting for extra bytes (gzip) */
31  NAME, /* i: waiting for end of file name (gzip) */
32  COMMENT, /* i: waiting for end of comment (gzip) */
33  HCRC, /* i: waiting for header crc (gzip) */
34  DICTID, /* i: waiting for dictionary check value */
35  DICT, /* waiting for inflateSetDictionary() call */
36  TYPE, /* i: waiting for type bits, including last-flag bit */
37  TYPEDO, /* i: same, but skip check to exit inflate on new block */
38  STORED, /* i: waiting for stored size (length and complement) */
39  COPY, /* i/o: waiting for input or output to copy stored block */
40  TABLE, /* i: waiting for dynamic block table lengths */
41  LENLENS, /* i: waiting for code length code lengths */
42  CODELENS, /* i: waiting for length/lit and distance code lengths */
43  LEN, /* i: waiting for length/lit code */
44  LENEXT, /* i: waiting for length extra bits */
45  DIST, /* i: waiting for distance code */
46  DISTEXT, /* i: waiting for distance extra bits */
47  MATCH, /* o: waiting for output space to copy string */
48  LIT, /* o: waiting for output space to write literal */
49  CHECK, /* i: waiting for 32-bit check value */
50  LENGTH, /* i: waiting for 32-bit length (gzip) */
51  DONE, /* finished check, done -- remain here until reset */
52  BAD, /* got a data error -- remain here until reset */
53  MEM, /* got an inflate() memory error -- remain here until reset */
54  SYNC /* looking for synchronization bytes to restart inflate() */
55 } inflate_mode;
56 
57 /*
58  State transitions between above modes -
59 
60  (most modes can go to the BAD or MEM mode -- not shown for clarity)
61 
62  Process header:
63  HEAD -> (gzip) or (zlib)
64  (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME
65  NAME -> COMMENT -> HCRC -> TYPE
66  (zlib) -> DICTID or TYPE
67  DICTID -> DICT -> TYPE
68  Read deflate blocks:
69  TYPE -> STORED or TABLE or LEN or CHECK
70  STORED -> COPY -> TYPE
71  TABLE -> LENLENS -> CODELENS -> LEN
72  Read deflate codes:
73  LEN -> LENEXT or LIT or TYPE
74  LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
75  LIT -> LEN
76  Process trailer:
77  CHECK -> LENGTH -> DONE
78  */
79 
80 /* state maintained between inflate() calls. Approximately 7K bytes. */
81 struct inflate_state {
82  inflate_mode mode; /* current inflate mode */
83  int last; /* true if processing last block */
84  int wrap; /* bit 0 true for zlib, bit 1 true for gzip */
85  int havedict; /* true if dictionary provided */
86  int flags; /* gzip header method and flags (0 if zlib) */
87  unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */
88  unsigned long check; /* protected copy of check value */
89  unsigned long total; /* protected copy of output count */
90  gz_headerp head; /* where to save gzip header information */
91  /* sliding window */
92  unsigned wbits; /* log base 2 of requested window size */
93  unsigned wsize; /* window size or zero if not using window */
94  unsigned whave; /* valid bytes in the window */
95  unsigned write; /* window write index */
96  unsigned char FAR *window; /* allocated sliding window, if needed */
97  /* bit accumulator */
98  unsigned long hold; /* input bit accumulator */
99  unsigned bits; /* number of bits in "in" */
100  /* for string and stored block copying */
101  unsigned length; /* literal or length of data to copy */
102  unsigned offset; /* distance back to copy string from */
103  /* for table and code decoding */
104  unsigned extra; /* extra bits needed */
105  /* fixed and dynamic code tables */
106  code const FAR *lencode; /* starting table for length/literal codes */
107  code const FAR *distcode; /* starting table for distance codes */
108  unsigned lenbits; /* index bits for lencode */
109  unsigned distbits; /* index bits for distcode */
110  /* dynamic table building */
111  unsigned ncode; /* number of code length code lengths */
112  unsigned nlen; /* number of length code lengths */
113  unsigned ndist; /* number of distance code lengths */
114  unsigned have; /* number of code lengths in lens[] */
115  code FAR *next; /* next available space in codes[] */
116  unsigned short lens[320]; /* temporary storage for code lengths */
117  unsigned short work[288]; /* work area for code table building */
118  code codes[ENOUGH]; /* space for code tables */
119 };
unsigned nlen
Definition: inflate.h:112
Definition: inflate.h:39
int havedict
Definition: inflate.h:85
Definition: inflate.h:38
unsigned ndist
Definition: inflate.h:113
unsigned long total
Definition: inflate.h:89
gz_headerp head
Definition: inflate.h:90
unsigned wsize
Definition: inflate.h:93
unsigned have
Definition: inflate.h:114
unsigned distbits
Definition: inflate.h:109
#define ENOUGH
Definition: inftrees.h:47
unsigned extra
Definition: inflate.h:104
code const FAR * distcode
Definition: inflate.h:107
unsigned long check
Definition: inflate.h:88
Definition: inflate.h:51
Definition: inflate.h:31
Definition: inflate.h:36
Definition: inflate.h:34
gz_header FAR * gz_headerp
Definition: zlib.h:105
Definition: inflate.h:28
unsigned lenbits
Definition: inflate.h:108
unsigned short lens[320]
Definition: inflate.h:116
Definition: inflate.h:43
unsigned ncode
Definition: inflate.h:111
Definition: inflate.h:40
Definition: inflate.h:50
code FAR * next
Definition: inflate.h:115
Definition: inflate.h:54
Definition: inflate.h:30
code codes[ENOUGH]
Definition: inflate.h:118
unsigned long hold
Definition: inflate.h:98
Definition: inflate.h:49
Definition: inflate.h:44
Definition: inflate.h:48
Definition: inflate.h:27
Definition: inflate.h:35
unsigned short work[288]
Definition: inflate.h:117
Definition: inflate.h:33
Definition: inflate.h:25
unsigned write
Definition: inflate.h:95
Definition: inftrees.h:28
unsigned dmax
Definition: inflate.h:87
unsigned bits
Definition: inflate.h:99
Definition: inflate.h:47
Definition: inflate.h:37
inflate_mode
Definition: inflate.h:24
Definition: inflate.h:29
unsigned char FAR * window
Definition: inflate.h:96
inflate_mode mode
Definition: inflate.h:82
Definition: inflate.h:52
unsigned whave
Definition: inflate.h:94
#define FAR
Definition: zconf.h:261
unsigned offset
Definition: inflate.h:102
Definition: inflate.h:45
code const FAR * lencode
Definition: inflate.h:106
Definition: inflate.h:26
unsigned wbits
Definition: inflate.h:92
Definition: inflate.h:53
unsigned length
Definition: inflate.h:101



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