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 */
47typedef 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 EXTRA, /* i: waiting for extra bytes (gzip) */
54 NAME, /* i: waiting for end of file name (gzip) */
55 COMMENT, /* 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. */
104struct 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; /* 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