ROX-Filer/src/xdgmime.c

   1 /* -*- mode: C; c-file-style: "gnu" -*- */
   2 /* xdgmime.c: XDG Mime Spec mime resolver.  Based on version 0.11 of the spec.
   3  *
   4  * More info can be found at http://www.freedesktop.org/standards/
   5  *
   6  * Copyright (C) 2003,2004  Red Hat, Inc.
   7  * Copyright (C) 2003,2004  Jonathan Blandford <jrb@alum.mit.edu>
   8  *
   9  * Licensed under the Academic Free License version 2.0
  10  * Or under the following terms:
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this library; if not, write to the
  24  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25  * Boston, MA 02111-1307, USA.
  26  */
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include <config.h>
  30 #endif
  31
  32 #include "xdgmime.h"
  33 #include "xdgmimeint.h"
  34 #include "xdgmimeglob.h"
  35 #include "xdgmimemagic.h"
  36 #include "xdgmimealias.h"
  37 #include "xdgmimeparent.h"
  38 #include "xdgmimecache.h"
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <sys/stat.h>
  42 #include <sys/types.h>
  43 #include <sys/time.h>
  44 #include <unistd.h>
  45 #include <assert.h>
  46
  47 /* ROX: */
  48 #include "global.h"
  49 #include "main.h"
  50
  51 typedef struct XdgDirTimeList XdgDirTimeList;
  52 typedef struct XdgCallbackList XdgCallbackList;
  53
  54 static int need_reread = TRUE;
  55 static time_t last_stat_time = 0;
  56
  57 static XdgGlobHash *global_hash = NULL;
  58 static XdgMimeMagic *global_magic = NULL;
  59 static XdgAliasList *alias_list = NULL;
  60 static XdgParentList *parent_list = NULL;
  61 static XdgDirTimeList *dir_time_list = NULL;
  62 static XdgCallbackList *callback_list = NULL;
  63
  64 XdgMimeCache **_xdg_mime_caches = NULL;
  65 static int n_caches = 0;
  66
  67 const char xdg_mime_type_unknown[] = "application/octet-stream";
  68 const char xdg_mime_type_unknown_text[] = "text/plain"; /* ROX: */
  69
  70
  71 enum
  72 {
  73   XDG_CHECKED_UNCHECKED,
  74   XDG_CHECKED_VALID,
  75   XDG_CHECKED_INVALID
  76 };
  77
  78 struct XdgDirTimeList
  79 {
  80   time_t mtime;
  81   char *directory_name;
  82   int checked;
  83   XdgDirTimeList *next;
  84   XdgMimeCache *cache;
  85 };
  86
  87 struct XdgCallbackList
  88 {
  89   XdgCallbackList *next;
  90   XdgCallbackList *prev;
  91   int              callback_id;
  92   XdgMimeCallback  callback;
  93   void            *data;
  94   XdgMimeDestroy   destroy;
  95 };
  96
  97 /* Function called by xdg_run_command_on_dirs.  If it returns TRUE, further
  98  * directories aren't looked at */
  99 typedef int (*XdgDirectoryFunc) (const char *directory,
 100                                  void       *user_data);
 101
 102 static XdgDirTimeList *
 103 xdg_dir_time_list_new (void)
 104 {
 105   XdgDirTimeList *retval;
 106
 107   retval = calloc (1, sizeof (XdgDirTimeList));
 108   retval->checked = XDG_CHECKED_UNCHECKED;
 109
 110   return retval;
 111 }
 112
 113 static void
 114 xdg_dir_time_list_free (XdgDirTimeList *list)
 115 {
 116   XdgDirTimeList *next;
 117
 118   while (list)
 119     {
 120       next = list->next;
 121       free (list->directory_name);
 122       free (list);
 123       list = next;
 124     }
 125 }
 126
 127 static int
 128 xdg_mime_init_from_directory (const char *directory)
 129 {
 130   char *file_name;
 131   struct stat st;
 132   XdgDirTimeList *list;
 133
 134   assert (directory != NULL);
 135
 136   file_name = malloc (strlen (directory) + strlen ("/mime/mime.cache") + 1);
 137   strcpy (file_name, directory); strcat (file_name, "/mime/mime.cache");
 138   if (stat (file_name, &st) == 0)
 139     {
 140       XdgMimeCache *cache = _xdg_mime_cache_new_from_file (file_name);
