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6973fc01 | 1 | /* Provide access to the collection of available transformation modules. |
9e26f129 | 2 | Copyright (C) 1997-2003, 2004 Free Software Foundation, Inc. |
6973fc01 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
6973fc01 UD |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
6973fc01 | 15 | |
41bdb6e2 AJ |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, write to the Free | |
18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
19 | 02111-1307 USA. */ | |
6973fc01 | 20 | |
2bd60880 | 21 | #include <limits.h> |
6973fc01 UD |
22 | #include <search.h> |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
2bd60880 | 25 | #include <sys/param.h> |
6973fc01 | 26 | #include <bits/libc-lock.h> |
7c11c4a1 | 27 | #include <locale/localeinfo.h> |
816e6eb5 | 28 | |
b3fc5f84 | 29 | #include <dlfcn.h> |
e62c19f1 UD |
30 | #include <gconv_int.h> |
31 | ||
6973fc01 UD |
32 | |
33 | /* Simple data structure for alias mapping. We have two names, `from' | |
34 | and `to'. */ | |
35 | void *__gconv_alias_db; | |
36 | ||
37 | /* Array with available modules. */ | |
2bd60880 | 38 | struct gconv_module *__gconv_modules_db; |
6973fc01 | 39 | |
0d9f6793 | 40 | /* We modify global data. */ |
9e26f129 | 41 | __libc_lock_define_initialized (, __gconv_lock) |
0d9f6793 | 42 | |
6973fc01 | 43 | |
230491f0 UD |
44 | /* Provide access to module database. */ |
45 | struct gconv_module * | |
46 | __gconv_get_modules_db (void) | |
47 | { | |
48 | return __gconv_modules_db; | |
49 | } | |
50 | ||
51 | void * | |
52 | __gconv_get_alias_db (void) | |
53 | { | |
54 | return __gconv_alias_db; | |
55 | } | |
56 | ||
57 | ||
6973fc01 UD |
58 | /* Function for searching alias. */ |
59 | int | |
60 | __gconv_alias_compare (const void *p1, const void *p2) | |
61 | { | |
17427edd UD |
62 | const struct gconv_alias *s1 = (const struct gconv_alias *) p1; |
63 | const struct gconv_alias *s2 = (const struct gconv_alias *) p2; | |
bd4848fb | 64 | return strcmp (s1->fromname, s2->fromname); |
6973fc01 UD |
65 | } |
66 | ||
67 | ||
68 | /* To search for a derivation we create a list of intermediate steps. | |
69 | Each element contains a pointer to the element which precedes it | |
70 | in the derivation order. */ | |
71 | struct derivation_step | |
72 | { | |
73 | const char *result_set; | |
2bd60880 UD |
74 | size_t result_set_len; |
75 | int cost_lo; | |
76 | int cost_hi; | |
6973fc01 UD |
77 | struct gconv_module *code; |
78 | struct derivation_step *last; | |
79 | struct derivation_step *next; | |
80 | }; | |
81 | ||
2bd60880 | 82 | #define NEW_STEP(result, hi, lo, module, last_mod) \ |
6973fc01 UD |
83 | ({ struct derivation_step *newp = alloca (sizeof (struct derivation_step)); \ |
84 | newp->result_set = result; \ | |
2bd60880 UD |
85 | newp->result_set_len = strlen (result); \ |
86 | newp->cost_hi = hi; \ | |
87 | newp->cost_lo = lo; \ | |
6973fc01 UD |
88 | newp->code = module; \ |
89 | newp->last = last_mod; \ | |
90 | newp->next = NULL; \ | |
91 | newp; }) | |
92 | ||
93 | ||
94 | /* If a specific transformation is used more than once we should not need | |
95 | to start looking for it again. Instead cache each successful result. */ | |
96 | struct known_derivation | |
97 | { | |
98 | const char *from; | |
99 | const char *to; | |
d64b6ad0 | 100 | struct __gconv_step *steps; |
6973fc01 UD |
101 | size_t nsteps; |
102 | }; | |
103 | ||
104 | /* Compare function for database of found derivations. */ | |
105 | static int | |
106 | derivation_compare (const void *p1, const void *p2) | |
107 | { | |
17427edd UD |
108 | const struct known_derivation *s1 = (const struct known_derivation *) p1; |
109 | const struct known_derivation *s2 = (const struct known_derivation *) p2; | |
6973fc01 UD |
110 | int result; |
