xref: /dragonfly/lib/libc/citrus/citrus_lookup.c (revision cecb9aae)
1 /* $NetBSD: citrus_lookup.c,v 1.5 2006/03/27 01:09:11 christos Exp $ */
2 /* $DragonFly: src/lib/libc/citrus/citrus_lookup.c,v 1.3 2008/04/10 10:21:01 hasso Exp $ */
3 
4 /*-
5  * Copyright (c)2003 Citrus Project,
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <assert.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <paths.h>
39 #include <dirent.h>
40 #include <sys/types.h>
41 
42 #include "citrus_namespace.h"
43 #include "citrus_bcs.h"
44 #include "citrus_region.h"
45 #include "citrus_memstream.h"
46 #include "citrus_mmap.h"
47 #include "citrus_db.h"
48 #include "citrus_db_hash.h"
49 #include "citrus_lookup.h"
50 #include "citrus_lookup_file.h"
51 
52 struct _citrus_lookup {
53 	union {
54 		struct {
55 			struct _citrus_db *db;
56 			struct _citrus_region file;
57 			int num, idx;
58 			struct _db_locator locator;
59 		} db;
60 		struct {
61 			struct _region r;
62 			struct _memstream ms;
63 		} plain;
64 	} u;
65 #define cl_db		u.db.db
66 #define cl_dbidx	u.db.idx
67 #define cl_dbfile	u.db.file
68 #define cl_dbnum	u.db.num
69 #define cl_dblocator	u.db.locator
70 #define cl_plainr	u.plain.r
71 #define cl_plainms	u.plain.ms
72 	int cl_ignore_case;
73 	int cl_rewind;
74 	char *cl_key;
75 	size_t cl_keylen;
76 	int (*cl_next)(struct _citrus_lookup *, struct _region *,
77 		       struct _region *);
78 	int (*cl_lookup)(struct _citrus_lookup *, const char *,
79 			 struct _region *);
80 	int (*cl_num_entries)(struct _citrus_lookup *);
81 	void (*cl_close)(struct _citrus_lookup *);
82 };
83 
84 static int
85 seq_get_num_entries_db(struct _citrus_lookup *cl)
86 {
87 	return cl->cl_dbnum;
88 }
89 
90 static int
91 seq_next_db(struct _citrus_lookup *cl,
92 	    struct _region *key, struct _region *data)
93 {
94 
95 	if (cl->cl_key) {
96 		if (key)
97 			_region_init(key, cl->cl_key, cl->cl_keylen);
98 		return _db_lookup_by_s(cl->cl_db, cl->cl_key, data,
99 				       &cl->cl_dblocator);
100 	}
101 
102 	if (cl->cl_rewind) {
103 		cl->cl_dbidx = 0;
104 	}
105 	cl->cl_rewind = 0;
106 	if (cl->cl_dbidx >= cl->cl_dbnum)
107 		return ENOENT;
108 
109 	return _db_get_entry(cl->cl_db, cl->cl_dbidx++, key, data);
110 }
111 
112 static int
113 seq_lookup_db(struct _citrus_lookup *cl, const char *key,
114 	      struct _region *data)
115 {
116 	cl->cl_rewind = 0;
117 	free(cl->cl_key);
118 	cl->cl_key = strdup(key);
119 	if (cl->cl_ignore_case)
120 		_bcs_convert_to_lower(cl->cl_key);
121 	cl->cl_keylen = strlen(cl->cl_key);
122 	_db_locator_init(&cl->cl_dblocator);
123 	return _db_lookup_by_s(cl->cl_db, cl->cl_key, data, &cl->cl_dblocator);
124 }
125 
126 static void
127 seq_close_db(struct _citrus_lookup *cl)
128 {
129 	_db_close(cl->cl_db);
130 	_unmap_file(&cl->cl_dbfile);
131 }
132 
133 static int
134 seq_open_db(struct _citrus_lookup *cl, const char *name)
135 {
136 	int ret;
137 	struct _region r;
138 	char path[PATH_MAX];
139 
140 	snprintf(path, sizeof(path), "%s.db", name);
141 	ret = _map_file(&r, path);
142 	if (ret)
143 		return ret;
144 
145 	ret = _db_open(&cl->cl_db, &r, _CITRUS_LOOKUP_MAGIC,
146 		       _db_hash_std, NULL);
147 	if (ret) {
148 		_unmap_file(&r);
149 		return ret;
150 	}
151 
152 	cl->cl_dbfile = r;
153 	cl->cl_dbnum = _db_get_num_entries(cl->cl_db);
154 	cl->cl_dbidx = 0;
155 	cl->cl_rewind = 1;
156 	cl->cl_lookup = &seq_lookup_db;
157 	cl->cl_next = &seq_next_db;
158 	cl->cl_num_entries = &seq_get_num_entries_db;
159 	cl->cl_close = &seq_close_db;
160 
161 	return 0;
162 }
163 
164 #define T_COMM '#'
165 static int
166 seq_next_plain(struct _citrus_lookup *cl, struct _region *key,
167 	       struct _region *data)
168 {
169 	const char *p, *q;
170 	size_t len;
171 
172 	if (cl->cl_rewind)
173 		_memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
174 	cl->cl_rewind = 0;
175 
176 retry:
177 	p = _memstream_getln(&cl->cl_plainms, &len);
178 	if (p == NULL)
179 		return ENOENT;
180 	/* ignore comment */
