1 /* 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1995-2022 Wolfram Schneider <wosch@FreeBSD.org> 5 * Copyright (c) 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * James A. Woods. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if 0 37 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1989, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 static char sccsid[] = "@(#)locate.code.c 8.1 (Berkeley) 6/6/93"; 45 #endif /* not lint */ 46 #endif 47 48 /* 49 * PURPOSE: sorted list compressor (works with a modified 'find' 50 * to encode/decode a filename database) 51 * 52 * USAGE: bigram < list > bigrams 53 * process bigrams (see updatedb) > common_bigrams 54 * code common_bigrams < list > squozen_list 55 * 56 * METHOD: Uses 'front compression' (see ";login:", Volume 8, Number 1 57 * February/March 1983, p. 8). Output format is, per line, an 58 * offset differential count byte followed by a partially bigram- 59 * encoded ascii residue. A bigram is a two-character sequence, 60 * the first 128 most common of which are encoded in one byte. 61 * 62 * EXAMPLE: For simple front compression with no bigram encoding, 63 * if the input is... then the output is... 64 * 65 * /usr/src 0 /usr/src 66 * /usr/src/cmd/aardvark.c 8 /cmd/aardvark.c 67 * /usr/src/cmd/armadillo.c 14 armadillo.c 68 * /usr/tmp/zoo 5 tmp/zoo 69 * 70 * The codes are: 71 * 72 * 0-28 likeliest differential counts + offset to make nonnegative 73 * 30 switch code for out-of-range count to follow in next word 74 * 31 an 8 bit char followed 75 * 128-255 bigram codes (128 most common, as determined by 'updatedb') 76 * 32-127 single character (printable) ascii residue (ie, literal) 77 * 78 * The locate database store any character except newline ('\n') 79 * and NUL ('\0'). The 8-bit character support don't wast extra 80 * space until you have characters in file names less than 32 81 * or greather than 127. 82 * 83 * 84 * SEE ALSO: updatedb.sh, ../bigram/locate.bigram.c 85 * 86 * AUTHOR: James A. Woods, Informatics General Corp., 87 * NASA Ames Research Center, 10/82 88 * 8-bit file names characters: 89 * Wolfram Schneider, Berlin September 1996 90 */ 91 92 #include <sys/param.h> 93 #include <err.h> 94 #include <errno.h> 95 #include <stdlib.h> 96 #include <string.h> 97 #include <stdio.h> 98 #include <unistd.h> 99 #include "locate.h" 100 101 #define BGBUFSIZE (NBG * 2) /* size of bigram buffer */ 102 103 u_char buf1[LOCATE_PATH_MAX] = " "; 104 u_char buf2[LOCATE_PATH_MAX]; 105 u_char bigrams[BGBUFSIZE + 1] = { 0 }; 106 107 /* use a lookup array instead a function, 3x faster than linear search */ 108 int big [UCHAR_MAX + 1][UCHAR_MAX + 1]; 109 #define BGINDEX(x) (big[(u_char)*x][(u_char)*(x + 1)]) 110 111 void usage(void); 112 113 int 114 main(int argc, char *argv[]) 115 { 116 u_char *cp, *oldpath, *path; 117 int ch, code, count, diffcount, oldcount; 118 u_int i, j; 119 FILE *fp; 120 121 while ((ch = getopt(argc, argv, "")) != -1) 122 switch(ch) { 123 default: 124 usage(); 125 } 126 argc -= optind; 127 argv += optind; 128 129 if (argc != 1) 130 usage(); 131 132 if ((fp = fopen(argv[0], "r")) == NULL) 133 err(1, "%s", argv[0]); 134 135 /* First copy bigram array to stdout. */ 136 if (fgets(bigrams, BGBUFSIZE + 1, fp) == NULL) { 137 if (!feof(fp) || ferror(fp)) 138 err(1, "get bigram array"); 139 } 140 141 if (fwrite(bigrams, 1, BGBUFSIZE, stdout) != BGBUFSIZE) 142 err(1, "stdout"); 143 (void)fclose(fp); 144 145 /* init lookup table */ 146 for (i = 0; i < UCHAR_MAX + 1; i++) 147 for (j = 0; j < UCHAR_MAX + 1; j++) 148 big[i][j] = -1; 149 150 for (cp = bigrams, i = 0; *cp != '\0'; i += 2, cp += 2) 151 big[(u_char)*cp][(u_char)*(cp + 1)] = i; 152 153 oldpath = buf1; 154 path = buf2; 155 oldcount = 0; 156 157 while (fgets(path, sizeof(buf2), stdin) != NULL) { 158 159 /* skip empty lines */ 160 if (*path == '\n') 161 continue; 162 163 /* remove newline */ 164 for (cp = path; *cp != '\0'; cp++) { 165 /* chop newline */ 166 if (*cp == '\n') 167 *cp = '\0'; 168 } 169 170 /* Skip longest common prefix. */ 171 for (cp = path; *cp == *oldpath; cp++, oldpath++) 172 if (*cp == '\0') 173 break; 174 175 count = cp - path; 176 diffcount = count - oldcount + OFFSET; 177 oldcount = count; 178 if (diffcount < 0 || diffcount > 2 * OFFSET) { 179 if (putchar(SWITCH) == EOF || 180 putw(diffcount, stdout) == EOF) 181 err(1, "stdout"); 182 } else 183 if (putchar(diffcount) == EOF) 184 err(1, "stdout"); 185 186 while (*cp != '\0') { 187 /* print *two* characters */ 188 189 if ((code = BGINDEX(cp)) != -1) { 190 /* 191 * print *one* as bigram 192 * Found, so mark byte with 193 * parity bit. 194 */ 195 if (putchar((code / 2) | PARITY) == EOF) 196 err(1, "stdout"); 197 cp += 2; 198 } 199 200 else { 201 for (i = 0; i < 2; i++) { 202 if (*cp == '\0') 203 break; 204 205 /* print umlauts in file names */ 206 if (*cp < ASCII_MIN || 207 *cp > ASCII_MAX) { 208 if (putchar(UMLAUT) == EOF || 209 putchar(*cp++) == EOF) 210 err(1, "stdout"); 211 } 212 213 else { 214 /* normal character */ 215 if(putchar(*cp++) == EOF) 216 err(1, "stdout"); 217 } 218 } 219 220 } 221 } 222 223 if (path == buf1) { /* swap pointers */ 224 path = buf2; 225 oldpath = buf1; 226 } else { 227 path = buf1; 228 oldpath = buf2; 229 } 230 } 231 232 /* Non-zero status if there were errors */ 233 if (fflush(stdout) != 0 || ferror(stdout)) 234 errx(1, "stdout"); 235 236 exit(0); 237 } 238 239 void 240 usage(void) 241 { 242 (void)fprintf(stderr, 243 "usage: locate.code common_bigrams < list > squozen_list\n"); 244 exit(1); 245 } 246