Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
Erik Andersen | 61677fe | 2000-04-13 01:18:56 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Gzip implementation for busybox |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 4 | * |
Erik Andersen | 61677fe | 2000-04-13 01:18:56 +0000 | [diff] [blame] | 5 | * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly. |
| 6 | * |
| 7 | * Originally adjusted for busybox by Charles P. Wright <cpw@unix.asb.com> |
| 8 | * "this is a stripped down version of gzip I put into busybox, it does |
| 9 | * only standard in to standard out with -9 compression. It also requires |
| 10 | * the zcat module for some important functions." |
| 11 | * |
| 12 | * Adjusted further by Erik Andersen <andersen@lineo.com>, <andersee@debian.org> |
| 13 | * to support files as well as stdin/stdout, and to generally behave itself wrt |
| 14 | * command line handling. |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or modify |
| 17 | * it under the terms of the GNU General Public License as published by |
| 18 | * the Free Software Foundation; either version 2 of the License, or |
| 19 | * (at your option) any later version. |
| 20 | * |
| 21 | * This program is distributed in the hope that it will be useful, |
| 22 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 23 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 24 | * General Public License for more details. |
| 25 | * |
| 26 | * You should have received a copy of the GNU General Public License |
| 27 | * along with this program; if not, write to the Free Software |
| 28 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 29 | * |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 30 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 31 | |
Erik Andersen | 61677fe | 2000-04-13 01:18:56 +0000 | [diff] [blame] | 32 | /* These defines are very important for BusyBox. Without these, |
| 33 | * huge chunks of ram are pre-allocated making the BusyBox bss |
| 34 | * size Freaking Huge(tm), which is a bad thing.*/ |
| 35 | #define SMALL_MEM |
| 36 | #define DYN_ALLOC |
| 37 | |
Eric Andersen | cbe31da | 2001-02-20 06:14:08 +0000 | [diff] [blame] | 38 | #include <stdlib.h> |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 39 | #include <stdio.h> |
Erik Andersen | 61677fe | 2000-04-13 01:18:56 +0000 | [diff] [blame] | 40 | #include <string.h> |
Eric Andersen | ed3ef50 | 2001-01-27 08:24:39 +0000 | [diff] [blame] | 41 | #include <unistd.h> |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 42 | #include <errno.h> |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 43 | #include <sys/types.h> |
| 44 | #include <signal.h> |
| 45 | #include <utime.h> |
| 46 | #include <ctype.h> |
| 47 | #include <sys/types.h> |
| 48 | #include <unistd.h> |
| 49 | #include <dirent.h> |
| 50 | #include <fcntl.h> |
| 51 | #include <time.h> |
Eric Andersen | cbe31da | 2001-02-20 06:14:08 +0000 | [diff] [blame] | 52 | #include "busybox.h" |
Eric Andersen | cbe31da | 2001-02-20 06:14:08 +0000 | [diff] [blame] | 53 | |
Erik Andersen | 61677fe | 2000-04-13 01:18:56 +0000 | [diff] [blame] | 54 | #define memzero(s, n) memset ((void *)(s), 0, (n)) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 55 | |
| 56 | #ifndef RETSIGTYPE |
| 57 | # define RETSIGTYPE void |
| 58 | #endif |
| 59 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 60 | typedef unsigned char uch; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 61 | typedef unsigned short ush; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 62 | typedef unsigned long ulg; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 63 | |
| 64 | /* Return codes from gzip */ |
| 65 | #define OK 0 |
| 66 | #define ERROR 1 |
| 67 | #define WARNING 2 |
| 68 | |
| 69 | /* Compression methods (see algorithm.doc) */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 70 | /* Only STORED and DEFLATED are supported by this BusyBox module */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 71 | #define STORED 0 |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 72 | /* methods 4 to 7 reserved */ |
| 73 | #define DEFLATED 8 |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 74 | |
| 75 | /* To save memory for 16 bit systems, some arrays are overlaid between |
| 76 | * the various modules: |
| 77 | * deflate: prev+head window d_buf l_buf outbuf |
| 78 | * unlzw: tab_prefix tab_suffix stack inbuf outbuf |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 79 | * For compression, input is done in window[]. For decompression, output |
| 80 | * is done in window except for unlzw. |
| 81 | */ |
| 82 | |
| 83 | #ifndef INBUFSIZ |
| 84 | # ifdef SMALL_MEM |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 85 | # define INBUFSIZ 0x2000 /* input buffer size */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 86 | # else |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 87 | # define INBUFSIZ 0x8000 /* input buffer size */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 88 | # endif |
| 89 | #endif |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 90 | #define INBUF_EXTRA 64 /* required by unlzw() */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 91 | |
| 92 | #ifndef OUTBUFSIZ |
| 93 | # ifdef SMALL_MEM |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 94 | # define OUTBUFSIZ 8192 /* output buffer size */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 95 | # else |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 96 | # define OUTBUFSIZ 16384 /* output buffer size */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 97 | # endif |
| 98 | #endif |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 99 | #define OUTBUF_EXTRA 2048 /* required by unlzw() */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 100 | |
| 101 | #ifndef DIST_BUFSIZE |
| 102 | # ifdef SMALL_MEM |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 103 | # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 104 | # else |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 105 | # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 106 | # endif |
| 107 | #endif |
| 108 | |
| 109 | #ifdef DYN_ALLOC |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 110 | # define DECLARE(type, array, size) static type * array |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 111 | # define ALLOC(type, array, size) { \ |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 112 | array = (type*)xcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 113 | } |
Aaron Lehmann | a170e1c | 2002-11-28 11:27:31 +0000 | [diff] [blame^] | 114 | # define FREE(array) {free(array), array=NULL;} |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 115 | #else |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 116 | # define DECLARE(type, array, size) static type array[size] |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 117 | # define ALLOC(type, array, size) |
| 118 | # define FREE(array) |
| 119 | #endif |
| 120 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 121 | #define tab_suffix window |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 122 | #define tab_prefix prev /* hash link (see deflate.c) */ |
| 123 | #define head (prev+WSIZE) /* hash head (see deflate.c) */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 124 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 125 | static long bytes_in; /* number of input bytes */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 126 | |
| 127 | #define isize bytes_in |
| 128 | /* for compatibility with old zip sources (to be cleaned) */ |
| 129 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 130 | typedef int file_t; /* Do not use stdio */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 131 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 132 | #define NO_FILE (-1) /* in memory compression */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 133 | |
| 134 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 135 | #define PACK_MAGIC "\037\036" /* Magic header for packed files */ |
| 136 | #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */ |
| 137 | #define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */ |
| 138 | #define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files */ |
| 139 | #define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 140 | |
| 141 | /* gzip flag byte */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 142 | #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ |
| 143 | #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ |
| 144 | #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ |
| 145 | #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ |
| 146 | #define COMMENT 0x10 /* bit 4 set: file comment present */ |
| 147 | #define RESERVED 0xC0 /* bit 6,7: reserved */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 148 | |
| 149 | /* internal file attribute */ |
| 150 | #define UNKNOWN 0xffff |
| 151 | #define BINARY 0 |
| 152 | #define ASCII 1 |
| 153 | |
| 154 | #ifndef WSIZE |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 155 | # define WSIZE 0x8000 /* window size--must be a power of two, and */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 156 | #endif /* at least 32K for zip's deflate method */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 157 | |
| 158 | #define MIN_MATCH 3 |
| 159 | #define MAX_MATCH 258 |
| 160 | /* The minimum and maximum match lengths */ |
| 161 | |
| 162 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) |
| 163 | /* Minimum amount of lookahead, except at the end of the input file. |
| 164 | * See deflate.c for comments about the MIN_MATCH+1. |
| 165 | */ |
| 166 | |
| 167 | #define MAX_DIST (WSIZE-MIN_LOOKAHEAD) |
| 168 | /* In order to simplify the code, particularly on 16 bit machines, match |
| 169 | * distances are limited to MAX_DIST instead of WSIZE. |
| 170 | */ |
| 171 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 172 | /* put_byte is used for the compressed output */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 173 | #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\ |
| 174 | flush_outbuf();} |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 175 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 176 | |
| 177 | /* Output a 32 bit value to the bit stream, lsb first */ |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 178 | #if 0 |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 179 | #define put_long(n) { \ |
| 180 | put_short((n) & 0xffff); \ |
| 181 | put_short(((ulg)(n)) >> 16); \ |
| 182 | } |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 183 | #endif |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 184 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 185 | #define seekable() 0 /* force sequential output */ |
| 186 | #define translate_eol 0 /* no option -a yet */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 187 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 188 | /* Diagnostic functions */ |
| 189 | #ifdef DEBUG |
Mark Whitley | f57c944 | 2000-12-07 19:56:48 +0000 | [diff] [blame] | 190 | # define Assert(cond,msg) {if(!(cond)) error_msg(msg);} |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 191 | # define Trace(x) fprintf x |
| 192 | # define Tracev(x) {if (verbose) fprintf x ;} |
| 193 | # define Tracevv(x) {if (verbose>1) fprintf x ;} |
| 194 | # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} |
| 195 | # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} |
| 196 | #else |
| 197 | # define Assert(cond,msg) |
| 198 | # define Trace(x) |
| 199 | # define Tracev(x) |
| 200 | # define Tracevv(x) |
| 201 | # define Tracec(c,x) |
| 202 | # define Tracecv(c,x) |
| 203 | #endif |
| 204 | |
| 205 | #define WARN(msg) {if (!quiet) fprintf msg ; \ |
| 206 | if (exit_code == OK) exit_code = WARNING;} |
| 207 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 208 | #ifndef MAX_PATH_LEN |
| 209 | # define MAX_PATH_LEN 1024 /* max pathname length */ |
| 210 | #endif |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 211 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 212 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 213 | /* from zip.c: */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 214 | static int zip(int in, int out); |
| 215 | static int file_read(char *buf, unsigned size); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 216 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 217 | /* from gzip.c */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 218 | static RETSIGTYPE abort_gzip(void); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 219 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 220 | /* from deflate.c */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 221 | static void lm_init(ush * flags); |
| 222 | static ulg deflate(void); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 223 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 224 | /* from trees.c */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 225 | static void ct_init(ush * attr, int *methodp); |
| 226 | static int ct_tally(int dist, int lc); |
| 227 | static ulg flush_block(char *buf, ulg stored_len, int eof); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 228 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 229 | /* from bits.c */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 230 | static void bi_init(file_t zipfile); |
| 231 | static void send_bits(int value, int length); |
| 232 | static unsigned bi_reverse(unsigned value, int length); |
| 233 | static void bi_windup(void); |
| 234 | static void copy_block(char *buf, unsigned len, int header); |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 235 | static int (*read_buf) (char *buf, unsigned size); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 236 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 237 | /* from util.c: */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 238 | static void flush_outbuf(void); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 239 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 240 | /* lzw.h -- define the lzw functions. |
| 241 | * Copyright (C) 1992-1993 Jean-loup Gailly. |
| 242 | * This is free software; you can redistribute it and/or modify it under the |
| 243 | * terms of the GNU General Public License, see the file COPYING. |
| 244 | */ |
| 245 | |
| 246 | #if !defined(OF) && defined(lint) |
| 247 | # include "gzip.h" |
| 248 | #endif |
| 249 | |
| 250 | #ifndef BITS |
| 251 | # define BITS 16 |
| 252 | #endif |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 253 | #define INIT_BITS 9 /* Initial number of bits per code */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 254 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 255 | #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 256 | /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free. |
| 257 | * It's a pity that old uncompress does not check bit 0x20. That makes |
| 258 | * extension of the format actually undesirable because old compress |
| 259 | * would just crash on the new format instead of giving a meaningful |
| 260 | * error message. It does check the number of bits, but it's more |
| 261 | * helpful to say "unsupported format, get a new version" than |
| 262 | * "can only handle 16 bits". |
| 263 | */ |
| 264 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 265 | /* tailor.h -- target dependent definitions |
| 266 | * Copyright (C) 1992-1993 Jean-loup Gailly. |
| 267 | * This is free software; you can redistribute it and/or modify it under the |
| 268 | * terms of the GNU General Public License, see the file COPYING. |
| 269 | */ |
| 270 | |
| 271 | /* The target dependent definitions should be defined here only. |
| 272 | * The target dependent functions should be defined in tailor.c. |
| 273 | */ |
| 274 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 275 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 276 | /* Common defaults */ |
| 277 | |
| 278 | #ifndef OS_CODE |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 279 | # define OS_CODE 0x03 /* assume Unix */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 280 | #endif |
| 281 | |
| 282 | #ifndef PATH_SEP |
| 283 | # define PATH_SEP '/' |
| 284 | #endif |
| 285 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 286 | #ifndef OPTIONS_VAR |
| 287 | # define OPTIONS_VAR "GZIP" |
| 288 | #endif |
| 289 | |
| 290 | #ifndef Z_SUFFIX |
| 291 | # define Z_SUFFIX ".gz" |
| 292 | #endif |
| 293 | |
| 294 | #ifdef MAX_EXT_CHARS |
| 295 | # define MAX_SUFFIX MAX_EXT_CHARS |
| 296 | #else |
| 297 | # define MAX_SUFFIX 30 |
| 298 | #endif |
| 299 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 300 | /* global buffers */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 301 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 302 | DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA); |
| 303 | DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA); |
| 304 | DECLARE(ush, d_buf, DIST_BUFSIZE); |
| 305 | DECLARE(uch, window, 2L * WSIZE); |
| 306 | DECLARE(ush, tab_prefix, 1L << BITS); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 307 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 308 | static int crc_table_empty = 1; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 309 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 310 | static int foreground; /* set if program run in foreground */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 311 | static int method = DEFLATED; /* compression method */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 312 | static int exit_code = OK; /* program exit code */ |
| 313 | static int part_nb; /* number of parts in .gz file */ |