 141
 142       if (cache != NULL)
 143         {
 144           list = xdg_dir_time_list_new ();
 145           list->directory_name = file_name;
 146           list->mtime = st.st_mtime;
 147           list->next = dir_time_list;
 148           list->cache = cache;
 149           dir_time_list = list;
 150
 151           _xdg_mime_caches = realloc (_xdg_mime_caches, sizeof (XdgMimeCache *) * (n_caches + 2));
 152           _xdg_mime_caches[n_caches] = cache;
 153           _xdg_mime_caches[n_caches + 1] = NULL;
 154           n_caches++;
 155
 156           return FALSE;
 157         }
 158     }
 159   free (file_name);
 160
 161   file_name = malloc (strlen (directory) + strlen ("/mime/globs") + 1);
 162   strcpy (file_name, directory); strcat (file_name, "/mime/globs");
 163   if (stat (file_name, &st) == 0)
 164     {
 165       _xdg_mime_glob_read_from_file (global_hash, file_name);
 166
 167       list = xdg_dir_time_list_new ();
 168       list->directory_name = file_name;
 169       list->mtime = st.st_mtime;
 170       list->next = dir_time_list;
 171       dir_time_list = list;
 172     }
 173   else
 174     {
 175       free (file_name);
 176     }
 177
 178   file_name = malloc (strlen (directory) + strlen ("/mime/magic") + 1);
 179   strcpy (file_name, directory); strcat (file_name, "/mime/magic");
 180   if (stat (file_name, &st) == 0)
 181     {
 182       _xdg_mime_magic_read_from_file (global_magic, file_name);
 183
 184       list = xdg_dir_time_list_new ();
 185       list->directory_name = file_name;
 186       list->mtime = st.st_mtime;
 187       list->next = dir_time_list;
 188       dir_time_list = list;
 189     }
 190   else
 191     {
 192       free (file_name);
 193     }
 194
 195   file_name = malloc (strlen (directory) + strlen ("/mime/aliases") + 1);
 196   strcpy (file_name, directory); strcat (file_name, "/mime/aliases");
 197   _xdg_mime_alias_read_from_file (alias_list, file_name);
 198   free (file_name);
 199
 200   file_name = malloc (strlen (directory) + strlen ("/mime/subclasses") + 1);
 201   strcpy (file_name, directory); strcat (file_name, "/mime/subclasses");
 202   _xdg_mime_parent_read_from_file (parent_list, file_name);
 203   free (file_name);
 204
 205   return FALSE; /* Keep processing */
 206 }
 207
 208 /* Runs a command on all the directories in the search path */
 209 static void
 210 xdg_run_command_on_dirs (XdgDirectoryFunc  func,
 211                          void             *user_data)
 212 {
 213   const char *xdg_data_home;
 214   const char *xdg_data_dirs;
 215   const char *ptr;
 216
 217   xdg_data_home = getenv ("XDG_DATA_HOME");
 218   if (xdg_data_home)
 219     {
 220       if ((func) (xdg_data_home, user_data))
 221         return;
 222     }
 223   else
 224     {
 225       const char *home;
 226
 227       home = getenv ("HOME");
 228       if (home != NULL)
 229         {
 230           char *guessed_xdg_home;
 231           int stop_processing;
 232
 233           guessed_xdg_home = malloc (strlen (home) + strlen ("/.local/share/") + 1);
 234           strcpy (guessed_xdg_home, home);
 235           strcat (guessed_xdg_home, "/.local/share/");
 236           stop_processing = (func) (guessed_xdg_home, user_data);
 237           free (guessed_xdg_home);
 238
 239           if (stop_processing)
 240             return;
 241         }
 242     }
 243
 244   xdg_data_dirs = getenv ("XDG_DATA_DIRS");
 245   if (xdg_data_dirs == NULL)
 246     xdg_data_dirs = "/usr/local/share/:/usr/share/";
 247
 248   ptr = xdg_data_dirs;
 249
 250   while (*ptr != '\000')
 251     {
 252       const char *end_ptr;
 253       char *dir;
 254       int len;
