xref: /netbsd-src/lib/libc/citrus/citrus_mapper.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: citrus_mapper.c,v 1.1 2003/06/25 09:51:36 tshiozak Exp $	*/
2 
3 /*-
4  * Copyright (c)2003 Citrus Project,
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #if defined(LIBC_SCCS) && !defined(lint)
31 __RCSID("$NetBSD: citrus_mapper.c,v 1.1 2003/06/25 09:51:36 tshiozak Exp $");
32 #endif /* LIBC_SCCS and not lint */
33 
34 #include "namespace.h"
35 #include "reentrant.h"
36 #include <assert.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <errno.h>
41 #include <limits.h>
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 
45 #include "citrus_namespace.h"
46 #include "citrus_types.h"
47 #include "citrus_region.h"
48 #include "citrus_memstream.h"
49 #include "citrus_bcs.h"
50 #include "citrus_mmap.h"
51 #include "citrus_module.h"
52 #include "citrus_hash.h"
53 #include "citrus_mapper.h"
54 
55 #define _CITRUS_MAPPER_DIR	"mapper.dir"
56 
57 #define CM_HASH_SIZE 101
58 #define REFCOUNT_PERSISTENT	-1
59 
60 #ifdef _REENTRANT
61 static rwlock_t lock = RWLOCK_INITIALIZER;
62 #endif
63 
64 struct _citrus_mapper_area {
65 	_CITRUS_HASH_HEAD(, _citrus_mapper, CM_HASH_SIZE)	ma_cache;
66 	char							*ma_dir;
67 };
68 
69 /*
70  * _citrus_mapper_create_area:
71  *	create mapper area
72  */
73 
74 int
75 _citrus_mapper_create_area(
76 	struct _citrus_mapper_area *__restrict *__restrict rma,
77 	const char *__restrict area)
78 {
79 	struct stat st;
80 	int ret;
81 	char path[PATH_MAX];
82 	struct _citrus_mapper_area *ma;
83 
84 	rwlock_wrlock(&lock);
85 
86 	if (*rma != NULL) {
87 		ret = 0;
88 		goto quit;
89 	}
90 
91 	snprintf(path, PATH_MAX, "%s/%s", area, _CITRUS_MAPPER_DIR);
92 
93 	ret = stat(path, &st);
94 	if (ret)
95 		goto quit;
96 
97 	ma = malloc(sizeof(*ma));
98 	if (ma == NULL) {
99 		ret = errno;
100 		goto quit;
101 	}
102 	ma->ma_dir = strdup(area);
103 	if (ma->ma_dir == NULL) {
104 		ret = errno;
105 		free(ma->ma_dir);
106 		goto quit;
107 	}
108 	_CITRUS_HASH_INIT(&ma->ma_cache, CM_HASH_SIZE);
109 
110 	*rma = ma;
111 	ret = 0;
112 quit:
113 	rwlock_unlock(&lock);
114 
115 	return ret;
116 }
117 
118 
119 /*
120  * lookup_mapper_entry:
121  *	lookup mapper.dir entry in the specified directory.
122  *
123  * line format of iconv.dir file:
124  *	mapper	module	arg
125  * mapper : mapper name.
126  * module : mapper module name.