| 314 | static long time_stamp; /* original time stamp (modification time) */ |
| 315 | static long ifile_size; /* input file size, -1 for devices (debug only) */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 316 | static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 317 | static int z_len; /* strlen(z_suffix) */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 318 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 319 | static int ifd; /* input file descriptor */ |
| 320 | static int ofd; /* output file descriptor */ |
| 321 | static unsigned insize; /* valid bytes in inbuf */ |
| 322 | static unsigned outcnt; /* bytes in output buffer */ |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 323 | |
Aaron Lehmann | b9df470 | 2001-12-06 03:22:43 +0000 | [diff] [blame] | 324 | |
| 325 | /* Output a 16 bit value, lsb first */ |
| 326 | static void put_short(ush w) |
| 327 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 328 | if (outcnt < OUTBUFSIZ - 2) { |
| 329 | outbuf[outcnt++] = (uch) ((w) & 0xff); |
| 330 | outbuf[outcnt++] = (uch) ((ush) (w) >> 8); |
| 331 | } else { |
| 332 | put_byte((uch) ((w) & 0xff)); |
| 333 | put_byte((uch) ((ush) (w) >> 8)); |
| 334 | } |
Aaron Lehmann | b9df470 | 2001-12-06 03:22:43 +0000 | [diff] [blame] | 335 | } |
| 336 | |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 337 | /* ======================================================================== |
| 338 | * Signal and error handler. |
| 339 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 340 | static void abort_gzip() |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 341 | { |
| 342 | exit(ERROR); |
| 343 | } |
| 344 | |
| 345 | /* =========================================================================== |
| 346 | * Clear input and output buffers |
| 347 | */ |
| 348 | static void clear_bufs(void) |
| 349 | { |
| 350 | outcnt = 0; |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 351 | insize = 0; |
| 352 | bytes_in = 0L; |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 353 | } |
| 354 | |
Eric Andersen | 74400cc | 2001-10-18 04:11:39 +0000 | [diff] [blame] | 355 | static void write_error_msg(void) |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 356 | { |
Glenn L McGrath | d211214 | 2002-11-28 09:22:14 +0000 | [diff] [blame] | 357 | fputc('\n', stderr); |
| 358 | perror_msg(""); |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 359 | abort_gzip(); |
| 360 | } |
| 361 | |
| 362 | /* =========================================================================== |
| 363 | * Does the same as write(), but also handles partial pipe writes and checks |
| 364 | * for error return. |
| 365 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 366 | static void write_buf(int fd, void *buf, unsigned cnt) |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 367 | { |
| 368 | unsigned n; |
| 369 | |
| 370 | while ((n = write(fd, buf, cnt)) != cnt) { |
| 371 | if (n == (unsigned) (-1)) { |
| 372 | write_error_msg(); |
| 373 | } |
| 374 | cnt -= n; |
| 375 | buf = (void *) ((char *) buf + n); |
| 376 | } |
| 377 | } |
| 378 | |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 379 | /* =========================================================================== |
| 380 | * Run a set of bytes through the crc shift register. If s is a NULL |
| 381 | * pointer, then initialize the crc shift register contents instead. |
| 382 | * Return the current crc in either case. |
| 383 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 384 | static ulg updcrc(uch * s, unsigned n) |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 385 | { |
| 386 | static ulg crc = (ulg) 0xffffffffL; /* shift register contents */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 387 | register ulg c; /* temporary variable */ |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 388 | static unsigned long crc_32_tab[256]; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 389 | |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 390 | if (crc_table_empty) { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 391 | unsigned long csr; /* crc shift register */ |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 392 | const unsigned long e = 0xedb88320L; /* polynomial exclusive-or pattern */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 393 | int i; /* counter for all possible eight bit values */ |
| 394 | int k; /* byte being shifted into crc apparatus */ |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 395 | |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 396 | /* Compute table of CRC's. */ |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 397 | crc_32_tab[0] = 0x00000000L; |
| 398 | for (i = 1; i < 256; i++) { |
| 399 | csr = i; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 400 | /* The idea to initialize the register with the byte instead of |
| 401 | * zero was stolen from Haruhiko Okumura's ar002 |
| 402 | */ |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 403 | for (k = 8; k; k--) |
| 404 | csr = csr & 1 ? (csr >> 1) ^ e : csr >> 1; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 405 | crc_32_tab[i] = csr; |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 406 | } |
| 407 | } |
| 408 | |
| 409 | if (s == NULL) { |
| 410 | c = 0xffffffffL; |
| 411 | } else { |
| 412 | c = crc; |
| 413 | if (n) |
| 414 | do { |
| 415 | c = crc_32_tab[((int) c ^ (*s++)) & 0xff] ^ (c >> 8); |
| 416 | } while (--n); |
| 417 | } |
| 418 | crc = c; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 419 | return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */ |
Glenn L McGrath | f58efb5 | 2001-03-28 05:35:16 +0000 | [diff] [blame] | 420 | } |
| 421 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 422 | /* bits.c -- output variable-length bit strings |
| 423 | * Copyright (C) 1992-1993 Jean-loup Gailly |
| 424 | * This is free software; you can redistribute it and/or modify it under the |
| 425 | * terms of the GNU General Public License, see the file COPYING. |
| 426 | */ |
| 427 | |
| 428 | |
| 429 | /* |
| 430 | * PURPOSE |
| 431 | * |
| 432 | * Output variable-length bit strings. Compression can be done |
| 433 | * to a file or to memory. (The latter is not supported in this version.) |
| 434 | * |
| 435 | * DISCUSSION |
| 436 | * |
| 437 | * The PKZIP "deflate" file format interprets compressed file data |
| 438 | * as a sequence of bits. Multi-bit strings in the file may cross |
| 439 | * byte boundaries without restriction. |
| 440 | * |
| 441 | * The first bit of each byte is the low-order bit. |
| 442 | * |
| 443 | * The routines in this file allow a variable-length bit value to |
| 444 | * be output right-to-left (useful for literal values). For |
| 445 | * left-to-right output (useful for code strings from the tree routines), |
| 446 | * the bits must have been reversed first with bi_reverse(). |
| 447 | * |
| 448 | * For in-memory compression, the compressed bit stream goes directly |
| 449 | * into the requested output buffer. The input data is read in blocks |
| 450 | * by the mem_read() function. The buffer is limited to 64K on 16 bit |
| 451 | * machines. |
| 452 | * |
| 453 | * INTERFACE |
| 454 | * |
| 455 | * void bi_init (FILE *zipfile) |
| 456 | * Initialize the bit string routines. |
| 457 | * |
| 458 | * void send_bits (int value, int length) |
| 459 | * Write out a bit string, taking the source bits right to |
| 460 | * left. |
| 461 | * |
| 462 | * int bi_reverse (int value, int length) |
| 463 | * Reverse the bits of a bit string, taking the source bits left to |
| 464 | * right and emitting them right to left. |
| 465 | * |
| 466 | * void bi_windup (void) |
| 467 | * Write out any remaining bits in an incomplete byte. |
| 468 | * |
| 469 | * void copy_block(char *buf, unsigned len, int header) |
| 470 | * Copy a stored block to the zip file, storing first the length and |
| 471 | * its one's complement if requested. |
| 472 | * |
| 473 | */ |
| 474 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 475 | /* =========================================================================== |
| 476 | * Local data used by the "bit string" routines. |
| 477 | */ |
| 478 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 479 | static file_t zfile; /* output gzip file */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 480 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 481 | static unsigned short bi_buf; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 482 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 483 | /* Output buffer. bits are inserted starting at the bottom (least significant |
| 484 | * bits). |
| 485 | */ |
| 486 | |
| 487 | #define Buf_size (8 * 2*sizeof(char)) |
| 488 | /* Number of bits used within bi_buf. (bi_buf might be implemented on |
| 489 | * more than 16 bits on some systems.) |
| 490 | */ |
| 491 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 492 | static int bi_valid; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 493 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 494 | /* Current input function. Set to mem_read for in-memory compression */ |
| 495 | |
| 496 | #ifdef DEBUG |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 497 | ulg bits_sent; /* bit length of the compressed data */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 498 | #endif |
| 499 | |
| 500 | /* =========================================================================== |
| 501 | * Initialize the bit string routines. |
| 502 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 503 | static void bi_init(file_t zipfile) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 504 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 505 | zfile = zipfile; |
| 506 | bi_buf = 0; |
| 507 | bi_valid = 0; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 508 | #ifdef DEBUG |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 509 | bits_sent = 0L; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 510 | #endif |
| 511 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 512 | /* Set the defaults for file compression. They are set by memcompress |
| 513 | * for in-memory compression. |
| 514 | */ |
| 515 | if (zfile != NO_FILE) { |
| 516 | read_buf = file_read; |
| 517 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 518 | } |
| 519 | |
| 520 | /* =========================================================================== |
| 521 | * Send a value on a given number of bits. |
| 522 | * IN assertion: length <= 16 and value fits in length bits. |
| 523 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 524 | static void send_bits(int value, int length) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 525 | { |
| 526 | #ifdef DEBUG |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 527 | Tracev((stderr, " l %2d v %4x ", length, value)); |
| 528 | Assert(length > 0 && length <= 15, "invalid length"); |
| 529 | bits_sent += (ulg) length; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 530 | #endif |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 531 | /* If not enough room in bi_buf, use (valid) bits from bi_buf and |
| 532 | * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) |
| 533 | * unused bits in value. |
| 534 | */ |
| 535 | if (bi_valid > (int) Buf_size - length) { |
| 536 | bi_buf |= (value << bi_valid); |
| 537 | put_short(bi_buf); |
| 538 | bi_buf = (ush) value >> (Buf_size - bi_valid); |
| 539 | bi_valid += length - Buf_size; |
| 540 | } else { |
| 541 | bi_buf |= value << bi_valid; |
| 542 | bi_valid += length; |
| 543 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 544 | } |
| 545 | |
| 546 | /* =========================================================================== |
| 547 | * Reverse the first len bits of a code, using straightforward code (a faster |
| 548 | * method would use a table) |
| 549 | * IN assertion: 1 <= len <= 15 |
| 550 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 551 | static unsigned bi_reverse(unsigned code, int len) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 552 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 553 | register unsigned res = 0; |
| 554 | |
| 555 | do { |
| 556 | res |= code & 1; |
| 557 | code >>= 1, res <<= 1; |
| 558 | } while (--len > 0); |
| 559 | return res >> 1; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 560 | } |
| 561 | |
| 562 | /* =========================================================================== |
| 563 | * Write out any remaining bits in an incomplete byte. |
| 564 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 565 | static void bi_windup() |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 566 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 567 | if (bi_valid > 8) { |
| 568 | put_short(bi_buf); |
| 569 | } else if (bi_valid > 0) { |
| 570 | put_byte(bi_buf); |
| 571 | } |
| 572 | bi_buf = 0; |
| 573 | bi_valid = 0; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 574 | #ifdef DEBUG |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 575 | bits_sent = (bits_sent + 7) & ~7; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 576 | #endif |
| 577 | } |
| 578 | |
| 579 | /* =========================================================================== |
| 580 | * Copy a stored block to the zip file, storing first the length and its |
| 581 | * one's complement if requested. |
| 582 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 583 | static void copy_block(char *buf, unsigned len, int header) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 584 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 585 | bi_windup(); /* align on byte boundary */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 586 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 587 | if (header) { |
| 588 | put_short((ush) len); |
| 589 | put_short((ush) ~ len); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 590 | #ifdef DEBUG |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 591 | bits_sent += 2 * 16; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 592 | #endif |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 593 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 594 | #ifdef DEBUG |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 595 | bits_sent += (ulg) len << 3; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 596 | #endif |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 597 | while (len--) { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 598 | put_byte(*buf++); |
| 599 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 600 | } |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 601 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 602 | /* deflate.c -- compress data using the deflation algorithm |
| 603 | * Copyright (C) 1992-1993 Jean-loup Gailly |
| 604 | * This is free software; you can redistribute it and/or modify it under the |
| 605 | * terms of the GNU General Public License, see the file COPYING. |
| 606 | */ |
| 607 | |
| 608 | /* |
| 609 | * PURPOSE |
| 610 | * |
| 611 | * Identify new text as repetitions of old text within a fixed- |
| 612 | * length sliding window trailing behind the new text. |
| 613 | * |
| 614 | * DISCUSSION |
| 615 | * |
| 616 | * The "deflation" process depends on being able to identify portions |
| 617 | * of the input text which are identical to earlier input (within a |
| 618 | * sliding window trailing behind the input currently being processed). |
| 619 | * |
| 620 | * The most straightforward technique turns out to be the fastest for |
| 621 | * most input files: try all possible matches and select the longest. |
| 622 | * The key feature of this algorithm is that insertions into the string |
| 623 | * dictionary are very simple and thus fast, and deletions are avoided |
| 624 | * completely. Insertions are performed at each input character, whereas |
| 625 | * string matches are performed only when the previous match ends. So it |
| 626 | * is preferable to spend more time in matches to allow very fast string |
| 627 | * insertions and avoid deletions. The matching algorithm for small |
| 628 | * strings is inspired from that of Rabin & Karp. A brute force approach |
| 629 | * is used to find longer strings when a small match has been found. |
| 630 | * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze |
| 631 | * (by Leonid Broukhis). |
| 632 | * A previous version of this file used a more sophisticated algorithm |
| 633 | * (by Fiala and Greene) which is guaranteed to run in linear amortized |
| 634 | * time, but has a larger average cost, uses more memory and is patented. |
| 635 | * However the F&G algorithm may be faster for some highly redundant |
| 636 | * files if the parameter max_chain_length (described below) is too large. |
| 637 | * |
| 638 | * ACKNOWLEDGEMENTS |
| 639 | * |
| 640 | * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and |
| 641 | * I found it in 'freeze' written by Leonid Broukhis. |
| 642 | * Thanks to many info-zippers for bug reports and testing. |
| 643 | * |
| 644 | * REFERENCES |
| 645 | * |
| 646 | * APPNOTE.TXT documentation file in PKZIP 1.93a distribution. |
| 647 | * |
| 648 | * A description of the Rabin and Karp algorithm is given in the book |
| 649 | * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. |
| 650 | * |
| 651 | * Fiala,E.R., and Greene,D.H. |
| 652 | * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 |
| 653 | * |
| 654 | * INTERFACE |
| 655 | * |
| 656 | * void lm_init (int pack_level, ush *flags) |
| 657 | * Initialize the "longest match" routines for a new file |
| 658 | * |
| 659 | * ulg deflate (void) |
| 660 | * Processes a new input file and return its compressed length. Sets |
| 661 | * the compressed length, crc, deflate flags and internal file |
| 662 | * attributes. |