 255       int stop_processing;
 256
 257       end_ptr = ptr;
 258       while (*end_ptr != ':' && *end_ptr != '\000')
 259         end_ptr ++;
 260
 261       if (end_ptr == ptr)
 262         {
 263           ptr++;
 264           continue;
 265         }
 266
 267       if (*end_ptr == ':')
 268         len = end_ptr - ptr;
 269       else
 270         len = end_ptr - ptr + 1;
 271       dir = malloc (len + 1);
 272       strncpy (dir, ptr, len);
 273       dir[len] = '\0';
 274       stop_processing = (func) (dir, user_data);
 275       free (dir);
 276
 277       if (stop_processing)
 278         return;
 279
 280       ptr = end_ptr;
 281     }
 282 }
 283
 284 static XdgMimeCache *
 285 xdg_lookup_cache_for_file (const char *file_path)
 286 {
 287   XdgDirTimeList *list;
 288
 289   for (list = dir_time_list; list; list = list->next)
 290       if (! strcmp (list->directory_name, file_path))
 291          return list->cache;
 292
 293   return NULL;
 294 }
 295
 296 /* Checks file_path to make sure it has the same mtime as last time it was
 297  * checked.  If it has a different mtime, or if the file doesn't exist, it
 298  * returns FALSE.
 299  *
 300  * FIXME: This doesn't protect against permission changes.
 301  */
 302 static int
 303 xdg_check_file (const char *file_path)
 304 {
 305   struct stat st;
 306
 307   /* If the file exists */
 308   if (stat (file_path, &st) == 0)
 309     {
 310       XdgDirTimeList *list;
 311
 312       for (list = dir_time_list; list; list = list->next)
 313         {
 314           if (! strcmp (list->directory_name, file_path) &&
 315               st.st_mtime == list->mtime)
 316             {
 317               if (list->checked == XDG_CHECKED_UNCHECKED)
 318                 list->checked = XDG_CHECKED_VALID;
 319               else if (list->checked == XDG_CHECKED_VALID)
 320                 list->checked = XDG_CHECKED_INVALID;
 321
 322               return (list->checked != XDG_CHECKED_VALID);
 323             }
 324         }
 325       return TRUE;
 326     }
 327
 328   return FALSE;
 329 }
 330
 331 static int
 332 xdg_check_dir (const char *directory,
 333                int        *invalid_dir_list)
 334 {
 335   int invalid, has_cache;
 336   char *file_name;
 337
 338   assert (directory != NULL);
 339
 340   /* Check the mime.cache file */
 341   file_name = malloc (strlen (directory) + strlen ("/mime/mime.cache") + 1);
 342   strcpy (file_name, directory); strcat (file_name, "/mime/mime.cache");
 343   invalid = xdg_check_file (file_name);
 344   has_cache = xdg_lookup_cache_for_file (file_name) != NULL;
 345   free (file_name);
 346
 347   if (has_cache)
 348     {
 349       if (invalid)
 350         {
 351           *invalid_dir_list = TRUE;
 352           return TRUE;
 353         }
 354
 355       return FALSE;
 356     }
 357
 358   /* Check the globs file */
 359   file_name = malloc (strlen (directory) + strlen ("/mime/globs") + 1);
 360   strcpy (file_name, directory); strcat (file_name, "/mime/globs");
 361   invalid = xdg_check_file (file_name);
 362   free (file_name);
 363   if (invalid)
 364     {
 365       *invalid_dir_list = TRUE;
 366       return TRUE;
 367     }
 368
 369   /* Check the magic file */
 370   file_name = malloc (strlen (directory) + strlen ("/mime/magic") + 1);
 371   strcpy (file_name, directory); strcat (file_name, "/mime/magic");
 372   invalid = xdg_check_file (file_name);
 373   free (file_name);
 374   if (invalid)
 375     {
 376       *invalid_dir_list = TRUE;
 377       return TRUE;
 378     }
 379
 380   return FALSE; /* Keep processing */
 381 }
 382
 383 /* Walks through all the mime files stat()ing them to see if they've changed.
