xref: /freebsd/usr.bin/locate/locate/fastfind.c (revision 47e46b1123b9c732c366848e8184ce42e086a0fb)
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  * $FreeBSD$
36  */
37 
38 
39 #ifndef _LOCATE_STATISTIC_
40 #define _LOCATE_STATISTIC_
41 
42 void
43 statistic (fp, path_fcodes)
44 	FILE *fp;               /* open database */
45 	char *path_fcodes;  	/* for error message */
46 {
47 	long lines, chars, size, big, zwerg, umlaut;
48 	register u_char *p, *s;
49 	register int c;
50 	int count;
51 	int error = 0;
52 	u_char bigram1[NBG], bigram2[NBG], path[MAXPATHLEN];
53 
54 	for (c = 0, p = bigram1, s = bigram2; c < NBG; c++) {
55 		p[c] = check_bigram_char(getc(fp));
56 		s[c] = check_bigram_char(getc(fp));
57 	}
58 
59 	lines = chars = big = zwerg = umlaut = 0;
60 	size = NBG + NBG;
61 
62 	for (c = getc(fp), count = 0; c != EOF; size++) {
63 		if (c == SWITCH) {
64 			count += getwf(fp) - OFFSET;
65 			size += sizeof(int);
66 			zwerg++;
67 		} else
68 			count += c - OFFSET;
69 
70 		if (count < 0 || count > MAXPATHLEN) {
71 			/* stop on error and display the statstics anyway */
72 			warnx("corrupted database: %s", path_fcodes);
73 			error = 1;
74 			break;
75 		}
76 
77 		for (p = path + count; (c = getc(fp)) > SWITCH; size++)
78 			if (c < PARITY) {
79 				if (c == UMLAUT) {
80 					c = getc(fp);
81 					size++;
82 					umlaut++;
83 				}
84 				p++;
85 			} else {
86 				/* bigram char */
87 				big++;
88 				p += 2;
89 			}
90 
91 		p++;
92 		lines++;
93 		chars += (p - path);
94 	}
95 
96 	(void)printf("\nDatabase: %s\n", path_fcodes);
97 	(void)printf("Compression: Front: %2.2f%%, ",
98 		     (size + big - (2 * NBG)) / (chars / (float)100));
99 	(void)printf("Bigram: %2.2f%%, ", (size - big) / (size / (float)100));
100 	(void)printf("Total: %2.2f%%\n",
101 		     (size - (2 * NBG)) / (chars / (float)100));
102 	(void)printf("Filenames: %ld, ", lines);
103 	(void)printf("Characters: %ld, ", chars);
104 	(void)printf("Database size: %ld\n", size);
105 	(void)printf("Bigram characters: %ld, ", big);
106 	(void)printf("Integers: %ld, ", zwerg);
107 	(void)printf("8-Bit characters: %ld\n", umlaut);
108 
109 	/* non zero exit on corrupt database */
110 	if (error)
111 		exit(error);
112 }
113 #endif /* _LOCATE_STATISTIC_ */
114 
115 extern	char	separator;
116 
117 void
118 #ifdef FF_MMAP
119 
120 
121 #ifdef FF_ICASE
122 fastfind_mmap_icase
123 #else
124 fastfind_mmap
125 #endif /* FF_ICASE */
126 (pathpart, paddr, len, database)
127 	char *pathpart; 	/* search string */
128 	caddr_t paddr;  	/* mmap pointer */
129 	off_t len;        	/* length of database */
130 	char *database; 	/* for error message */
131 
132 
133 #else /* MMAP */
134 
135 
136 #ifdef FF_ICASE
137 fastfind_icase
138 #else
139 fastfind
140 #endif /* FF_ICASE */
141 
142 (fp, pathpart, database)
143 	FILE *fp;               /* open database */
144 	char *pathpart;		/* search string */
145 	char *database;		/* for error message */
146 
147 
148 #endif /* MMAP */
149 
150 {
151 	register u_char *p, *s, *patend, *q, *foundchar;
152 	register int c, cc;
153 	int count, found, globflag;
154 	u_char *cutoff;
155 	u_char bigram1[NBG], bigram2[NBG], path[MAXPATHLEN];
156 
157 #ifdef FF_ICASE
158 	/* use a lookup table for case insensitive search */
159 	u_char table[UCHAR_MAX + 1];
160 
161 	tolower_word(pathpart);
162 #endif /* FF_ICASE*/
163 
164 	/* init bigram table */
165 #ifdef FF_MMAP
166 	for (c = 0, p = bigram1, s = bigram2; c < NBG; c++, len-= 2) {
167 		p[c] = check_bigram_char(*paddr++);
168 		s[c] = check_bigram_char(*paddr++);
169 	}
170 #else
171 	for (c = 0, p = bigram1, s = bigram2; c < NBG; c++) {
172 		p[c] = check_bigram_char(getc(fp));
173 		s[c] = check_bigram_char(getc(fp));
174 	}
175 #endif /* FF_MMAP */
176 
177 	/* find optimal (last) char for searching */