111 | ||
112 | result = strcmp (s1->from, s2->from); | |
113 | if (result == 0) | |
114 | result = strcmp (s1->to, s2->to); | |
115 | return result; | |
116 | } | |
117 | ||
118 | /* The search tree for known derivations. */ | |
119 | static void *known_derivations; | |
120 | ||
121 | /* Look up whether given transformation was already requested before. */ | |
122 | static int | |
e62c19f1 | 123 | internal_function |
6973fc01 | 124 | derivation_lookup (const char *fromset, const char *toset, |
d64b6ad0 | 125 | struct __gconv_step **handle, size_t *nsteps) |
6973fc01 UD |
126 | { |
127 | struct known_derivation key = { fromset, toset, NULL, 0 }; | |
bd687f7a | 128 | struct known_derivation **result; |
6973fc01 | 129 | |
e34b0f29 | 130 | result = __tfind (&key, &known_derivations, derivation_compare); |
6973fc01 UD |
131 | |
132 | if (result == NULL) | |
d64b6ad0 | 133 | return __GCONV_NOCONV; |
6973fc01 | 134 | |
bd687f7a UD |
135 | *handle = (*result)->steps; |
136 | *nsteps = (*result)->nsteps; | |
6973fc01 UD |
137 | |
138 | /* Please note that we return GCONV_OK even if the last search for | |
139 | this transformation was unsuccessful. */ | |
d64b6ad0 | 140 | return __GCONV_OK; |
6973fc01 UD |
141 | } |
142 | ||
143 | /* Add new derivation to list of known ones. */ | |
144 | static void | |
e62c19f1 | 145 | internal_function |
6973fc01 | 146 | add_derivation (const char *fromset, const char *toset, |
d64b6ad0 | 147 | struct __gconv_step *handle, size_t nsteps) |
6973fc01 UD |
148 | { |
149 | struct known_derivation *new_deriv; | |
150 | size_t fromset_len = strlen (fromset) + 1; | |
151 | size_t toset_len = strlen (toset) + 1; | |
152 | ||
153 | new_deriv = (struct known_derivation *) | |
154 | malloc (sizeof (struct known_derivation) + fromset_len + toset_len); | |
155 | if (new_deriv != NULL) | |
156 | { | |
390500b1 UD |
157 | new_deriv->from = (char *) (new_deriv + 1); |
158 | new_deriv->to = memcpy (__mempcpy (new_deriv + 1, fromset, fromset_len), | |
6973fc01 UD |
159 | toset, toset_len); |
160 | ||
161 | new_deriv->steps = handle; | |
162 | new_deriv->nsteps = nsteps; | |
163 | ||
390500b1 UD |
164 | if (__tsearch (new_deriv, &known_derivations, derivation_compare) |
165 | == NULL) | |
166 | /* There is some kind of memory allocation problem. */ | |
167 | free (new_deriv); | |
6973fc01 UD |
168 | } |
169 | /* Please note that we don't complain if the allocation failed. This | |
170 | is not tragically but in case we use the memory debugging facilities | |
171 | not all memory will be freed. */ | |
172 | } | |
173 | ||
7c11c4a1 | 174 | static void __libc_freeres_fn_section |
6973fc01 UD |
175 | free_derivation (void *p) |
176 | { | |
177 | struct known_derivation *deriv = (struct known_derivation *) p; | |
0d9f6793 UD |
178 | size_t cnt; |
179 | ||
180 | for (cnt = 0; cnt < deriv->nsteps; ++cnt) | |
b79f74cd UD |
181 | if (deriv->steps[cnt].__counter > 0 |
182 | && deriv->steps[cnt].__end_fct != NULL) | |
94e365c6 | 183 | DL_CALL_FCT (deriv->steps[cnt].__end_fct, (&deriv->steps[cnt])); |
6973fc01 | 184 | |
74454183 | 185 | /* Free the name strings. */ |
d64b6ad0 UD |
186 | free ((char *) deriv->steps[0].__from_name); |
187 | free ((char *) deriv->steps[deriv->nsteps - 1].__to_name); | |
74454183 | 188 | |
d64b6ad0 | 189 | free ((struct __gconv_step *) deriv->steps); |
6973fc01 UD |
190 | free (deriv); |
191 | } | |
192 | ||
193 | ||
b79f74cd | 194 | /* Decrement the reference count for a single step in a steps array. */ |
6b98979f UD |
195 | void |
196 | internal_function | |
197 | __gconv_release_step (struct __gconv_step *step) | |
b79f74cd UD |
198 | { |
199 | if (--step->__counter == 0) | |
200 | { | |
201 | /* Call the destructor. */ | |
202 | if (step->__end_fct != NULL) | |
203 | DL_CALL_FCT (step->__end_fct, (step)); | |