181 	q = memchr(p, T_COMM, len);
182 	if (q) {
183 		len = q-p;
184 	}
185 	/* ignore trailing spaces */
186 	_bcs_trunc_rws_len(p, &len);
187 	p = _bcs_skip_ws_len(p, &len);
188 	q = _bcs_skip_nonws_len(p, &len);
189 	if (p==q)
190 		goto retry;
191 	if (cl->cl_key && ((size_t)(q-p) != cl->cl_keylen ||
192 			   memcmp(p, cl->cl_key, (size_t)(q-p)) != 0))
193 		goto retry;
194 
195 	/* found a entry */
196 	if (key)
197 		_region_init(key, __DECONST(char *, p), q-p);
198 	p = _bcs_skip_ws_len(q, &len);
199 	if (data)
200 		_region_init(data, len ? __DECONST(char *, p) : NULL, len);
201 
202 	return 0;
203 }
204 
205 static int
206 seq_get_num_entries_plain(struct _citrus_lookup *cl)
207 {
208 	int num;
209 
210 	num = 0;
211 	while (seq_next_plain(cl, NULL, NULL) == 0)
212 		num++;
213 
214 	return num;
215 }
216 
217 static int
218 seq_lookup_plain(struct _citrus_lookup *cl, const char *key,
219 		 struct _region *data)
220 {
221 	size_t len;
222 	const char *p;
223 
224 	cl->cl_rewind = 0;
225 	free(cl->cl_key);
226 	cl->cl_key = strdup(key);
227 	if (cl->cl_ignore_case)
228 		_bcs_convert_to_lower(cl->cl_key);
229 	cl->cl_keylen = strlen(cl->cl_key);
230 	_memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
231 	p = _memstream_matchline(&cl->cl_plainms, cl->cl_key, &len, 0);
232 	if (p == NULL)
233 		return ENOENT;
234 	if (data)
235 		_region_init(data, __DECONST(char *, p), len);
236 
237 	return 0;
238 }
239 
240 static void
241 seq_close_plain(struct _citrus_lookup *cl)
242 {
243 	_unmap_file(&cl->cl_plainr);
244 }
245 
246 static int
247 seq_open_plain(struct _citrus_lookup *cl, const char *name)
248 {
249 	int ret;
250 
251 	/* open read stream */
252 	ret = _map_file(&cl->cl_plainr, name);
253 	if (ret)
254 		return ret;
255 
256 	cl->cl_rewind = 1;
257 	cl->cl_next = &seq_next_plain;
258 	cl->cl_lookup = &seq_lookup_plain;
259 	cl->cl_num_entries = &seq_get_num_entries_plain;
260 	cl->cl_close = &seq_close_plain;
261 
262 	return 0;
263 }
264 
265 int
266 _citrus_lookup_seq_open(struct _citrus_lookup **rcl, const char *name,
267 			int ignore_case)
268 {
269 	int ret;
270 	struct _citrus_lookup *cl;
271 
272 	cl = malloc(sizeof(*cl));
273 	if (cl == NULL)
274 		return errno;
275 
276 	cl->cl_key = NULL;
277 	cl->cl_keylen = 0;
278 	cl->cl_ignore_case = ignore_case;
279 	ret = seq_open_db(cl, name);
280 	if (ret == ENOENT)
281 		ret = seq_open_plain(cl, name);
282 	if (!ret)
283 		*rcl = cl;
284 	else
285 		free(cl);
286 
287 	return ret;
288 }
289 
290 void
291 _citrus_lookup_seq_rewind(struct _citrus_lookup *cl)
292 {
293 	cl->cl_rewind = 1;
294 	free(cl->cl_key);
295 	cl->cl_key = NULL;
296 	cl->cl_keylen = 0;
297 }
298 
299 int
300 _citrus_lookup_seq_next(struct _citrus_lookup *cl,
301 			struct _region *key, struct _region *data)
302 {
303 	return (*cl->cl_next)(cl, key, data);
304 }
305 
306 int
307 _citrus_lookup_seq_lookup(struct _citrus_lookup *cl, const char *key,
308 			  struct _region *data)
309 {
310 	return (*cl->cl_lookup)(cl, key, data);
311 }
312 
313 int
314 _citrus_lookup_get_number_of_entries(struct _citrus_lookup *cl)
315 {
316 	return (*cl->cl_num_entries)(cl);
317 }
318 
319 void
320 _citrus_lookup_seq_close(struct _citrus_lookup *cl)
321 {
322 	free(cl->cl_key);
323 	(*cl->cl_close)(cl);
324 	free(cl);
325 }
326 
327 char *
328 _citrus_lookup_simple(const char *name, const char *key,
329 		      char *linebuf, size_t linebufsize, int ignore_case)
330 {
331 	int ret;
332 	struct _citrus_lookup *cl;
333 	struct _region data;
334 
335 	ret = _citrus_lookup_seq_open(&cl, name, ignore_case);
336 	if (ret)
337 		return NULL;
338 
339 	ret = _citrus_lookup_seq_lookup(cl, key, &data);
340 	if (ret) {
341 		_citrus_lookup_seq_close(cl);
342 		return NULL;
343 	}
344 
345 	snprintf(linebuf, linebufsize, "%.*s",
346 		 (int)_region_size(&data), (const char *)_region_head(&data));
347 
348 	_citrus_lookup_seq_close(cl);
349 
350 	return linebuf;
351 }
352