 384  * Returns TRUE if they have. */
 385 static int
 386 xdg_check_dirs (void)
 387 {
 388   XdgDirTimeList *list;
 389   int invalid_dir_list = FALSE;
 390
 391   for (list = dir_time_list; list; list = list->next)
 392     list->checked = XDG_CHECKED_UNCHECKED;
 393
 394   xdg_run_command_on_dirs ((XdgDirectoryFunc) xdg_check_dir,
 395                            &invalid_dir_list);
 396
 397   if (invalid_dir_list)
 398     return TRUE;
 399
 400   for (list = dir_time_list; list; list = list->next)
 401     {
 402       if (list->checked != XDG_CHECKED_VALID)
 403         return TRUE;
 404     }
 405
 406   return FALSE;
 407 }
 408
 409 /* We want to avoid stat()ing on every single mime call, so we only look for
 410  * newer files every 5 seconds.  This will return TRUE if we need to reread the
 411  * mime data from disk.
 412  */
 413 static int
 414 xdg_check_time_and_dirs (void)
 415 {
 416   struct timeval tv;
 417   time_t current_time;
 418   int retval = FALSE;
 419
 420   gettimeofday (&tv, NULL);
 421   current_time = tv.tv_sec;
 422
 423   if (current_time >= last_stat_time + 5)
 424     {
 425       retval = xdg_check_dirs ();
 426       last_stat_time = current_time;
 427     }
 428
 429   return retval;
 430 }
 431
 432 /* Called in every public function.  It reloads the hash function if need be.
 433  */
 434 static void
 435 xdg_mime_init (void)
 436 {
 437   if (xdg_check_time_and_dirs ())
 438     {
 439       xdg_mime_shutdown ();
 440     }
 441
 442   if (need_reread)
 443     {
 444       char *mime_parents;
 445       int l;
 446
 447       global_hash = _xdg_glob_hash_new ();
 448       global_magic = _xdg_mime_magic_new ();
 449       alias_list = _xdg_mime_alias_list_new ();
 450       parent_list = _xdg_mime_parent_list_new ();
 451
 452       xdg_run_command_on_dirs ((XdgDirectoryFunc) xdg_mime_init_from_directory,
 453                                NULL);
 454
 455       /* ROX: We want to support shared-mime-database < 0.16, where we can't
 456        * do this with the rox.xml file.
