gio/gcontenttype.c

   1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
   2
   3 /* GIO - GLib Input, Output and Streaming Library
   4  *
   5  * Copyright (C) 2006-2007 Red Hat, Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this library; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  *
  22  * Author: Alexander Larsson <alexl@redhat.com>
  23  */
  24
  25 #include "config.h"
  26 #include <sys/types.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <stdio.h>
  30 #include "gcontenttypeprivate.h"
  31 #include "gthemedicon.h"
  32 #include "gicon.h"
  33 #include "gfile.h"
  34 #include "gfileenumerator.h"
  35 #include "gfileinfo.h"
  36 #include "glibintl.h"
  37
  38
  39 /**
  40  * SECTION:gcontenttype
  41  * @short_description: Platform-specific content typing
  42  * @include: gio/gio.h
  43  *
  44  * A content type is a platform specific string that defines the type
  45  * of a file. On UNIX it is a <ulink url="http://www.wikipedia.org/wiki/Internet_media_type">mime type</ulink> like "text/plain" or "image/png".
  46  * On Win32 it is an extension string like ".doc", ".txt" or a perceived
  47  * string like "audio". Such strings can be looked up in the registry at
  48  * HKEY_CLASSES_ROOT.
  49  **/
  50
  51 #include <dirent.h>
  52
  53 #define XDG_PREFIX _gio_xdg
  54 #include "xdgmime/xdgmime.h"
  55
  56 /* We lock this mutex whenever we modify global state in this module.  */
  57 G_LOCK_DEFINE_STATIC (gio_xdgmime);
  58
  59 gsize
  60 _g_unix_content_type_get_sniff_len (void)
  61 {
  62   gsize size;
  63
  64   G_LOCK (gio_xdgmime);
  65   size = xdg_mime_get_max_buffer_extents ();
  66   G_UNLOCK (gio_xdgmime);
  67
  68   return size;
  69 }
  70
  71 gchar *
  72 _g_unix_content_type_unalias (const gchar *type)
  73 {
  74   gchar *res;
  75
  76   G_LOCK (gio_xdgmime);
  77   res = g_strdup (xdg_mime_unalias_mime_type (type));
  78   G_UNLOCK (gio_xdgmime);
  79
  80   return res;
  81 }
  82
  83 gchar **
  84 _g_unix_content_type_get_parents (const gchar *type)
  85 {
  86   const gchar *umime;
  87   gchar **parents;
  88   GPtrArray *array;
  89   int i;
  90
  91   array = g_ptr_array_new ();
  92
  93   G_LOCK (gio_xdgmime);
  94
  95   umime = xdg_mime_unalias_mime_type (type);
  96
  97   g_ptr_array_add (array, g_strdup (umime));
  98
  99   parents = xdg_mime_list_mime_parents (umime);
 100   for (i = 0; parents && parents[i] != NULL; i++)
 101     g_ptr_array_add (array, g_strdup (parents[i]));
 102
 103   free (parents);
 104
 105   G_UNLOCK (gio_xdgmime);
 106
 107   g_ptr_array_add (array, NULL);
 108
 109   return (gchar **)g_ptr_array_free (array, FALSE);
 110 }
 111
 112 /**
 113  * g_content_type_equals:
 114  * @type1: a content type string
 115  * @type2: a content type string
 116  *
 117  * Compares two content types for equality.
 118  *
 119  * Returns: %TRUE if the two strings are identical or equivalent,
 120  *     %FALSE otherwise.
 121  */
 122 gboolean
 123 g_content_type_equals (const gchar *type1,
 124                        const gchar *type2)
 125 {
 126   gboolean res;
 127
 128   g_return_val_if_fail (type1 != NULL, FALSE);
 129   g_return_val_if_fail (type2 != NULL, FALSE);
 130
 131   G_LOCK (gio_xdgmime);
 132   res = xdg_mime_mime_type_equal (type1, type2);
 133   G_UNLOCK (gio_xdgmime);
 134
 135   return res;
 136 }
 137
 138 /**
 139  * g_content_type_is_a:
 140  * @type: a content type string
 141  * @supertype: a content type string
 142  *
 143  * Determines if @type is a subset of @supertype.
 144  *
 145  * Returns: %TRUE if @type is a kind of @supertype,
 146  *     %FALSE otherwise.
 147  */
 148 gboolean
 149 g_content_type_is_a (const gchar *type,
 150                      const gchar *supertype)
 151 {
 152   gboolean res;
 153
 154   g_return_val_if_fail (type != NULL, FALSE);
 155   g_return_val_if_fail (supertype != NULL, FALSE);
 156
 157   G_LOCK (gio_xdgmime);
 158   res = xdg_mime_mime_type_subclass (type, supertype);
 159   G_UNLOCK (gio_xdgmime);
 160
 161   return res;
 162 }
 163
 164 /**
 165  * g_content_type_is_unknown:
 166  * @type: a content type string
 167  *
 168  * Checks if the content type is the generic "unknown" type.
