xref: /freebsd/lib/libc/iconv/citrus_lookup.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*	$NetBSD: citrus_lookup.c,v 1.7 2012/05/04 16:45:05 joerg Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause
5  *
6  * Copyright (c)2003 Citrus Project,
7  * All rights reserved.
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  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/types.h>
32 
33 #include <assert.h>
34 #include <dirent.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <limits.h>
38 #include <paths.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "citrus_namespace.h"
45 #include "citrus_bcs.h"
46 #include "citrus_region.h"
47 #include "citrus_memstream.h"
48 #include "citrus_mmap.h"
49 #include "citrus_db.h"
50 #include "citrus_db_hash.h"
51 #include "citrus_lookup.h"
52 #include "citrus_lookup_file.h"
53 
54 struct _citrus_lookup {
55 	union {
56 		struct {
57 			struct _citrus_db *db;
58 			struct _citrus_region file;
59 			int num, idx;
60 			struct _db_locator locator;
61 		} db;
62 		struct {
63 			struct _region r;
64 			struct _memstream ms;
65 		} plain;
66 	} u;
67 #define cl_db		u.db.db
68 #define cl_dbidx	u.db.idx
69 #define cl_dbfile	u.db.file
70 #define cl_dbnum	u.db.num
71 #define cl_dblocator	u.db.locator
72 #define cl_plainr	u.plain.r
73 #define cl_plainms	u.plain.ms
74 	int cl_ignore_case;
75 	int cl_rewind;
76 	char *cl_key;
77 	size_t cl_keylen;
78 	int (*cl_next)(struct _citrus_lookup *, struct _region *,
79 		       struct _region *);
80 	int (*cl_lookup)(struct _citrus_lookup *, const char *,
81 			 struct _region *);
82 	int (*cl_num_entries)(struct _citrus_lookup *);
83 	void (*cl_close)(struct _citrus_lookup *);
84 };
85 
86 static int
87 seq_get_num_entries_db(struct _citrus_lookup *cl)
88 {
89 
90 	return (cl->cl_dbnum);
91 }
92 
93 static int
94 seq_next_db(struct _citrus_lookup *cl, struct _region *key,
95     struct _region *data)
96 {
97 
98 	if (cl->cl_key) {
99 		if (key)
100 			_region_init(key, cl->cl_key, cl->cl_keylen);
101 		return (_db_lookup_by_s(cl->cl_db, cl->cl_key, data,
102 		    &cl->cl_dblocator));
103 	}
104 
105 	if (cl->cl_rewind) {
106 		cl->cl_dbidx = 0;
107 	}
108 	cl->cl_rewind = 0;
109 	if (cl->cl_dbidx >= cl->cl_dbnum)
110 		return (ENOENT);
111 
112 	return (_db_get_entry(cl->cl_db, cl->cl_dbidx++, key, data));
113 }
114 
115 static int
116 seq_lookup_db(struct _citrus_lookup *cl, const char *key, struct _region *data)
117 {
118 
119 	cl->cl_rewind = 0;
120 	free(cl->cl_key);
121 	cl->cl_key = strdup(key);
122 	if (cl->cl_ignore_case)
123 		_bcs_convert_to_lower(cl->cl_key);
124 	cl->cl_keylen = strlen(cl->cl_key);
125 	_db_locator_init(&cl->cl_dblocator);
126 	return (_db_lookup_by_s(cl->cl_db, cl->cl_key, data,
127 	    &cl->cl_dblocator));
128 }
129 
130 static void
131 seq_close_db(struct _citrus_lookup *cl)
132 {
133 
134 	_db_close(cl->cl_db);
135 	_unmap_file(&cl->cl_dbfile);
136 }
137 
138 static int
139 seq_open_db(struct _citrus_lookup *cl, const char *name)
140 {
141 	struct _region r;
142 	char path[PATH_MAX];
143 	int ret;
144 
145 	snprintf(path, sizeof(path), "%s.db", name);
146 	ret = _map_file(&r, path);
147 	if (ret)
148 		return (ret);
149 
150 	ret = _db_open(&cl->cl_db, &r, _CITRUS_LOOKUP_MAGIC,
151 	    _db_hash_std, NULL);
152 	if (ret) {
153 		_unmap_file(&r);
154 		return (ret);
155 	}
156 
157 	cl->cl_dbfile = r;
158 	cl->cl_dbnum = _db_get_num_entries(cl->cl_db);
159 	cl->cl_dbidx = 0;
160 	cl->cl_rewind = 1;
161 	cl->cl_lookup = &seq_lookup_db;
162 	cl->cl_next = &seq_next_db;
163 	cl->cl_num_entries = &seq_get_num_entries_db;
164 	cl->cl_close = &seq_close_db;
165 
166 	return (0);
167 }
168 
169 #define T_COMM '#'
170 static int
171 seq_next_plain(struct _citrus_lookup *cl, struct _region *key,
172 	       struct _region *data)
173 {
174 	const char *p, *q;
175 	size_t len;
176 
177 	if (cl->cl_rewind)
178 		_memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
179 	cl->cl_rewind = 0;
180 
181 retry:
182 	p = _memstream_getln(&cl->cl_plainms, &len);
183 	if (p == NULL)