204 | ||
205 | #ifndef STATIC_GCONV | |
206 | /* Skip builtin modules; they are not reference counted. */ | |
207 | if (step->__shlib_handle != NULL) | |
208 | { | |
209 | /* Release the loaded module. */ | |
210 | __gconv_release_shlib (step->__shlib_handle); | |
211 | step->__shlib_handle = NULL; | |
212 | } | |
213 | #endif | |
214 | } | |
215 | } | |
216 | ||
6973fc01 UD |
217 | static int |
218 | internal_function | |
219 | gen_steps (struct derivation_step *best, const char *toset, | |
d64b6ad0 | 220 | const char *fromset, struct __gconv_step **handle, size_t *nsteps) |
6973fc01 UD |
221 | { |
222 | size_t step_cnt = 0; | |
d64b6ad0 | 223 | struct __gconv_step *result; |
6973fc01 | 224 | struct derivation_step *current; |
d64b6ad0 | 225 | int status = __GCONV_NOMEM; |
6973fc01 UD |
226 | |
227 | /* First determine number of steps. */ | |
228 | for (current = best; current->last != NULL; current = current->last) | |
229 | ++step_cnt; | |
230 | ||
d64b6ad0 UD |
231 | result = (struct __gconv_step *) malloc (sizeof (struct __gconv_step) |
232 | * step_cnt); | |
6973fc01 UD |
233 | if (result != NULL) |
234 | { | |
e34b0f29 UD |
235 | int failed = 0; |
236 | ||
d64b6ad0 | 237 | status = __GCONV_OK; |
e34b0f29 | 238 | *nsteps = step_cnt; |
6973fc01 UD |
239 | current = best; |
240 | while (step_cnt-- > 0) | |
241 | { | |
d64b6ad0 UD |
242 | result[step_cnt].__from_name = (step_cnt == 0 |
243 | ? __strdup (fromset) | |
8a0746ae | 244 | : (char *)current->last->result_set); |
d64b6ad0 UD |
245 | result[step_cnt].__to_name = (step_cnt + 1 == *nsteps |
246 | ? __strdup (current->result_set) | |
247 | : result[step_cnt + 1].__from_name); | |
6973fc01 | 248 | |
6b98979f UD |
249 | result[step_cnt].__counter = 1; |
250 | result[step_cnt].__data = NULL; | |
251 | ||
8619129f | 252 | #ifndef STATIC_GCONV |
6973fc01 UD |
253 | if (current->code->module_name[0] == '/') |
254 | { | |
255 | /* Load the module, return handle for it. */ | |
d64b6ad0 | 256 | struct __gconv_loaded_object *shlib_handle = |
6973fc01 UD |
257 | __gconv_find_shlib (current->code->module_name); |
258 | ||
259 | if (shlib_handle == NULL) | |
e34b0f29 UD |
260 | { |
261 | failed = 1; | |
262 | break; | |
263 | } | |
6973fc01 | 264 | |
d64b6ad0 UD |
265 | result[step_cnt].__shlib_handle = shlib_handle; |
266 | result[step_cnt].__modname = shlib_handle->name; | |
d64b6ad0 UD |
267 | result[step_cnt].__fct = shlib_handle->fct; |
268 | result[step_cnt].__init_fct = shlib_handle->init_fct; | |
269 | result[step_cnt].__end_fct = shlib_handle->end_fct; | |
6b98979f | 270 | |
f9ad060c UD |
271 | /* These settings can be overridden by the init function. */ |
272 | result[step_cnt].__btowc_fct = NULL; | |
273 | ||
6b98979f UD |
274 | /* Call the init function. */ |
275 | if (result[step_cnt].__init_fct != NULL) | |
276 | { | |
277 | status = DL_CALL_FCT (result[step_cnt].__init_fct, | |
278 | (&result[step_cnt])); | |
279 | ||
280 | if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK) | |
281 | { | |
282 | failed = 1; | |
283 | /* Make sure we unload this modules. */ | |
284 | --step_cnt; | |
285 | result[step_cnt].__end_fct = NULL; | |
286 | break; | |
287 | } | |
288 | } | |
6973fc01 UD |
289 | } |
290 | else | |
8619129f | 291 | #endif |
6973fc01 UD |
292 | /* It's a builtin transformation. */ |
293 | __gconv_get_builtin_trans (current->code->module_name, | |
294 | &result[step_cnt]); | |
295 | ||
296 | current = current->last; | |
297 | } | |
298 | ||
5ea1a82d | 299 | if (__builtin_expect (failed, 0) != 0) |
6973fc01 UD |
300 | { |
301 | /* Something went wrong while initializing the modules. */ | |
e34b0f29 | 302 | while (++step_cnt < *nsteps) |
6b98979f | 303 | __gconv_release_step (&result[step_cnt]); |
6973fc01 | 304 | free (result); |
e34b0f29 | 305 | *nsteps = 0; |
