xref: /dragonfly/lib/libc/citrus/citrus_mapper.c (revision 0bb9290e)
1 /*	$NetBSD: src/lib/libc/citrus/citrus_mapper.c,v 1.6 2004/12/30 05:05:01 christos Exp $	*/
2 /*	$DragonFly: src/lib/libc/citrus/citrus_mapper.c,v 1.1 2005/03/11 23:33:53 joerg 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 "namespace.h"
31 
32 #include <sys/types.h>
33 #include <sys/queue.h>
34 #include <sys/stat.h>
35 #include <assert.h>
36 #include <errno.h>
37 #include <limits.h>
38 #include <pthread.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include "un-namespace.h"
43 
44 #include "libc_private.h"
45 
46 #include "citrus_namespace.h"
47 #include "citrus_types.h"
48 #include "citrus_region.h"
49 #include "citrus_memstream.h"
50 #include "citrus_bcs.h"
51 #include "citrus_mmap.h"
52 #include "citrus_module.h"
53 #include "citrus_hash.h"
54 #include "citrus_mapper.h"
55 
56 #define _CITRUS_MAPPER_DIR	"mapper.dir"
57 
58 #define CM_HASH_SIZE 101
59 #define REFCOUNT_PERSISTENT	-1
60 
61 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
62 
63 struct _citrus_mapper_area {
64 	_CITRUS_HASH_HEAD(, _citrus_mapper, CM_HASH_SIZE)	ma_cache;
65 	char							*ma_dir;
66 };
67 
68 /*
69  * _citrus_mapper_create_area:
70  *	create mapper area
71  */
72 
73 int
74 _citrus_mapper_create_area(
75 	struct _citrus_mapper_area *__restrict *__restrict rma,
76 	const char *__restrict area)
77 {
78 	struct stat st;
79 	int ret;
80 	char path[PATH_MAX];
81 	struct _citrus_mapper_area *ma;
82 
83 	if (__isthreaded)
84 		_pthread_mutex_lock(&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 	if (__isthreaded)
114 		_pthread_mutex_unlock(&lock);
115 
116 	return ret;
117 }
118 
119 
120 /*
121  * lookup_mapper_entry:
122  *	lookup mapper.dir entry in the specified directory.
123  *
124  * line format of iconv.dir file:
125  *	mapper	module	arg
126  * mapper : mapper name.
127  * module : mapper module name.
128  * arg    : argument for the module (generally, description file name)
129  */
130 
131 static int
132 lookup_mapper_entry(const char *dir, const char *mapname,
133 		    void *linebuf, size_t linebufsize,
134 		    const char **module, const char **variable)
135 {
136 	struct _region r;
137 	struct _memstream ms;
138 	int ret;
139 	const char *cp, *cq;
140 	char *p;
141 	size_t len;
142 	char path[PATH_MAX];
143 
144 	/* create mapper.dir path */
145 	snprintf(path, PATH_MAX, "%s/%s", dir, _CITRUS_MAPPER_DIR);
146 
147 	/* open read stream */
148 	ret = _map_file(&r, path);
149 	if (ret)
150 		return ret;
151 
152 	_memstream_bind(&ms, &r);
153 
154 	/* search the line matching to the map name */
155 	cp = _memstream_matchline(&ms, mapname, &len, 0);
156 	if (!cp) {
157 		ret = ENOENT;
158 		goto quit;
159 	}
160 	if (!len || len>linebufsize-1) {
161 		ret = EINVAL;
162 		goto quit;
163 	}
164 
165 	p = linebuf;
166 	/* get module name */
167 	*module = p;
168 	cq = _bcs_skip_nonws_len(cp, &len);
169 	strlcpy(p, cp, (size_t)(cq-cp+1));
170 	p += cq-cp+1;
171 
172 	/* get variable */
173 	*variable = p;
174 	cp = _bcs_skip_ws_len(cq, &len);
175 	strlcpy(p, cp, len+1);
176 
177 	ret = 0;
178 
179 quit:
180 	_unmap_file(&r);
181 	return ret;
182 }
183 
184 /*
185  * mapper_close:
186  *	simply close a mapper. (without handling hash)
187  */
188 static void
189 mapper_close(struct _citrus_mapper *cm)
190 {
191 	if (cm->cm_module) {
192 		if (cm->cm_ops) {
193 			if (cm->cm_closure)
194 				(*cm->cm_ops->mo_uninit)(cm);
195 			free(cm->cm_ops);
196 		}
197 		_citrus_unload_module(cm->cm_module);
198 	}
199 	free(cm->cm_traits);
200 	free(cm);
201 }
202 
203 /*
204  * mapper_open:
205  *	simply open a mapper. (without handling hash)
206  */
207 static int
208 mapper_open(struct _citrus_mapper_area *__restrict ma,
209 	    struct _citrus_mapper * __restrict * __restrict rcm,
210 	    const char * __restrict module,
211 	    const char * __restrict variable)
212 {
213 	int ret;
214 	struct _citrus_mapper *cm;
215 	_citrus_mapper_getops_t getops;
216 
217 	/* initialize mapper handle */
218 	cm = malloc(sizeof(*cm));
219 	if (!cm)
220 		return errno;
221 
222 	cm->cm_module = NULL;
223 	cm->cm_ops = NULL;
224 	cm->cm_closure = NULL;
225 	cm->cm_traits = NULL;
226 	cm->cm_refcount = 0;
227 	cm->cm_key = NULL;
228 
229 	/* load module */
230 	ret = _citrus_load_module(&cm->cm_module, module);
231 	if (ret)
232 		goto err;
233 
234 	/* get operators */
235 	getops = (_citrus_mapper_getops_t)
236 	    _citrus_find_getops(cm->cm_module, module, "mapper");
237 	if (!getops) {
238 		ret = EOPNOTSUPP;
239 		goto err;
240 	}
241 	cm->cm_ops = malloc(sizeof(*cm->cm_ops));
242 	if (!cm->cm_ops) {
243 		ret = errno;
244 		goto err;
245 	}
246 	ret = (*getops)(cm->cm_ops, sizeof(*cm->cm_ops),
247 			_CITRUS_MAPPER_ABI_VERSION);
248 	if (ret)
249 		goto err;
250 
251 	if (!cm->cm_ops->mo_init ||
252 	    !cm->cm_ops->mo_uninit ||
253 	    !cm->cm_ops->mo_convert ||
254 	    !cm->cm_ops->mo_init_state)
255 		goto err;
256 
257 	/* allocate traits structure */
258 	cm->cm_traits = malloc(sizeof(*cm->cm_traits));
259 	if (cm->cm_traits == NULL) {
260 		ret = errno;
261 		goto err;
262 	}
263 	/* initialize the mapper */
264 	ret = (*cm->cm_ops->mo_init)(ma, cm, ma->ma_dir,
265 				     (const void *)variable,
266 				     strlen(variable)+1,
267 				     cm->cm_traits, sizeof(*cm->cm_traits));
268 	if (ret)
269 		goto err;
270 
271 	*rcm = cm;
272 
273 	return 0;
274 
275 err:
276 	mapper_close(cm);
277 	return ret;
278 }
279 
280 /*
281  * _citrus_mapper_open_direct:
282  *	open a mapper.