 169  * On UNIX this is the "application/octet-stream" mimetype,
 170  * while on win32 it is "*".
 171  *
 172  * Returns: %TRUE if the type is the unknown type.
 173  */
 174 gboolean
 175 g_content_type_is_unknown (const gchar *type)
 176 {
 177   g_return_val_if_fail (type != NULL, FALSE);
 178
 179   return strcmp (XDG_MIME_TYPE_UNKNOWN, type) == 0;
 180 }
 181
 182
 183 typedef enum {
 184   MIME_TAG_TYPE_OTHER,
 185   MIME_TAG_TYPE_COMMENT
 186 } MimeTagType;
 187
 188 typedef struct {
 189   int current_type;
 190   int current_lang_level;
 191   int comment_lang_level;
 192   char *comment;
 193 } MimeParser;
 194
 195
 196 static int
 197 language_level (const char *lang)
 198 {
 199   const char * const *lang_list;
 200   int i;
 201
 202   /* The returned list is sorted from most desirable to least
 203      desirable and always contains the default locale "C". */
 204   lang_list = g_get_language_names ();
 205
 206   for (i = 0; lang_list[i]; i++)
 207     if (strcmp (lang_list[i], lang) == 0)
 208       return 1000-i;
 209
 210   return 0;
 211 }
 212
 213 static void
 214 mime_info_start_element (GMarkupParseContext  *context,
 215                          const gchar          *element_name,
 216                          const gchar         **attribute_names,
 217                          const gchar         **attribute_values,
 218                          gpointer              user_data,
 219                          GError              **error)
 220 {
 221   int i;
 222   const char *lang;
 223   MimeParser *parser = user_data;
 224
 225   if (strcmp (element_name, "comment") == 0)
 226     {
 227       lang = "C";
 228       for (i = 0; attribute_names[i]; i++)
 229         if (strcmp (attribute_names[i], "xml:lang") == 0)
 230           {
 231             lang = attribute_values[i];
 232             break;
 233           }
 234
 235       parser->current_lang_level = language_level (lang);
 236       parser->current_type = MIME_TAG_TYPE_COMMENT;
 237     }
 238   else
 239     parser->current_type = MIME_TAG_TYPE_OTHER;
 240 }
 241
 242 static void
 243 mime_info_end_element (GMarkupParseContext  *context,
 244                        const gchar          *element_name,
 245                        gpointer              user_data,
 246                        GError              **error)
 247 {
 248   MimeParser *parser = user_data;
 249
 250   parser->current_type = MIME_TAG_TYPE_OTHER;
 251 }
 252
 253 static void
 254 mime_info_text (GMarkupParseContext  *context,
 255                 const gchar          *text,
 256                 gsize                 text_len,
 257                 gpointer              user_data,
 258                 GError              **error)
 259 {
 260   MimeParser *parser = user_data;
 261
 262   if (parser->current_type == MIME_TAG_TYPE_COMMENT &&
 263       parser->current_lang_level > parser->comment_lang_level)
 264     {
 265       g_free (parser->comment);
 266       parser->comment = g_strndup (text, text_len);
 267       parser->comment_lang_level = parser->current_lang_level;
 268     }
 269 }
 270
 271 static char *
 272 load_comment_for_mime_helper (const char *dir,
 273                               const char *basename)
 274 {
 275   GMarkupParseContext *context;
 276   char *filename, *data;
 277   gsize len;
 278   gboolean res;
 279   MimeParser parse_data = {0};
 280   GMarkupParser parser = {
 281     mime_info_start_element,
 282     mime_info_end_element,
 283     mime_info_text
 284   };
 285
 286   filename = g_build_filename (dir, "mime", basename, NULL);
 287
 288   res = g_file_get_contents (filename,  &data,  &len,  NULL);
 289   g_free (filename);
 290   if (!res)
 291     return NULL;
 292
 293   context = g_markup_parse_context_new   (&parser, 0, &parse_data, NULL);
 294   res = g_markup_parse_context_parse (context, data, len, NULL);
 295   g_free (data);
 296   g_markup_parse_context_free (context);
 297
 298   if (!res)
 299     return NULL;
 300
 301   return parse_data.comment;
 302 }
 303
 304
 305 static char *
 306 load_comment_for_mime (const char *mimetype)
 307 {
 308   const char * const* dirs;
 309   char *basename;
 310   char *comment;
 311   int i;
 312
 313   basename = g_strdup_printf ("%s.xml", mimetype);
 314
 315   comment = load_comment_for_mime_helper (g_get_user_data_dir (), basename);
 316   if (comment)
 317     {
 318       g_free (basename);
 319       return comment;
 320     }
 321
 322   dirs = g_get_system_data_dirs ();
 323
 324   for (i = 0; dirs[i] != NULL; i++)
 325     {
 326       comment = load_comment_for_mime_helper (dirs[i], basename);
 327       if (comment)
 328         {
 329           g_free (basename);
 330           return comment;
 331         }
 332     }
 333   g_free (basename);
 334
 335   return g_strdup_printf (_("%s type"), mimetype);
 336 }
 337
 338 /**
 339  * g_content_type_get_description:
 340  * @type: a content type string
 341  *
 342  * Gets the human readable description of the content type.