| 663 | */ |
| 664 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 665 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 666 | /* =========================================================================== |
| 667 | * Configuration parameters |
| 668 | */ |
| 669 | |
| 670 | /* Compile with MEDIUM_MEM to reduce the memory requirements or |
| 671 | * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the |
| 672 | * entire input file can be held in memory (not possible on 16 bit systems). |
| 673 | * Warning: defining these symbols affects HASH_BITS (see below) and thus |
| 674 | * affects the compression ratio. The compressed output |
| 675 | * is still correct, and might even be smaller in some cases. |
| 676 | */ |
| 677 | |
| 678 | #ifdef SMALL_MEM |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 679 | # define HASH_BITS 13 /* Number of bits used to hash strings */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 680 | #endif |
| 681 | #ifdef MEDIUM_MEM |
| 682 | # define HASH_BITS 14 |
| 683 | #endif |
| 684 | #ifndef HASH_BITS |
| 685 | # define HASH_BITS 15 |
| 686 | /* For portability to 16 bit machines, do not use values above 15. */ |
| 687 | #endif |
| 688 | |
| 689 | /* To save space (see unlzw.c), we overlay prev+head with tab_prefix and |
| 690 | * window with tab_suffix. Check that we can do this: |
| 691 | */ |
| 692 | #if (WSIZE<<1) > (1<<BITS) |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 693 | # error cannot overlay window with tab_suffix and prev with tab_prefix0 |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 694 | #endif |
| 695 | #if HASH_BITS > BITS-1 |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 696 | # error cannot overlay head with tab_prefix1 |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 697 | #endif |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 698 | #define HASH_SIZE (unsigned)(1<<HASH_BITS) |
| 699 | #define HASH_MASK (HASH_SIZE-1) |
| 700 | #define WMASK (WSIZE-1) |
| 701 | /* HASH_SIZE and WSIZE must be powers of two */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 702 | #define NIL 0 |
| 703 | /* Tail of hash chains */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 704 | #define FAST 4 |
| 705 | #define SLOW 2 |
| 706 | /* speed options for the general purpose bit flag */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 707 | #ifndef TOO_FAR |
| 708 | # define TOO_FAR 4096 |
| 709 | #endif |
| 710 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 711 | /* =========================================================================== |
| 712 | * Local data used by the "longest match" routines. |
| 713 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 714 | typedef ush Pos; |
| 715 | typedef unsigned IPos; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 716 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 717 | /* A Pos is an index in the character window. We use short instead of int to |
| 718 | * save space in the various tables. IPos is used only for parameter passing. |
| 719 | */ |
| 720 | |
| 721 | /* DECLARE(uch, window, 2L*WSIZE); */ |
| 722 | /* Sliding window. Input bytes are read into the second half of the window, |
| 723 | * and move to the first half later to keep a dictionary of at least WSIZE |
| 724 | * bytes. With this organization, matches are limited to a distance of |
| 725 | * WSIZE-MAX_MATCH bytes, but this ensures that IO is always |
| 726 | * performed with a length multiple of the block size. Also, it limits |
| 727 | * the window size to 64K, which is quite useful on MSDOS. |
| 728 | * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would |
| 729 | * be less efficient). |
| 730 | */ |
| 731 | |
| 732 | /* DECLARE(Pos, prev, WSIZE); */ |
| 733 | /* Link to older string with same hash index. To limit the size of this |
| 734 | * array to 64K, this link is maintained only for the last 32K strings. |
| 735 | * An index in this array is thus a window index modulo 32K. |
| 736 | */ |
| 737 | |
| 738 | /* DECLARE(Pos, head, 1<<HASH_BITS); */ |
| 739 | /* Heads of the hash chains or NIL. */ |
| 740 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 741 | static const ulg window_size = (ulg) 2 * WSIZE; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 742 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 743 | /* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the |
| 744 | * input file length plus MIN_LOOKAHEAD. |
| 745 | */ |
| 746 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 747 | static long block_start; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 748 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 749 | /* window position at the beginning of the current output block. Gets |
| 750 | * negative when the window is moved backwards. |
| 751 | */ |
| 752 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 753 | static unsigned ins_h; /* hash index of string to be inserted */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 754 | |
| 755 | #define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH) |
| 756 | /* Number of bits by which ins_h and del_h must be shifted at each |
| 757 | * input step. It must be such that after MIN_MATCH steps, the oldest |
| 758 | * byte no longer takes part in the hash key, that is: |
| 759 | * H_SHIFT * MIN_MATCH >= HASH_BITS |
| 760 | */ |
| 761 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 762 | static unsigned int prev_length; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 763 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 764 | /* Length of the best match at previous step. Matches not greater than this |
| 765 | * are discarded. This is used in the lazy match evaluation. |
| 766 | */ |
| 767 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 768 | static unsigned strstart; /* start of string to insert */ |
| 769 | static unsigned match_start; /* start of matching string */ |
| 770 | static int eofile; /* flag set at end of input file */ |
| 771 | static unsigned lookahead; /* number of valid bytes ahead in window */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 772 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 773 | static const unsigned max_chain_length = 4096; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 774 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 775 | /* To speed up deflation, hash chains are never searched beyond this length. |
| 776 | * A higher limit improves compression ratio but degrades the speed. |
| 777 | */ |
| 778 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 779 | static const unsigned int max_lazy_match = 258; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 780 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 781 | /* Attempt to find a better match only when the current match is strictly |
| 782 | * smaller than this value. This mechanism is used only for compression |
| 783 | * levels >= 4. |
| 784 | */ |
| 785 | #define max_insert_length max_lazy_match |
| 786 | /* Insert new strings in the hash table only if the match length |
| 787 | * is not greater than this length. This saves time but degrades compression. |
| 788 | * max_insert_length is used only for compression levels <= 3. |
| 789 | */ |
| 790 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 791 | static const unsigned good_match = 32; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 792 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 793 | /* Use a faster search when the previous match is longer than this */ |
| 794 | |
| 795 | |
| 796 | /* Values for max_lazy_match, good_match and max_chain_length, depending on |
| 797 | * the desired pack level (0..9). The values given below have been tuned to |
| 798 | * exclude worst case performance for pathological files. Better values may be |
| 799 | * found for specific files. |
| 800 | */ |
| 801 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 802 | static const int nice_match = 258; /* Stop searching when current match exceeds this */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 803 | |
| 804 | /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 |
| 805 | * For deflate_fast() (levels <= 3) good is ignored and lazy has a different |
| 806 | * meaning. |
| 807 | */ |
| 808 | |
| 809 | #define EQUAL 0 |
| 810 | /* result of memcmp for equal strings */ |
| 811 | |
| 812 | /* =========================================================================== |
| 813 | * Prototypes for local functions. |
| 814 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 815 | static void fill_window(void); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 816 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 817 | static int longest_match(IPos cur_match); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 818 | |
| 819 | #ifdef DEBUG |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 820 | static void check_match(IPos start, IPos match, int length); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 821 | #endif |
| 822 | |
| 823 | /* =========================================================================== |
| 824 | * Update a hash value with the given input byte |
| 825 | * IN assertion: all calls to to UPDATE_HASH are made with consecutive |
| 826 | * input characters, so that a running hash key can be computed from the |
| 827 | * previous key instead of complete recalculation each time. |
| 828 | */ |
| 829 | #define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK) |
| 830 | |
| 831 | /* =========================================================================== |
| 832 | * Insert string s in the dictionary and set match_head to the previous head |
| 833 | * of the hash chain (the most recent string with same hash key). Return |
| 834 | * the previous length of the hash chain. |
| 835 | * IN assertion: all calls to to INSERT_STRING are made with consecutive |
| 836 | * input characters and the first MIN_MATCH bytes of s are valid |
| 837 | * (except for the last MIN_MATCH-1 bytes of the input file). |
| 838 | */ |
| 839 | #define INSERT_STRING(s, match_head) \ |
| 840 | (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \ |
| 841 | prev[(s) & WMASK] = match_head = head[ins_h], \ |
| 842 | head[ins_h] = (s)) |
| 843 | |
| 844 | /* =========================================================================== |
| 845 | * Initialize the "longest match" routines for a new file |
| 846 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 847 | static void lm_init(ush * flags) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 848 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 849 | register unsigned j; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 850 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 851 | /* Initialize the hash table. */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 852 | memzero((char *) head, HASH_SIZE * sizeof(*head)); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 853 | /* prev will be initialized on the fly */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 854 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 855 | *flags |= SLOW; |
| 856 | /* ??? reduce max_chain_length for binary files */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 857 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 858 | strstart = 0; |
| 859 | block_start = 0L; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 860 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 861 | lookahead = read_buf((char *) window, |
| 862 | sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 863 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 864 | if (lookahead == 0 || lookahead == (unsigned) EOF) { |
| 865 | eofile = 1, lookahead = 0; |
| 866 | return; |
| 867 | } |
| 868 | eofile = 0; |
| 869 | /* Make sure that we always have enough lookahead. This is important |
| 870 | * if input comes from a device such as a tty. |
| 871 | */ |
| 872 | while (lookahead < MIN_LOOKAHEAD && !eofile) |
| 873 | fill_window(); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 874 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 875 | ins_h = 0; |
| 876 | for (j = 0; j < MIN_MATCH - 1; j++) |
| 877 | UPDATE_HASH(ins_h, window[j]); |
| 878 | /* If lookahead < MIN_MATCH, ins_h is garbage, but this is |
| 879 | * not important since only literal bytes will be emitted. |
| 880 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 881 | } |
| 882 | |
| 883 | /* =========================================================================== |
| 884 | * Set match_start to the longest match starting at the given string and |
| 885 | * return its length. Matches shorter or equal to prev_length are discarded, |
| 886 | * in which case the result is equal to prev_length and match_start is |
| 887 | * garbage. |
| 888 | * IN assertions: cur_match is the head of the hash chain for the current |
| 889 | * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 |
| 890 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 891 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 892 | /* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or |
| 893 | * match.s. The code is functionally equivalent, so you can use the C version |
| 894 | * if desired. |
| 895 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 896 | static int longest_match(IPos cur_match) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 897 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 898 | unsigned chain_length = max_chain_length; /* max hash chain length */ |
| 899 | register uch *scan = window + strstart; /* current string */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 900 | register uch *match; /* matched string */ |
| 901 | register int len; /* length of current match */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 902 | int best_len = prev_length; /* best match length so far */ |
| 903 | IPos limit = |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 904 | strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL; |
| 905 | /* Stop when cur_match becomes <= limit. To simplify the code, |
| 906 | * we prevent matches with the string of window index 0. |
| 907 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 908 | |
| 909 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
| 910 | * It is easy to get rid of this optimization if necessary. |
| 911 | */ |
| 912 | #if HASH_BITS < 8 || MAX_MATCH != 258 |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 913 | # error Code too clever |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 914 | #endif |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 915 | register uch *strend = window + strstart + MAX_MATCH; |
| 916 | register uch scan_end1 = scan[best_len - 1]; |
| 917 | register uch scan_end = scan[best_len]; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 918 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 919 | /* Do not waste too much time if we already have a good match: */ |
| 920 | if (prev_length >= good_match) { |
| 921 | chain_length >>= 2; |
| 922 | } |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 923 | Assert(strstart <= window_size - MIN_LOOKAHEAD, "insufficient lookahead"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 924 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 925 | do { |
| 926 | Assert(cur_match < strstart, "no future"); |
| 927 | match = window + cur_match; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 928 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 929 | /* Skip to next match if the match length cannot increase |
| 930 | * or if the match length is less than 2: |
| 931 | */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 932 | if (match[best_len] != scan_end || |
| 933 | match[best_len - 1] != scan_end1 || |
| 934 | *match != *scan || *++match != scan[1]) |
| 935 | continue; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 936 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 937 | /* The check at best_len-1 can be removed because it will be made |
| 938 | * again later. (This heuristic is not always a win.) |
| 939 | * It is not necessary to compare scan[2] and match[2] since they |
| 940 | * are always equal when the other bytes match, given that |
| 941 | * the hash keys are equal and that HASH_BITS >= 8. |
| 942 | */ |
| 943 | scan += 2, match++; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 944 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 945 | /* We check for insufficient lookahead only every 8th comparison; |
| 946 | * the 256th check will be made at strstart+258. |
| 947 | */ |
| 948 | do { |
| 949 | } while (*++scan == *++match && *++scan == *++match && |
| 950 | *++scan == *++match && *++scan == *++match && |
| 951 | *++scan == *++match && *++scan == *++match && |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 952 | *++scan == *++match && *++scan == *++match && scan < strend); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 953 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 954 | len = MAX_MATCH - (int) (strend - scan); |
| 955 | scan = strend - MAX_MATCH; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 956 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 957 | if (len > best_len) { |
| 958 | match_start = cur_match; |
| 959 | best_len = len; |
| 960 | if (len >= nice_match) |
| 961 | break; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 962 | scan_end1 = scan[best_len - 1]; |
| 963 | scan_end = scan[best_len]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 964 | } |
| 965 | } while ((cur_match = prev[cur_match & WMASK]) > limit |
| 966 | && --chain_length != 0); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 967 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 968 | return best_len; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 969 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 970 | |