 457        */
 458       mime_parents = g_build_filename(app_dir, "subclasses", NULL);
 459       _xdg_mime_parent_read_from_file(parent_list, mime_parents);
 460       g_free(mime_parents);
 461
 462       need_reread = FALSE;
 463     }
 464 }
 465
 466 const char *
 467 xdg_mime_get_mime_type_for_data (const void *data,
 468                                  size_t      len)
 469 {
 470   const char *mime_type;
 471
 472   xdg_mime_init ();
 473
 474   if (_xdg_mime_caches)
 475     return _xdg_mime_cache_get_mime_type_for_data (data, len);
 476
 477   mime_type = _xdg_mime_magic_lookup_data (global_magic, data, len, NULL, 0);
 478
 479   if (mime_type)
 480     return mime_type;
 481
 482   return XDG_MIME_TYPE_UNKNOWN;
 483 }
 484
 485 const char *
 486 xdg_mime_get_mime_type_for_file (const char  *file_name,
 487                                  struct stat *statbuf)
 488 {
 489   const char *mime_type;
 490   /* Used to detect whether multiple MIME types match file_name */
 491   const char *mime_types[2];
 492   FILE *file;
 493   unsigned char *data;
 494   int max_extent;
 495   int bytes_read;
 496   struct stat buf;
 497   const char *base_name;
 498   int n;
 499
 500   if (file_name == NULL)
 501     return NULL;
 502   if (! _xdg_utf8_validate (file_name))
 503     return NULL;
 504
 505   xdg_mime_init ();
 506
 507   if (_xdg_mime_caches)
 508     return _xdg_mime_cache_get_mime_type_for_file (file_name, statbuf);
 509
 510   base_name = _xdg_get_base_name (file_name);
 511   n = _xdg_glob_hash_lookup_file_name (global_hash, base_name, mime_types, 2);
 512
 513   if (n == 1)
 514     return mime_types[0];
 515
 516   if (!statbuf)
 517     {
 518       if (stat (file_name, &buf) != 0)
 519         return XDG_MIME_TYPE_UNKNOWN;
 520
 521       statbuf = &buf;
 522     }
 523
 524   if (!S_ISREG (statbuf->st_mode))
 525     return XDG_MIME_TYPE_UNKNOWN;
 526
 527   /* FIXME: Need to make sure that max_extent isn't totally broken.  This could
 528    * be large and need getting from a stream instead of just reading it all
 529    * in. */
 530   max_extent = _xdg_mime_magic_get_buffer_extents (global_magic);
 531   data = malloc (max_extent);
 532   if (data == NULL)
 533     return XDG_MIME_TYPE_UNKNOWN;
 534
 535   file = fopen (file_name, "r");
 536   if (file == NULL)
 537     {
 538       free (data);
 539       return XDG_MIME_TYPE_UNKNOWN;
 540     }
 541
 542   bytes_read = fread (data, 1, max_extent, file);
 543   if (ferror (file))
 544     {
 545       free (data);
 546       fclose (file);
 547       return XDG_MIME_TYPE_UNKNOWN;
 548     }
 549
 550   mime_type = _xdg_mime_magic_lookup_data (global_magic, data, bytes_read,
 551                                            mime_types, n);
 552
 553   free (data);
 554   fclose (file);
 555
 556   if (mime_type)
 557     return mime_type;
 558
 559   return XDG_MIME_TYPE_UNKNOWN;
 560 }
 561
 562 const char *
 563 xdg_mime_get_mime_type_from_file_name (const char *file_name)
 564 {
 565   const char *mime_types[2];
 566
 567   xdg_mime_init ();
 568
 569   if (_xdg_mime_caches)
 570     return _xdg_mime_cache_get_mime_type_from_file_name (file_name);
 571
 572   if (_xdg_glob_hash_lookup_file_name (global_hash, file_name, mime_types, 2) == 1)
 573     return mime_types[0];
 574   else
 575     return XDG_MIME_TYPE_UNKNOWN;
 576 }
 577
 578 int
 579 xdg_mime_is_valid_mime_type (const char *mime_type)
 580 {
 581   /* FIXME: We should make this a better test
 582    */
 583   return _xdg_utf8_validate (mime_type);
 584 }
 585
 586 void
 587 xdg_mime_shutdown (void)
 588 {
 589   XdgCallbackList *list;
 590
