xref: /freebsd/lib/libc/iconv/citrus_lookup.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /* $FreeBSD$ */
2 /*	$NetBSD: citrus_lookup.c,v 1.7 2012/05/04 16:45:05 joerg Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-2-Clause
6  *
7  * Copyright (c)2003 Citrus Project,
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <sys/types.h>
34 
35 #include <assert.h>
36 #include <dirent.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <limits.h>
40 #include <paths.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #include "citrus_namespace.h"
47 #include "citrus_bcs.h"
48 #include "citrus_region.h"
49 #include "citrus_memstream.h"
50 #include "citrus_mmap.h"
51 #include "citrus_db.h"
52 #include "citrus_db_hash.h"
53 #include "citrus_lookup.h"
54 #include "citrus_lookup_file.h"
55 
56 struct _citrus_lookup {
57 	union {
58 		struct {
59 			struct _citrus_db *db;
60 			struct _citrus_region file;
61 			int num, idx;
62 			struct _db_locator locator;
63 		} db;
64 		struct {
65 			struct _region r;
66 			struct _memstream ms;
67 		} plain;
68 	} u;
69 #define cl_db		u.db.db
70 #define cl_dbidx	u.db.idx
71 #define cl_dbfile	u.db.file
72 #define cl_dbnum	u.db.num
73 #define cl_dblocator	u.db.locator
74 #define cl_plainr	u.plain.r
75 #define cl_plainms	u.plain.ms
76 	int cl_ignore_case;
77 	int cl_rewind;
78 	char *cl_key;
79 	size_t cl_keylen;
80 	int (*cl_next)(struct _citrus_lookup *, struct _region *,
81 		       struct _region *);
82 	int (*cl_lookup)(struct _citrus_lookup *, const char *,
83 			 struct _region *);
84 	int (*cl_num_entries)(struct _citrus_lookup *);
85 	void (*cl_close)(struct _citrus_lookup *);
86 };
87 
88 static int
89 seq_get_num_entries_db(struct _citrus_lookup *cl)
90 {
91 
92 	return (cl->cl_dbnum);
93 }
94 
95 static int
96 seq_next_db(struct _citrus_lookup *cl, struct _region *key,
97     struct _region *data)
98 {
99 
100 	if (cl->cl_key) {
101 		if (key)
102 			_region_init(key, cl->cl_key, cl->cl_keylen);
103 		return (_db_lookup_by_s(cl->cl_db, cl->cl_key, data,
104 		    &cl->cl_dblocator));
105 	}
106 
107 	if (cl->cl_rewind) {
108 		cl->cl_dbidx = 0;
109 	}
110 	cl->cl_rewind = 0;
111 	if (cl->cl_dbidx >= cl->cl_dbnum)
112 		return (ENOENT);
113 
114 	return (_db_get_entry(cl->cl_db, cl->cl_dbidx++, key, data));
115 }
116 
117 static int
118 seq_lookup_db(struct _citrus_lookup *cl, const char *key, struct _region *data)
119 {
120 
121 	cl->cl_rewind = 0;
122 	free(cl->cl_key);
123 	cl->cl_key = strdup(key);
124 	if (cl->cl_ignore_case)
125 		_bcs_convert_to_lower(cl->cl_key);
126 	cl->cl_keylen = strlen(cl->cl_key);
127 	_db_locator_init(&cl->cl_dblocator);
128 	return (_db_lookup_by_s(cl->cl_db, cl->cl_key, data,
129 	    &cl->cl_dblocator));
130 }
131 
132 static void
133 seq_close_db(struct _citrus_lookup *cl)
134 {
135 
136 	_db_close(cl->cl_db);
137 	_unmap_file(&cl->cl_dbfile);
138 }
139 
140 static int
141 seq_open_db(struct _citrus_lookup *cl, const char *name)
142 {
143 	struct _region r;
144 	char path[PATH_MAX];
145 	int ret;
146 
147 	snprintf(path, sizeof(path), "%s.db", name);
148 	ret = _map_file(&r, path);
149 	if (ret)
150 		return (ret);
151 
152 	ret = _db_open(&cl->cl_db, &r, _CITRUS_LOOKUP_MAGIC,
153 	    _db_hash_std, NULL);
154 	if (ret) {
155 		_unmap_file(&r);
156 		return (ret);
157 	}
158 
159 	cl->cl_dbfile = r;
160 	cl->cl_dbnum = _db_get_num_entries(cl->cl_db);
161 	cl->cl_dbidx = 0;
162 	cl->cl_rewind = 1;
163 	cl->cl_lookup = &seq_lookup_db;
164 	cl->cl_next = &seq_next_db;
165 	cl->cl_num_entries = &seq_get_num_entries_db;
166 	cl->cl_close = &seq_close_db;
167 
168 	return (0);
169 }
170 
171 #define T_COMM '#'
172 static int
173 seq_next_plain(struct _citrus_lookup *cl, struct _region *key,
174 	       struct _region *data)
175 {
176 	const char *p, *q;
177 	size_t len;
178 
179 	if (cl->cl_rewind)
180 		_memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
181 	cl->cl_rewind = 0;
182 
183 retry:
184 	p = _memstream_getln(&cl->cl_plainms, &len);
185 	if (p == NULL)
186 		return (ENOENT);