| 971 | #ifdef DEBUG |
| 972 | /* =========================================================================== |
| 973 | * Check that the match at match_start is indeed a match. |
| 974 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 975 | static void check_match(IPos start, IPos match, int length) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 976 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 977 | /* check that the match is indeed a match */ |
| 978 | if (memcmp((char *) window + match, |
| 979 | (char *) window + start, length) != EQUAL) { |
Glenn L McGrath | d211214 | 2002-11-28 09:22:14 +0000 | [diff] [blame] | 980 | error_msg(" start %d, match %d, length %d", start, match, length); |
Matt Kraai | dd19c69 | 2001-01-31 19:00:21 +0000 | [diff] [blame] | 981 | error_msg("invalid match"); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 982 | } |
| 983 | if (verbose > 1) { |
Glenn L McGrath | d211214 | 2002-11-28 09:22:14 +0000 | [diff] [blame] | 984 | error_msg("\\[%d,%d]", start - match, length); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 985 | do { |
| 986 | putc(window[start++], stderr); |
| 987 | } while (--length != 0); |
| 988 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 989 | } |
| 990 | #else |
| 991 | # define check_match(start, match, length) |
| 992 | #endif |
| 993 | |
| 994 | /* =========================================================================== |
| 995 | * Fill the window when the lookahead becomes insufficient. |
| 996 | * Updates strstart and lookahead, and sets eofile if end of input file. |
| 997 | * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0 |
| 998 | * OUT assertions: at least one byte has been read, or eofile is set; |
| 999 | * file reads are performed for at least two bytes (required for the |
| 1000 | * translate_eol option). |
| 1001 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1002 | static void fill_window() |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1003 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1004 | register unsigned n, m; |
| 1005 | unsigned more = |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1006 | (unsigned) (window_size - (ulg) lookahead - (ulg) strstart); |
| 1007 | /* Amount of free space at the end of the window. */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1008 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1009 | /* If the window is almost full and there is insufficient lookahead, |
| 1010 | * move the upper half to the lower one to make room in the upper half. |
| 1011 | */ |
| 1012 | if (more == (unsigned) EOF) { |
| 1013 | /* Very unlikely, but possible on 16 bit machine if strstart == 0 |
| 1014 | * and lookahead == 1 (input done one byte at time) |
| 1015 | */ |
| 1016 | more--; |
| 1017 | } else if (strstart >= WSIZE + MAX_DIST) { |
| 1018 | /* By the IN assertion, the window is not empty so we can't confuse |
| 1019 | * more == 0 with more == 64K on a 16 bit machine. |
| 1020 | */ |
| 1021 | Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1022 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1023 | memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE); |
| 1024 | match_start -= WSIZE; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1025 | strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1026 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1027 | block_start -= (long) WSIZE; |
| 1028 | |
| 1029 | for (n = 0; n < HASH_SIZE; n++) { |
| 1030 | m = head[n]; |
| 1031 | head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL); |
| 1032 | } |
| 1033 | for (n = 0; n < WSIZE; n++) { |
| 1034 | m = prev[n]; |
| 1035 | prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL); |
| 1036 | /* If n is not on any hash chain, prev[n] is garbage but |
| 1037 | * its value will never be used. |
| 1038 | */ |
| 1039 | } |
| 1040 | more += WSIZE; |
| 1041 | } |
| 1042 | /* At this point, more >= 2 */ |
| 1043 | if (!eofile) { |
| 1044 | n = read_buf((char *) window + strstart + lookahead, more); |
| 1045 | if (n == 0 || n == (unsigned) EOF) { |
| 1046 | eofile = 1; |
| 1047 | } else { |
| 1048 | lookahead += n; |
| 1049 | } |
| 1050 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1051 | } |
| 1052 | |
| 1053 | /* =========================================================================== |
| 1054 | * Flush the current block, with given end-of-file flag. |
| 1055 | * IN assertion: strstart is set to the end of the current match. |
| 1056 | */ |
| 1057 | #define FLUSH_BLOCK(eof) \ |
| 1058 | flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \ |
| 1059 | (char*)NULL, (long)strstart - block_start, (eof)) |
| 1060 | |
| 1061 | /* =========================================================================== |
| 1062 | * Same as above, but achieves better compression. We use a lazy |
| 1063 | * evaluation for matches: a match is finally adopted only if there is |
| 1064 | * no better match at the next window position. |
| 1065 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1066 | static ulg deflate() |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1067 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1068 | IPos hash_head; /* head of hash chain */ |
| 1069 | IPos prev_match; /* previous match */ |
| 1070 | int flush; /* set if current block must be flushed */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1071 | int match_available = 0; /* set if previous match exists */ |
| 1072 | register unsigned match_length = MIN_MATCH - 1; /* length of best match */ |
| 1073 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1074 | /* Process the input block. */ |
| 1075 | while (lookahead != 0) { |
| 1076 | /* Insert the string window[strstart .. strstart+2] in the |
| 1077 | * dictionary, and set hash_head to the head of the hash chain: |
| 1078 | */ |
| 1079 | INSERT_STRING(strstart, hash_head); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1080 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1081 | /* Find the longest match, discarding those <= prev_length. |
| 1082 | */ |
| 1083 | prev_length = match_length, prev_match = match_start; |
| 1084 | match_length = MIN_MATCH - 1; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1085 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1086 | if (hash_head != NIL && prev_length < max_lazy_match && |
| 1087 | strstart - hash_head <= MAX_DIST) { |
| 1088 | /* To simplify the code, we prevent matches with the string |
| 1089 | * of window index 0 (in particular we have to avoid a match |
| 1090 | * of the string with itself at the start of the input file). |
| 1091 | */ |
| 1092 | match_length = longest_match(hash_head); |
| 1093 | /* longest_match() sets match_start */ |
| 1094 | if (match_length > lookahead) |
| 1095 | match_length = lookahead; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1096 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1097 | /* Ignore a length 3 match if it is too distant: */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1098 | if (match_length == MIN_MATCH && strstart - match_start > TOO_FAR) { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1099 | /* If prev_match is also MIN_MATCH, match_start is garbage |
| 1100 | * but we will ignore the current match anyway. |
| 1101 | */ |
| 1102 | match_length--; |
| 1103 | } |
| 1104 | } |
| 1105 | /* If there was a match at the previous step and the current |
| 1106 | * match is not better, output the previous match: |
| 1107 | */ |
| 1108 | if (prev_length >= MIN_MATCH && match_length <= prev_length) { |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1109 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1110 | check_match(strstart - 1, prev_match, prev_length); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1111 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1112 | flush = |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1113 | ct_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1114 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1115 | /* Insert in hash table all strings up to the end of the match. |
| 1116 | * strstart-1 and strstart are already inserted. |
| 1117 | */ |
| 1118 | lookahead -= prev_length - 1; |
| 1119 | prev_length -= 2; |
| 1120 | do { |
| 1121 | strstart++; |
| 1122 | INSERT_STRING(strstart, hash_head); |
| 1123 | /* strstart never exceeds WSIZE-MAX_MATCH, so there are |
| 1124 | * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH |
| 1125 | * these bytes are garbage, but it does not matter since the |
| 1126 | * next lookahead bytes will always be emitted as literals. |
| 1127 | */ |
| 1128 | } while (--prev_length != 0); |
| 1129 | match_available = 0; |
| 1130 | match_length = MIN_MATCH - 1; |
| 1131 | strstart++; |
| 1132 | if (flush) |
| 1133 | FLUSH_BLOCK(0), block_start = strstart; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1134 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1135 | } else if (match_available) { |
| 1136 | /* If there was no match at the previous position, output a |
| 1137 | * single literal. If there was a match but the current match |
| 1138 | * is longer, truncate the previous match to a single literal. |
| 1139 | */ |
| 1140 | Tracevv((stderr, "%c", window[strstart - 1])); |
| 1141 | if (ct_tally(0, window[strstart - 1])) { |
| 1142 | FLUSH_BLOCK(0), block_start = strstart; |
| 1143 | } |
| 1144 | strstart++; |
| 1145 | lookahead--; |
| 1146 | } else { |
| 1147 | /* There is no previous match to compare with, wait for |
| 1148 | * the next step to decide. |
| 1149 | */ |
| 1150 | match_available = 1; |
| 1151 | strstart++; |
| 1152 | lookahead--; |
| 1153 | } |
| 1154 | Assert(strstart <= isize && lookahead <= isize, "a bit too far"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1155 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1156 | /* Make sure that we always have enough lookahead, except |
| 1157 | * at the end of the input file. We need MAX_MATCH bytes |
| 1158 | * for the next match, plus MIN_MATCH bytes to insert the |
| 1159 | * string following the next match. |
| 1160 | */ |
| 1161 | while (lookahead < MIN_LOOKAHEAD && !eofile) |
| 1162 | fill_window(); |
| 1163 | } |
| 1164 | if (match_available) |
| 1165 | ct_tally(0, window[strstart - 1]); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1166 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1167 | return FLUSH_BLOCK(1); /* eof */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1168 | } |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1169 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1170 | /* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface |
| 1171 | * Copyright (C) 1992-1993 Jean-loup Gailly |
| 1172 | * The unzip code was written and put in the public domain by Mark Adler. |
| 1173 | * Portions of the lzw code are derived from the public domain 'compress' |
| 1174 | * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies, |
| 1175 | * Ken Turkowski, Dave Mack and Peter Jannesen. |
| 1176 | * |
| 1177 | * See the license_msg below and the file COPYING for the software license. |
| 1178 | * See the file algorithm.doc for the compression algorithms and file formats. |
| 1179 | */ |
| 1180 | |
| 1181 | /* Compress files with zip algorithm and 'compress' interface. |
| 1182 | * See usage() and help() functions below for all options. |
| 1183 | * Outputs: |
| 1184 | * file.gz: compressed file with same mode, owner, and utimes |
| 1185 | * or stdout with -c option or if stdin used as input. |
| 1186 | * If the output file name had to be truncated, the original name is kept |
| 1187 | * in the compressed file. |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1188 | */ |
| 1189 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1190 | /* configuration */ |
| 1191 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1192 | typedef struct dirent dir_type; |
| 1193 | |
Erik Andersen | 61677fe | 2000-04-13 01:18:56 +0000 | [diff] [blame] | 1194 | typedef RETSIGTYPE(*sig_type) (int); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1195 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1196 | /* ======================================================================== */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1197 | int gzip_main(int argc, char **argv) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1198 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1199 | int result; |
| 1200 | int inFileNum; |
| 1201 | int outFileNum; |
| 1202 | struct stat statBuf; |
| 1203 | char *delFileName; |
| 1204 | int tostdout = 0; |
Eric Andersen | ea824fb | 2000-07-21 22:17:39 +0000 | [diff] [blame] | 1205 | int force = 0; |
Matt Kraai | 5326554 | 2001-04-18 16:05:34 +0000 | [diff] [blame] | 1206 | int opt; |
Eric Andersen | 96bcfd3 | 1999-11-12 01:30:18 +0000 | [diff] [blame] | 1207 | |
Glenn L McGrath | 5bcfc9b | 2001-05-07 12:01:58 +0000 | [diff] [blame] | 1208 | while ((opt = getopt(argc, argv, "cf123456789dq")) != -1) { |
Matt Kraai | 5326554 | 2001-04-18 16:05:34 +0000 | [diff] [blame] | 1209 | switch (opt) { |
| 1210 | case 'c': |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1211 | tostdout = 1; |
Matt Kraai | 5326554 | 2001-04-18 16:05:34 +0000 | [diff] [blame] | 1212 | break; |
| 1213 | case 'f': |
| 1214 | force = 1; |
| 1215 | break; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1216 | /* Ignore 1-9 (compression level) options */ |
| 1217 | case '1': |
| 1218 | case '2': |
| 1219 | case '3': |
| 1220 | case '4': |
| 1221 | case '5': |
| 1222 | case '6': |
| 1223 | case '7': |
| 1224 | case '8': |
| 1225 | case '9': |
Matt Kraai | 5326554 | 2001-04-18 16:05:34 +0000 | [diff] [blame] | 1226 | break; |
Glenn L McGrath | 5bcfc9b | 2001-05-07 12:01:58 +0000 | [diff] [blame] | 1227 | case 'q': |
| 1228 | break; |
Eric Andersen | bdfd0d7 | 2001-10-24 05:00:29 +0000 | [diff] [blame] | 1229 | #ifdef CONFIG_GUNZIP |
Matt Kraai | 5326554 | 2001-04-18 16:05:34 +0000 | [diff] [blame] | 1230 | case 'd': |
| 1231 | optind = 1; |
| 1232 | return gunzip_main(argc, argv); |
Glenn L McGrath | 528ef50 | 2001-04-11 03:45:37 +0000 | [diff] [blame] | 1233 | #endif |
Matt Kraai | 5326554 | 2001-04-18 16:05:34 +0000 | [diff] [blame] | 1234 | default: |
| 1235 | show_usage(); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1236 | } |
| 1237 | } |
| 1238 | |
| 1239 | foreground = signal(SIGINT, SIG_IGN) != SIG_IGN; |
| 1240 | if (foreground) { |
| 1241 | (void) signal(SIGINT, (sig_type) abort_gzip); |
| 1242 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1243 | #ifdef SIGTERM |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1244 | if (signal(SIGTERM, SIG_IGN) != SIG_IGN) { |
| 1245 | (void) signal(SIGTERM, (sig_type) abort_gzip); |
| 1246 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1247 | #endif |
| 1248 | #ifdef SIGHUP |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1249 | if (signal(SIGHUP, SIG_IGN) != SIG_IGN) { |
| 1250 | (void) signal(SIGHUP, (sig_type) abort_gzip); |
| 1251 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1252 | #endif |
| 1253 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1254 | strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1); |
| 1255 | z_len = strlen(z_suffix); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1256 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1257 | /* Allocate all global buffers (for DYN_ALLOC option) */ |
| 1258 | ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA); |
| 1259 | ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA); |
| 1260 | ALLOC(ush, d_buf, DIST_BUFSIZE); |
| 1261 | ALLOC(uch, window, 2L * WSIZE); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1262 | ALLOC(ush, tab_prefix, 1L << BITS); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1263 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1264 | clear_bufs(); |
| 1265 | part_nb = 0; |
Eric Andersen | 96bcfd3 | 1999-11-12 01:30:18 +0000 | [diff] [blame] | 1266 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1267 | if (optind == argc) { |
| 1268 | time_stamp = 0; |
| 1269 | ifile_size = -1L; |
| 1270 | zip(STDIN_FILENO, STDOUT_FILENO); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1271 | } else { |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1272 | int i; |
Eric Andersen | 96bcfd3 | 1999-11-12 01:30:18 +0000 | [diff] [blame] | 1273 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1274 | for (i = optind; i < argc; i++) { |
| 1275 | char *path = NULL; |
Eric Andersen | 96bcfd3 | 1999-11-12 01:30:18 +0000 | [diff] [blame] | 1276 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1277 | if (strcmp(argv[i], "-") == 0) { |
| 1278 | time_stamp = 0; |
| 1279 | ifile_size = -1L; |
| 1280 | inFileNum = STDIN_FILENO; |
| 1281 | outFileNum = STDOUT_FILENO; |
| 1282 | } else { |
| 1283 | inFileNum = open(argv[i], O_RDONLY); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1284 | if (inFileNum < 0 || fstat(inFileNum, &statBuf) < 0) |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1285 | perror_msg_and_die("%s", argv[i]); |
| 1286 | time_stamp = statBuf.st_ctime; |
| 1287 | ifile_size = statBuf.st_size; |
Eric Andersen | 96bcfd3 | 1999-11-12 01:30:18 +0000 | [diff] [blame] | 1288 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1289 | if (!tostdout) { |
| 1290 | path = xmalloc(strlen(argv[i]) + 4); |
| 1291 | strcpy(path, argv[i]); |
| 1292 | strcat(path, ".gz"); |
Eric Andersen | 0dfac6b | 1999-11-11 05:46:32 +0000 | [diff] [blame] | 1293 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1294 | /* Open output file */ |
Erik Andersen | 4d1d011 | 1999-12-17 18:44:15 +0000 | [diff] [blame] | 1295 | #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1296 | outFileNum = |