 591   /* FIXME: Need to make this (and the whole library) thread safe */
 592   if (dir_time_list)
 593     {
 594       xdg_dir_time_list_free (dir_time_list);
 595       dir_time_list = NULL;
 596     }
 597
 598   if (global_hash)
 599     {
 600       _xdg_glob_hash_free (global_hash);
 601       global_hash = NULL;
 602     }
 603   if (global_magic)
 604     {
 605       _xdg_mime_magic_free (global_magic);
 606       global_magic = NULL;
 607     }
 608
 609   if (alias_list)
 610     {
 611       _xdg_mime_alias_list_free (alias_list);
 612       alias_list = NULL;
 613     }
 614
 615   if (parent_list)
 616     {
 617       _xdg_mime_parent_list_free (parent_list);
 618       parent_list = NULL;
 619     }
 620
 621   if (_xdg_mime_caches)
 622     {
 623       int i;
 624       for (i = 0; i < n_caches; i++)
 625         _xdg_mime_cache_unref (_xdg_mime_caches[i]);
 626       free (_xdg_mime_caches);
 627       _xdg_mime_caches = NULL;
 628       n_caches = 0;
 629     }
 630
 631   for (list = callback_list; list; list = list->next)
 632     (list->callback) (list->data);
 633
 634   need_reread = TRUE;
 635 }
 636
 637 int
 638 xdg_mime_get_max_buffer_extents (void)
 639 {
 640   xdg_mime_init ();
 641
 642   if (_xdg_mime_caches)
 643     return _xdg_mime_cache_get_max_buffer_extents ();
 644
 645   return _xdg_mime_magic_get_buffer_extents (global_magic);
 646 }
 647
 648 static const char *
 649 _xdg_mime_unalias_mime_type (const char *mime_type)
 650 {
 651   const char *lookup;
 652
 653   if (_xdg_mime_caches)
 654     return _xdg_mime_cache_unalias_mime_type (mime_type);
 655
 656   if ((lookup = _xdg_mime_alias_list_lookup (alias_list, mime_type)) != NULL)
 657     return lookup;
 658
 659   return mime_type;
 660 }
 661
 662 const char *
 663 xdg_mime_unalias_mime_type (const char *mime_type)
 664 {
 665   xdg_mime_init ();
 666
 667   return _xdg_mime_unalias_mime_type (mime_type);
 668 }
 669
 670 int
 671 _xdg_mime_mime_type_equal (const char *mime_a,
 672                            const char *mime_b)
 673 {
 674   const char *unalias_a, *unalias_b;
 675
 676   unalias_a = _xdg_mime_unalias_mime_type (mime_a);
 677   unalias_b = _xdg_mime_unalias_mime_type (mime_b);
 678
 679   if (strcmp (unalias_a, unalias_b) == 0)
 680     return 1;
 681
 682   return 0;
 683 }
 684
 685 int
 686 xdg_mime_mime_type_equal (const char *mime_a,
 687                           const char *mime_b)
 688 {
 689   xdg_mime_init ();
 690
 691   return _xdg_mime_mime_type_equal (mime_a, mime_b);
 692 }
 693
 694 int
 695 _xdg_mime_media_type_equal (const char *mime_a,
 696                             const char *mime_b)
 697 {
 698   char *sep;
 699
 700   xdg_mime_init ();
 701
 702   sep = strchr (mime_a, '/');
 703
 704   if (sep && strncmp (mime_a, mime_b, sep - mime_a + 1) == 0)
 705     return 1;
 706
 707   return 0;
 708 }
 709
 710 int
 711 xdg_mime_media_type_equal (const char *mime_a,
 712                            const char *mime_b)
 713 {
 714   xdg_mime_init ();
 715
 716   return _xdg_mime_media_type_equal (mime_a, mime_b);
 717 }
 718
 719 #if 0
 720 static int
 721 xdg_mime_is_super_type (const char *mime)
 722 {
 723   int length;
 724   const char *type;
 725
 726   length = strlen (mime);
 727   type = &(mime[length - 2]);
 728
 729   if (strcmp (type, "/*") == 0)
 730     return 1;
 731
 732   return 0;
 733 }
 734 #endif
 735
 736 int
 737 _xdg_mime_mime_type_subclass (const char *mime,
 738                               const char *base)
 739 {
 740   const char *umime, *ubase;
 741   const char **parents;
 742
 743   if (_xdg_mime_caches)
 744     return _xdg_mime_cache_mime_type_subclass (mime, base);
 745