 343  *
 344  * Returns: a short description of the content type @type. Free the
 345  *     returned string with g_free()
 346  */
 347 gchar *
 348 g_content_type_get_description (const gchar *type)
 349 {
 350   static GHashTable *type_comment_cache = NULL;
 351   gchar *comment;
 352
 353   g_return_val_if_fail (type != NULL, NULL);
 354
 355   G_LOCK (gio_xdgmime);
 356   type = xdg_mime_unalias_mime_type (type);
 357
 358   if (type_comment_cache == NULL)
 359     type_comment_cache = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
 360
 361   comment = g_hash_table_lookup (type_comment_cache, type);
 362   comment = g_strdup (comment);
 363   G_UNLOCK (gio_xdgmime);
 364
 365   if (comment != NULL)
 366     return comment;
 367
 368   comment = load_comment_for_mime (type);
 369
 370   G_LOCK (gio_xdgmime);
 371   g_hash_table_insert (type_comment_cache,
 372                        g_strdup (type),
 373                        g_strdup (comment));
 374   G_UNLOCK (gio_xdgmime);
 375
 376   return comment;
 377 }
 378
 379 /**
 380  * g_content_type_get_mime_type:
 381  * @type: a content type string
 382  *
 383  * Gets the mime type for the content type, if one is registered.
 384  *
 385  * Returns: (allow-none): the registered mime type for the given @type,
 386  *     or %NULL if unknown.
 387  */
 388 char *
 389 g_content_type_get_mime_type (const char *type)
 390 {
 391   g_return_val_if_fail (type != NULL, NULL);
 392
 393   return g_strdup (type);
 394 }
 395
 396
 397 static GIcon *
 398 g_content_type_get_icon_internal (const gchar *type,
 399                                   gboolean     symbolic)
 400 {
 401   char *mimetype_icon;
 402   char *generic_mimetype_icon = NULL;
 403   char *q;
 404   char *xdg_mimetype_icon = NULL;
 405   char *legacy_mimetype_icon;
 406   char *xdg_mimetype_generic_icon;
 407   char *icon_names[5];
 408   int n = 0;
 409   GIcon *themed_icon;
 410   const char *file_template;
 411   const char  *xdg_icon;
 412
 413   g_return_val_if_fail (type != NULL, NULL);
 414
 415   if (symbolic)
 416     {
 417       file_template = "%s-symbolic";
 418     }
 419   else
 420     {
 421       file_template = "%s";
 422     }
 423
 424   G_LOCK (gio_xdgmime);
 425   xdg_icon = xdg_mime_get_icon (type);
 426   G_UNLOCK (gio_xdgmime);
 427   if (xdg_icon != NULL)
 428     xdg_mimetype_icon = g_strdup_printf (file_template, xdg_icon);
 429   xdg_mimetype_generic_icon = g_content_type_get_generic_icon_name (type);
 430
 431   mimetype_icon = g_strdup_printf (file_template, type);
 432   if (xdg_mimetype_generic_icon)
 433     generic_mimetype_icon = g_strdup_printf (file_template, xdg_mimetype_generic_icon);
 434
 435   while ((q = strchr (mimetype_icon, '/')) != NULL)
 436     *q = '-';
 437
 438   /* Not all icons have migrated to the new icon theme spec, look for old names too */
 439   legacy_mimetype_icon = g_strconcat ("gnome-mime-", mimetype_icon, NULL);
 440
 441   if (xdg_mimetype_icon)
 442     icon_names[n++] = xdg_mimetype_icon;
 443
 444   icon_names[n++] = mimetype_icon;
 445   icon_names[n++] = legacy_mimetype_icon;
 446
 447   if (generic_mimetype_icon)
 448     icon_names[n++] = generic_mimetype_icon;
 449
 450   themed_icon = g_themed_icon_new_from_names (icon_names, n);
 451
 452   g_free (xdg_mimetype_icon);
 453   g_free (xdg_mimetype_generic_icon);
 454   g_free (mimetype_icon);
 455   g_free (legacy_mimetype_icon);
 456   g_free (generic_mimetype_icon);
 457
 458   return themed_icon;
 459 }
 460
 461 /**
 462  * g_content_type_get_icon:
 463  * @type: a content type string
 464  *
 465  * Gets the icon for a content type.