| 1297 | open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW); |
Erik Andersen | 4d1d011 | 1999-12-17 18:44:15 +0000 | [diff] [blame] | 1298 | #else |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1299 | outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL); |
Erik Andersen | 4d1d011 | 1999-12-17 18:44:15 +0000 | [diff] [blame] | 1300 | #endif |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1301 | if (outFileNum < 0) { |
| 1302 | perror_msg("%s", path); |
| 1303 | free(path); |
| 1304 | continue; |
| 1305 | } |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1306 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1307 | /* Set permissions on the file */ |
| 1308 | fchmod(outFileNum, statBuf.st_mode); |
| 1309 | } else |
| 1310 | outFileNum = STDOUT_FILENO; |
| 1311 | } |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1312 | |
Matt Kraai | ef8b112 | 2002-03-22 22:55:51 +0000 | [diff] [blame] | 1313 | if (path == NULL && isatty(outFileNum) && force == 0) { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1314 | error_msg |
| 1315 | ("compressed data not written to a terminal. Use -f to force compression."); |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1316 | free(path); |
| 1317 | continue; |
| 1318 | } |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1319 | |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1320 | result = zip(inFileNum, outFileNum); |
| 1321 | |
| 1322 | if (path != NULL) { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1323 | close(inFileNum); |
| 1324 | close(outFileNum); |
Matt Kraai | 9bd49d6 | 2002-02-05 22:31:48 +0000 | [diff] [blame] | 1325 | |
| 1326 | /* Delete the original file */ |
| 1327 | if (result == OK) |
| 1328 | delFileName = argv[i]; |
| 1329 | else |
| 1330 | delFileName = path; |
| 1331 | |
| 1332 | if (unlink(delFileName) < 0) |
| 1333 | perror_msg("%s", delFileName); |
| 1334 | } |
| 1335 | |
| 1336 | free(path); |
| 1337 | } |
Eric Andersen | 0dfac6b | 1999-11-11 05:46:32 +0000 | [diff] [blame] | 1338 | } |
Eric Andersen | 0dfac6b | 1999-11-11 05:46:32 +0000 | [diff] [blame] | 1339 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1340 | return (exit_code); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1341 | } |
| 1342 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1343 | /* trees.c -- output deflated data using Huffman coding |
| 1344 | * Copyright (C) 1992-1993 Jean-loup Gailly |
| 1345 | * This is free software; you can redistribute it and/or modify it under the |
| 1346 | * terms of the GNU General Public License, see the file COPYING. |
| 1347 | */ |
| 1348 | |
| 1349 | /* |
| 1350 | * PURPOSE |
| 1351 | * |
| 1352 | * Encode various sets of source values using variable-length |
| 1353 | * binary code trees. |
| 1354 | * |
| 1355 | * DISCUSSION |
| 1356 | * |
| 1357 | * The PKZIP "deflation" process uses several Huffman trees. The more |
| 1358 | * common source values are represented by shorter bit sequences. |
| 1359 | * |
| 1360 | * Each code tree is stored in the ZIP file in a compressed form |
| 1361 | * which is itself a Huffman encoding of the lengths of |
| 1362 | * all the code strings (in ascending order by source values). |
| 1363 | * The actual code strings are reconstructed from the lengths in |
| 1364 | * the UNZIP process, as described in the "application note" |
| 1365 | * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program. |
| 1366 | * |
| 1367 | * REFERENCES |
| 1368 | * |
| 1369 | * Lynch, Thomas J. |
| 1370 | * Data Compression: Techniques and Applications, pp. 53-55. |
| 1371 | * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7. |
| 1372 | * |
| 1373 | * Storer, James A. |
| 1374 | * Data Compression: Methods and Theory, pp. 49-50. |
| 1375 | * Computer Science Press, 1988. ISBN 0-7167-8156-5. |
| 1376 | * |
| 1377 | * Sedgewick, R. |
| 1378 | * Algorithms, p290. |
| 1379 | * Addison-Wesley, 1983. ISBN 0-201-06672-6. |
| 1380 | * |
| 1381 | * INTERFACE |
| 1382 | * |
| 1383 | * void ct_init (ush *attr, int *methodp) |
| 1384 | * Allocate the match buffer, initialize the various tables and save |
| 1385 | * the location of the internal file attribute (ascii/binary) and |
| 1386 | * method (DEFLATE/STORE) |
| 1387 | * |
| 1388 | * void ct_tally (int dist, int lc); |
| 1389 | * Save the match info and tally the frequency counts. |
| 1390 | * |
| 1391 | * long flush_block (char *buf, ulg stored_len, int eof) |
| 1392 | * Determine the best encoding for the current block: dynamic trees, |
| 1393 | * static trees or store, and output the encoded block to the zip |
| 1394 | * file. Returns the total compressed length for the file so far. |
| 1395 | * |
| 1396 | */ |
| 1397 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1398 | /* =========================================================================== |
| 1399 | * Constants |
| 1400 | */ |
| 1401 | |
| 1402 | #define MAX_BITS 15 |
| 1403 | /* All codes must not exceed MAX_BITS bits */ |
| 1404 | |
| 1405 | #define MAX_BL_BITS 7 |
| 1406 | /* Bit length codes must not exceed MAX_BL_BITS bits */ |
| 1407 | |
| 1408 | #define LENGTH_CODES 29 |
| 1409 | /* number of length codes, not counting the special END_BLOCK code */ |
| 1410 | |
| 1411 | #define LITERALS 256 |
| 1412 | /* number of literal bytes 0..255 */ |
| 1413 | |
| 1414 | #define END_BLOCK 256 |
| 1415 | /* end of block literal code */ |
| 1416 | |
| 1417 | #define L_CODES (LITERALS+1+LENGTH_CODES) |
| 1418 | /* number of Literal or Length codes, including the END_BLOCK code */ |
| 1419 | |
| 1420 | #define D_CODES 30 |
| 1421 | /* number of distance codes */ |
| 1422 | |
| 1423 | #define BL_CODES 19 |
| 1424 | /* number of codes used to transfer the bit lengths */ |
| 1425 | |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 1426 | typedef uch extra_bits_t; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1427 | |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 1428 | /* extra bits for each length code */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1429 | static const extra_bits_t extra_lbits[LENGTH_CODES] |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1430 | = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1431 | 4, 4, 5, 5, 5, 5, 0 |
| 1432 | }; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1433 | |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 1434 | /* extra bits for each distance code */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1435 | static const extra_bits_t extra_dbits[D_CODES] |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1436 | = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1437 | 10, 10, 11, 11, 12, 12, 13, 13 |
| 1438 | }; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1439 | |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 1440 | /* extra bits for each bit length code */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1441 | static const extra_bits_t extra_blbits[BL_CODES] |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1442 | = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 }; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1443 | |
| 1444 | #define STORED_BLOCK 0 |
| 1445 | #define STATIC_TREES 1 |
| 1446 | #define DYN_TREES 2 |
| 1447 | /* The three kinds of block type */ |
| 1448 | |
| 1449 | #ifndef LIT_BUFSIZE |
| 1450 | # ifdef SMALL_MEM |
| 1451 | # define LIT_BUFSIZE 0x2000 |
| 1452 | # else |
| 1453 | # ifdef MEDIUM_MEM |
| 1454 | # define LIT_BUFSIZE 0x4000 |
| 1455 | # else |
| 1456 | # define LIT_BUFSIZE 0x8000 |
| 1457 | # endif |
| 1458 | # endif |
| 1459 | #endif |
| 1460 | #ifndef DIST_BUFSIZE |
| 1461 | # define DIST_BUFSIZE LIT_BUFSIZE |
| 1462 | #endif |
| 1463 | /* Sizes of match buffers for literals/lengths and distances. There are |
| 1464 | * 4 reasons for limiting LIT_BUFSIZE to 64K: |
| 1465 | * - frequencies can be kept in 16 bit counters |
| 1466 | * - if compression is not successful for the first block, all input data is |
| 1467 | * still in the window so we can still emit a stored block even when input |
| 1468 | * comes from standard input. (This can also be done for all blocks if |
| 1469 | * LIT_BUFSIZE is not greater than 32K.) |
| 1470 | * - if compression is not successful for a file smaller than 64K, we can |
| 1471 | * even emit a stored file instead of a stored block (saving 5 bytes). |
| 1472 | * - creating new Huffman trees less frequently may not provide fast |
| 1473 | * adaptation to changes in the input data statistics. (Take for |
| 1474 | * example a binary file with poorly compressible code followed by |
| 1475 | * a highly compressible string table.) Smaller buffer sizes give |
| 1476 | * fast adaptation but have of course the overhead of transmitting trees |
| 1477 | * more frequently. |
| 1478 | * - I can't count above 4 |
| 1479 | * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save |
| 1480 | * memory at the expense of compression). Some optimizations would be possible |
| 1481 | * if we rely on DIST_BUFSIZE == LIT_BUFSIZE. |
| 1482 | */ |
| 1483 | #if LIT_BUFSIZE > INBUFSIZ |
Aaron Lehmann | b9df470 | 2001-12-06 03:22:43 +0000 | [diff] [blame] | 1484 | #error cannot overlay l_buf and inbuf |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1485 | #endif |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1486 | #define REP_3_6 16 |
| 1487 | /* repeat previous bit length 3-6 times (2 bits of repeat count) */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1488 | #define REPZ_3_10 17 |
| 1489 | /* repeat a zero length 3-10 times (3 bits of repeat count) */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1490 | #define REPZ_11_138 18 |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1491 | /* repeat a zero length 11-138 times (7 bits of repeat count) */ |
| 1492 | |
| 1493 | /* =========================================================================== |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1494 | * Local data |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1495 | */ |
| 1496 | |
| 1497 | /* Data structure describing a single value and its code string. */ |
| 1498 | typedef struct ct_data { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1499 | union { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1500 | ush freq; /* frequency count */ |
| 1501 | ush code; /* bit string */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1502 | } fc; |
| 1503 | union { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1504 | ush dad; /* father node in Huffman tree */ |
| 1505 | ush len; /* length of bit string */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1506 | } dl; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1507 | } ct_data; |
| 1508 | |
| 1509 | #define Freq fc.freq |
| 1510 | #define Code fc.code |
| 1511 | #define Dad dl.dad |
| 1512 | #define Len dl.len |
| 1513 | |
| 1514 | #define HEAP_SIZE (2*L_CODES+1) |
| 1515 | /* maximum heap size */ |
| 1516 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1517 | static ct_data dyn_ltree[HEAP_SIZE]; /* literal and length tree */ |
| 1518 | static ct_data dyn_dtree[2 * D_CODES + 1]; /* distance tree */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1519 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1520 | static ct_data static_ltree[L_CODES + 2]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1521 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1522 | /* The static literal tree. Since the bit lengths are imposed, there is no |
| 1523 | * need for the L_CODES extra codes used during heap construction. However |
| 1524 | * The codes 286 and 287 are needed to build a canonical tree (see ct_init |
| 1525 | * below). |
| 1526 | */ |
| 1527 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1528 | static ct_data static_dtree[D_CODES]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1529 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1530 | /* The static distance tree. (Actually a trivial tree since all codes use |
| 1531 | * 5 bits.) |
| 1532 | */ |
| 1533 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1534 | static ct_data bl_tree[2 * BL_CODES + 1]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1535 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1536 | /* Huffman tree for the bit lengths */ |
| 1537 | |
| 1538 | typedef struct tree_desc { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1539 | ct_data *dyn_tree; /* the dynamic tree */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1540 | ct_data *static_tree; /* corresponding static tree or NULL */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1541 | const extra_bits_t *extra_bits; /* extra bits for each code or NULL */ |
| 1542 | int extra_base; /* base index for extra_bits */ |
| 1543 | int elems; /* max number of elements in the tree */ |
| 1544 | int max_length; /* max bit length for the codes */ |
| 1545 | int max_code; /* largest code with non zero frequency */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1546 | } tree_desc; |
| 1547 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1548 | static tree_desc l_desc = |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1549 | { dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES, |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1550 | MAX_BITS, 0 |
| 1551 | }; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1552 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1553 | static tree_desc d_desc = |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1554 | { dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 }; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1555 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1556 | static tree_desc bl_desc = |
| 1557 | { bl_tree, (ct_data *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS, |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1558 | 0 |
| 1559 | }; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1560 | |
| 1561 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1562 | static ush bl_count[MAX_BITS + 1]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1563 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1564 | /* number of codes at each bit length for an optimal tree */ |
| 1565 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1566 | static const uch bl_order[BL_CODES] |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1567 | = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; |
| 1568 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1569 | /* The lengths of the bit length codes are sent in order of decreasing |
| 1570 | * probability, to avoid transmitting the lengths for unused bit length codes. |
| 1571 | */ |
| 1572 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1573 | static int heap[2 * L_CODES + 1]; /* heap used to build the Huffman trees */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1574 | static int heap_len; /* number of elements in the heap */ |
| 1575 | static int heap_max; /* element of largest frequency */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1576 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1577 | /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. |
| 1578 | * The same heap array is used to build all trees. |
| 1579 | */ |
| 1580 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1581 | static uch depth[2 * L_CODES + 1]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1582 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1583 | /* Depth of each subtree used as tie breaker for trees of equal frequency */ |
| 1584 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1585 | static uch length_code[MAX_MATCH - MIN_MATCH + 1]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1586 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1587 | /* length code for each normalized match length (0 == MIN_MATCH) */ |
| 1588 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1589 | static uch dist_code[512]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1590 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1591 | /* distance codes. The first 256 values correspond to the distances |
| 1592 | * 3 .. 258, the last 256 values correspond to the top 8 bits of |
| 1593 | * the 15 bit distances. |
| 1594 | */ |
| 1595 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1596 | static int base_length[LENGTH_CODES]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1597 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1598 | /* First normalized length for each code (0 = MIN_MATCH) */ |
| 1599 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1600 | static int base_dist[D_CODES]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1601 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1602 | /* First normalized distance for each code (0 = distance of 1) */ |
| 1603 | |
| 1604 | #define l_buf inbuf |
| 1605 | /* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */ |
| 1606 | |
| 1607 | /* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */ |
| 1608 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1609 | static uch flag_buf[(LIT_BUFSIZE / 8)]; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1610 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1611 | /* flag_buf is a bit array distinguishing literals from lengths in |
| 1612 | * l_buf, thus indicating the presence or absence of a distance. |
| 1613 | */ |
| 1614 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1615 | static unsigned last_lit; /* running index in l_buf */ |
| 1616 | static unsigned last_dist; /* running index in d_buf */ |
| 1617 | static unsigned last_flags; /* running index in flag_buf */ |
| 1618 | static uch flags; /* current flags not yet saved in flag_buf */ |
