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6973fc01 | 1 | /* Provide access to the collection of available transformation modules. |
dd9423a6 | 2 | Copyright (C) 1997,98,99,2000,2001,2002,2003 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> |
816e6eb5 | 27 | |
b3fc5f84 | 28 | #include <dlfcn.h> |
e62c19f1 UD |
29 | #include <gconv_int.h> |
30 | ||
6973fc01 UD |
31 | |
32 | /* Simple data structure for alias mapping. We have two names, `from' | |
33 | and `to'. */ | |
34 | void *__gconv_alias_db; | |
35 | ||
36 | /* Array with available modules. */ | |
2bd60880 | 37 | struct gconv_module *__gconv_modules_db; |
6973fc01 | 38 | |
0d9f6793 UD |
39 | /* We modify global data. */ |
40 | __libc_lock_define_initialized (static, lock) | |
41 | ||
6973fc01 | 42 | |
230491f0 UD |
43 | /* Provide access to module database. */ |
44 | struct gconv_module * | |
45 | __gconv_get_modules_db (void) | |
46 | { | |
47 | return __gconv_modules_db; | |
48 | } | |
49 | ||
50 | void * | |
51 | __gconv_get_alias_db (void) | |
52 | { | |
53 | return __gconv_alias_db; | |
54 | } | |
55 | ||
56 | ||
6973fc01 UD |
57 | /* Function for searching alias. */ |
58 | int | |
59 | __gconv_alias_compare (const void *p1, const void *p2) | |
60 | { | |
17427edd UD |
61 | const struct gconv_alias *s1 = (const struct gconv_alias *) p1; |
62 | const struct gconv_alias *s2 = (const struct gconv_alias *) p2; | |
bd4848fb | 63 | return strcmp (s1->fromname, s2->fromname); |
6973fc01 UD |
64 | } |
65 | ||
66 | ||
67 | /* To search for a derivation we create a list of intermediate steps. | |
68 | Each element contains a pointer to the element which precedes it | |
69 | in the derivation order. */ | |
70 | struct derivation_step | |
71 | { | |
72 | const char *result_set; | |
2bd60880 UD |
73 | size_t result_set_len; |
74 | int cost_lo; | |
75 | int cost_hi; | |
6973fc01 UD |
76 | struct gconv_module *code; |
77 | struct derivation_step *last; | |
78 | struct derivation_step *next; | |
79 | }; | |
80 | ||
2bd60880 | 81 | #define NEW_STEP(result, hi, lo, module, last_mod) \ |
6973fc01 UD |
82 | ({ struct derivation_step *newp = alloca (sizeof (struct derivation_step)); \ |
83 | newp->result_set = result; \ | |
2bd60880 UD |
84 | newp->result_set_len = strlen (result); \ |
85 | newp->cost_hi = hi; \ | |
86 | newp->cost_lo = lo; \ | |
6973fc01 UD |
87 | newp->code = module; \ |
88 | newp->last = last_mod; \ | |
89 | newp->next = NULL; \ | |
90 | newp; }) | |
91 | ||
92 | ||
93 | /* If a specific transformation is used more than once we should not need | |
94 | to start looking for it again. Instead cache each successful result. */ | |
95 | struct known_derivation | |
96 | { | |
97 | const char *from; | |
98 | const char *to; | |
d64b6ad0 | 99 | struct __gconv_step *steps; |
6973fc01 UD |
100 | size_t nsteps; |
101 | }; | |
102 | ||
103 | /* Compare function for database of found derivations. */ | |
104 | static int | |
105 | derivation_compare (const void *p1, const void *p2) | |
106 | { | |
17427edd UD |
107 | const struct known_derivation *s1 = (const struct known_derivation *) p1; |
108 | const struct known_derivation *s2 = (const struct known_derivation *) p2; | |
6973fc01 UD |
109 | int result; |
110 | ||
111 | result = strcmp (s1->from, s2->from); | |
112 | if (result == 0) | |
113 | result = strcmp (s1->to, s2->to); | |
114 | return result; | |
115 | } | |
116 | ||
117 | /* The search tree for known derivations. */ | |
118 | static void *known_derivations; | |
119 | ||
120 | /* Look up whether given transformation was already requested before. */ | |
121 | static int | |
e62c19f1 | 122 | internal_function |