 466  *
 467  * Returns: (transfer full): #GIcon corresponding to the content type. Free the returned
 468  *     object with g_object_unref()
 469  */
 470 GIcon *
 471 g_content_type_get_icon (const gchar *type)
 472 {
 473   return g_content_type_get_icon_internal (type, FALSE);
 474 }
 475
 476 /**
 477  * g_content_type_get_symbolic_icon:
 478  * @type: a content type string
 479  *
 480  * Gets the symbolic icon for a content type.
 481  *
 482  * Returns: (transfer full): symbolic #GIcon corresponding to the content type.
 483  *     Free the returned object with g_object_unref()
 484  *
 485  * Since: 2.34
 486  */
 487 GIcon *
 488 g_content_type_get_symbolic_icon (const gchar *type)
 489 {
 490   return g_content_type_get_icon_internal (type, TRUE);
 491 }
 492
 493 /**
 494  * g_content_type_get_generic_icon_name:
 495  * @type: a content type string
 496  *
 497  * Gets the generic icon name for a content type.
 498  *
 499  * See the <ulink url="http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec">shared-mime-info</ulink>
 500  * specification for more on the generic icon name.
 501  *
 502  * Returns: (allow-none): the registered generic icon name for the given @type,
 503  *     or %NULL if unknown. Free with g_free()
 504  *
 505  * Since: 2.34
 506  */
 507 gchar *
 508 g_content_type_get_generic_icon_name (const gchar *type)
 509 {
 510   const gchar *xdg_icon_name;
 511   gchar *icon_name;
 512
 513   G_LOCK (gio_xdgmime);
 514   xdg_icon_name = xdg_mime_get_generic_icon (type);
 515   G_UNLOCK (gio_xdgmime);
 516
 517   if (!xdg_icon_name)
 518     {
 519       const char *p;
 520       const char *suffix = "-x-generic";
 521
 522       p = strchr (type, '/');
 523       if (p == NULL)
 524         p = type + strlen (type);
 525
 526       icon_name = g_malloc (p - type + strlen (suffix) + 1);
 527       memcpy (icon_name, type, p - type);
 528       memcpy (icon_name + (p - type), suffix, strlen (suffix));
 529       icon_name[(p - type) + strlen (suffix)] = 0;
 530     }
 531   else
 532     {
 533       icon_name = g_strdup (xdg_icon_name);
 534     }
 535
 536   return icon_name;
 537 }
 538
 539 /**
 540  * g_content_type_can_be_executable:
 541  * @type: a content type string
 542  *
 543  * Checks if a content type can be executable. Note that for instance
 544  * things like text files can be executables (i.e. scripts and batch files).
 545  *
 546  * Returns: %TRUE if the file type corresponds to a type that
 547  *     can be executable, %FALSE otherwise.
 548  */
 549 gboolean
 550 g_content_type_can_be_executable (const gchar *type)
 551 {
 552   g_return_val_if_fail (type != NULL, FALSE);
 553
 554   if (g_content_type_is_a (type, "application/x-executable")  ||
 555       g_content_type_is_a (type, "text/plain"))
 556     return TRUE;
 557
 558   return FALSE;
 559 }
 560
 561 static gboolean
 562 looks_like_text (const guchar *data, gsize data_size)
 563 {
 564   gsize i;
 565   char c;
 566
 567   for (i = 0; i < data_size; i++)
 568     {
 569       c = data[i];
 570
 571       if (g_ascii_iscntrl (c) &&
 572           !g_ascii_isspace (c) &&
 573           c != '\b')
 574         return FALSE;
 575     }
 576   return TRUE;
 577 }
 578
 579 /**
 580  * g_content_type_from_mime_type:
 581  * @mime_type: a mime type string
 582  *
 583  * Tries to find a content type based on the mime type name.
 584  *
 585  * Returns: (allow-none): Newly allocated string with content type
 586  *     or %NULL. Free with g_free()
 587  *
 588  * Since: 2.18
 589  **/
 590 gchar *
 591 g_content_type_from_mime_type (const gchar *mime_type)
 592 {
 593   char *umime;
 594
 595   g_return_val_if_fail (mime_type != NULL, NULL);
 596
 597   G_LOCK (gio_xdgmime);
 598   /* mime type and content type are same on unixes */
 599   umime = g_strdup (xdg_mime_unalias_mime_type (mime_type));
 600   G_UNLOCK (gio_xdgmime);
 601
 602   return umime;
 603 }
 604
 605 /**
 606  * g_content_type_guess:
 607  * @filename: (allow-none): a string, or %NULL
 608  * @data: (allow-none) (array length=data_size): a stream of data, or %NULL
 609  * @data_size: the size of @data
 610  * @result_uncertain: (allow-none) (out): return location for the certainty
 611  *     of the result, or %NULL
 612  *
 613  * Guesses the content type based on example data. If the function is
 614  * uncertain, @result_uncertain will be set to %TRUE. Either @filename
 615  * or @data may be %NULL, in which case the guess will be based solely
 616  * on the other argument.