184 		return (ENOENT);
185 	/* ignore comment */
186 	q = memchr(p, T_COMM, len);
187 	if (q) {
188 		len = q - p;
189 	}
190 	/* ignore trailing spaces */
191 	_bcs_trunc_rws_len(p, &len);
192 	p = _bcs_skip_ws_len(p, &len);
193 	q = _bcs_skip_nonws_len(p, &len);
194 	if (p == q)
195 		goto retry;
196 	if (cl->cl_key && ((size_t)(q - p) != cl->cl_keylen ||
197 	    memcmp(p, cl->cl_key, (size_t)(q - p)) != 0))
198 		goto retry;
199 
200 	/* found a entry */
201 	if (key)
202 		_region_init(key, __DECONST(void *, p), (size_t)(q - p));
203 	p = _bcs_skip_ws_len(q, &len);
204 	if (data)
205 		_region_init(data, len ? __DECONST(void *, p) : NULL, len);
206 
207 	return (0);
208 }
209 
210 static int
211 seq_get_num_entries_plain(struct _citrus_lookup *cl)
212 {
213 	int num;
214 
215 	num = 0;
216 	while (seq_next_plain(cl, NULL, NULL) == 0)
217 		num++;
218 
219 	return (num);
220 }
221 
222 static int
223 seq_lookup_plain(struct _citrus_lookup *cl, const char *key,
224     struct _region *data)
225 {
226 	size_t len;
227 	const char *p;
228 
229 	cl->cl_rewind = 0;
230 	free(cl->cl_key);
231 	cl->cl_key = strdup(key);
232 	if (cl->cl_ignore_case)
233 		_bcs_convert_to_lower(cl->cl_key);
234 	cl->cl_keylen = strlen(cl->cl_key);
235 	_memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
236 	p = _memstream_matchline(&cl->cl_plainms, cl->cl_key, &len, 0);
237 	if (p == NULL)
238 		return (ENOENT);
239 	if (data)
240 		_region_init(data, __DECONST(void *, p), len);
241 
242 	return (0);
243 }
244 
245 static void
246 seq_close_plain(struct _citrus_lookup *cl)
247 {
248 
249 	_unmap_file(&cl->cl_plainr);
250 }
251 
252 static int
253 seq_open_plain(struct _citrus_lookup *cl, const char *name)
254 {
255 	int ret;
256 
257 	/* open read stream */
258 	ret = _map_file(&cl->cl_plainr, name);
259 	if (ret)
260 		return (ret);
261 
262 	cl->cl_rewind = 1;
263 	cl->cl_next = &seq_next_plain;
264 	cl->cl_lookup = &seq_lookup_plain;
265 	cl->cl_num_entries = &seq_get_num_entries_plain;
266 	cl->cl_close = &seq_close_plain;
267 
268 	return (0);
269 }
270 
271 int
272 _citrus_lookup_seq_open(struct _citrus_lookup **rcl, const char *name,
273     int ignore_case)
274 {
275 	int ret;
276 	struct _citrus_lookup *cl;
277 
278 	cl = malloc(sizeof(*cl));
279 	if (cl == NULL)
280 		return (errno);
281 
282 	cl->cl_key = NULL;
283 	cl->cl_keylen = 0;
284 	cl->cl_ignore_case = ignore_case;
285 	ret = seq_open_db(cl, name);
286 	if (ret == ENOENT)
287 		ret = seq_open_plain(cl, name);
288 	if (!ret)
289 		*rcl = cl;
290 	else
291 		free(cl);
292 
293 	return (ret);
294 }
295 
296 void
297 _citrus_lookup_seq_rewind(struct _citrus_lookup *cl)
298 {
299 
300 	cl->cl_rewind = 1;
301 	free(cl->cl_key);
302 	cl->cl_key = NULL;
303 	cl->cl_keylen = 0;
304 }
305 
306 int
307 _citrus_lookup_seq_next(struct _citrus_lookup *cl,
308     struct _region *key, struct _region *data)
309 {
310 
311 	return ((*cl->cl_next)(cl, key, data));
312 }
313 
314 int
315 _citrus_lookup_seq_lookup(struct _citrus_lookup *cl, const char *key,
316     struct _region *data)
317 {
318 
319 	return ((*cl->cl_lookup)(cl, key, data));
320 }
321 
322 int
323 _citrus_lookup_get_number_of_entries(struct _citrus_lookup *cl)
324 {
325 
326 	return ((*cl->cl_num_entries)(cl));
327 }
328 
329 void
330 _citrus_lookup_seq_close(struct _citrus_lookup *cl)
331 {
332 
333 	free(cl->cl_key);
334 	(*cl->cl_close)(cl);
335 	free(cl);
336 }
337 
338 char *
339 _citrus_lookup_simple(const char *name, const char *key,
340     char *linebuf, size_t linebufsize, int ignore_case)
341 {
342 	struct _citrus_lookup *cl;
343 	struct _region data;
344 	int ret;
345 
346 	ret = _citrus_lookup_seq_open(&cl, name, ignore_case);
347 	if (ret)
348 		return (NULL);
349 
350 	ret = _citrus_lookup_seq_lookup(cl, key, &data);
351 	if (ret) {
352 		_citrus_lookup_seq_close(cl);
353 		return (NULL);
354 	}
355 
356 	snprintf(linebuf, linebufsize, "%.*s", (int)_region_size(&data),
357 	    (const char *)_region_head(&data));
358 
359 	_citrus_lookup_seq_close(cl);
360 
361 	return (linebuf);
362 }
363