7a68c94a | 306 | *handle = NULL; |
d64b6ad0 UD |
307 | if (status == __GCONV_OK) |
308 | status = __GCONV_NOCONV; | |
6973fc01 UD |
309 | } |
310 | else | |
c7ec9d75 | 311 | *handle = result; |
6973fc01 | 312 | } |
7a68c94a UD |
313 | else |
314 | { | |
315 | *nsteps = 0; | |
316 | *handle = NULL; | |
317 | } | |
6973fc01 UD |
318 | |
319 | return status; | |
320 | } | |
321 | ||
322 | ||
76a2102b UD |
323 | #ifndef STATIC_GCONV |
324 | static int | |
325 | internal_function | |
326 | increment_counter (struct __gconv_step *steps, size_t nsteps) | |
327 | { | |
328 | /* Increment the user counter. */ | |
329 | size_t cnt = nsteps; | |
330 | int result = __GCONV_OK; | |
331 | ||
332 | while (cnt-- > 0) | |
b79f74cd UD |
333 | { |
334 | struct __gconv_step *step = &steps[cnt]; | |
335 | ||
336 | if (step->__counter++ == 0) | |
337 | { | |
338 | /* Skip builtin modules. */ | |
339 | if (step->__modname != NULL) | |
340 | { | |
341 | /* Reopen a previously used module. */ | |
342 | step->__shlib_handle = __gconv_find_shlib (step->__modname); | |
343 | if (step->__shlib_handle == NULL) | |
344 | { | |
345 | /* Oops, this is the second time we use this module | |
346 | (after unloading) and this time loading failed!? */ | |
347 | --step->__counter; | |
348 | while (++cnt < nsteps) | |
6b98979f | 349 | __gconv_release_step (&steps[cnt]); |
b79f74cd UD |
350 | result = __GCONV_NOCONV; |
351 | break; | |
352 | } | |
353 | ||
354 | /* The function addresses defined by the module may | |
355 | have changed. */ | |
356 | step->__fct = step->__shlib_handle->fct; | |
357 | step->__init_fct = step->__shlib_handle->init_fct; | |
358 | step->__end_fct = step->__shlib_handle->end_fct; | |
f9ad060c UD |
359 | |
360 | /* These settings can be overridden by the init function. */ | |
361 | step->__btowc_fct = NULL; | |
b79f74cd UD |
362 | } |
363 | ||
f9ad060c | 364 | /* Call the init function. */ |
b79f74cd UD |
365 | if (step->__init_fct != NULL) |
366 | DL_CALL_FCT (step->__init_fct, (step)); | |
367 | } | |
368 | } | |
76a2102b UD |
369 | return result; |
370 | } | |
371 | #endif | |
372 | ||
373 | ||
6973fc01 UD |
374 | /* The main function: find a possible derivation from the `fromset' (either |
375 | the given name or the alias) to the `toset' (again with alias). */ | |
376 | static int | |
e34b0f29 | 377 | internal_function |
6973fc01 UD |
378 | find_derivation (const char *toset, const char *toset_expand, |
379 | const char *fromset, const char *fromset_expand, | |
d64b6ad0 | 380 | struct __gconv_step **handle, size_t *nsteps) |
6973fc01 | 381 | { |
2bd60880 UD |
382 | struct derivation_step *first, *current, **lastp, *solution = NULL; |
383 | int best_cost_hi = INT_MAX; | |
384 | int best_cost_lo = INT_MAX; | |
6973fc01 UD |
385 | int result; |
386 | ||
b79f74cd UD |
387 | /* Look whether an earlier call to `find_derivation' has already |
388 | computed a possible derivation. If so, return it immediately. */ | |
6973fc01 UD |
389 | result = derivation_lookup (fromset_expand ?: fromset, toset_expand ?: toset, |
390 | handle, nsteps); | |
d64b6ad0 | 391 | if (result == __GCONV_OK) |
3c5edd4d | 392 | { |
76a2102b UD |
393 | #ifndef STATIC_GCONV |
394 | result = increment_counter (*handle, *nsteps); | |
395 | #endif | |
3c5edd4d UD |
396 | return result; |
397 | } | |
6973fc01 | 398 | |
b79f74cd UD |
399 | /* The task is to find a sequence of transformations, backed by the |
400 | existing modules - whether builtin or dynamically loadable -, | |
401 | starting at `fromset' (or `fromset_expand') and ending at `toset' | |
402 | (or `toset_expand'), and with minimal cost. | |
403 | ||
404 | For computer scientists, this is a shortest path search in the | |
405 | graph where the nodes are all possible charsets and the edges are | |