6973fc01 | 123 | derivation_lookup (const char *fromset, const char *toset, |
d64b6ad0 | 124 | struct __gconv_step **handle, size_t *nsteps) |
6973fc01 UD |
125 | { |
126 | struct known_derivation key = { fromset, toset, NULL, 0 }; | |
bd687f7a | 127 | struct known_derivation **result; |
6973fc01 | 128 | |
e34b0f29 | 129 | result = __tfind (&key, &known_derivations, derivation_compare); |
6973fc01 UD |
130 | |
131 | if (result == NULL) | |
d64b6ad0 | 132 | return __GCONV_NOCONV; |
6973fc01 | 133 | |
bd687f7a UD |
134 | *handle = (*result)->steps; |
135 | *nsteps = (*result)->nsteps; | |
6973fc01 UD |
136 | |
137 | /* Please note that we return GCONV_OK even if the last search for | |
138 | this transformation was unsuccessful. */ | |
d64b6ad0 | 139 | return __GCONV_OK; |
6973fc01 UD |
140 | } |
141 | ||
142 | /* Add new derivation to list of known ones. */ | |
143 | static void | |
e62c19f1 | 144 | internal_function |
6973fc01 | 145 | add_derivation (const char *fromset, const char *toset, |
d64b6ad0 | 146 | struct __gconv_step *handle, size_t nsteps) |
6973fc01 UD |
147 | { |
148 | struct known_derivation *new_deriv; | |
149 | size_t fromset_len = strlen (fromset) + 1; | |
150 | size_t toset_len = strlen (toset) + 1; | |
151 | ||
152 | new_deriv = (struct known_derivation *) | |
153 | malloc (sizeof (struct known_derivation) + fromset_len + toset_len); | |
154 | if (new_deriv != NULL) | |
155 | { | |
390500b1 UD |
156 | new_deriv->from = (char *) (new_deriv + 1); |
157 | new_deriv->to = memcpy (__mempcpy (new_deriv + 1, fromset, fromset_len), | |
6973fc01 UD |
158 | toset, toset_len); |
159 | ||
160 | new_deriv->steps = handle; | |
161 | new_deriv->nsteps = nsteps; | |
162 | ||
390500b1 UD |
163 | if (__tsearch (new_deriv, &known_derivations, derivation_compare) |
164 | == NULL) | |
165 | /* There is some kind of memory allocation problem. */ | |
166 | free (new_deriv); | |
6973fc01 UD |
167 | } |
168 | /* Please note that we don't complain if the allocation failed. This | |
169 | is not tragically but in case we use the memory debugging facilities | |
170 | not all memory will be freed. */ | |
171 | } | |
172 | ||
173 | static void | |
174 | free_derivation (void *p) | |
175 | { | |
176 | struct known_derivation *deriv = (struct known_derivation *) p; | |
0d9f6793 UD |
177 | size_t cnt; |
178 | ||
179 | for (cnt = 0; cnt < deriv->nsteps; ++cnt) | |
b79f74cd UD |
180 | if (deriv->steps[cnt].__counter > 0 |
181 | && deriv->steps[cnt].__end_fct != NULL) | |
94e365c6 | 182 | DL_CALL_FCT (deriv->steps[cnt].__end_fct, (&deriv->steps[cnt])); |
6973fc01 | 183 | |
74454183 | 184 | /* Free the name strings. */ |
d64b6ad0 UD |
185 | free ((char *) deriv->steps[0].__from_name); |
186 | free ((char *) deriv->steps[deriv->nsteps - 1].__to_name); | |
74454183 | 187 | |
d64b6ad0 | 188 | free ((struct __gconv_step *) deriv->steps); |
6973fc01 UD |
189 | free (deriv); |
190 | } | |
191 | ||
192 | ||
b79f74cd | 193 | /* Decrement the reference count for a single step in a steps array. */ |
6b98979f UD |
194 | void |
195 | internal_function | |
196 | __gconv_release_step (struct __gconv_step *step) | |
b79f74cd UD |
197 | { |
198 | if (--step->__counter == 0) | |
199 | { | |
200 | /* Call the destructor. */ | |
201 | if (step->__end_fct != NULL) | |
202 | DL_CALL_FCT (step->__end_fct, (step)); | |
203 | ||
204 | #ifndef STATIC_GCONV | |
205 | /* Skip builtin modules; they are not reference counted. */ | |
206 | if (step->__shlib_handle != NULL) | |
207 | { | |
208 | /* Release the loaded module. */ | |
209 | __gconv_release_shlib (step->__shlib_handle); | |
210 | step->__shlib_handle = NULL; | |
211 | } | |
212 | #endif | |
213 | } | |
