1 /*
2 * Copyright (c) 1995 Wolfram Schneider <wosch@FreeBSD.org>. Berlin.
3 * Copyright (c) 1989, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * James A. Woods.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * $FreeBSD: src/usr.bin/locate/code/locate.code.c,v 1.11.2.1 2001/03/04 08:46:46 kris Exp $
38 *
39 * @(#) Copyright (c) 1989, 1993 The Regents of the University of California. All rights reserved.
40 * @(#)locate.code.c 8.1 (Berkeley) 6/6/93
41 */
42
43 /*
44 * PURPOSE: sorted list compressor (works with a modified 'find'
45 * to encode/decode a filename database)
46 *
47 * USAGE: bigram < list > bigrams
48 * process bigrams (see updatedb) > common_bigrams
49 * code common_bigrams < list > squozen_list
50 *
51 * METHOD: Uses 'front compression' (see ";login:", Volume 8, Number 1
52 * February/March 1983, p. 8). Output format is, per line, an
53 * offset differential count byte followed by a partially bigram-
54 * encoded ascii residue. A bigram is a two-character sequence,
55 * the first 128 most common of which are encoded in one byte.
56 *
57 * EXAMPLE: For simple front compression with no bigram encoding,
58 * if the input is... then the output is...
59 *
60 * /usr/src 0 /usr/src
61 * /usr/src/cmd/aardvark.c 8 /cmd/aardvark.c
62 * /usr/src/cmd/armadillo.c 14 armadillo.c
63 * /usr/tmp/zoo 5 tmp/zoo
64 *
65 * The codes are:
66 *
67 * 0-28 likeliest differential counts + offset to make nonnegative
68 * 30 switch code for out-of-range count to follow in next word
69 * 31 an 8 bit char followed
70 * 128-255 bigram codes (128 most common, as determined by 'updatedb')
71 * 32-127 single character (printable) ascii residue (ie, literal)
72 *
73 * The locate database store any character except newline ('\n')
74 * and NUL ('\0'). The 8-bit character support don't wast extra
75 * space until you have characters in file names less than 32
76 * or greather than 127.
77 *
78 *
79 * SEE ALSO: updatedb.sh, ../bigram/locate.bigram.c
80 *
81 * AUTHOR: James A. Woods, Informatics General Corp.,
82 * NASA Ames Research Center, 10/82
83 * 8-bit file names characters:
84 * Wolfram Schneider, Berlin September 1996
85 */
86
87 #include <sys/param.h>
88 #include <err.h>
89 #include <errno.h>
90 #include <stdlib.h>
91 #include <string.h>
92 #include <stdio.h>
93 #include <unistd.h>
94 #include "locate.h"
95
96 #define BGBUFSIZE (NBG * 2) /* size of bigram buffer */
97
98 static u_char buf1[MAXPATHLEN] = " ";
99 static u_char buf2[MAXPATHLEN];
100 static u_char bigrams[BGBUFSIZE + 1] = { 0 };
101
102 #define LOOKUP 1 /* use a lookup array instead a function, 3x faster */
103
104 #ifdef LOOKUP
105 #define BGINDEX(x) (big[(u_char)*x][(u_char)*(x + 1)])
106 typedef short bg_t;
107 static bg_t big[UCHAR_MAX + 1][UCHAR_MAX + 1];
108 #else
109 #define BGINDEX(x) bgindex(x)
110 typedef int bg_t;
111 static int bgindex(char *);
112 #endif /* LOOKUP */
113
114
115 static void usage(void) __dead2;
116
117 int
main(int argc,char * argv[])118 main(int argc, char *argv[])
119 {
120 u_char *cp, *oldpath, *path;
121 int ch, code, count, diffcount, oldcount;
122 FILE *fp;
123 int i, j;
124