406 | the transformations listed in __gconv_modules_db. | |
407 | ||
408 | For now we use a simple algorithm with quadratic runtime behaviour. | |
409 | A breadth-first search, starting at `fromset' and `fromset_expand'. | |
410 | The list starting at `first' contains all nodes that have been | |
411 | visited up to now, in the order in which they have been visited -- | |
412 | excluding the goal nodes `toset' and `toset_expand' which get | |
413 | managed in the list starting at `solution'. | |
414 | `current' walks through the list starting at `first' and looks | |
415 | which nodes are reachable from the current node, adding them to | |
416 | the end of the list [`first' or `solution' respectively] (if | |
417 | they are visited the first time) or updating them in place (if | |
418 | they have have already been visited). | |
419 | In each node of either list, cost_lo and cost_hi contain the | |
420 | minimum cost over any paths found up to now, starting at `fromset' | |
421 | or `fromset_expand', ending at that node. best_cost_lo and | |
422 | best_cost_hi represent the minimum over the elements of the | |
423 | `solution' list. */ | |
424 | ||
6973fc01 UD |
425 | if (fromset_expand != NULL) |
426 | { | |
2bd60880 UD |
427 | first = NEW_STEP (fromset_expand, 0, 0, NULL, NULL); |
428 | first->next = NEW_STEP (fromset, 0, 0, NULL, NULL); | |
e34b0f29 | 429 | lastp = &first->next->next; |
6973fc01 UD |
430 | } |
431 | else | |
432 | { | |
2bd60880 | 433 | first = NEW_STEP (fromset, 0, 0, NULL, NULL); |
e34b0f29 | 434 | lastp = &first->next; |
6973fc01 UD |
435 | } |
436 | ||
2bd60880 | 437 | for (current = first; current != NULL; current = current->next) |
6973fc01 UD |
438 | { |
439 | /* Now match all the available module specifications against the | |
440 | current charset name. If any of them matches check whether | |
441 | we already have a derivation for this charset. If yes, use the | |
442 | one with the lower costs. Otherwise add the new charset at the | |
2bd60880 UD |
443 | end. |
444 | ||
e8b1163e AJ |
445 | The module database is organized in a tree form which allows |
446 | searching for prefixes. So we search for the first entry with a | |
2bd60880 UD |
447 | matching prefix and any other matching entry can be found from |
448 | this place. */ | |
b79f74cd | 449 | struct gconv_module *node; |
2bd60880 UD |
450 | |
451 | /* Maybe it is not necessary anymore to look for a solution for | |
b79f74cd | 452 | this entry since the cost is already as high (or higher) as |
2bd60880 UD |
453 | the cost for the best solution so far. */ |
454 | if (current->cost_hi > best_cost_hi | |
455 | || (current->cost_hi == best_cost_hi | |
456 | && current->cost_lo >= best_cost_lo)) | |
457 | continue; | |
458 | ||
b79f74cd | 459 | node = __gconv_modules_db; |
2bd60880 UD |
460 | while (node != NULL) |
461 | { | |
d2dfc5de | 462 | int cmpres = strcmp (current->result_set, node->from_string); |
2bd60880 | 463 | if (cmpres == 0) |
6973fc01 | 464 | { |
2bd60880 UD |
465 | /* Walk through the list of modules with this prefix and |
466 | try to match the name. */ | |
467 | struct gconv_module *runp; | |
468 | ||
2bd60880 UD |
469 | /* Check all the modules with this prefix. */ |
470 | runp = node; | |
471 | do | |
6973fc01 | 472 | { |
d2dfc5de UD |
473 | const char *result_set = (strcmp (runp->to_string, "-") == 0 |
474 | ? (toset_expand ?: toset) | |
475 | : runp->to_string); | |
476 | int cost_hi = runp->cost_hi + current->cost_hi; | |
477 | int cost_lo = runp->cost_lo + current->cost_lo; | |
478 | struct derivation_step *step; | |
479 | ||
480 | /* We managed to find a derivation. First see whether | |
b79f74cd | 481 | we have reached one of the goal nodes. */ |
d2dfc5de UD |
482 | if (strcmp (result_set, toset) == 0 |
483 | || (toset_expand != NULL | |