 746   umime = _xdg_mime_unalias_mime_type (mime);
 747   ubase = _xdg_mime_unalias_mime_type (base);
 748
 749   if (strcmp (umime, ubase) == 0)
 750     return 1;
 751
 752 #if 0
 753   /* Handle supertypes */
 754   if (xdg_mime_is_super_type (ubase) &&
 755       _xdg_mime_media_type_equal (umime, ubase))
 756     return 1;
 757 #endif
 758
 759   /*  Handle special cases text/plain and application/octet-stream */
 760   if (strcmp (ubase, "text/plain") == 0 &&
 761       strncmp (umime, "text/", 5) == 0)
 762     return 1;
 763
 764   if (strcmp (ubase, "application/octet-stream") == 0)
 765     return 1;
 766
 767   parents = _xdg_mime_parent_list_lookup (parent_list, umime);
 768   for (; parents && *parents; parents++)
 769     {
 770       if (_xdg_mime_mime_type_subclass (*parents, ubase))
 771         return 1;
 772     }
 773
 774   return 0;
 775 }
 776
 777 int
 778 xdg_mime_mime_type_subclass (const char *mime,
 779                              const char *base)
 780 {
 781   xdg_mime_init ();
 782
 783   return _xdg_mime_mime_type_subclass (mime, base);
 784 }
 785
 786 char **
 787 xdg_mime_list_mime_parents (const char *mime)
 788 {
 789   const char **parents;
 790   char **result;
 791   int i, n;
 792
 793   if (_xdg_mime_caches)
 794     return _xdg_mime_cache_list_mime_parents (mime);
 795
 796   parents = xdg_mime_get_mime_parents (mime);
 797
 798   if (!parents)
 799     return NULL;
 800
 801   for (i = 0; parents[i]; i++) ;
 802
 803   n = (i + 1) * sizeof (char *);
 804   result = (char **) malloc (n);
 805   memcpy (result, parents, n);
 806
 807   return result;
 808 }
 809
 810 const char **
 811 xdg_mime_get_mime_parents (const char *mime)
 812 {
 813   const char *umime;
 814
 815   xdg_mime_init ();
 816
 817   umime = _xdg_mime_unalias_mime_type (mime);
 818
 819   return _xdg_mime_parent_list_lookup (parent_list, umime);
 820 }
 821
 822 void
 823 xdg_mime_dump (void)
 824 {
 825   printf ("*** ALIASES ***\n\n");
 826   _xdg_mime_alias_list_dump (alias_list);
 827   printf ("\n*** PARENTS ***\n\n");
 828   _xdg_mime_parent_list_dump (parent_list);
 829   printf ("\n*** CACHE ***\n\n");
 830   _xdg_glob_hash_dump (global_hash);
 831 }
 832
 833
 834 /* Registers a function to be called every time the mime database reloads its files
 835  */
 836 int
 837 xdg_mime_register_reload_callback (XdgMimeCallback  callback,
 838                                    void            *data,
 839                                    XdgMimeDestroy   destroy)
 840 {
 841   XdgCallbackList *list_el;
 842   static int callback_id = 1;
 843
 844   /* Make a new list element */
 845   list_el = calloc (1, sizeof (XdgCallbackList));
 846   list_el->callback_id = callback_id;
 847   list_el->callback = callback;
 848   list_el->data = data;
 849   list_el->destroy = destroy;
 850   list_el->next = callback_list;
 851   if (list_el->next)
 852     list_el->next->prev = list_el;
 853
 854   callback_list = list_el;
 855   callback_id ++;
 856
 857   return callback_id - 1;
 858 }
 859
 860 void
 861 xdg_mime_remove_callback (int callback_id)
 862 {
 863   XdgCallbackList *list;
 864
 865   for (list = callback_list; list; list = list->next)
 866     {
 867       if (list->callback_id == callback_id)
 868         {
 869           if (list->next)
 870             list->next = list->prev;
 871
 872           if (list->prev)
 873             list->prev->next = list->next;
 874           else
 875             callback_list = list->next;
 876
 877           /* invoke the destroy handler */
 878           (list->destroy) (list->data);
 879           free (list);
 880           return;
 881         }
 882     }
 883 }