125 while ((ch = getopt(argc, argv, "")) != -1)
126 switch(ch) {
127 default:
128 usage();
129 }
130 argc -= optind;
131 argv += optind;
132
133 if (argc != 1)
134 usage();
135
136 if ((fp = fopen(argv[0], "r")) == NULL)
137 err(1, "%s", argv[0]);
138
139 /* First copy bigram array to stdout. */
140 (void)fgets(bigrams, BGBUFSIZE + 1, fp);
141
142 if (fwrite(bigrams, 1, BGBUFSIZE, stdout) != BGBUFSIZE)
143 err(1, "stdout");
144 (void)fclose(fp);
145
146 #ifdef LOOKUP
147 /* init lookup table */
148 for (i = 0; i < UCHAR_MAX + 1; i++)
149 for (j = 0; j < UCHAR_MAX + 1; j++)
150 big[i][j] = (bg_t)-1;
151
152 for (cp = bigrams, i = 0; *cp != '\0'; i += 2, cp += 2)
153 big[(u_char)*cp][(u_char)*(cp + 1)] = (bg_t)i;
154
155 #endif /* LOOKUP */
156
157 oldpath = buf1;
158 path = buf2;
159 oldcount = 0;
160
161 while (fgets(path, sizeof(buf2), stdin) != NULL) {
162
163 /* skip empty lines */
164 if (*path == '\n')
165 continue;
166
167 /* remove newline */
168 for (cp = path; *cp != '\0'; cp++) {
169 #ifndef LOCATE_CHAR30
170 /* old locate implementations core'd for char 30 */
171 if (*cp == SWITCH)
172 *cp = '?';
173 else
174 #endif /* !LOCATE_CHAR30 */
175
176 /* chop newline */
177 if (*cp == '\n')
178 *cp = '\0';
179 }
180
181 /* Skip longest common prefix. */
182 for (cp = path; *cp == *oldpath; cp++, oldpath++)
183 if (*cp == '\0')
184 break;
185
186 count = cp - path;
187 diffcount = count - oldcount + OFFSET;
188 oldcount = count;
189 if (diffcount < 0 || diffcount > 2 * OFFSET) {
190 if (putchar(SWITCH) == EOF ||
191 putw(diffcount, stdout) == EOF)
192 err(1, "stdout");
193 } else
194 if (putchar(diffcount) == EOF)
195 err(1, "stdout");
196
197 while (*cp != '\0') {
198 /* print *two* characters */
199
200 if ((code = BGINDEX(cp)) != (bg_t)-1) {
201 /*
202 * print *one* as bigram
203 * Found, so mark byte with
204 * parity bit.
205 */
206 if (putchar((code / 2) | PARITY) == EOF)
207 err(1, "stdout");
208 cp += 2;
209 }
210
211 else {
212 for (i = 0; i < 2; i++) {
213 if (*cp == '\0')
214 break;
215
216 /* print umlauts in file names */
217 if (*cp < ASCII_MIN ||
218 *cp > ASCII_MAX) {
219 if (putchar(UMLAUT) == EOF ||
220 putchar(*cp++) == EOF)
221 err(1, "stdout");
222 }
223
224 else {
225 /* normal character */
226 if(putchar(*cp++) == EOF)
227 err(1, "stdout");
228 }
229 }
230
231 }
232 }
233
234 if (path == buf1) { /* swap pointers */
235 path = buf2;
236 oldpath = buf1;
237 } else {
238 path = buf1;
239 oldpath = buf2;
240 }
241 }
242 /* Non-zero status if there were errors */
243 if (fflush(stdout) != 0 || ferror(stdout))
244 exit(1);
245 exit(0);
246 }
247
248 #ifndef LOOKUP
249 static int
bgindex(bg)250 bgindex(bg) /* Return location of bg in bigrams or -1. */
251 char *bg;
252 {
253 char bg0, bg1, *p;
254
255 bg0 = bg[0];
256 bg1 = bg[1];
257 for (p = bigrams; *p != NULL; p++)
258 if (*p++ == bg0 && *p == bg1)
259 break;
260 return (*p == NULL ? -1 : (--p - bigrams));
261 }
262 #endif /* !LOOKUP */
263
264 static void
usage(void)265 usage(void)
266 {
267 (void)fprintf(stderr,
268 "usage: locate.code common_bigrams < list > squozen_list\n");
269 exit(1);
270 }
271