| 1619 | static uch flag_bit; /* current bit used in flags */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1620 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1621 | /* bits are filled in flags starting at bit 0 (least significant). |
| 1622 | * Note: these flags are overkill in the current code since we don't |
| 1623 | * take advantage of DIST_BUFSIZE == LIT_BUFSIZE. |
| 1624 | */ |
| 1625 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1626 | static ulg opt_len; /* bit length of current block with optimal trees */ |
| 1627 | static ulg static_len; /* bit length of current block with static trees */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1628 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1629 | static ulg compressed_len; /* total bit length of compressed file */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1630 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1631 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1632 | static ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */ |
| 1633 | static int *file_method; /* pointer to DEFLATE or STORE */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1634 | |
| 1635 | /* =========================================================================== |
| 1636 | * Local (static) routines in this file. |
| 1637 | */ |
| 1638 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1639 | static void init_block(void); |
| 1640 | static void pqdownheap(ct_data * tree, int k); |
| 1641 | static void gen_bitlen(tree_desc * desc); |
| 1642 | static void gen_codes(ct_data * tree, int max_code); |
| 1643 | static void build_tree(tree_desc * desc); |
| 1644 | static void scan_tree(ct_data * tree, int max_code); |
| 1645 | static void send_tree(ct_data * tree, int max_code); |
| 1646 | static int build_bl_tree(void); |
| 1647 | static void send_all_trees(int lcodes, int dcodes, int blcodes); |
| 1648 | static void compress_block(ct_data * ltree, ct_data * dtree); |
| 1649 | static void set_file_type(void); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1650 | |
| 1651 | |
| 1652 | #ifndef DEBUG |
| 1653 | # define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len) |
| 1654 | /* Send a code of the given tree. c and tree must not have side effects */ |
| 1655 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1656 | #else /* DEBUG */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1657 | # define send_code(c, tree) \ |
Glenn L McGrath | d211214 | 2002-11-28 09:22:14 +0000 | [diff] [blame] | 1658 | { if (verbose>1) error_msg("\ncd %3d ",(c)); \ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1659 | send_bits(tree[c].Code, tree[c].Len); } |
| 1660 | #endif |
| 1661 | |
| 1662 | #define d_code(dist) \ |
| 1663 | ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) |
| 1664 | /* Mapping from a distance to a distance code. dist is the distance - 1 and |
| 1665 | * must not have side effects. dist_code[256] and dist_code[257] are never |
| 1666 | * used. |
| 1667 | */ |
| 1668 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1669 | /* the arguments must not have side effects */ |
| 1670 | |
| 1671 | /* =========================================================================== |
| 1672 | * Allocate the match buffer, initialize the various tables and save the |
| 1673 | * location of the internal file attribute (ascii/binary) and method |
| 1674 | * (DEFLATE/STORE). |
| 1675 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1676 | static void ct_init(ush * attr, int *methodp) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1677 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1678 | int n; /* iterates over tree elements */ |
| 1679 | int bits; /* bit counter */ |
| 1680 | int length; /* length value */ |
| 1681 | int code; /* code value */ |
| 1682 | int dist; /* distance index */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1683 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1684 | file_type = attr; |
| 1685 | file_method = methodp; |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1686 | compressed_len = 0L; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1687 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1688 | if (static_dtree[0].Len != 0) |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1689 | return; /* ct_init already called */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1690 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1691 | /* Initialize the mapping length (0..255) -> length code (0..28) */ |
| 1692 | length = 0; |
| 1693 | for (code = 0; code < LENGTH_CODES - 1; code++) { |
| 1694 | base_length[code] = length; |
| 1695 | for (n = 0; n < (1 << extra_lbits[code]); n++) { |
| 1696 | length_code[length++] = (uch) code; |
| 1697 | } |
| 1698 | } |
| 1699 | Assert(length == 256, "ct_init: length != 256"); |
| 1700 | /* Note that the length 255 (match length 258) can be represented |
| 1701 | * in two different ways: code 284 + 5 bits or code 285, so we |
| 1702 | * overwrite length_code[255] to use the best encoding: |
| 1703 | */ |
| 1704 | length_code[length - 1] = (uch) code; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1705 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1706 | /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ |
| 1707 | dist = 0; |
| 1708 | for (code = 0; code < 16; code++) { |
| 1709 | base_dist[code] = dist; |
| 1710 | for (n = 0; n < (1 << extra_dbits[code]); n++) { |
| 1711 | dist_code[dist++] = (uch) code; |
| 1712 | } |
| 1713 | } |
| 1714 | Assert(dist == 256, "ct_init: dist != 256"); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1715 | dist >>= 7; /* from now on, all distances are divided by 128 */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1716 | for (; code < D_CODES; code++) { |
| 1717 | base_dist[code] = dist << 7; |
| 1718 | for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) { |
| 1719 | dist_code[256 + dist++] = (uch) code; |
| 1720 | } |
| 1721 | } |
| 1722 | Assert(dist == 256, "ct_init: 256+dist != 512"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1723 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1724 | /* Construct the codes of the static literal tree */ |
| 1725 | for (bits = 0; bits <= MAX_BITS; bits++) |
| 1726 | bl_count[bits] = 0; |
| 1727 | n = 0; |
| 1728 | while (n <= 143) |
| 1729 | static_ltree[n++].Len = 8, bl_count[8]++; |
| 1730 | while (n <= 255) |
| 1731 | static_ltree[n++].Len = 9, bl_count[9]++; |
| 1732 | while (n <= 279) |
| 1733 | static_ltree[n++].Len = 7, bl_count[7]++; |
| 1734 | while (n <= 287) |
| 1735 | static_ltree[n++].Len = 8, bl_count[8]++; |
| 1736 | /* Codes 286 and 287 do not exist, but we must include them in the |
| 1737 | * tree construction to get a canonical Huffman tree (longest code |
| 1738 | * all ones) |
| 1739 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1740 | gen_codes((ct_data *) static_ltree, L_CODES + 1); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1741 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1742 | /* The static distance tree is trivial: */ |
| 1743 | for (n = 0; n < D_CODES; n++) { |
| 1744 | static_dtree[n].Len = 5; |
| 1745 | static_dtree[n].Code = bi_reverse(n, 5); |
| 1746 | } |
| 1747 | |
| 1748 | /* Initialize the first block of the first file: */ |
| 1749 | init_block(); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1750 | } |
| 1751 | |
| 1752 | /* =========================================================================== |
| 1753 | * Initialize a new block. |
| 1754 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1755 | static void init_block() |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1756 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1757 | int n; /* iterates over tree elements */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1758 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1759 | /* Initialize the trees. */ |
| 1760 | for (n = 0; n < L_CODES; n++) |
| 1761 | dyn_ltree[n].Freq = 0; |
| 1762 | for (n = 0; n < D_CODES; n++) |
| 1763 | dyn_dtree[n].Freq = 0; |
| 1764 | for (n = 0; n < BL_CODES; n++) |
| 1765 | bl_tree[n].Freq = 0; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1766 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1767 | dyn_ltree[END_BLOCK].Freq = 1; |
| 1768 | opt_len = static_len = 0L; |
| 1769 | last_lit = last_dist = last_flags = 0; |
| 1770 | flags = 0; |
| 1771 | flag_bit = 1; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1772 | } |
| 1773 | |
| 1774 | #define SMALLEST 1 |
| 1775 | /* Index within the heap array of least frequent node in the Huffman tree */ |
| 1776 | |
| 1777 | |
| 1778 | /* =========================================================================== |
| 1779 | * Remove the smallest element from the heap and recreate the heap with |
| 1780 | * one less element. Updates heap and heap_len. |
| 1781 | */ |
| 1782 | #define pqremove(tree, top) \ |
| 1783 | {\ |
| 1784 | top = heap[SMALLEST]; \ |
| 1785 | heap[SMALLEST] = heap[heap_len--]; \ |
| 1786 | pqdownheap(tree, SMALLEST); \ |
| 1787 | } |
| 1788 | |
| 1789 | /* =========================================================================== |
| 1790 | * Compares to subtrees, using the tree depth as tie breaker when |
| 1791 | * the subtrees have equal frequency. This minimizes the worst case length. |
| 1792 | */ |
| 1793 | #define smaller(tree, n, m) \ |
| 1794 | (tree[n].Freq < tree[m].Freq || \ |
| 1795 | (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) |
| 1796 | |
| 1797 | /* =========================================================================== |
| 1798 | * Restore the heap property by moving down the tree starting at node k, |
| 1799 | * exchanging a node with the smallest of its two sons if necessary, stopping |
| 1800 | * when the heap property is re-established (each father smaller than its |
| 1801 | * two sons). |
| 1802 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1803 | static void pqdownheap(ct_data * tree, int k) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1804 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1805 | int v = heap[k]; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1806 | int j = k << 1; /* left son of k */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1807 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1808 | while (j <= heap_len) { |
| 1809 | /* Set j to the smallest of the two sons: */ |
| 1810 | if (j < heap_len && smaller(tree, heap[j + 1], heap[j])) |
| 1811 | j++; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1812 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1813 | /* Exit if v is smaller than both sons */ |
| 1814 | if (smaller(tree, v, heap[j])) |
| 1815 | break; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1816 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1817 | /* Exchange v with the smallest son */ |
| 1818 | heap[k] = heap[j]; |
| 1819 | k = j; |
| 1820 | |
| 1821 | /* And continue down the tree, setting j to the left son of k */ |
| 1822 | j <<= 1; |
| 1823 | } |
| 1824 | heap[k] = v; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1825 | } |
| 1826 | |
| 1827 | /* =========================================================================== |
| 1828 | * Compute the optimal bit lengths for a tree and update the total bit length |
| 1829 | * for the current block. |
| 1830 | * IN assertion: the fields freq and dad are set, heap[heap_max] and |
| 1831 | * above are the tree nodes sorted by increasing frequency. |
| 1832 | * OUT assertions: the field len is set to the optimal bit length, the |
| 1833 | * array bl_count contains the frequencies for each bit length. |
| 1834 | * The length opt_len is updated; static_len is also updated if stree is |
| 1835 | * not null. |
| 1836 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1837 | static void gen_bitlen(tree_desc * desc) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1838 | { |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1839 | ct_data *tree = desc->dyn_tree; |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 1840 | const extra_bits_t *extra = desc->extra_bits; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1841 | int base = desc->extra_base; |
| 1842 | int max_code = desc->max_code; |
| 1843 | int max_length = desc->max_length; |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1844 | ct_data *stree = desc->static_tree; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1845 | int h; /* heap index */ |
| 1846 | int n, m; /* iterate over the tree elements */ |
| 1847 | int bits; /* bit length */ |
| 1848 | int xbits; /* extra bits */ |
| 1849 | ush f; /* frequency */ |
| 1850 | int overflow = 0; /* number of elements with bit length too large */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1851 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1852 | for (bits = 0; bits <= MAX_BITS; bits++) |
| 1853 | bl_count[bits] = 0; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1854 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1855 | /* In a first pass, compute the optimal bit lengths (which may |
| 1856 | * overflow in the case of the bit length tree). |
| 1857 | */ |
| 1858 | tree[heap[heap_max]].Len = 0; /* root of the heap */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1859 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1860 | for (h = heap_max + 1; h < HEAP_SIZE; h++) { |
| 1861 | n = heap[h]; |
| 1862 | bits = tree[tree[n].Dad].Len + 1; |
| 1863 | if (bits > max_length) |
| 1864 | bits = max_length, overflow++; |
| 1865 | tree[n].Len = (ush) bits; |
| 1866 | /* We overwrite tree[n].Dad which is no longer needed */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1867 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1868 | if (n > max_code) |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1869 | continue; /* not a leaf node */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1870 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1871 | bl_count[bits]++; |
| 1872 | xbits = 0; |
| 1873 | if (n >= base) |
| 1874 | xbits = extra[n - base]; |
| 1875 | f = tree[n].Freq; |
| 1876 | opt_len += (ulg) f *(bits + xbits); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1877 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1878 | if (stree) |
| 1879 | static_len += (ulg) f *(stree[n].Len + xbits); |
| 1880 | } |
| 1881 | if (overflow == 0) |
| 1882 | return; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1883 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1884 | Trace((stderr, "\nbit length overflow\n")); |
| 1885 | /* This happens for example on obj2 and pic of the Calgary corpus */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1886 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1887 | /* Find the first bit length which could increase: */ |
| 1888 | do { |
| 1889 | bits = max_length - 1; |
| 1890 | while (bl_count[bits] == 0) |
| 1891 | bits--; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1892 | bl_count[bits]--; /* move one leaf down the tree */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1893 | bl_count[bits + 1] += 2; /* move one overflow item as its brother */ |
| 1894 | bl_count[max_length]--; |
| 1895 | /* The brother of the overflow item also moves one step up, |
| 1896 | * but this does not affect bl_count[max_length] |
| 1897 | */ |
| 1898 | overflow -= 2; |
| 1899 | } while (overflow > 0); |
| 1900 | |
| 1901 | /* Now recompute all bit lengths, scanning in increasing frequency. |
| 1902 | * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all |
| 1903 | * lengths instead of fixing only the wrong ones. This idea is taken |
| 1904 | * from 'ar' written by Haruhiko Okumura.) |
| 1905 | */ |
| 1906 | for (bits = max_length; bits != 0; bits--) { |
| 1907 | n = bl_count[bits]; |
| 1908 | while (n != 0) { |
| 1909 | m = heap[--h]; |
| 1910 | if (m > max_code) |
| 1911 | continue; |
| 1912 | if (tree[m].Len != (unsigned) bits) { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1913 | Trace((stderr, "code %d bits %d->%d\n", m, tree[m].Len, |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1914 | bits)); |
| 1915 | opt_len += |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1916 | ((long) bits - (long) tree[m].Len) * (long) tree[m].Freq; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1917 | tree[m].Len = (ush) bits; |
| 1918 | } |
| 1919 | n--; |
| 1920 | } |
| 1921 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1922 | } |
| 1923 | |
| 1924 | /* =========================================================================== |
| 1925 | * Generate the codes for a given tree and bit counts (which need not be |
| 1926 | * optimal). |
| 1927 | * IN assertion: the array bl_count contains the bit length statistics for |
| 1928 | * the given tree and the field len is set for all tree elements. |
| 1929 | * OUT assertion: the field code is set for all tree elements of non |
| 1930 | * zero code length. |
| 1931 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1932 | static void gen_codes(ct_data * tree, int max_code) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1933 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1934 | ush next_code[MAX_BITS + 1]; /* next code value for each bit length */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1935 | ush code = 0; /* running code value */ |
| 1936 | int bits; /* bit index */ |
| 1937 | int n; /* code index */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1938 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1939 | /* The distribution counts are first used to generate the code values |
| 1940 | * without bit reversal. |
| 1941 | */ |
| 1942 | for (bits = 1; bits <= MAX_BITS; bits++) { |
| 1943 | next_code[bits] = code = (code + bl_count[bits - 1]) << 1; |