214 | } | |
215 | ||
6973fc01 UD |
216 | static int |
217 | internal_function | |
218 | gen_steps (struct derivation_step *best, const char *toset, | |
d64b6ad0 | 219 | const char *fromset, struct __gconv_step **handle, size_t *nsteps) |
6973fc01 UD |
220 | { |
221 | size_t step_cnt = 0; | |
d64b6ad0 | 222 | struct __gconv_step *result; |
6973fc01 | 223 | struct derivation_step *current; |
d64b6ad0 | 224 | int status = __GCONV_NOMEM; |
6973fc01 UD |
225 | |
226 | /* First determine number of steps. */ | |
227 | for (current = best; current->last != NULL; current = current->last) | |
228 | ++step_cnt; | |
229 | ||
d64b6ad0 UD |
230 | result = (struct __gconv_step *) malloc (sizeof (struct __gconv_step) |
231 | * step_cnt); | |
6973fc01 UD |
232 | if (result != NULL) |
233 | { | |
e34b0f29 UD |
234 | int failed = 0; |
235 | ||
d64b6ad0 | 236 | status = __GCONV_OK; |
e34b0f29 | 237 | *nsteps = step_cnt; |
6973fc01 UD |
238 | current = best; |
239 | while (step_cnt-- > 0) | |
240 | { | |
d64b6ad0 UD |
241 | result[step_cnt].__from_name = (step_cnt == 0 |
242 | ? __strdup (fromset) | |
8a0746ae | 243 | : (char *)current->last->result_set); |
d64b6ad0 UD |
244 | result[step_cnt].__to_name = (step_cnt + 1 == *nsteps |
245 | ? __strdup (current->result_set) | |
246 | : result[step_cnt + 1].__from_name); | |
6973fc01 | 247 | |
6b98979f UD |
248 | result[step_cnt].__counter = 1; |
249 | result[step_cnt].__data = NULL; | |
250 | ||
8619129f | 251 | #ifndef STATIC_GCONV |
6973fc01 UD |
252 | if (current->code->module_name[0] == '/') |
253 | { | |
254 | /* Load the module, return handle for it. */ | |
d64b6ad0 | 255 | struct __gconv_loaded_object *shlib_handle = |
6973fc01 UD |
256 | __gconv_find_shlib (current->code->module_name); |
257 | ||
258 | if (shlib_handle == NULL) | |
e34b0f29 UD |
259 | { |
260 | failed = 1; | |
261 | break; | |
262 | } | |
6973fc01 | 263 | |
d64b6ad0 UD |
264 | result[step_cnt].__shlib_handle = shlib_handle; |
265 | result[step_cnt].__modname = shlib_handle->name; | |
d64b6ad0 UD |
266 | result[step_cnt].__fct = shlib_handle->fct; |
267 | result[step_cnt].__init_fct = shlib_handle->init_fct; | |
268 | result[step_cnt].__end_fct = shlib_handle->end_fct; | |
6b98979f | 269 | |
f9ad060c UD |
270 | /* These settings can be overridden by the init function. */ |
271 | result[step_cnt].__btowc_fct = NULL; | |
272 | ||
6b98979f UD |
273 | /* Call the init function. */ |
274 | if (result[step_cnt].__init_fct != NULL) | |
275 | { | |
276 | status = DL_CALL_FCT (result[step_cnt].__init_fct, | |
277 | (&result[step_cnt])); | |
278 | ||
279 | if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK) | |
280 | { | |
281 | failed = 1; | |
282 | /* Make sure we unload this modules. */ | |
283 | --step_cnt; | |
284 | result[step_cnt].__end_fct = NULL; | |
285 | break; | |
286 | } | |
287 | } | |
6973fc01 UD |
288 | } |
289 | else | |
8619129f | 290 | #endif |
6973fc01 UD |
291 | /* It's a builtin transformation. */ |
292 | __gconv_get_builtin_trans (current->code->module_name, | |
293 | &result[step_cnt]); | |
294 | ||
295 | current = current->last; | |
296 | } | |
297 | ||
5ea1a82d | 298 | if (__builtin_expect (failed, 0) != 0) |
6973fc01 UD |
299 | { |
300 | /* Something went wrong while initializing the modules. */ | |
e34b0f29 | 301 | while (++step_cnt < *nsteps) |
6b98979f | 302 | __gconv_release_step (&result[step_cnt]); |
6973fc01 | 303 | free (result); |
e34b0f29 | 304 | *nsteps = 0; |
7a68c94a | 305 | *handle = NULL; |
d64b6ad0 UD |
306 | if (status == __GCONV_OK) |
307 | status = __GCONV_NOCONV; | |
6973fc01 UD |
308 | } |
309 | else | |
c7ec9d75 | 310 | *handle = result; |
6973fc01 | 311 | } |