484 | && strcmp (result_set, toset_expand) == 0)) | |
2bd60880 | 485 | { |
b79f74cd UD |
486 | /* Append to the `solution' list if there |
487 | is no entry with this name. */ | |
488 | for (step = solution; step != NULL; step = step->next) | |
489 | if (strcmp (result_set, step->result_set) == 0) | |
490 | break; | |
491 | ||
492 | if (step == NULL) | |
493 | { | |
494 | step = NEW_STEP (result_set, | |
495 | cost_hi, cost_lo, | |
496 | runp, current); | |
497 | step->next = solution; | |
498 | solution = step; | |
499 | } | |
500 | else if (step->cost_hi > cost_hi | |
501 | || (step->cost_hi == cost_hi | |
502 | && step->cost_lo > cost_lo)) | |
503 | { | |
504 | /* A better path was found for the node, | |
505 | on the `solution' list. */ | |
506 | step->code = runp; | |
507 | step->last = current; | |
508 | step->cost_hi = cost_hi; | |
509 | step->cost_lo = cost_lo; | |
510 | } | |
511 | ||
512 | /* Update best_cost accordingly. */ | |
513 | if (cost_hi < best_cost_hi | |
d2dfc5de UD |
514 | || (cost_hi == best_cost_hi |
515 | && cost_lo < best_cost_lo)) | |
2bd60880 | 516 | { |
d2dfc5de UD |
517 | best_cost_hi = cost_hi; |
518 | best_cost_lo = cost_lo; | |
2bd60880 | 519 | } |
6973fc01 | 520 | } |
d2dfc5de UD |
521 | else if (cost_hi < best_cost_hi |
522 | || (cost_hi == best_cost_hi | |
523 | && cost_lo < best_cost_lo)) | |
6973fc01 | 524 | { |
b79f74cd UD |
525 | /* Append at the end of the `first' list if there |
526 | is no entry with this name. */ | |
d2dfc5de UD |
527 | for (step = first; step != NULL; step = step->next) |
528 | if (strcmp (result_set, step->result_set) == 0) | |
529 | break; | |
2bd60880 | 530 | |
d2dfc5de UD |
531 | if (step == NULL) |
532 | { | |
533 | *lastp = NEW_STEP (result_set, | |
534 | cost_hi, cost_lo, | |
535 | runp, current); | |
536 | lastp = &(*lastp)->next; | |
2bd60880 | 537 | } |
d2dfc5de UD |
538 | else if (step->cost_hi > cost_hi |
539 | || (step->cost_hi == cost_hi | |
540 | && step->cost_lo > cost_lo)) | |
2bd60880 | 541 | { |
b79f74cd UD |
542 | /* A better path was found for the node, |
543 | on the `first' list. */ | |
d2dfc5de UD |
544 | step->code = runp; |
545 | step->last = current; | |
2bd60880 | 546 | |
d2dfc5de UD |
547 | /* Update the cost for all steps. */ |
548 | for (step = first; step != NULL; | |
549 | step = step->next) | |
b79f74cd UD |
550 | /* But don't update the start nodes. */ |
551 | if (step->code != NULL) | |
552 | { | |
553 | struct derivation_step *back; | |
554 | int hi, lo; | |
555 | ||
556 | hi = step->code->cost_hi; | |
557 | lo = step->code->cost_lo; | |
558 | ||
559 | for (back = step->last; back->code != NULL; | |
560 | back = back->last) | |
561 | { | |
562 | hi += back->code->cost_hi; | |
563 | lo += back->code->cost_lo; | |
564 | } | |
565 | ||
566 | step->cost_hi = hi; | |
567 | step->cost_lo = lo; | |
568 | } | |
569 | ||
570 | /* Likewise for the nodes on the solution list. | |
571 | Also update best_cost accordingly. */ | |
d2dfc5de UD |
572 | for (step = solution; step != NULL; |
573 | step = step->next) | |
574 | { | |
575 | step->cost_hi = (step->code->cost_hi | |
576 | + step->last->cost_hi); | |
577 | step->cost_lo = (step->code->cost_lo | |
578 | + step->last->cost_lo); | |
579 | ||
580 | if (step->cost_hi < best_cost_hi | |
581 | || (step->cost_hi == best_cost_hi | |
582 | && step->cost_lo < best_cost_lo)) | |
2bd60880 | 583 | { |
d2dfc5de UD |
584 | best_cost_hi = step->cost_hi; |
585 | best_cost_lo = step->cost_lo; | |
2bd60880 UD |
586 | } |
587 | } | |
588 | } | |
6973fc01 | 589 | } |
2bd60880 UD |
590 | |
591 | runp = runp->same; | |
6973fc01 | 592 | } |
2bd60880 | 593 | while (runp != NULL); |
e34b0f29 | 594 | |
d2dfc5de | 595 | break; |
6973fc01 | 596 | } |
2bd60880 UD |
597 | else if (cmpres < 0) |
598 | node = node->left; | |
599 | else | |
