1 | /* |
2 | * Copyright (c) 2008 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | /* inflate.h -- internal inflate state definition |
29 | * Copyright (C) 1995-2004 Mark Adler |
30 | * For conditions of distribution and use, see copyright notice in zlib.h |
31 | */ |
32 | |
33 | /* WARNING: this file should *not* be used by applications. It is |
34 | part of the implementation of the compression library and is |
35 | subject to change. Applications should only use zlib.h. |
36 | */ |
37 | |
38 | /* define NO_GZIP when compiling if you want to disable gzip header and |
39 | trailer decoding by inflate(). NO_GZIP would be used to avoid linking in |
40 | the crc code when it is not needed. For shared libraries, gzip decoding |
41 | should be left enabled. */ |
42 | #ifndef NO_GZIP |
43 | # define GUNZIP |
44 | #endif |
45 | |
46 | /* Possible inflate modes between inflate() calls */ |
47 | typedef enum { |
48 | HEAD, /* i: waiting for magic header */ |
49 | FLAGS, /* i: waiting for method and flags (gzip) */ |
50 | TIME, /* i: waiting for modification time (gzip) */ |
51 | OS, /* i: waiting for extra flags and operating system (gzip) */ |
52 | EXLEN, /* i: waiting for extra length (gzip) */ |
53 | , /* i: waiting for extra bytes (gzip) */ |
54 | NAME, /* i: waiting for end of file name (gzip) */ |
55 | , /* i: waiting for end of comment (gzip) */ |
56 | HCRC, /* i: waiting for header crc (gzip) */ |
57 | DICTID, /* i: waiting for dictionary check value */ |
58 | DICT, /* waiting for inflateSetDictionary() call */ |
59 | TYPE, /* i: waiting for type bits, including last-flag bit */ |
60 | TYPEDO, /* i: same, but skip check to exit inflate on new block */ |
61 | STORED, /* i: waiting for stored size (length and complement) */ |
62 | COPY, /* i/o: waiting for input or output to copy stored block */ |
63 | TABLE, /* i: waiting for dynamic block table lengths */ |
64 | LENLENS, /* i: waiting for code length code lengths */ |
65 | CODELENS, /* i: waiting for length/lit and distance code lengths */ |
66 | LEN, /* i: waiting for length/lit code */ |
67 | LENEXT, /* i: waiting for length extra bits */ |
68 | DIST, /* i: waiting for distance code */ |
69 | DISTEXT, /* i: waiting for distance extra bits */ |
70 | MATCH, /* o: waiting for output space to copy string */ |
71 | LIT, /* o: waiting for output space to write literal */ |
72 | CHECK, /* i: waiting for 32-bit check value */ |
73 | LENGTH, /* i: waiting for 32-bit length (gzip) */ |
74 | DONE, /* finished check, done -- remain here until reset */ |
75 | BAD, /* got a data error -- remain here until reset */ |
76 | MEM, /* got an inflate() memory error -- remain here until reset */ |
77 | SYNC /* looking for synchronization bytes to restart inflate() */ |
78 | } inflate_mode; |
79 | |
80 | /* |
81 | State transitions between above modes - |
82 | |
83 | (most modes can go to the BAD or MEM mode -- not shown for clarity) |
84 | |
85 | Process header: |
86 | HEAD -> (gzip) or (zlib) |
87 | (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME |
88 | NAME -> COMMENT -> HCRC -> TYPE |
89 | (zlib) -> DICTID or TYPE |
90 | DICTID -> DICT -> TYPE |
91 | Read deflate blocks: |
92 | TYPE -> STORED or TABLE or LEN or CHECK |
93 | STORED -> COPY -> TYPE |
94 | TABLE -> LENLENS -> CODELENS -> LEN |
95 | Read deflate codes: |
96 | LEN -> LENEXT or LIT or TYPE |
97 | LENEXT -> DIST -> DISTEXT -> MATCH -> LEN |
98 | LIT -> LEN |
99 | Process trailer: |
100 | CHECK -> LENGTH -> DONE |
101 | */ |
102 | |
103 | /* state maintained between inflate() calls. Approximately 7K bytes. */ |
104 | struct inflate_state { |
105 | inflate_mode mode; /* current inflate mode */ |
106 | int last; /* true if processing last block */ |
107 | int wrap; /* bit 0 true for zlib, bit 1 true for gzip */ |
108 | int havedict; /* true if dictionary provided */ |
109 | int flags; /* gzip header method and flags (0 if zlib) */ |
110 | unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */ |
111 | unsigned long check; /* protected copy of check value */ |
112 | unsigned long total; /* protected copy of output count */ |
113 | gz_headerp head; /* where to save gzip header information */ |
114 | /* sliding window */ |
115 | unsigned wbits; /* log base 2 of requested window size */ |
116 | unsigned wsize; /* window size or zero if not using window */ |
117 | unsigned whave; /* valid bytes in the window */ |
118 | unsigned write; /* window write index */ |
119 | unsigned char FAR *window; /* allocated sliding window, if needed */ |
120 | /* bit accumulator */ |
121 | unsigned long hold; /* input bit accumulator */ |
122 | unsigned bits; /* number of bits in "in" */ |
123 | /* for string and stored block copying */ |
124 | unsigned length; /* literal or length of data to copy */ |
125 | unsigned offset; /* distance back to copy string from */ |
126 | /* for table and code decoding */ |
127 | unsigned ; /* extra bits needed */ |
128 | /* fixed and dynamic code tables */ |
129 | code const FAR *lencode; /* starting table for length/literal codes */ |
130 | code const FAR *distcode; /* starting table for distance codes */ |
131 | unsigned lenbits; /* index bits for lencode */ |
132 | unsigned distbits; /* index bits for distcode */ |
133 | /* dynamic table building */ |
134 | unsigned ncode; /* number of code length code lengths */ |
135 | unsigned nlen; /* number of length code lengths */ |
136 | unsigned ndist; /* number of distance code lengths */ |
137 | unsigned have; /* number of code lengths in lens[] */ |
138 | code FAR *next; /* next available space in codes[] */ |
139 | unsigned short lens[320]; /* temporary storage for code lengths */ |
140 | unsigned short work[288]; /* work area for code table building */ |
141 | code codes[ENOUGH]; /* space for code tables */ |
142 | }; |
143 | |