7a68c94a UD |
312 | else |
313 | { | |
314 | *nsteps = 0; | |
315 | *handle = NULL; | |
316 | } | |
6973fc01 UD |
317 | |
318 | return status; | |
319 | } | |
320 | ||
321 | ||
76a2102b UD |
322 | #ifndef STATIC_GCONV |
323 | static int | |
324 | internal_function | |
325 | increment_counter (struct __gconv_step *steps, size_t nsteps) | |
326 | { | |
327 | /* Increment the user counter. */ | |
328 | size_t cnt = nsteps; | |
329 | int result = __GCONV_OK; | |
330 | ||
331 | while (cnt-- > 0) | |
b79f74cd UD |
332 | { |
333 | struct __gconv_step *step = &steps[cnt]; | |
334 | ||
335 | if (step->__counter++ == 0) | |
336 | { | |
337 | /* Skip builtin modules. */ | |
338 | if (step->__modname != NULL) | |
339 | { | |
340 | /* Reopen a previously used module. */ | |
341 | step->__shlib_handle = __gconv_find_shlib (step->__modname); | |
342 | if (step->__shlib_handle == NULL) | |
343 | { | |
344 | /* Oops, this is the second time we use this module | |
345 | (after unloading) and this time loading failed!? */ | |
346 | --step->__counter; | |
347 | while (++cnt < nsteps) | |
6b98979f | 348 | __gconv_release_step (&steps[cnt]); |
b79f74cd UD |
349 | result = __GCONV_NOCONV; |
350 | break; | |
351 | } | |
352 | ||
353 | /* The function addresses defined by the module may | |
354 | have changed. */ | |
355 | step->__fct = step->__shlib_handle->fct; | |
356 | step->__init_fct = step->__shlib_handle->init_fct; | |
357 | step->__end_fct = step->__shlib_handle->end_fct; | |
f9ad060c UD |
358 | |
359 | /* These settings can be overridden by the init function. */ | |
360 | step->__btowc_fct = NULL; | |
b79f74cd UD |
361 | } |
362 | ||
f9ad060c | 363 | /* Call the init function. */ |
b79f74cd UD |
364 | if (step->__init_fct != NULL) |
365 | DL_CALL_FCT (step->__init_fct, (step)); | |
366 | } | |
367 | } | |
76a2102b UD |
368 | return result; |
369 | } | |
370 | #endif | |
371 | ||
372 | ||
6973fc01 UD |
373 | /* The main function: find a possible derivation from the `fromset' (either |
374 | the given name or the alias) to the `toset' (again with alias). */ | |
375 | static int | |
e34b0f29 | 376 | internal_function |
6973fc01 UD |
377 | find_derivation (const char *toset, const char *toset_expand, |
378 | const char *fromset, const char *fromset_expand, | |
d64b6ad0 | 379 | struct __gconv_step **handle, size_t *nsteps) |
6973fc01 | 380 | { |
2bd60880 UD |
381 | struct derivation_step *first, *current, **lastp, *solution = NULL; |
382 | int best_cost_hi = INT_MAX; | |
383 | int best_cost_lo = INT_MAX; | |
6973fc01 UD |
384 | int result; |
385 | ||
b79f74cd UD |
386 | /* Look whether an earlier call to `find_derivation' has already |
387 | computed a possible derivation. If so, return it immediately. */ | |
6973fc01 UD |
388 | result = derivation_lookup (fromset_expand ?: fromset, toset_expand ?: toset, |
389 | handle, nsteps); | |
d64b6ad0 | 390 | if (result == __GCONV_OK) |
3c5edd4d | 391 | { |
76a2102b UD |
392 | #ifndef STATIC_GCONV |
393 | result = increment_counter (*handle, *nsteps); | |
394 | #endif | |
3c5edd4d UD |
395 | return result; |
396 | } | |
6973fc01 | 397 | |
b79f74cd UD |
398 | /* The task is to find a sequence of transformations, backed by the |
399 | existing modules - whether builtin or dynamically loadable -, | |
400 | starting at `fromset' (or `fromset_expand') and ending at `toset' | |
401 | (or `toset_expand'), and with minimal cost. | |
402 | ||
403 | For computer scientists, this is a shortest path search in the | |
404 | graph where the nodes are all possible charsets and the edges are | |
405 | the transformations listed in __gconv_modules_db. | |
406 | ||