600 | node = node->right; | |
6973fc01 UD |
601 | } |
602 | } | |
603 | ||
2bd60880 | 604 | if (solution != NULL) |
b79f74cd UD |
605 | { |
606 | /* We really found a way to do the transformation. */ | |
607 | ||
608 | /* Choose the best solution. This is easy because we know that | |
609 | the solution list has at most length 2 (one for every possible | |
610 | goal node). */ | |
611 | if (solution->next != NULL) | |
612 | { | |
613 | struct derivation_step *solution2 = solution->next; | |
614 | ||
615 | if (solution2->cost_hi < solution->cost_hi | |
616 | || (solution2->cost_hi == solution->cost_hi | |
617 | && solution2->cost_lo < solution->cost_lo)) | |
618 | solution = solution2; | |
619 | } | |
620 | ||
621 | /* Now build a data structure describing the transformation steps. */ | |
622 | result = gen_steps (solution, toset_expand ?: toset, | |
623 | fromset_expand ?: fromset, handle, nsteps); | |
624 | } | |
6973fc01 UD |
625 | else |
626 | { | |
627 | /* We haven't found a transformation. Clear the result values. */ | |
628 | *handle = NULL; | |
629 | *nsteps = 0; | |
630 | } | |
631 | ||
632 | /* Add result in any case to list of known derivations. */ | |
633 | add_derivation (fromset_expand ?: fromset, toset_expand ?: toset, | |
634 | *handle, *nsteps); | |
635 | ||
6973fc01 UD |
636 | return result; |
637 | } | |
638 | ||
639 | ||
e7f21fa6 UD |
640 | /* Control of initialization. */ |
641 | __libc_once_define (static, once); | |
642 | ||
643 | ||
644 | static const char * | |
645 | do_lookup_alias (const char *name) | |
646 | { | |
647 | struct gconv_alias key; | |
648 | struct gconv_alias **found; | |
649 | ||
650 | key.fromname = (char *) name; | |
651 | found = __tfind (&key, &__gconv_alias_db, __gconv_alias_compare); | |
652 | return found != NULL ? (*found)->toname : NULL; | |
653 | } | |
654 | ||
655 | ||
9a018f6c UD |
656 | int |
657 | internal_function | |
658 | __gconv_compare_alias (const char *name1, const char *name2) | |
e7f21fa6 | 659 | { |
9a018f6c UD |
660 | int result; |
661 | ||
e7f21fa6 UD |
662 | /* Ensure that the configuration data is read. */ |
663 | __libc_once (once, __gconv_read_conf); | |
664 | ||
9a018f6c UD |
665 | if (__gconv_compare_alias_cache (name1, name2, &result) != 0) |
666 | result = strcmp (do_lookup_alias (name1) ?: name1, | |
667 | do_lookup_alias (name2) ?: name2); | |
668 | ||
669 | return result; | |
e7f21fa6 UD |
670 | } |
671 | ||
672 | ||
6973fc01 | 673 | int |
e62c19f1 | 674 | internal_function |
6973fc01 | 675 | __gconv_find_transform (const char *toset, const char *fromset, |
60c53a12 UD |
676 | struct __gconv_step **handle, size_t *nsteps, |
677 | int flags) | |
6973fc01 | 678 | { |
6b98979f UD |
679 | const char *fromset_expand; |
680 | const char *toset_expand; | |
6973fc01 UD |
681 | int result; |
682 | ||
683 | /* Ensure that the configuration data is read. */ | |
684 | __libc_once (once, __gconv_read_conf); | |
685 | ||
0d9f6793 | 686 | /* Acquire the lock. */ |
9e26f129 | 687 | __libc_lock_lock (__gconv_lock); |
0d9f6793 | 688 | |
6b98979f UD |
689 | result = __gconv_lookup_cache (toset, fromset, handle, nsteps, flags); |
690 | if (result != __GCONV_NODB) | |
691 | { | |
692 | /* We have a cache and could resolve the request, successful or not. */ | |
9e26f129 | 693 | __libc_lock_unlock (__gconv_lock); |
6b98979f UD |
694 | return result; |
695 | } | |
696 | ||
6973fc01 UD |
697 | /* If we don't have a module database return with an error. */ |
698 | if (__gconv_modules_db == NULL) | |
3c5edd4d | 699 | { |
9e26f129 | 700 | __libc_lock_unlock (__gconv_lock); |
d64b6ad0 | 701 | return __GCONV_NOCONV; |
3c5edd4d | 702 | } |
6973fc01 UD |
703 | |
704 | /* See whether the names are aliases. */ | |
6b98979f UD |
705 | fromset_expand = do_lookup_alias (fromset); |