| 1944 | } |
| 1945 | /* Check that the bit counts in bl_count are consistent. The last code |
| 1946 | * must be all ones. |
| 1947 | */ |
| 1948 | Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1, |
| 1949 | "inconsistent bit counts"); |
| 1950 | Tracev((stderr, "\ngen_codes: max_code %d ", max_code)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1951 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1952 | for (n = 0; n <= max_code; n++) { |
| 1953 | int len = tree[n].Len; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1954 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1955 | if (len == 0) |
| 1956 | continue; |
| 1957 | /* Now reverse the bits */ |
| 1958 | tree[n].Code = bi_reverse(next_code[len]++, len); |
| 1959 | |
| 1960 | Tracec(tree != static_ltree, |
| 1961 | (stderr, "\nn %3d %c l %2d c %4x (%x) ", n, |
| 1962 | (isgraph(n) ? n : ' '), len, tree[n].Code, |
| 1963 | next_code[len] - 1)); |
| 1964 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1965 | } |
| 1966 | |
| 1967 | /* =========================================================================== |
| 1968 | * Construct one Huffman tree and assigns the code bit strings and lengths. |
| 1969 | * Update the total bit length for the current block. |
| 1970 | * IN assertion: the field freq is set for all tree elements. |
| 1971 | * OUT assertions: the fields len and code are set to the optimal bit length |
| 1972 | * and corresponding code. The length opt_len is updated; static_len is |
| 1973 | * also updated if stree is not null. The field max_code is set. |
| 1974 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1975 | static void build_tree(tree_desc * desc) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1976 | { |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 1977 | ct_data *tree = desc->dyn_tree; |
| 1978 | ct_data *stree = desc->static_tree; |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1979 | int elems = desc->elems; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 1980 | int n, m; /* iterate over heap elements */ |
| 1981 | int max_code = -1; /* largest code with non zero frequency */ |
| 1982 | int node = elems; /* next internal node of the tree */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1983 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1984 | /* Construct the initial heap, with least frequent element in |
| 1985 | * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. |
| 1986 | * heap[0] is not used. |
| 1987 | */ |
| 1988 | heap_len = 0, heap_max = HEAP_SIZE; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1989 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1990 | for (n = 0; n < elems; n++) { |
| 1991 | if (tree[n].Freq != 0) { |
| 1992 | heap[++heap_len] = max_code = n; |
| 1993 | depth[n] = 0; |
| 1994 | } else { |
| 1995 | tree[n].Len = 0; |
| 1996 | } |
| 1997 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 1998 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 1999 | /* The pkzip format requires that at least one distance code exists, |
| 2000 | * and that at least one bit should be sent even if there is only one |
| 2001 | * possible code. So to avoid special checks later on we force at least |
| 2002 | * two codes of non zero frequency. |
| 2003 | */ |
| 2004 | while (heap_len < 2) { |
| 2005 | int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2006 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2007 | tree[new].Freq = 1; |
| 2008 | depth[new] = 0; |
| 2009 | opt_len--; |
| 2010 | if (stree) |
| 2011 | static_len -= stree[new].Len; |
| 2012 | /* new is 0 or 1 so it does not have extra bits */ |
| 2013 | } |
| 2014 | desc->max_code = max_code; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2015 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2016 | /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, |
| 2017 | * establish sub-heaps of increasing lengths: |
| 2018 | */ |
| 2019 | for (n = heap_len / 2; n >= 1; n--) |
| 2020 | pqdownheap(tree, n); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2021 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2022 | /* Construct the Huffman tree by repeatedly combining the least two |
| 2023 | * frequent nodes. |
| 2024 | */ |
| 2025 | do { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2026 | pqremove(tree, n); /* n = node of least frequency */ |
| 2027 | m = heap[SMALLEST]; /* m = node of next least frequency */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2028 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2029 | heap[--heap_max] = n; /* keep the nodes sorted by frequency */ |
| 2030 | heap[--heap_max] = m; |
| 2031 | |
| 2032 | /* Create a new node father of n and m */ |
| 2033 | tree[node].Freq = tree[n].Freq + tree[m].Freq; |
| 2034 | depth[node] = (uch) (MAX(depth[n], depth[m]) + 1); |
| 2035 | tree[n].Dad = tree[m].Dad = (ush) node; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2036 | #ifdef DUMP_BL_TREE |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2037 | if (tree == bl_tree) { |
Glenn L McGrath | d211214 | 2002-11-28 09:22:14 +0000 | [diff] [blame] | 2038 | error_msg("\nnode %d(%d), sons %d(%d) %d(%d)", |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2039 | node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2040 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2041 | #endif |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2042 | /* and insert the new node in the heap */ |
| 2043 | heap[SMALLEST] = node++; |
| 2044 | pqdownheap(tree, SMALLEST); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2045 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2046 | } while (heap_len >= 2); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2047 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2048 | heap[--heap_max] = heap[SMALLEST]; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2049 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2050 | /* At this point, the fields freq and dad are set. We can now |
| 2051 | * generate the bit lengths. |
| 2052 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2053 | gen_bitlen((tree_desc *) desc); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2054 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2055 | /* The field len is now set, we can generate the bit codes */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2056 | gen_codes((ct_data *) tree, max_code); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2057 | } |
| 2058 | |
| 2059 | /* =========================================================================== |
| 2060 | * Scan a literal or distance tree to determine the frequencies of the codes |
| 2061 | * in the bit length tree. Updates opt_len to take into account the repeat |
| 2062 | * counts. (The contribution of the bit length codes will be added later |
| 2063 | * during the construction of bl_tree.) |
| 2064 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2065 | static void scan_tree(ct_data * tree, int max_code) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2066 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2067 | int n; /* iterates over all tree elements */ |
| 2068 | int prevlen = -1; /* last emitted length */ |
| 2069 | int curlen; /* length of current code */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2070 | int nextlen = tree[0].Len; /* length of next code */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2071 | int count = 0; /* repeat count of the current code */ |
| 2072 | int max_count = 7; /* max repeat count */ |
| 2073 | int min_count = 4; /* min repeat count */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2074 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2075 | if (nextlen == 0) |
| 2076 | max_count = 138, min_count = 3; |
| 2077 | tree[max_code + 1].Len = (ush) 0xffff; /* guard */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2078 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2079 | for (n = 0; n <= max_code; n++) { |
| 2080 | curlen = nextlen; |
| 2081 | nextlen = tree[n + 1].Len; |
| 2082 | if (++count < max_count && curlen == nextlen) { |
| 2083 | continue; |
| 2084 | } else if (count < min_count) { |
| 2085 | bl_tree[curlen].Freq += count; |
| 2086 | } else if (curlen != 0) { |
| 2087 | if (curlen != prevlen) |
| 2088 | bl_tree[curlen].Freq++; |
| 2089 | bl_tree[REP_3_6].Freq++; |
| 2090 | } else if (count <= 10) { |
| 2091 | bl_tree[REPZ_3_10].Freq++; |
| 2092 | } else { |
| 2093 | bl_tree[REPZ_11_138].Freq++; |
| 2094 | } |
| 2095 | count = 0; |
| 2096 | prevlen = curlen; |
| 2097 | if (nextlen == 0) { |
| 2098 | max_count = 138, min_count = 3; |
| 2099 | } else if (curlen == nextlen) { |
| 2100 | max_count = 6, min_count = 3; |
| 2101 | } else { |
| 2102 | max_count = 7, min_count = 4; |
| 2103 | } |
| 2104 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2105 | } |
| 2106 | |
| 2107 | /* =========================================================================== |
| 2108 | * Send a literal or distance tree in compressed form, using the codes in |
| 2109 | * bl_tree. |
| 2110 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2111 | static void send_tree(ct_data * tree, int max_code) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2112 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2113 | int n; /* iterates over all tree elements */ |
| 2114 | int prevlen = -1; /* last emitted length */ |
| 2115 | int curlen; /* length of current code */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2116 | int nextlen = tree[0].Len; /* length of next code */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2117 | int count = 0; /* repeat count of the current code */ |
| 2118 | int max_count = 7; /* max repeat count */ |
| 2119 | int min_count = 4; /* min repeat count */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2120 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2121 | /* tree[max_code+1].Len = -1; *//* guard already set */ |
| 2122 | if (nextlen == 0) |
| 2123 | max_count = 138, min_count = 3; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2124 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2125 | for (n = 0; n <= max_code; n++) { |
| 2126 | curlen = nextlen; |
| 2127 | nextlen = tree[n + 1].Len; |
| 2128 | if (++count < max_count && curlen == nextlen) { |
| 2129 | continue; |
| 2130 | } else if (count < min_count) { |
| 2131 | do { |
| 2132 | send_code(curlen, bl_tree); |
| 2133 | } while (--count != 0); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2134 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2135 | } else if (curlen != 0) { |
| 2136 | if (curlen != prevlen) { |
| 2137 | send_code(curlen, bl_tree); |
| 2138 | count--; |
| 2139 | } |
| 2140 | Assert(count >= 3 && count <= 6, " 3_6?"); |
| 2141 | send_code(REP_3_6, bl_tree); |
| 2142 | send_bits(count - 3, 2); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2143 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2144 | } else if (count <= 10) { |
| 2145 | send_code(REPZ_3_10, bl_tree); |
| 2146 | send_bits(count - 3, 3); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2147 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2148 | } else { |
| 2149 | send_code(REPZ_11_138, bl_tree); |
| 2150 | send_bits(count - 11, 7); |
| 2151 | } |
| 2152 | count = 0; |
| 2153 | prevlen = curlen; |
| 2154 | if (nextlen == 0) { |
| 2155 | max_count = 138, min_count = 3; |
| 2156 | } else if (curlen == nextlen) { |
| 2157 | max_count = 6, min_count = 3; |
| 2158 | } else { |
| 2159 | max_count = 7, min_count = 4; |
| 2160 | } |
| 2161 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2162 | } |
| 2163 | |
| 2164 | /* =========================================================================== |
| 2165 | * Construct the Huffman tree for the bit lengths and return the index in |
| 2166 | * bl_order of the last bit length code to send. |
| 2167 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2168 | static const int build_bl_tree() |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2169 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2170 | int max_blindex; /* index of last bit length code of non zero freq */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2171 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2172 | /* Determine the bit length frequencies for literal and distance trees */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2173 | scan_tree((ct_data *) dyn_ltree, l_desc.max_code); |
| 2174 | scan_tree((ct_data *) dyn_dtree, d_desc.max_code); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2175 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2176 | /* Build the bit length tree: */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2177 | build_tree((tree_desc *) (&bl_desc)); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2178 | /* opt_len now includes the length of the tree representations, except |
| 2179 | * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. |
| 2180 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2181 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2182 | /* Determine the number of bit length codes to send. The pkzip format |
| 2183 | * requires that at least 4 bit length codes be sent. (appnote.txt says |
| 2184 | * 3 but the actual value used is 4.) |
| 2185 | */ |
| 2186 | for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) { |
| 2187 | if (bl_tree[bl_order[max_blindex]].Len != 0) |
| 2188 | break; |
| 2189 | } |
| 2190 | /* Update opt_len to include the bit length tree and counts */ |
| 2191 | opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2192 | Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2193 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2194 | return max_blindex; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2195 | } |
| 2196 | |
| 2197 | /* =========================================================================== |
| 2198 | * Send the header for a block using dynamic Huffman trees: the counts, the |
| 2199 | * lengths of the bit length codes, the literal tree and the distance tree. |
| 2200 | * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. |
| 2201 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2202 | static void send_all_trees(int lcodes, int dcodes, int blcodes) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2203 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2204 | int rank; /* index in bl_order */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2205 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2206 | Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2207 | Assert(lcodes <= L_CODES && dcodes <= D_CODES |
| 2208 | && blcodes <= BL_CODES, "too many codes"); |
| 2209 | Tracev((stderr, "\nbl counts: ")); |
| 2210 | send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */ |
| 2211 | send_bits(dcodes - 1, 5); |
| 2212 | send_bits(blcodes - 4, 4); /* not -3 as stated in appnote.txt */ |
| 2213 | for (rank = 0; rank < blcodes; rank++) { |
| 2214 | Tracev((stderr, "\nbl code %2d ", bl_order[rank])); |
| 2215 | send_bits(bl_tree[bl_order[rank]].Len, 3); |
| 2216 | } |
| 2217 | Tracev((stderr, "\nbl tree: sent %ld", bits_sent)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2218 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2219 | send_tree((ct_data *) dyn_ltree, lcodes - 1); /* send the literal tree */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2220 | Tracev((stderr, "\nlit tree: sent %ld", bits_sent)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2221 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2222 | send_tree((ct_data *) dyn_dtree, dcodes - 1); /* send the distance tree */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2223 | Tracev((stderr, "\ndist tree: sent %ld", bits_sent)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2224 | } |
| 2225 | |
| 2226 | /* =========================================================================== |
| 2227 | * Determine the best encoding for the current block: dynamic trees, static |
| 2228 | * trees or store, and output the encoded block to the zip file. This function |
| 2229 | * returns the total compressed length for the file so far. |
| 2230 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2231 | static ulg flush_block(char *buf, ulg stored_len, int eof) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2232 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2233 | ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2234 | int max_blindex; /* index of last bit length code of non zero freq */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2235 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2236 | flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2237 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2238 | /* Check if the file is ascii or binary */ |
| 2239 | if (*file_type == (ush) UNKNOWN) |
| 2240 | set_file_type(); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2241 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2242 | /* Construct the literal and distance trees */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2243 | build_tree((tree_desc *) (&l_desc)); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2244 | Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2245 | |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2246 | build_tree((tree_desc *) (&d_desc)); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2247 | Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len)); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2248 | /* At this point, opt_len and static_len are the total bit lengths of |
| 2249 | * the compressed block data, excluding the tree representations. |