407 | For now we use a simple algorithm with quadratic runtime behaviour. | |
408 | A breadth-first search, starting at `fromset' and `fromset_expand'. | |
409 | The list starting at `first' contains all nodes that have been | |
410 | visited up to now, in the order in which they have been visited -- | |
411 | excluding the goal nodes `toset' and `toset_expand' which get | |
412 | managed in the list starting at `solution'. | |
413 | `current' walks through the list starting at `first' and looks | |
414 | which nodes are reachable from the current node, adding them to | |
415 | the end of the list [`first' or `solution' respectively] (if | |
416 | they are visited the first time) or updating them in place (if | |
417 | they have have already been visited). | |
418 | In each node of either list, cost_lo and cost_hi contain the | |
419 | minimum cost over any paths found up to now, starting at `fromset' | |
420 | or `fromset_expand', ending at that node. best_cost_lo and | |
421 | best_cost_hi represent the minimum over the elements of the | |
422 | `solution' list. */ | |
423 | ||
6973fc01 UD |
424 | if (fromset_expand != NULL) |
425 | { | |
2bd60880 UD |
426 | first = NEW_STEP (fromset_expand, 0, 0, NULL, NULL); |
427 | first->next = NEW_STEP (fromset, 0, 0, NULL, NULL); | |
e34b0f29 | 428 | lastp = &first->next->next; |
6973fc01 UD |
429 | } |
430 | else | |
431 | { | |
2bd60880 | 432 | first = NEW_STEP (fromset, 0, 0, NULL, NULL); |
e34b0f29 | 433 | lastp = &first->next; |
6973fc01 UD |
434 | } |
435 | ||
2bd60880 | 436 | for (current = first; current != NULL; current = current->next) |
6973fc01 UD |
437 | { |
438 | /* Now match all the available module specifications against the | |
439 | current charset name. If any of them matches check whether | |
440 | we already have a derivation for this charset. If yes, use the | |
441 | one with the lower costs. Otherwise add the new charset at the | |
2bd60880 UD |
442 | end. |
443 | ||
e8b1163e AJ |
444 | The module database is organized in a tree form which allows |
445 | searching for prefixes. So we search for the first entry with a | |
2bd60880 UD |
446 | matching prefix and any other matching entry can be found from |
447 | this place. */ | |
b79f74cd | 448 | struct gconv_module *node; |
2bd60880 UD |
449 | |
450 | /* Maybe it is not necessary anymore to look for a solution for | |
b79f74cd | 451 | this entry since the cost is already as high (or higher) as |
2bd60880 UD |
452 | the cost for the best solution so far. */ |
453 | if (current->cost_hi > best_cost_hi | |
454 | || (current->cost_hi == best_cost_hi | |
455 | && current->cost_lo >= best_cost_lo)) | |
456 | continue; | |
457 | ||
b79f74cd | 458 | node = __gconv_modules_db; |
2bd60880 UD |
459 | while (node != NULL) |
460 | { | |
d2dfc5de | 461 | int cmpres = strcmp (current->result_set, node->from_string); |
2bd60880 | 462 | if (cmpres == 0) |
6973fc01 | 463 | { |
2bd60880 UD |
464 | /* Walk through the list of modules with this prefix and |
465 | try to match the name. */ | |
466 | struct gconv_module *runp; | |
467 | ||
2bd60880 UD |
468 | /* Check all the modules with this prefix. */ |
469 | runp = node; | |
470 | do | |
6973fc01 | 471 | { |
d2dfc5de UD |
472 | const char *result_set = (strcmp (runp->to_string, "-") == 0 |
473 | ? (toset_expand ?: toset) | |
474 | : runp->to_string); | |
475 | int cost_hi = runp->cost_hi + current->cost_hi; | |
476 | int cost_lo = runp->cost_lo + current->cost_lo; | |
477 | struct derivation_step *step; | |
478 | ||
479 | /* We managed to find a derivation. First see whether | |
b79f74cd | 480 | we have reached one of the goal nodes. */ |
d2dfc5de UD |
481 | if (strcmp (result_set, toset) == 0 |