706 | toset_expand = do_lookup_alias (toset); | |
6973fc01 | 707 | |
5ea1a82d | 708 | if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0) |
60c53a12 UD |
709 | /* We are not supposed to create a pseudo transformation (means |
710 | copying) when the input and output character set are the same. */ | |
711 | && (strcmp (toset, fromset) == 0 | |
712 | || (toset_expand != NULL && strcmp (toset_expand, fromset) == 0) | |
713 | || (fromset_expand != NULL | |
714 | && (strcmp (toset, fromset_expand) == 0 | |
715 | || (toset_expand != NULL | |
716 | && strcmp (toset_expand, fromset_expand) == 0))))) | |
717 | { | |
718 | /* Both character sets are the same. */ | |
9e26f129 | 719 | __libc_lock_unlock (__gconv_lock); |
60c53a12 UD |
720 | return __GCONV_NOCONV; |
721 | } | |
722 | ||
6973fc01 UD |
723 | result = find_derivation (toset, toset_expand, fromset, fromset_expand, |
724 | handle, nsteps); | |
725 | ||
0d9f6793 | 726 | /* Release the lock. */ |
9e26f129 | 727 | __libc_lock_unlock (__gconv_lock); |
0d9f6793 | 728 | |
6973fc01 UD |
729 | /* The following code is necessary since `find_derivation' will return |
730 | GCONV_OK even when no derivation was found but the same request | |
731 | was processed before. I.e., negative results will also be cached. */ | |
d64b6ad0 UD |
732 | return (result == __GCONV_OK |
733 | ? (*handle == NULL ? __GCONV_NOCONV : __GCONV_OK) | |
6973fc01 UD |
734 | : result); |
735 | } | |
736 | ||
737 | ||
738 | /* Release the entries of the modules list. */ | |
739 | int | |
e62c19f1 | 740 | internal_function |
d64b6ad0 | 741 | __gconv_close_transform (struct __gconv_step *steps, size_t nsteps) |
6973fc01 | 742 | { |
d64b6ad0 | 743 | int result = __GCONV_OK; |
0db59742 | 744 | size_t cnt; |
6973fc01 | 745 | |
0d9f6793 | 746 | /* Acquire the lock. */ |
9e26f129 | 747 | __libc_lock_lock (__gconv_lock); |
0d9f6793 | 748 | |
0db59742 UD |
749 | #ifndef STATIC_GCONV |
750 | cnt = nsteps; | |
751 | while (cnt-- > 0) | |
752 | __gconv_release_step (&steps[cnt]); | |
753 | #endif | |
754 | ||
755 | /* If we use the cache we free a bit more since we don't keep any | |
756 | transformation records around, they are cheap enough to | |
757 | recreate. */ | |
758 | __gconv_release_cache (steps, nsteps); | |
6973fc01 | 759 | |
0d9f6793 | 760 | /* Release the lock. */ |
9e26f129 | 761 | __libc_lock_unlock (__gconv_lock); |
0d9f6793 | 762 | |
6973fc01 UD |
763 | return result; |
764 | } | |
765 | ||
766 | ||
2bd60880 UD |
767 | /* Free the modules mentioned. */ |
768 | static void | |
7c11c4a1 | 769 | internal_function __libc_freeres_fn_section |
2bd60880 UD |
770 | free_modules_db (struct gconv_module *node) |
771 | { | |
772 | if (node->left != NULL) | |
773 | free_modules_db (node->left); | |
774 | if (node->right != NULL) | |
775 | free_modules_db (node->right); | |
2bd60880 UD |
776 | do |
777 | { | |
778 | struct gconv_module *act = node; | |
d2dfc5de | 779 | node = node->same; |
8ce63ec0 UD |
780 | if (act->module_name[0] == '/') |
781 | free (act); | |
2bd60880 UD |
782 | } |
783 | while (node != NULL); | |
784 | } | |
785 | ||
786 | ||
6973fc01 | 787 | /* Free all resources if necessary. */ |
c877418f | 788 | libc_freeres_fn (free_mem) |
6973fc01 | 789 | { |
7c11c4a1 UD |
790 | /* First free locale memory. This needs to be done before freeing derivations, |
791 | as ctype cleanup functions dereference steps arrays which we free below. */ | |
792 | _nl_locale_subfreeres (); | |
793 | ||
6973fc01 UD |
794 | if (__gconv_alias_db != NULL) |
795 | __tdestroy (__gconv_alias_db, free); | |
796 | ||
0dbbad29 UD |
797 | if (__gconv_modules_db != NULL) |
798 | free_modules_db (__gconv_modules_db); | |
6973fc01 UD |
799 | |
800 | if (known_derivations != NULL) | |
801 | __tdestroy (known_derivations, free_derivation); | |
802 | } |