127  * arg    : argument for the module (generally, description file name)
128  */
129 
130 static int
131 lookup_mapper_entry(const char *dir, const char *mapname,
132 		    void *linebuf, size_t linebufsize,
133 		    const char **module, const char **variable)
134 {
135 	struct _region r;
136 	struct _memstream ms;
137 	int ret;
138 	const char *cp, *cq;
139 	char *p;
140 	size_t len;
141 	char path[PATH_MAX];
142 
143 	/* create mapper.dir path */
144 	snprintf(path, PATH_MAX, "%s/%s", dir, _CITRUS_MAPPER_DIR);
145 
146 	/* open read stream */
147 	ret = _map_file(&r, path);
148 	if (ret)
149 		return ret;
150 
151 	_memstream_bind(&ms, &r);
152 
153 	/* search the line matching to the map name */
154 	cp = _memstream_matchline(&ms, mapname, &len, 0);
155 	if (!cp) {
156 		ret = ENOENT;
157 		goto quit;
158 	}
159 	if (!len || len>linebufsize-1) {
160 		ret = EINVAL;
161 		goto quit;
162 	}
163 
164 	p = linebuf;
165 	/* get module name */
166 	*module = p;
167 	cq = _bcs_skip_nonws_len(cp, &len);
168 	strlcpy(p, cp, (size_t)(cq-cp+1));
169 	p += cq-cp+1;
170 
171 	/* get variable */
172 	*variable = p;
173 	cp = _bcs_skip_ws_len(cq, &len);
174 	strlcpy(p, cp, len+1);
175 
176 	ret = 0;
177 
178 quit:
179 	_unmap_file(&r);
180 	return ret;
181 }
182 
183 /*
184  * mapper_open:
185  */
186 static int
187 mapper_open(struct _citrus_mapper_area *__restrict ma,
188 	    struct _citrus_mapper * __restrict * __restrict rcm,
189 	    const char * __restrict module,
190 	    const char * __restrict variable)
191 {
192 	int ret;
193 	struct _citrus_mapper *cm;
194 	_citrus_mapper_getops_t getops;
195 
196 	/* initialize mapper handle */
197 	cm = malloc(sizeof(*cm));
198 	if (!cm)
199 		return errno;
200 
201 	cm->cm_module = NULL;
202 	cm->cm_ops = NULL;
203 	cm->cm_closure = NULL;
204 	cm->cm_traits = NULL;
205 	cm->cm_refcount = 0;
206 	cm->cm_key = NULL;
207 
208 	/* load module */
209 	ret = _citrus_load_module(&cm->cm_module, module);
210 	if (ret)
211 		goto err;
212 
213 	/* get operators */
214 	getops = (_citrus_mapper_getops_t)
215 	    _citrus_find_getops(cm->cm_module, module, "mapper");
216 	if (!getops) {
217 		ret = EOPNOTSUPP;
218 		goto err;
219 	}
220 	cm->cm_ops = malloc(sizeof(*cm->cm_ops));
221 	if (!cm->cm_ops) {
222 		ret = errno;
223 		goto err;
224 	}
225 	ret = (*getops)(cm->cm_ops, sizeof(*cm->cm_ops),
226 			_CITRUS_MAPPER_ABI_VERSION);
227 	if (ret)
228 		goto err;
229 
230 	if (!cm->cm_ops->mo_init ||
231 	    !cm->cm_ops->mo_uninit ||
232 	    !cm->cm_ops->mo_convert ||
233 	    !cm->cm_ops->mo_init_state)
234 		goto err;
235 
236 	/* allocate traits structure */
237 	cm->cm_traits = malloc(sizeof(*cm->cm_traits));
238 	if (cm->cm_traits == NULL) {
239 		ret = errno;
240 		goto err;
241 	}
242 	/* initialize the mapper */
243 	ret = (*cm->cm_ops->mo_init)(ma, cm, ma->ma_dir,
244 				     (const void *)variable,
245 				     strlen(variable)+1,
246 				     cm->cm_traits, sizeof(*cm->cm_traits));
247 	if (ret)
248 		goto err;
249 
250 	*rcm = cm;
251 
252 	return 0;
253 err:
254 	_citrus_mapper_close(cm);
255 	return ret;
256 }
257 
258 /*
259  * _citrus_mapper_open_direct:
260  *	open a mapper.