482 | || (toset_expand != NULL | |
483 | && strcmp (result_set, toset_expand) == 0)) | |
2bd60880 | 484 | { |
b79f74cd UD |
485 | /* Append to the `solution' list if there |
486 | is no entry with this name. */ | |
487 | for (step = solution; step != NULL; step = step->next) | |
488 | if (strcmp (result_set, step->result_set) == 0) | |
489 | break; | |
490 | ||
491 | if (step == NULL) | |
492 | { | |
493 | step = NEW_STEP (result_set, | |
494 | cost_hi, cost_lo, | |
495 | runp, current); | |
496 | step->next = solution; | |
497 | solution = step; | |
498 | } | |
499 | else if (step->cost_hi > cost_hi | |
500 | || (step->cost_hi == cost_hi | |
501 | && step->cost_lo > cost_lo)) | |
502 | { | |
503 | /* A better path was found for the node, | |
504 | on the `solution' list. */ | |
505 | step->code = runp; | |
506 | step->last = current; | |
507 | step->cost_hi = cost_hi; | |
508 | step->cost_lo = cost_lo; | |
509 | } | |
510 | ||
511 | /* Update best_cost accordingly. */ | |
512 | if (cost_hi < best_cost_hi | |
d2dfc5de UD |
513 | || (cost_hi == best_cost_hi |
514 | && cost_lo < best_cost_lo)) | |
2bd60880 | 515 | { |
d2dfc5de UD |
516 | best_cost_hi = cost_hi; |
517 | best_cost_lo = cost_lo; | |
2bd60880 | 518 | } |
6973fc01 | 519 | } |
d2dfc5de UD |
520 | else if (cost_hi < best_cost_hi |
521 | || (cost_hi == best_cost_hi | |
522 | && cost_lo < best_cost_lo)) | |
6973fc01 | 523 | { |
b79f74cd UD |
524 | /* Append at the end of the `first' list if there |
525 | is no entry with this name. */ | |
d2dfc5de UD |
526 | for (step = first; step != NULL; step = step->next) |
527 | if (strcmp (result_set, step->result_set) == 0) | |
528 | break; | |
2bd60880 | 529 | |
d2dfc5de UD |
530 | if (step == NULL) |
531 | { | |
532 | *lastp = NEW_STEP (result_set, | |
533 | cost_hi, cost_lo, | |
534 | runp, current); | |
535 | lastp = &(*lastp)->next; | |
2bd60880 | 536 | } |
d2dfc5de UD |
537 | else if (step->cost_hi > cost_hi |
538 | || (step->cost_hi == cost_hi | |
539 | && step->cost_lo > cost_lo)) | |
2bd60880 | 540 | { |
b79f74cd UD |
541 | /* A better path was found for the node, |
542 | on the `first' list. */ | |
d2dfc5de UD |
543 | step->code = runp; |
544 | step->last = current; | |
2bd60880 | 545 | |
d2dfc5de UD |
546 | /* Update the cost for all steps. */ |
547 | for (step = first; step != NULL; | |
548 | step = step->next) | |
b79f74cd UD |
549 | /* But don't update the start nodes. */ |
550 | if (step->code != NULL) | |
551 | { | |
552 | struct derivation_step *back; | |
553 | int hi, lo; | |
554 | ||
555 | hi = step->code->cost_hi; | |
556 | lo = step->code->cost_lo; | |
557 | ||
558 | for (back = step->last; back->code != NULL; | |
559 | back = back->last) | |
560 | { | |
561 | hi += back->code->cost_hi; | |
562 | lo += back->code->cost_lo; | |
563 | } | |
564 | ||
565 | step->cost_hi = hi; | |
566 | step->cost_lo = lo; | |
567 | } | |
568 | ||
569 | /* Likewise for the nodes on the solution list. | |
570 | Also update best_cost accordingly. */ | |
d2dfc5de UD |
571 | for (step = solution; step != NULL; |
572 | step = step->next) | |
573 | { | |
574 | step->cost_hi = (step->code->cost_hi | |
575 | + step->last->cost_hi); | |
576 | step->cost_lo = (step->code->cost_lo | |
577 | + step->last->cost_lo); | |
578 | ||
579 | if (step->cost_hi < best_cost_hi | |
580 | || (step->cost_hi == best_cost_hi | |
581 | && step->cost_lo < best_cost_lo)) | |
2bd60880 | 582 | { |
d2dfc5de UD |
583 | best_cost_hi = step->cost_hi; |
584 | best_cost_lo = step->cost_lo; | |
2bd60880 UD |
585 | } |
586 | } | |
587 | } | |
6973fc01 | 588 | } |
2bd60880 UD |
589 | |
590 | runp = runp->same; | |
6973fc01 | 591 | } |