| 2250 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2251 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2252 | /* Build the bit length tree for the above two trees, and get the index |
| 2253 | * in bl_order of the last bit length code to send. |
| 2254 | */ |
| 2255 | max_blindex = build_bl_tree(); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2256 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2257 | /* Determine the best encoding. Compute first the block length in bytes */ |
| 2258 | opt_lenb = (opt_len + 3 + 7) >> 3; |
| 2259 | static_lenb = (static_len + 3 + 7) >> 3; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2260 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2261 | Trace((stderr, |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2262 | "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ", |
| 2263 | opt_lenb, opt_len, static_lenb, static_len, stored_len, |
| 2264 | last_lit, last_dist)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2265 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2266 | if (static_lenb <= opt_lenb) |
| 2267 | opt_lenb = static_lenb; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2268 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2269 | /* If compression failed and this is the first and last block, |
| 2270 | * and if the zip file can be seeked (to rewrite the local header), |
| 2271 | * the whole file is transformed into a stored file: |
| 2272 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2273 | if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2274 | /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ |
| 2275 | if (buf == (char *) 0) |
Matt Kraai | dd19c69 | 2001-01-31 19:00:21 +0000 | [diff] [blame] | 2276 | error_msg("block vanished"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2277 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2278 | copy_block(buf, (unsigned) stored_len, 0); /* without header */ |
| 2279 | compressed_len = stored_len << 3; |
| 2280 | *file_method = STORED; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2281 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2282 | } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) { |
| 2283 | /* 4: two words for the lengths */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2284 | /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. |
| 2285 | * Otherwise we can't have processed more than WSIZE input bytes since |
| 2286 | * the last block flush, because compression would have been |
| 2287 | * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to |
| 2288 | * transform a block into a stored block. |
| 2289 | */ |
| 2290 | send_bits((STORED_BLOCK << 1) + eof, 3); /* send block type */ |
| 2291 | compressed_len = (compressed_len + 3 + 7) & ~7L; |
| 2292 | compressed_len += (stored_len + 4) << 3; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2293 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2294 | copy_block(buf, (unsigned) stored_len, 1); /* with header */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2295 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2296 | } else if (static_lenb == opt_lenb) { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2297 | send_bits((STATIC_TREES << 1) + eof, 3); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2298 | compress_block((ct_data *) static_ltree, (ct_data *) static_dtree); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2299 | compressed_len += 3 + static_len; |
| 2300 | } else { |
| 2301 | send_bits((DYN_TREES << 1) + eof, 3); |
| 2302 | send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, |
| 2303 | max_blindex + 1); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2304 | compress_block((ct_data *) dyn_ltree, (ct_data *) dyn_dtree); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2305 | compressed_len += 3 + opt_len; |
| 2306 | } |
| 2307 | Assert(compressed_len == bits_sent, "bad compressed size"); |
| 2308 | init_block(); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2309 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2310 | if (eof) { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2311 | bi_windup(); |
| 2312 | compressed_len += 7; /* align on byte boundary */ |
| 2313 | } |
| 2314 | Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3, |
| 2315 | compressed_len - 7 * eof)); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2316 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2317 | return compressed_len >> 3; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2318 | } |
| 2319 | |
| 2320 | /* =========================================================================== |
| 2321 | * Save the match info and tally the frequency counts. Return true if |
| 2322 | * the current block must be flushed. |
| 2323 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2324 | static int ct_tally(int dist, int lc) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2325 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2326 | l_buf[last_lit++] = (uch) lc; |
| 2327 | if (dist == 0) { |
| 2328 | /* lc is the unmatched char */ |
| 2329 | dyn_ltree[lc].Freq++; |
| 2330 | } else { |
| 2331 | /* Here, lc is the match length - MIN_MATCH */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2332 | dist--; /* dist = match distance - 1 */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2333 | Assert((ush) dist < (ush) MAX_DIST && |
| 2334 | (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) && |
| 2335 | (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2336 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2337 | dyn_ltree[length_code[lc] + LITERALS + 1].Freq++; |
| 2338 | dyn_dtree[d_code(dist)].Freq++; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2339 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2340 | d_buf[last_dist++] = (ush) dist; |
| 2341 | flags |= flag_bit; |
| 2342 | } |
| 2343 | flag_bit <<= 1; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2344 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2345 | /* Output the flags if they fill a byte: */ |
| 2346 | if ((last_lit & 7) == 0) { |
| 2347 | flag_buf[last_flags++] = flags; |
| 2348 | flags = 0, flag_bit = 1; |
| 2349 | } |
| 2350 | /* Try to guess if it is profitable to stop the current block here */ |
| 2351 | if ((last_lit & 0xfff) == 0) { |
| 2352 | /* Compute an upper bound for the compressed length */ |
| 2353 | ulg out_length = (ulg) last_lit * 8L; |
| 2354 | ulg in_length = (ulg) strstart - block_start; |
| 2355 | int dcode; |
| 2356 | |
| 2357 | for (dcode = 0; dcode < D_CODES; dcode++) { |
| 2358 | out_length += |
| 2359 | (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]); |
| 2360 | } |
| 2361 | out_length >>= 3; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2362 | Trace((stderr, |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2363 | "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ", |
| 2364 | last_lit, last_dist, in_length, out_length, |
| 2365 | 100L - out_length * 100L / in_length)); |
| 2366 | if (last_dist < last_lit / 2 && out_length < in_length / 2) |
| 2367 | return 1; |
| 2368 | } |
| 2369 | return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE); |
| 2370 | /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K |
| 2371 | * on 16 bit machines and because stored blocks are restricted to |
| 2372 | * 64K-1 bytes. |
| 2373 | */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2374 | } |
| 2375 | |
| 2376 | /* =========================================================================== |
| 2377 | * Send the block data compressed using the given Huffman trees |
| 2378 | */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2379 | static void compress_block(ct_data * ltree, ct_data * dtree) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2380 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2381 | unsigned dist; /* distance of matched string */ |
| 2382 | int lc; /* match length or unmatched char (if dist == 0) */ |
| 2383 | unsigned lx = 0; /* running index in l_buf */ |
| 2384 | unsigned dx = 0; /* running index in d_buf */ |
| 2385 | unsigned fx = 0; /* running index in flag_buf */ |
| 2386 | uch flag = 0; /* current flags */ |
| 2387 | unsigned code; /* the code to send */ |
| 2388 | int extra; /* number of extra bits to send */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2389 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2390 | if (last_lit != 0) |
| 2391 | do { |
| 2392 | if ((lx & 7) == 0) |
| 2393 | flag = flag_buf[fx++]; |
| 2394 | lc = l_buf[lx++]; |
| 2395 | if ((flag & 1) == 0) { |
| 2396 | send_code(lc, ltree); /* send a literal byte */ |
| 2397 | Tracecv(isgraph(lc), (stderr, " '%c' ", lc)); |
| 2398 | } else { |
| 2399 | /* Here, lc is the match length - MIN_MATCH */ |
| 2400 | code = length_code[lc]; |
| 2401 | send_code(code + LITERALS + 1, ltree); /* send the length code */ |
| 2402 | extra = extra_lbits[code]; |
| 2403 | if (extra != 0) { |
| 2404 | lc -= base_length[code]; |
| 2405 | send_bits(lc, extra); /* send the extra length bits */ |
| 2406 | } |
| 2407 | dist = d_buf[dx++]; |
| 2408 | /* Here, dist is the match distance - 1 */ |
| 2409 | code = d_code(dist); |
| 2410 | Assert(code < D_CODES, "bad d_code"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2411 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2412 | send_code(code, dtree); /* send the distance code */ |
| 2413 | extra = extra_dbits[code]; |
| 2414 | if (extra != 0) { |
| 2415 | dist -= base_dist[code]; |
| 2416 | send_bits(dist, extra); /* send the extra distance bits */ |
| 2417 | } |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2418 | } /* literal or match pair ? */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2419 | flag >>= 1; |
| 2420 | } while (lx < last_lit); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2421 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2422 | send_code(END_BLOCK, ltree); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2423 | } |
| 2424 | |
| 2425 | /* =========================================================================== |
| 2426 | * Set the file type to ASCII or BINARY, using a crude approximation: |
| 2427 | * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. |
| 2428 | * IN assertion: the fields freq of dyn_ltree are set and the total of all |
| 2429 | * frequencies does not exceed 64K (to fit in an int on 16 bit machines). |
| 2430 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2431 | static void set_file_type() |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2432 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2433 | int n = 0; |
| 2434 | unsigned ascii_freq = 0; |
| 2435 | unsigned bin_freq = 0; |
| 2436 | |
| 2437 | while (n < 7) |
| 2438 | bin_freq += dyn_ltree[n++].Freq; |
| 2439 | while (n < 128) |
| 2440 | ascii_freq += dyn_ltree[n++].Freq; |
| 2441 | while (n < LITERALS) |
| 2442 | bin_freq += dyn_ltree[n++].Freq; |
| 2443 | *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII; |
| 2444 | if (*file_type == BINARY && translate_eol) { |
Matt Kraai | dd19c69 | 2001-01-31 19:00:21 +0000 | [diff] [blame] | 2445 | error_msg("-l used on binary file"); |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2446 | } |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2447 | } |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2448 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2449 | /* zip.c -- compress files to the gzip or pkzip format |
| 2450 | * Copyright (C) 1992-1993 Jean-loup Gailly |
| 2451 | * This is free software; you can redistribute it and/or modify it under the |
| 2452 | * terms of the GNU General Public License, see the file COPYING. |
| 2453 | */ |
| 2454 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2455 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2456 | static ulg crc; /* crc on uncompressed file data */ |
| 2457 | static long header_bytes; /* number of bytes in gzip header */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2458 | |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 2459 | static void put_long(ulg n) |
| 2460 | { |
Aaron Lehmann | b9df470 | 2001-12-06 03:22:43 +0000 | [diff] [blame] | 2461 | put_short((n) & 0xffff); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2462 | put_short(((ulg) (n)) >> 16); |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 2463 | } |
| 2464 | |
| 2465 | /* put_header_byte is used for the compressed output |
| 2466 | * - for the initial 4 bytes that can't overflow the buffer. |
| 2467 | */ |
| 2468 | #define put_header_byte(c) {outbuf[outcnt++]=(uch)(c);} |
| 2469 | |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2470 | /* =========================================================================== |
| 2471 | * Deflate in to out. |
| 2472 | * IN assertions: the input and output buffers are cleared. |
| 2473 | * The variables time_stamp and save_orig_name are initialized. |
| 2474 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2475 | static int zip(int in, int out) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2476 | { |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2477 | uch my_flags = 0; /* general purpose bit flags */ |
| 2478 | ush attr = 0; /* ascii/binary flag */ |
| 2479 | ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2480 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2481 | ifd = in; |
| 2482 | ofd = out; |
| 2483 | outcnt = 0; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2484 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2485 | /* Write the header to the gzip file. See algorithm.doc for the format */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2486 | |
Eric Andersen | 96bcfd3 | 1999-11-12 01:30:18 +0000 | [diff] [blame] | 2487 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2488 | method = DEFLATED; |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2489 | put_header_byte(GZIP_MAGIC[0]); /* magic header */ |
Eric Andersen | 39eb040 | 2001-08-22 04:15:47 +0000 | [diff] [blame] | 2490 | put_header_byte(GZIP_MAGIC[1]); |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2491 | put_header_byte(DEFLATED); /* compression method */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2492 | |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2493 | put_header_byte(my_flags); /* general flags */ |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2494 | put_long(time_stamp); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2495 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2496 | /* Write deflated file to zip file */ |
| 2497 | crc = updcrc(0, 0); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2498 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2499 | bi_init(out); |
| 2500 | ct_init(&attr, &method); |
| 2501 | lm_init(&deflate_flags); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2502 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2503 | put_byte((uch) deflate_flags); /* extra flags */ |
Glenn L McGrath | d827e8b | 2002-08-22 13:21:26 +0000 | [diff] [blame] | 2504 | put_byte(OS_CODE); /* OS identifier */ |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2505 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2506 | header_bytes = (long) outcnt; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2507 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2508 | (void) deflate(); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2509 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2510 | /* Write the crc and uncompressed size */ |
| 2511 | put_long(crc); |
| 2512 | put_long(isize); |
| 2513 | header_bytes += 2 * sizeof(long); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2514 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2515 | flush_outbuf(); |
| 2516 | return OK; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2517 | } |
| 2518 | |
| 2519 | |
| 2520 | /* =========================================================================== |
| 2521 | * Read a new buffer from the current input file, perform end-of-line |
| 2522 | * translation, and update the crc and input file size. |
| 2523 | * IN assertion: size >= 2 (for end-of-line translation) |
| 2524 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2525 | static int file_read(char *buf, unsigned size) |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2526 | { |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2527 | unsigned len; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2528 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2529 | Assert(insize == 0, "inbuf not empty"); |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2530 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2531 | len = read(ifd, buf, size); |
| 2532 | if (len == (unsigned) (-1) || len == 0) |
| 2533 | return (int) len; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2534 | |
Erik Andersen | e49d5ec | 2000-02-08 19:58:47 +0000 | [diff] [blame] | 2535 | crc = updcrc((uch *) buf, len); |
| 2536 | isize += (ulg) len; |
| 2537 | return (int) len; |
Eric Andersen | cc8ed39 | 1999-10-05 16:24:54 +0000 | [diff] [blame] | 2538 | } |
Matt Kraai | 7918e1f | 2000-11-08 06:52:57 +0000 | [diff] [blame] | 2539 | |
| 2540 | /* =========================================================================== |
| 2541 | * Write the output buffer outbuf[0..outcnt-1] and update bytes_out. |
| 2542 | * (used for the compressed data only) |
| 2543 | */ |
Eric Andersen | 3073dfb | 2001-07-02 17:57:32 +0000 | [diff] [blame] | 2544 | static void flush_outbuf() |
Matt Kraai | 7918e1f | 2000-11-08 06:52:57 +0000 | [diff] [blame] | 2545 | { |
| 2546 | if (outcnt == 0) |
| 2547 | return; |
| 2548 | |
| 2549 | write_buf(ofd, (char *) outbuf, outcnt); |
Matt Kraai | 7918e1f | 2000-11-08 06:52:57 +0000 | [diff] [blame] | 2550 | outcnt = 0; |
| 2551 | } |