283  */
284 int
285 _citrus_mapper_open_direct(struct _citrus_mapper_area *__restrict ma,
286 			   struct _citrus_mapper * __restrict * __restrict rcm,
287 			   const char * __restrict module,
288 			   const char * __restrict variable)
289 {
290 	return mapper_open(ma, rcm, module, variable);
291 }
292 
293 /*
294  * hash_func
295  */
296 static __inline int
297 hash_func(const char *key)
298 {
299 	return _string_hash_func(key, CM_HASH_SIZE);
300 }
301 
302 /*
303  * match_func
304  */
305 static __inline int
306 match_func(struct _citrus_mapper *cm, const char *key)
307 {
308 	return strcmp(cm->cm_key, key);
309 }
310 
311 /*
312  * _citrus_mapper_open:
313  *	open a mapper with looking up "mapper.dir".
314  */
315 int
316 _citrus_mapper_open(struct _citrus_mapper_area *__restrict ma,
317 		    struct _citrus_mapper * __restrict * __restrict rcm,
318 		    const char * __restrict mapname)
319 {
320 	int ret;
321 	char linebuf[PATH_MAX];
322 	const char *module, *variable;
323 	struct _citrus_mapper *cm;
324 	int hashval;
325 
326 	if (__isthreaded)
327 		_pthread_mutex_lock(&lock);
328 
329 	/* search in the cache */
330 	hashval = hash_func(mapname);
331 	_CITRUS_HASH_SEARCH(&ma->ma_cache, cm, cm_entry, match_func, mapname,
332 			    hashval);
333 	if (cm) {
334 		/* found */
335 		cm->cm_refcount++;
336 		*rcm = cm;
337 		ret = 0;
338 		goto quit;
339 	}
340 
341 	/* search mapper entry */
342 	ret = lookup_mapper_entry(ma->ma_dir, mapname, linebuf, PATH_MAX,
343 				  &module, &variable);
344 	if (ret)
345 		goto quit;
346 
347 	/* open mapper */
348 	ret = mapper_open(ma, &cm, module, variable);
349 	if (ret)
350 		goto quit;
351 	cm->cm_key = strdup(mapname);
352 	if (cm->cm_key == NULL) {
353 		ret = errno;
354 		if (__isthreaded)
355 			_pthread_mutex_unlock(&lock);
356 		_mapper_close(cm);
357 		return ret;
358 	}
359 
360 	/* insert to the cache */
361 	cm->cm_refcount = 1;
362 	_CITRUS_HASH_INSERT(&ma->ma_cache, cm, cm_entry, hashval);
363 
364 	*rcm = cm;
365 	ret = 0;
366 quit:
367 	if (__isthreaded)
368 		_pthread_mutex_unlock(&lock);
369 	return ret;
370 }
371 
372 /*
373  * _citrus_mapper_close:
374  *	close the specified mapper.
375  */
376 void
377 _citrus_mapper_close(struct _citrus_mapper *cm)
378 {
379 	if (cm) {
380 		if (__isthreaded)
381 			_pthread_mutex_lock(&lock);
382 		if (cm->cm_refcount == REFCOUNT_PERSISTENT)
383 			goto quit;
384 		if (cm->cm_refcount > 0) {
385 			if (--cm->cm_refcount > 0)
386 				goto quit;
387 			_CITRUS_HASH_REMOVE(cm, cm_entry);
388 			free(cm->cm_key);
389 		}
390 		if (__isthreaded)
391 			_pthread_mutex_unlock(&lock);
392 		mapper_close(cm);
393 		return;
394 quit:
395 		if (__isthreaded)
396 			_pthread_mutex_unlock(&lock);
397 	}
398 }
399 
400 /*
401  * _citrus_mapper_set_persistent:
402  *	set persistent count.
403  */
404 void
405 _citrus_mapper_set_persistent(struct _citrus_mapper * __restrict cm)
406 {
407 	if (__isthreaded)
408 		_pthread_mutex_lock(&lock);
409 	cm->cm_refcount = REFCOUNT_PERSISTENT;
410 	if (__isthreaded)
411 		_pthread_mutex_unlock(&lock);
412 }
413