 617  *
 618  * Returns: a string indicating a guessed content type for the
 619  *     given data. Free with g_free()
 620  */
 621 gchar *
 622 g_content_type_guess (const gchar  *filename,
 623                       const guchar *data,
 624                       gsize         data_size,
 625                       gboolean     *result_uncertain)
 626 {
 627   char *basename;
 628   const char *name_mimetypes[10], *sniffed_mimetype;
 629   char *mimetype;
 630   int i;
 631   int n_name_mimetypes;
 632   int sniffed_prio;
 633
 634   sniffed_prio = 0;
 635   n_name_mimetypes = 0;
 636   sniffed_mimetype = XDG_MIME_TYPE_UNKNOWN;
 637
 638   if (result_uncertain)
 639     *result_uncertain = FALSE;
 640
 641   /* our test suite and potentially other code used -1 in the past, which is
 642    * not documented and not allowed; guard against that */
 643   g_return_val_if_fail (data_size != (gsize) -1, g_strdup (XDG_MIME_TYPE_UNKNOWN));
 644
 645   G_LOCK (gio_xdgmime);
 646
 647   if (filename)
 648     {
 649       i = strlen (filename);
 650       if (filename[i - 1] == '/')
 651         {
 652           name_mimetypes[0] = "inode/directory";
 653           name_mimetypes[1] = NULL;
 654           n_name_mimetypes = 1;
 655           if (result_uncertain)
 656             *result_uncertain = TRUE;
 657         }
 658       else
 659         {
 660           basename = g_path_get_basename (filename);
 661           n_name_mimetypes = xdg_mime_get_mime_types_from_file_name (basename, name_mimetypes, 10);
 662           g_free (basename);
 663         }
 664     }
 665
 666   /* Got an extension match, and no conflicts. This is it. */
 667   if (n_name_mimetypes == 1)
 668     {
 669       G_UNLOCK (gio_xdgmime);
 670       return g_strdup (name_mimetypes[0]);
 671     }
 672
 673   if (data)
 674     {
 675       sniffed_mimetype = xdg_mime_get_mime_type_for_data (data, data_size, &sniffed_prio);
 676       if (sniffed_mimetype == XDG_MIME_TYPE_UNKNOWN &&
 677           data &&
 678           looks_like_text (data, data_size))
 679         sniffed_mimetype = "text/plain";
 680
 681       /* For security reasons we don't ever want to sniff desktop files
 682        * where we know the filename and it doesn't have a .desktop extension.
 683        * This is because desktop files allow executing any application and
 684        * we don't want to make it possible to hide them looking like something
 685        * else.
 686        */
 687       if (filename != NULL &&
 688           strcmp (sniffed_mimetype, "application/x-desktop") == 0)
 689         sniffed_mimetype = "text/plain";
 690     }
 691
 692   if (n_name_mimetypes == 0)
 693     {
 694       if (sniffed_mimetype == XDG_MIME_TYPE_UNKNOWN &&
 695           result_uncertain)
 696         *result_uncertain = TRUE;
 697
 698       mimetype = g_strdup (sniffed_mimetype);
 699     }
 700   else
 701     {
 702       mimetype = NULL;
 703       if (sniffed_mimetype != XDG_MIME_TYPE_UNKNOWN)
 704         {
 705           if (sniffed_prio >= 80) /* High priority sniffing match, use that */
 706             mimetype = g_strdup (sniffed_mimetype);
 707           else
 708             {
 709               /* There are conflicts between the name matches and we
 710                * have a sniffed type, use that as a tie breaker.
 711                */
 712               for (i = 0; i < n_name_mimetypes; i++)
 713                 {
 714                   if ( xdg_mime_mime_type_subclass (name_mimetypes[i], sniffed_mimetype))
 715                     {
 716                       /* This nametype match is derived from (or the same as)
 717                        * the sniffed type). This is probably it.
 718                        */
 719                       mimetype = g_strdup (name_mimetypes[i]);
 720                       break;
 721                     }
 722                 }
 723             }
 724         }
 725
 726       if (mimetype == NULL)
 727         {
 728           /* Conflicts, and sniffed type was no help or not there.
