1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
/*
* $OpenBSD: locate.code.c,v 1.16 2009/10/27 23:59:39 deraadt Exp $
*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* James A. Woods.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: locate.code.c,v 1.16 2009/10/27 23:59:39 deraadt Exp $
*/
/*
* PURPOSE: sorted list compressor (works with a modified 'find'
* to encode/decode a filename database)
*
* USAGE: bigram < list > bigrams
* process bigrams (see updatedb) > common_bigrams
* code common_bigrams < list > squozen_list
*
* METHOD: Uses 'front compression' (see ";login:", Volume 8, Number 1
* February/March 1983, p. 8). Output format is, per line, an
* offset differential count byte followed by a partially bigram-
* encoded ascii residue. A bigram is a two-character sequence,
* the first 128 most common of which are encoded in one byte.
*
* EXAMPLE: For simple front compression with no bigram encoding,
* if the input is... then the output is...
*
* /usr/src 0 /usr/src
* /usr/src/cmd/aardvark.c 8 /cmd/aardvark.c
* /usr/src/cmd/armadillo.c 14 armadillo.c
* /usr/tmp/zoo 5 tmp/zoo
*
* The codes are:
*
* 0-28 likeliest differential counts + offset to make nonnegative
* 30 switch code for out-of-range count to follow in next word
* 31 an 8 bit char followed
* 128-255 bigram codes (128 most common, as determined by 'updatedb')
* 32-127 single character (printable) ascii residue (ie, literal)
*
* The locate database store any character except newline ('\n')
* and NUL ('\0'). The 8-bit character support don't wast extra
* space until you have characters in file names less than 32
* or greater than 127.
*
*
* SEE ALSO: updatedb.sh, ../bigram/locate.bigram.c
*
* AUTHOR: James A. Woods, Informatics General Corp.,
* NASA Ames Research Center, 10/82
* 8-bit file names characters:
* Wolfram Schneider, Berlin September 1996
*/
#include <sys/param.h>
#include <err.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "locate.h"
#define BGBUFSIZE (NBG * 2) /* size of bigram buffer */
u_char buf1[MAXPATHLEN] = " ";
u_char buf2[MAXPATHLEN];
u_char bigrams[BGBUFSIZE + 1] = { 0 };
#define LOOKUP 1 /* use a lookup array instead a function, 3x faster */
#ifdef LOOKUP
#define BGINDEX(x) (big[(u_char)*x][(u_char)*(x + 1)])
typedef short bg_t;
bg_t big[UCHAR_MAX + 1][UCHAR_MAX + 1];
#else
#define BGINDEX(x) bgindex(x)
typedef int bg_t;
int bgindex(char *);
#endif /* LOOKUP */
void usage(void);
extern int optind;
extern int optopt;
int
main(int argc, char *argv[])
{
u_char *cp, *oldpath, *path;
int ch, code, count, diffcount, oldcount;
FILE *fp;
int i, j;
while ((ch = getopt(argc, argv, "")) != -1)
switch (ch) {
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != 1)
usage();
if ((fp = fopen(argv[0], "r")) == NULL)
err(1, "%s", argv[0]);
/* First copy bigram array to stdout. */
if (fgets(bigrams, sizeof(bigrams), fp) == NULL)
err(1, "fgets");
if (strlen(bigrams) != BGBUFSIZE)
errx(1, "bigram array too small to build db, index more files");
if (fputs(bigrams, stdout) == EOF)
err(1, "stdout");
(void)fclose(fp);
#ifdef LOOKUP
/* init lookup table */
for (i = 0; i < UCHAR_MAX + 1; i++)
for (j = 0; j < UCHAR_MAX + 1; j++)
big[i][j] = (bg_t)-1;
for (cp = bigrams, i = 0; *cp != '\0'; i += 2, cp += 2)
big[(u_char)*cp][(u_char)*(cp + 1)] = (bg_t)i;
#endif /* LOOKUP */
oldpath = buf1;
path = buf2;
oldcount = 0;
while (fgets(path, sizeof(buf2), stdin) != NULL) {
/* skip empty lines */
if (*path == '\n')
continue;
/* remove newline */
for (cp = path; *cp != '\0'; cp++) {
/* chop newline */
if (*cp == '\n')
*cp = '\0';
}
/* Skip longest common prefix. */
for (cp = path; *cp == *oldpath; cp++, oldpath++)
if (*cp == '\0')
break;
count = cp - path;
diffcount = count - oldcount + OFFSET;
oldcount = count;
if (diffcount < 0 || diffcount > 2 * OFFSET) {
if (putchar(SWITCH) == EOF ||
putw(diffcount, stdout) == EOF)
err(1, "stdout");
} else
if (putchar(diffcount) == EOF)
err(1, "stdout");
while (*cp != '\0') {
/* print *two* characters */
if ((code = BGINDEX(cp)) != (bg_t)-1) {
/*
* print *one* as bigram
* Found, so mark byte with
* parity bit.
*/
if (putchar((code / 2) | PARITY) == EOF)
err(1, "stdout");
cp += 2;
} else {
for (i = 0; i < 2; i++) {
if (*cp == '\0')
break;
/* print umlauts in file names */
if (*cp < ASCII_MIN ||
*cp > ASCII_MAX) {
if (putchar(UMLAUT) == EOF ||
putchar(*cp++) == EOF)
err(1, "stdout");
} else {
/* normal character */
if (putchar(*cp++) == EOF)
err(1, "stdout");
}
}
}
}
if (path == buf1) { /* swap pointers */
path = buf2;
oldpath = buf1;
} else {
path = buf1;
oldpath = buf2;
}
}
/* Non-zero status if there were errors */
if (fflush(stdout) != 0 || ferror(stdout))
exit(1);
exit(0);
}
#ifndef LOOKUP
int
bgindex(char *bg) /* Return location of bg in bigrams or -1. */
{
char bg0, bg1, *p;
bg0 = bg[0];
bg1 = bg[1];
for (p = bigrams; *p != NULL; p++)
if (*p++ == bg0 && *p == bg1)
break;
return (*p == NULL ? -1 : (--p - bigrams));
}
#endif /* !LOOKUP */
void
usage(void)
{
(void)fprintf(stderr,
"usage: locate.code common_bigrams < list > squozen_list\n");
exit(1);
}
|
