1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. Oracle designates this 7 * particular file as subject to the "Classpath" exception as provided 8 * by Oracle in the LICENSE file that accompanied this code. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25 /* inflate.h -- internal inflate state definition 26 * Copyright (C) 1995-2016 Mark Adler 27 * For conditions of distribution and use, see copyright notice in zlib.h 28 */ 29 30 /* WARNING: this file should *not* be used by applications. It is 31 part of the implementation of the compression library and is 32 subject to change. Applications should only use zlib.h. 33 */ 34 35 /* define NO_GZIP when compiling if you want to disable gzip header and 36 trailer decoding by inflate(). NO_GZIP would be used to avoid linking in 37 the crc code when it is not needed. For shared libraries, gzip decoding 38 should be left enabled. */ 39 #ifndef NO_GZIP 40 # define GUNZIP 41 #endif 42 43 /* Possible inflate modes between inflate() calls */ 44 typedef enum { 45 HEAD = 16180, /* i: waiting for magic header */ 46 FLAGS, /* i: waiting for method and flags (gzip) */ 47 TIME, /* i: waiting for modification time (gzip) */ 48 OS, /* i: waiting for extra flags and operating system (gzip) */ 49 EXLEN, /* i: waiting for extra length (gzip) */ 50 EXTRA, /* i: waiting for extra bytes (gzip) */ 51 NAME, /* i: waiting for end of file name (gzip) */ 52 COMMENT, /* i: waiting for end of comment (gzip) */ 53 HCRC, /* i: waiting for header crc (gzip) */ 54 DICTID, /* i: waiting for dictionary check value */ 55 DICT, /* waiting for inflateSetDictionary() call */ 56 TYPE, /* i: waiting for type bits, including last-flag bit */ 57 TYPEDO, /* i: same, but skip check to exit inflate on new block */ 58 STORED, /* i: waiting for stored size (length and complement) */ 59 COPY_, /* i/o: same as COPY below, but only first time in */ 60 COPY, /* i/o: waiting for input or output to copy stored block */ 61 TABLE, /* i: waiting for dynamic block table lengths */ 62 LENLENS, /* i: waiting for code length code lengths */ 63 CODELENS, /* i: waiting for length/lit and distance code lengths */ 64 LEN_, /* i: same as LEN below, but only first time in */ 65 LEN, /* i: waiting for length/lit/eob code */ 66 LENEXT, /* i: waiting for length extra bits */ 67 DIST, /* i: waiting for distance code */ 68 DISTEXT, /* i: waiting for distance extra bits */ 69 MATCH, /* o: waiting for output space to copy string */ 70 LIT, /* o: waiting for output space to write literal */ 71 CHECK, /* i: waiting for 32-bit check value */ 72 LENGTH, /* i: waiting for 32-bit length (gzip) */ 73 DONE, /* finished check, done -- remain here until reset */ 74 BAD, /* got a data error -- remain here until reset */ 75 MEM, /* got an inflate() memory error -- remain here until reset */ 76 SYNC /* looking for synchronization bytes to restart inflate() */ 77 } inflate_mode; 78 79 /* 80 State transitions between above modes - 81 82 (most modes can go to BAD or MEM on error -- not shown for clarity) 83 84 Process header: 85 HEAD -> (gzip) or (zlib) or (raw) 86 (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME -> COMMENT -> 87 HCRC -> TYPE 88 (zlib) -> DICTID or TYPE 89 DICTID -> DICT -> TYPE 90 (raw) -> TYPEDO 91 Read deflate blocks: 92 TYPE -> TYPEDO -> STORED or TABLE or LEN_ or CHECK 93 STORED -> COPY_ -> COPY -> TYPE 94 TABLE -> LENLENS -> CODELENS -> LEN_ 95 LEN_ -> LEN 96 Read deflate codes in fixed or dynamic block: 97 LEN -> LENEXT or LIT or TYPE 98 LENEXT -> DIST -> DISTEXT -> MATCH -> LEN 99 LIT -> LEN 100 Process trailer: 101 CHECK -> LENGTH -> DONE 102 */ 103 104 /* State maintained between inflate() calls -- approximately 7K bytes, not 105 including the allocated sliding window, which is up to 32K bytes. */ 106 struct inflate_state { 107 z_streamp strm; /* pointer back to this zlib stream */ 108 inflate_mode mode; /* current inflate mode */ 109 int last; /* true if processing last block */ 110 int wrap; /* bit 0 true for zlib, bit 1 true for gzip, 111 bit 2 true to validate check value */ 112 int havedict; /* true if dictionary provided */ 113 int flags; /* gzip header method and flags (0 if zlib) */ 114 unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */ 115 unsigned long check; /* protected copy of check value */ 116 unsigned long total; /* protected copy of output count */ 117 gz_headerp head; /* where to save gzip header information */ 118 /* sliding window */ 119 unsigned wbits; /* log base 2 of requested window size */ 120 unsigned wsize; /* window size or zero if not using window */ 121 unsigned whave; /* valid bytes in the window */ 122 unsigned wnext; /* window write index */ 123 unsigned char FAR *window; /* allocated sliding window, if needed */ 124 /* bit accumulator */ 125 unsigned long hold; /* input bit accumulator */ 126 unsigned bits; /* number of bits in "in" */ 127 /* for string and stored block copying */ 128 unsigned length; /* literal or length of data to copy */ 129 unsigned offset; /* distance back to copy string from */ 130 /* for table and code decoding */ 131 unsigned extra; /* extra bits needed */ 132 /* fixed and dynamic code tables */ 133 code const FAR *lencode; /* starting table for length/literal codes */ 134 code const FAR *distcode; /* starting table for distance codes */ 135 unsigned lenbits; /* index bits for lencode */ 136 unsigned distbits; /* index bits for distcode */ 137 /* dynamic table building */ 138 unsigned ncode; /* number of code length code lengths */ 139 unsigned nlen; /* number of length code lengths */ 140 unsigned ndist; /* number of distance code lengths */ 141 unsigned have; /* number of code lengths in lens[] */ 142 code FAR *next; /* next available space in codes[] */ 143 unsigned short lens[320]; /* temporary storage for code lengths */ 144 unsigned short work[288]; /* work area for code table building */ 145 code codes[ENOUGH]; /* space for code tables */ 146 int sane; /* if false, allow invalid distance too far */ 147 int back; /* bits back of last unprocessed length/lit */ 148 unsigned was; /* initial length of match */ 149 };