 729            * Guess on the first one
 730            */
 731           mimetype = g_strdup (name_mimetypes[0]);
 732           if (result_uncertain)
 733             *result_uncertain = TRUE;
 734         }
 735     }
 736
 737   G_UNLOCK (gio_xdgmime);
 738
 739   return mimetype;
 740 }
 741
 742 static void
 743 enumerate_mimetypes_subdir (const char *dir,
 744                             const char *prefix,
 745                             GHashTable *mimetypes)
 746 {
 747   DIR *d;
 748   struct dirent *ent;
 749   char *mimetype;
 750
 751   d = opendir (dir);
 752   if (d)
 753     {
 754       while ((ent = readdir (d)) != NULL)
 755         {
 756           if (g_str_has_suffix (ent->d_name, ".xml"))
 757             {
 758               mimetype = g_strdup_printf ("%s/%.*s", prefix, (int) strlen (ent->d_name) - 4, ent->d_name);
 759               g_hash_table_replace (mimetypes, mimetype, NULL);
 760             }
 761         }
 762       closedir (d);
 763     }
 764 }
 765
 766 static void
 767 enumerate_mimetypes_dir (const char *dir,
 768                          GHashTable *mimetypes)
 769 {
 770   DIR *d;
 771   struct dirent *ent;
 772   char *mimedir;
 773   char *name;
 774
 775   mimedir = g_build_filename (dir, "mime", NULL);
 776
 777   d = opendir (mimedir);
 778   if (d)
 779     {
 780       while ((ent = readdir (d)) != NULL)
 781         {
 782           if (strcmp (ent->d_name, "packages") != 0)
 783             {
 784               name = g_build_filename (mimedir, ent->d_name, NULL);
 785               if (g_file_test (name, G_FILE_TEST_IS_DIR))
 786                 enumerate_mimetypes_subdir (name, ent->d_name, mimetypes);
 787               g_free (name);
 788             }
 789         }
 790       closedir (d);
 791     }
 792
 793   g_free (mimedir);
 794 }
 795
 796 /**
 797  * g_content_types_get_registered:
 798  *
 799  * Gets a list of strings containing all the registered content types
 800  * known to the system. The list and its data should be freed using
 801  * <programlisting>
 802  * g_list_free_full (list, g_free);
 803  * </programlisting>
 804  *
 805  * Returns: (element-type utf8) (transfer full): #GList of the registered content types
 806  */
 807 GList *
 808 g_content_types_get_registered (void)
 809 {
 810   const char * const* dirs;
 811   GHashTable *mimetypes;
 812   GHashTableIter iter;
 813   gpointer key;
 814   int i;
 815   GList *l;
 816
 817   mimetypes = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 818
 819   enumerate_mimetypes_dir (g_get_user_data_dir (), mimetypes);
 820   dirs = g_get_system_data_dirs ();
 821
 822   for (i = 0; dirs[i] != NULL; i++)
 823     enumerate_mimetypes_dir (dirs[i], mimetypes);
 824
 825   l = NULL;
 826   g_hash_table_iter_init (&iter, mimetypes);
 827   while (g_hash_table_iter_next (&iter, &key, NULL))
 828     {
 829       l = g_list_prepend (l, key);
 830       g_hash_table_iter_steal (&iter);
 831     }
 832
 833   g_hash_table_destroy (mimetypes);
 834
 835   return l;
 836 }
 837
 838
 839 /* tree magic data */
 840 static GList *tree_matches = NULL;
 841 static gboolean need_reload = FALSE;
 842
 843 G_LOCK_DEFINE_STATIC (gio_treemagic);
 844
 845 typedef struct
 846 {
 847   gchar *path;
 848   GFileType type;
 849   guint match_case : 1;
 850   guint executable : 1;
 851   guint non_empty  : 1;
 852   guint on_disc    : 1;
 853   gchar *mimetype;
 854   GList *matches;
 855 } TreeMatchlet;
 856
 857 typedef struct
 858 {
 859   gchar *contenttype;
 860   gint priority;
 861   GList *matches;
 862 } TreeMatch;
 863
 864
 865 static void
 866 tree_matchlet_free (TreeMatchlet *matchlet)
 867 {
 868   g_list_free_full (matchlet->matches, (GDestroyNotify) tree_matchlet_free);
 869   g_free (matchlet->path);
 870   g_free (matchlet->mimetype);
 871   g_slice_free (TreeMatchlet, matchlet);
 872 }
 873
 874 static void
 875 tree_match_free (TreeMatch *match)
 876 {
 877   g_list_free_full (match->matches, (GDestroyNotify) tree_matchlet_free);
 878   g_free (match->contenttype);
 879   g_slice_free (TreeMatch, match);
 880 }
 881
 882 static TreeMatch *
 883 parse_header (gchar *line)
 884 {
 885   gint len;
 886   gchar *s;
 887   TreeMatch *match;
 888
 889   len = strlen (line);
 890
 891   if (line[0] != '[' || line[len - 1] != ']')
 892     return NULL;
 893
 894   line[len - 1] = 0;
 895   s = strchr (line, ':');
 896
 897   match = g_slice_new0 (TreeMatch);
 898   match->priority = atoi (line + 1);
 899   match->contenttype = g_strdup (s + 1);
 900
 901   return match;
 902 }
 903
 904 static TreeMatchlet *
 905 parse_match_line (gchar *line,
 906                   gint  *depth)