261  */
262 int
263 _citrus_mapper_open_direct(struct _citrus_mapper_area *__restrict ma,
264 			   struct _citrus_mapper * __restrict * __restrict rcm,
265 			   const char * __restrict module,
266 			   const char * __restrict variable)
267 {
268 	return mapper_open(ma, rcm, module, variable);
269 }
270 
271 /*
272  * hash_func
273  */
274 static __inline int
275 hash_func(const char *key)
276 {
277 	return _string_hash_func(key, CM_HASH_SIZE);
278 }
279 
280 /*
281  * match_func
282  */
283 static __inline int
284 match_func(struct _citrus_mapper *cm, const char *key)
285 {
286 	return strcmp(cm->cm_key, key);
287 }
288 
289 /*
290  * _citrus_mapper_open:
291  *	open a mapper with looking up "mapper.dir".
292  */
293 int
294 _citrus_mapper_open(struct _citrus_mapper_area *__restrict ma,
295 		    struct _citrus_mapper * __restrict * __restrict rcm,
296 		    const char * __restrict mapname)
297 {
298 	int ret;
299 	char linebuf[PATH_MAX];
300 	const char *module, *variable;
301 	struct _citrus_mapper *cm;
302 	int hashval;
303 
304 	rwlock_wrlock(&lock);
305 
306 	/* search in the cache */
307 	hashval = hash_func(mapname);
308 	_CITRUS_HASH_SEARCH(&ma->ma_cache, cm, cm_entry, match_func, mapname,
309 			    hashval);
310 	if (cm) {
311 		/* found */
312 		cm->cm_refcount++;
313 		*rcm = cm;
314 		ret = 0;
315 		goto quit;
316 	}
317 
318 	/* search mapper entry */
319 	ret = lookup_mapper_entry(ma->ma_dir, mapname, linebuf, PATH_MAX,
320 				  &module, &variable);
321 	if (ret)
322 		goto quit;
323 
324 	/* open mapper */
325 	ret = mapper_open(ma, &cm, module, variable);
326 	if (ret)
327 		goto quit;
328 	cm->cm_key = strdup(mapname);
329 	if (cm->cm_key == NULL) {
330 		ret = errno;
331 		rwlock_unlock(&lock);
332 		_mapper_close(cm);
333 		return ret;
334 	}
335 
336 	/* insert to the cache */
337 	cm->cm_refcount = 1;
338 	_CITRUS_HASH_INSERT(&ma->ma_cache, cm, cm_entry, hashval);
339 
340 	*rcm = cm;
341 	ret = 0;
342 quit:
343 	rwlock_unlock(&lock);
344 	return ret;
345 }
346 
347 /*
348  * _citrus_mapper_close:
349  *	close the specified mapper.
350  */
351 void
352 _citrus_mapper_close(struct _citrus_mapper *cm)
353 {
354 	if (cm) {
355 		rwlock_wrlock(&lock);
356 		if (cm->cm_refcount == REFCOUNT_PERSISTENT) {
357 			rwlock_unlock(&lock);
358 			return;
359 		}
360 		if (cm->cm_refcount > 0) {
361 			if (--cm->cm_refcount > 0) {
362 				rwlock_unlock(&lock);
363 				return;
364 			} else {
365 				_CITRUS_HASH_REMOVE(cm, cm_entry);
366 			}
367 		}
368 		if (cm->cm_module) {
369 			if (cm->cm_ops) {
370 				if (cm->cm_closure)
371 					(*cm->cm_ops->mo_uninit)(cm);
372 				free(cm->cm_ops);
373 			}
374 			_citrus_unload_module(cm->cm_module);
375 		}
376 		free(cm->cm_key);
377 		free(cm->cm_traits);
378 		free(cm);
379 		rwlock_unlock(&lock);
380 	}
381 }
382 
383 /*
384  * _citrus_mapper_set_persistent:
385  *	set persistent count.
386  */
387 void
388 _citrus_mapper_set_persistent(struct _citrus_mapper * __restrict cm)
389 {
390 	rwlock_wrlock(&lock);
391 	cm->cm_refcount = REFCOUNT_PERSISTENT;
392 	rwlock_unlock(&lock);
393 }
394