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 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. */ 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; /* 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