2bd60880 | 592 | while (runp != NULL); |
e34b0f29 | 593 | |
d2dfc5de | 594 | break; |
6973fc01 | 595 | } |
2bd60880 UD |
596 | else if (cmpres < 0) |
597 | node = node->left; | |
598 | else | |
599 | node = node->right; | |
6973fc01 UD |
600 | } |
601 | } | |
602 | ||
2bd60880 | 603 | if (solution != NULL) |
b79f74cd UD |
604 | { |
605 | /* We really found a way to do the transformation. */ | |
606 | ||
607 | /* Choose the best solution. This is easy because we know that | |
608 | the solution list has at most length 2 (one for every possible | |
609 | goal node). */ | |
610 | if (solution->next != NULL) | |
611 | { | |
612 | struct derivation_step *solution2 = solution->next; | |
613 | ||
614 | if (solution2->cost_hi < solution->cost_hi | |
615 | || (solution2->cost_hi == solution->cost_hi | |
616 | && solution2->cost_lo < solution->cost_lo)) | |
617 | solution = solution2; | |
618 | } | |
619 | ||
620 | /* Now build a data structure describing the transformation steps. */ | |
621 | result = gen_steps (solution, toset_expand ?: toset, | |
622 | fromset_expand ?: fromset, handle, nsteps); | |
623 | } | |
6973fc01 UD |
624 | else |
625 | { | |
626 | /* We haven't found a transformation. Clear the result values. */ | |
627 | *handle = NULL; | |
628 | *nsteps = 0; | |
629 | } | |
630 | ||
631 | /* Add result in any case to list of known derivations. */ | |
632 | add_derivation (fromset_expand ?: fromset, toset_expand ?: toset, | |
633 | *handle, *nsteps); | |
634 | ||
6973fc01 UD |
635 | return result; |
636 | } | |
637 | ||
638 | ||
e7f21fa6 UD |
639 | /* Control of initialization. */ |
640 | __libc_once_define (static, once); | |
641 | ||
642 | ||
643 | static const char * | |
644 | do_lookup_alias (const char *name) | |
645 | { | |
646 | struct gconv_alias key; | |
647 | struct gconv_alias **found; | |
648 | ||
649 | key.fromname = (char *) name; | |
650 | found = __tfind (&key, &__gconv_alias_db, __gconv_alias_compare); | |
651 | return found != NULL ? (*found)->toname : NULL; | |
652 | } | |
653 | ||
654 | ||
9a018f6c UD |
655 | int |
656 | internal_function | |
657 | __gconv_compare_alias (const char *name1, const char *name2) | |
e7f21fa6 | 658 | { |
9a018f6c UD |
659 | int result; |
660 | ||
e7f21fa6 UD |
661 | /* Ensure that the configuration data is read. */ |
662 | __libc_once (once, __gconv_read_conf); | |
663 | ||
9a018f6c UD |
664 | if (__gconv_compare_alias_cache (name1, name2, &result) != 0) |
665 | result = strcmp (do_lookup_alias (name1) ?: name1, | |
666 | do_lookup_alias (name2) ?: name2); | |
667 | ||
668 | return result; | |
e7f21fa6 UD |
669 | } |
670 | ||
671 | ||
6973fc01 | 672 | int |
e62c19f1 | 673 | internal_function |
6973fc01 | 674 | __gconv_find_transform (const char *toset, const char *fromset, |
60c53a12 UD |
675 | struct __gconv_step **handle, size_t *nsteps, |
676 | int flags) | |
6973fc01 | 677 | { |
6b98979f UD |
678 | const char *fromset_expand; |
679 | const char *toset_expand; | |
6973fc01 UD |
680 | int result; |
681 | ||
682 | /* Ensure that the configuration data is read. */ | |
683 | __libc_once (once, __gconv_read_conf); | |
684 | ||
0d9f6793 UD |
685 | /* Acquire the lock. */ |
686 | __libc_lock_lock (lock); | |
687 | ||
6b98979f UD |
688 | result = __gconv_lookup_cache (toset, fromset, handle, nsteps, flags); |
689 | if (result != __GCONV_NODB) | |
690 | { | |
691 | /* We have a cache and could resolve the request, successful or not. */ | |
692 | __libc_lock_unlock (lock); | |
693 | return result; | |
694 | } | |
695 | ||
6973fc01 UD |
696 | /* If we don't have a module database return with an error. */ |
697 | if (__gconv_modules_db == NULL) | |
3c5edd4d UD |
698 | { |