187 	/* ignore comment */
188 	q = memchr(p, T_COMM, len);
189 	if (q) {
190 		len = q - p;
191 	}
192 	/* ignore trailing spaces */
193 	_bcs_trunc_rws_len(p, &len);
194 	p = _bcs_skip_ws_len(p, &len);
195 	q = _bcs_skip_nonws_len(p, &len);
196 	if (p == q)
197 		goto retry;
198 	if (cl->cl_key && ((size_t)(q - p) != cl->cl_keylen ||
199 	    memcmp(p, cl->cl_key, (size_t)(q - p)) != 0))
200 		goto retry;
201 
202 	/* found a entry */
203 	if (key)
204 		_region_init(key, __DECONST(void *, p), (size_t)(q - p));
205 	p = _bcs_skip_ws_len(q, &len);
206 	if (data)
207 		_region_init(data, len ? __DECONST(void *, p) : NULL, len);
208 
209 	return (0);
210 }
211 
212 static int
213 seq_get_num_entries_plain(struct _citrus_lookup *cl)
214 {
215 	int num;
216 
217 	num = 0;
218 	while (seq_next_plain(cl, NULL, NULL) == 0)
219 		num++;
220 
221 	return (num);
222 }
223 
224 static int
225 seq_lookup_plain(struct _citrus_lookup *cl, const char *key,
226     struct _region *data)
227 {
228 	size_t len;
229 	const char *p;
230 
231 	cl->cl_rewind = 0;
232 	free(cl->cl_key);
233 	cl->cl_key = strdup(key);
234 	if (cl->cl_ignore_case)
235 		_bcs_convert_to_lower(cl->cl_key);
236 	cl->cl_keylen = strlen(cl->cl_key);
237 	_memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
238 	p = _memstream_matchline(&cl->cl_plainms, cl->cl_key, &len, 0);
239 	if (p == NULL)
240 		return (ENOENT);
241 	if (data)
242 		_region_init(data, __DECONST(void *, p), len);
243 
244 	return (0);
245 }
246 
247 static void
248 seq_close_plain(struct _citrus_lookup *cl)
249 {
250 
251 	_unmap_file(&cl->cl_plainr);
252 }
253 
254 static int
255 seq_open_plain(struct _citrus_lookup *cl, const char *name)
256 {
257 	int ret;
258 
259 	/* open read stream */
260 	ret = _map_file(&cl->cl_plainr, name);
261 	if (ret)
262 		return (ret);
263 
264 	cl->cl_rewind = 1;
265 	cl->cl_next = &seq_next_plain;
266 	cl->cl_lookup = &seq_lookup_plain;
267 	cl->cl_num_entries = &seq_get_num_entries_plain;
268 	cl->cl_close = &seq_close_plain;
269 
270 	return (0);
271 }
272 
273 int
274 _citrus_lookup_seq_open(struct _citrus_lookup **rcl, const char *name,
275     int ignore_case)
276 {
277 	int ret;
278 	struct _citrus_lookup *cl;
279 
280 	cl = malloc(sizeof(*cl));
281 	if (cl == NULL)
282 		return (errno);
283 
284 	cl->cl_key = NULL;
285 	cl->cl_keylen = 0;
286 	cl->cl_ignore_case = ignore_case;
287 	ret = seq_open_db(cl, name);
288 	if (ret == ENOENT)
289 		ret = seq_open_plain(cl, name);
290 	if (!ret)
291 		*rcl = cl;
292 	else
293 		free(cl);
294 
295 	return (ret);
296 }
297 
298 void
299 _citrus_lookup_seq_rewind(struct _citrus_lookup *cl)
300 {
301 
302 	cl->cl_rewind = 1;
303 	free(cl->cl_key);
304 	cl->cl_key = NULL;
305 	cl->cl_keylen = 0;
306 }
307 
308 int
309 _citrus_lookup_seq_next(struct _citrus_lookup *cl,
310     struct _region *key, struct _region *data)
311 {
312 
313 	return ((*cl->cl_next)(cl, key, data));
314 }
315 
316 int
317 _citrus_lookup_seq_lookup(struct _citrus_lookup *cl, const char *key,
318     struct _region *data)
319 {
320 
321 	return ((*cl->cl_lookup)(cl, key, data));
322 }
323 
324 int
325 _citrus_lookup_get_number_of_entries(struct _citrus_lookup *cl)
326 {
327 
328 	return ((*cl->cl_num_entries)(cl));
329 }
330 
331 void
332 _citrus_lookup_seq_close(struct _citrus_lookup *cl)
333 {
334 
335 	free(cl->cl_key);
336 	(*cl->cl_close)(cl);
337 	free(cl);
338 }
339 
340 char *
341 _citrus_lookup_simple(const char *name, const char *key,
342     char *linebuf, size_t linebufsize, int ignore_case)
343 {
344 	struct _citrus_lookup *cl;
345 	struct _region data;
346 	int ret;
347 
348 	ret = _citrus_lookup_seq_open(&cl, name, ignore_case);
349 	if (ret)
350 		return (NULL);
351 
352 	ret = _citrus_lookup_seq_lookup(cl, key, &data);
353 	if (ret) {
354 		_citrus_lookup_seq_close(cl);
355 		return (NULL);
356 	}
357 
358 	snprintf(linebuf, linebufsize, "%.*s", (int)_region_size(&data),
359 	    (const char *)_region_head(&data));
360 
361 	_citrus_lookup_seq_close(cl);
362 
363 	return (linebuf);
364 }
365