 907 {
 908   gchar *s, *p;
 909   TreeMatchlet *matchlet;
 910   gchar **parts;
 911   gint i;
 912
 913   matchlet = g_slice_new0 (TreeMatchlet);
 914
 915   if (line[0] == '>')
 916     {
 917       *depth = 0;
 918       s = line;
 919     }
 920   else
 921     {
 922       *depth = atoi (line);
 923       s = strchr (line, '>');
 924     }
 925   s += 2;
 926   p = strchr (s, '"');
 927   *p = 0;
 928
 929   matchlet->path = g_strdup (s);
 930   s = p + 1;
 931   parts = g_strsplit (s, ",", 0);
 932   if (strcmp (parts[0], "=file") == 0)
 933     matchlet->type = G_FILE_TYPE_REGULAR;
 934   else if (strcmp (parts[0], "=directory") == 0)
 935     matchlet->type = G_FILE_TYPE_DIRECTORY;
 936   else if (strcmp (parts[0], "=link") == 0)
 937     matchlet->type = G_FILE_TYPE_SYMBOLIC_LINK;
 938   else
 939     matchlet->type = G_FILE_TYPE_UNKNOWN;
 940   for (i = 1; parts[i]; i++)
 941     {
 942       if (strcmp (parts[i], "executable") == 0)
 943         matchlet->executable = 1;
 944       else if (strcmp (parts[i], "match-case") == 0)
 945         matchlet->match_case = 1;
 946       else if (strcmp (parts[i], "non-empty") == 0)
 947         matchlet->non_empty = 1;
 948       else if (strcmp (parts[i], "on-disc") == 0)
 949         matchlet->on_disc = 1;
 950       else
 951         matchlet->mimetype = g_strdup (parts[i]);
 952     }
 953
 954   g_strfreev (parts);
 955
 956   return matchlet;
 957 }
 958
 959 static gint
 960 cmp_match (gconstpointer a, gconstpointer b)
 961 {
 962   const TreeMatch *aa = (const TreeMatch *)a;
 963   const TreeMatch *bb = (const TreeMatch *)b;
 964
 965   return bb->priority - aa->priority;
 966 }
 967
 968 static void
 969 insert_match (TreeMatch *match)
 970 {
 971   tree_matches = g_list_insert_sorted (tree_matches, match, cmp_match);
 972 }
 973
 974 static void
 975 insert_matchlet (TreeMatch    *match,
 976                  TreeMatchlet *matchlet,
 977                  gint          depth)
 978 {
 979   if (depth == 0)
 980     match->matches = g_list_append (match->matches, matchlet);
 981   else
 982     {
 983       GList *last;
 984       TreeMatchlet *m;
 985
 986       last = g_list_last (match->matches);
 987       if (!last)
 988         {
 989           tree_matchlet_free (matchlet);
 990           g_warning ("can't insert tree matchlet at depth %d", depth);
 991           return;
 992         }
 993
 994       m = (TreeMatchlet *) last->data;
 995       while (--depth > 0)
 996         {
 997           last = g_list_last (m->matches);
 998           if (!last)
 999             {
1000               tree_matchlet_free (matchlet);
1001               g_warning ("can't insert tree matchlet at depth %d", depth);
1002               return;
1003             }
1004
1005           m = (TreeMatchlet *) last->data;
1006         }
1007       m->matches = g_list_append (m->matches, matchlet);
1008     }
1009 }
1010
1011 static void
1012 read_tree_magic_from_directory (const gchar *prefix)
1013 {
1014   gchar *filename;
1015   gchar *text;
1016   gsize len;
1017   gchar **lines;
1018   gint i;
1019   TreeMatch *match;
1020   TreeMatchlet *matchlet;
1021   gint depth;
1022
1023   filename = g_build_filename (prefix, "mime", "treemagic", NULL);
1024
1025   if (g_file_get_contents (filename, &text, &len, NULL))
1026     {
1027       if (strcmp (text, "MIME-TreeMagic") == 0)
1028         {
1029           lines = g_strsplit (text + strlen ("MIME-TreeMagic") + 2, "\n", 0);
1030           match = NULL;
1031           for (i = 0; lines[i] && lines[i][0]; i++)
1032             {
1033               if (lines[i][0] == '[')
1034                 {
1035                   match = parse_header (lines[i]);
1036                   insert_match (match);
1037                 }
1038               else
1039                 {
1040                   matchlet = parse_match_line (lines[i], &depth);
1041                   insert_matchlet (match, matchlet, depth);
1042                 }
1043             }
1044
1045           g_strfreev (lines);
1046         }
1047       else
1048         g_warning ("%s: header not found, skipping\n", filename);
1049
1050       g_free (text);
1051     }
1052
1053   g_free (filename);
1054 }
1055
1056
1057 static void
1058 xdg_mime_reload (void *user_data)
1059 {
1060   need_reload = TRUE;
1061 }
1062
1063 static void
1064 tree_magic_shutdown (void)
1065 {
1066   g_list_free_full (tree_matches, (GDestroyNotify) tree_match_free);
1067   tree_matches = NULL;
1068 }
1069
1070 static void
1071 tree_magic_init (void)
1072 {
1073   static gboolean initialized = FALSE;
1074   const gchar *dir;
1075   const gchar * const * dirs;
1076   int i;