699 | __libc_lock_unlock (lock); | |
d64b6ad0 | 700 | return __GCONV_NOCONV; |
3c5edd4d | 701 | } |
6973fc01 UD |
702 | |
703 | /* See whether the names are aliases. */ | |
6b98979f UD |
704 | fromset_expand = do_lookup_alias (fromset); |
705 | toset_expand = do_lookup_alias (toset); | |
6973fc01 | 706 | |
5ea1a82d | 707 | if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0) |
60c53a12 UD |
708 | /* We are not supposed to create a pseudo transformation (means |
709 | copying) when the input and output character set are the same. */ | |
710 | && (strcmp (toset, fromset) == 0 | |
711 | || (toset_expand != NULL && strcmp (toset_expand, fromset) == 0) | |
712 | || (fromset_expand != NULL | |
713 | && (strcmp (toset, fromset_expand) == 0 | |
714 | || (toset_expand != NULL | |
715 | && strcmp (toset_expand, fromset_expand) == 0))))) | |
716 | { | |
717 | /* Both character sets are the same. */ | |
718 | __libc_lock_unlock (lock); | |
719 | return __GCONV_NOCONV; | |
720 | } | |
721 | ||
6973fc01 UD |
722 | result = find_derivation (toset, toset_expand, fromset, fromset_expand, |
723 | handle, nsteps); | |
724 | ||
0d9f6793 UD |
725 | /* Release the lock. */ |
726 | __libc_lock_unlock (lock); | |
727 | ||
6973fc01 UD |
728 | /* The following code is necessary since `find_derivation' will return |
729 | GCONV_OK even when no derivation was found but the same request | |
730 | was processed before. I.e., negative results will also be cached. */ | |
d64b6ad0 UD |
731 | return (result == __GCONV_OK |
732 | ? (*handle == NULL ? __GCONV_NOCONV : __GCONV_OK) | |
6973fc01 UD |
733 | : result); |
734 | } | |
735 | ||
736 | ||
737 | /* Release the entries of the modules list. */ | |
738 | int | |
e62c19f1 | 739 | internal_function |
d64b6ad0 | 740 | __gconv_close_transform (struct __gconv_step *steps, size_t nsteps) |
6973fc01 | 741 | { |
d64b6ad0 | 742 | int result = __GCONV_OK; |
0db59742 | 743 | size_t cnt; |
6973fc01 | 744 | |
0d9f6793 UD |
745 | /* Acquire the lock. */ |
746 | __libc_lock_lock (lock); | |
747 | ||
0db59742 UD |
748 | #ifndef STATIC_GCONV |
749 | cnt = nsteps; | |
750 | while (cnt-- > 0) | |
751 | __gconv_release_step (&steps[cnt]); | |
752 | #endif | |
753 | ||
754 | /* If we use the cache we free a bit more since we don't keep any | |
755 | transformation records around, they are cheap enough to | |
756 | recreate. */ | |
757 | __gconv_release_cache (steps, nsteps); | |
6973fc01 | 758 | |
0d9f6793 UD |
759 | /* Release the lock. */ |
760 | __libc_lock_unlock (lock); | |
761 | ||
6973fc01 UD |
762 | return result; |
763 | } | |
764 | ||
765 | ||
2bd60880 UD |
766 | /* Free the modules mentioned. */ |
767 | static void | |
768 | internal_function | |
769 | free_modules_db (struct gconv_module *node) | |
770 | { | |
771 | if (node->left != NULL) | |
772 | free_modules_db (node->left); | |
773 | if (node->right != NULL) | |
774 | free_modules_db (node->right); | |
2bd60880 UD |
775 | do |
776 | { | |
777 | struct gconv_module *act = node; | |
d2dfc5de | 778 | node = node->same; |
8ce63ec0 UD |
779 | if (act->module_name[0] == '/') |
780 | free (act); | |
2bd60880 UD |
781 | } |
782 | while (node != NULL); | |
783 | } | |
784 | ||
785 | ||
6973fc01 | 786 | /* Free all resources if necessary. */ |
c877418f | 787 | libc_freeres_fn (free_mem) |
6973fc01 | 788 | { |
6973fc01 UD |
789 | if (__gconv_alias_db != NULL) |
790 | __tdestroy (__gconv_alias_db, free); | |
791 | ||
0dbbad29 UD |
792 | if (__gconv_modules_db != NULL) |
793 | free_modules_db (__gconv_modules_db); | |
6973fc01 UD |
794 | |
795 | if (known_derivations != NULL) | |
796 | __tdestroy (known_derivations, free_derivation); | |
797 | } |