178 	for (p = pathpart; *p != '\0'; p++)
179 		if (strchr(LOCATE_REG, *p) != NULL)
180 			break;
181 
182 	if (*p == '\0')
183 		globflag = 0;
184 	else
185 		globflag = 1;
186 
187 	p = pathpart;
188 	patend = patprep(p);
189 	cc = *patend;
190 
191 #ifdef FF_ICASE
192 	/* set patend char to true */
193         for (c = 0; c < UCHAR_MAX + 1; c++)
194                 table[c] = 0;
195 
196 	table[TOLOWER(*patend)] = 1;
197 	table[toupper(*patend)] = 1;
198 #endif /* FF_ICASE */
199 
200 
201 	/* main loop */
202 	found = count = 0;
203 	foundchar = 0;
204 
205 #ifdef FF_MMAP
206 	c = (u_char)*paddr++; len--;
207 	for (; len > 0; ) {
208 #else
209 	c = getc(fp);
210 	for (; c != EOF; ) {
211 #endif /* FF_MMAP */
212 
213 		/* go forward or backward */
214 		if (c == SWITCH) { /* big step, an integer */
215 #ifdef FF_MMAP
216 			count += getwm(paddr) - OFFSET;
217 			len -= INTSIZE; paddr += INTSIZE;
218 #else
219 			count +=  getwf(fp) - OFFSET;
220 #endif /* FF_MMAP */
221 		} else {	   /* slow step, =< 14 chars */
222 			count += c - OFFSET;
223 		}
224 
225 		if (count < 0 || count > MAXPATHLEN)
226 			errx(1, "corrupted database: %s", database);
227 		/* overlay old path */
228 		p = path + count;
229 		foundchar = p - 1;
230 
231 #ifdef FF_MMAP
232 		for (; len > 0;) {
233 			c = (u_char)*paddr++;
234 		        len--;
235 #else
236 		for (;;) {
237 			c = getc(fp);
238 #endif /* FF_MMAP */
239 			/*
240 			 * == UMLAUT: 8 bit char followed
241 			 * <= SWITCH: offset
242 			 * >= PARITY: bigram
243 			 * rest:      single ascii char
244 			 *
245 			 * offset < SWITCH < UMLAUT < ascii < PARITY < bigram
246 			 */
247 			if (c < PARITY) {
248 				if (c <= UMLAUT) {
249 					if (c == UMLAUT) {
250 #ifdef FF_MMAP
251 						c = (u_char)*paddr++;
252 						len--;
253 #else
254 						c = getc(fp);
255 #endif /* FF_MMAP */
256 
257 					} else
258 						break; /* SWITCH */
259 				}
260 #ifdef FF_ICASE
261 				if (table[c])
262 #else
263 				if (c == cc)
264 #endif /* FF_ICASE */
265 					foundchar = p;
266 				*p++ = c;
267 			}
268 			else {
269 				/* bigrams are parity-marked */
270 				TO7BIT(c);
271 
272 #ifndef FF_ICASE
273 				if (bigram1[c] == cc ||
274 				    bigram2[c] == cc)
275 #else
276 
277 					if (table[bigram1[c]] ||
278 					    table[bigram2[c]])
279 #endif /* FF_ICASE */
280 						foundchar = p + 1;
281 
282 				*p++ = bigram1[c];
283 				*p++ = bigram2[c];
284 			}
285 		}
286 
287 		if (found) {                     /* previous line matched */
288 			cutoff = path;
289 			*p-- = '\0';
290 			foundchar = p;
291 		} else if (foundchar >= path + count) { /* a char matched */
292 			*p-- = '\0';
293 			cutoff = path + count;
294 		} else                           /* nothing to do */
295 			continue;
296 
297 		found = 0;
298 		for (s = foundchar; s >= cutoff; s--) {
299 			if (*s == cc
300 #ifdef FF_ICASE
301 			    || TOLOWER(*s) == cc
302 #endif /* FF_ICASE */
303 			    ) {	/* fast first char check */
304 				for (p = patend - 1, q = s - 1; *p != '\0';
305 				     p--, q--)
306 					if (*q != *p
307 #ifdef FF_ICASE
308 					    && TOLOWER(*q) != *p
309 #endif /* FF_ICASE */
310 					    )
311 						break;
312 				if (*p == '\0') {   /* fast match success */
313 					found = 1;
314 					if (!globflag ||
315 #ifndef FF_ICASE
316 					    !fnmatch(pathpart, path, 0))
317 #else
318 					    !fnmatch(pathpart, path,
319 						     FNM_CASEFOLD))
320 #endif /* !FF_ICASE */
321 					{
322 						if (f_silent)
323 							counter++;
324 						else if (f_limit) {
325 							counter++;
326 							if (f_limit >= counter)
327 								(void)printf("%s%c",path,separator);
328 							else
329 								errx(0, "[show only %ld lines]", counter - 1);
330 						} else
331 							(void)printf("%s%c",path,separator);
332 					}
333 					break;
334 				}
335 			}
336 		}
337 	}
338 }
339