1077
1078   if (!initialized)
1079     {
1080       initialized = TRUE;
1081
1082       xdg_mime_register_reload_callback (xdg_mime_reload, NULL, NULL);
1083       need_reload = TRUE;
1084     }
1085
1086   if (need_reload)
1087     {
1088       need_reload = FALSE;
1089
1090       tree_magic_shutdown ();
1091
1092       dir = g_get_user_data_dir ();
1093       read_tree_magic_from_directory (dir);
1094       dirs = g_get_system_data_dirs ();
1095       for (i = 0; dirs[i]; i++)
1096         read_tree_magic_from_directory (dirs[i]);
1097     }
1098 }
1099
1100 /* a filtering enumerator */
1101
1102 typedef struct
1103 {
1104   gchar *path;
1105   gint depth;
1106   gboolean ignore_case;
1107   gchar **components;
1108   gchar **case_components;
1109   GFileEnumerator **enumerators;
1110   GFile **children;
1111 } Enumerator;
1112
1113 static gboolean
1114 component_match (Enumerator  *e,
1115                  gint         depth,
1116                  const gchar *name)
1117 {
1118   gchar *case_folded, *key;
1119   gboolean found;
1120
1121   if (strcmp (name, e->components[depth]) == 0)
1122     return TRUE;
1123
1124   if (!e->ignore_case)
1125     return FALSE;
1126
1127   case_folded = g_utf8_casefold (name, -1);
1128   key = g_utf8_collate_key (case_folded, -1);
1129
1130   found = strcmp (key, e->case_components[depth]) == 0;
1131
1132   g_free (case_folded);
1133   g_free (key);
1134
1135   return found;
1136 }
1137
1138 static GFile *
1139 next_match_recurse (Enumerator *e,
1140                     gint        depth)
1141 {
1142   GFile *file;
1143   GFileInfo *info;
1144   const gchar *name;
1145
1146   while (TRUE)
1147     {
1148       if (e->enumerators[depth] == NULL)
1149         {
1150           if (depth > 0)
1151             {
1152               file = next_match_recurse (e, depth - 1);
1153               if (file)
1154                 {
1155                   e->children[depth] = file;
1156                   e->enumerators[depth] = g_file_enumerate_children (file,
1157                                                                      G_FILE_ATTRIBUTE_STANDARD_NAME,
1158                                                                      G_FILE_QUERY_INFO_NONE,
1159                                                                      NULL,
1160                                                                      NULL);
1161                 }
1162             }
1163           if (e->enumerators[depth] == NULL)
1164             return NULL;
1165         }
1166
1167       while ((info = g_file_enumerator_next_file (e->enumerators[depth], NULL, NULL)))
1168         {
1169           name = g_file_info_get_name (info);
1170           if (component_match (e, depth, name))
1171             {
1172               file = g_file_get_child (e->children[depth], name);
1173               g_object_unref (info);
1174               return file;
1175             }
1176           g_object_unref (info);
1177         }
1178
1179       g_object_unref (e->enumerators[depth]);
1180       e->enumerators[depth] = NULL;
1181       g_object_unref (e->children[depth]);
1182       e->children[depth] = NULL;
1183     }
1184 }
1185
1186 static GFile *
1187 enumerator_next (Enumerator *e)
1188 {
1189   return next_match_recurse (e, e->depth - 1);
1190 }
1191
1192 static Enumerator *
1193 enumerator_new (GFile      *root,
1194                 const char *path,
1195                 gboolean    ignore_case)
1196 {
1197   Enumerator *e;
1198   gint i;
1199   gchar *case_folded;
1200
1201   e = g_new0 (Enumerator, 1);
1202   e->path = g_strdup (path);
1203   e->ignore_case = ignore_case;
1204
1205   e->components = g_strsplit (e->path, G_DIR_SEPARATOR_S, -1);
1206   e->depth = g_strv_length (e->components);
1207   if (e->ignore_case)
1208     {
1209       e->case_components = g_new0 (char *, e->depth + 1);
1210       for (i = 0; e->components[i]; i++)
1211         {
1212           case_folded = g_utf8_casefold (e->components[i], -1);
1213           e->case_components[i] = g_utf8_collate_key (case_folded, -1);
1214           g_free (case_folded);
1215         }
1216     }
1217
1218   e->children = g_new0 (GFile *, e->depth);
1219   e->children[0] = g_object_ref (root);
1220   e->enumerators = g_new0 (GFileEnumerator *, e->depth);
1221   e->enumerators[0] = g_file_enumerate_children (root,
1222                                                  G_FILE_ATTRIBUTE_STANDARD_NAME,
1223                                                  G_FILE_QUERY_INFO_NONE,
1224                                                  NULL,
1225                                                  NULL);
1226
1227   return e;
1228 }
1229
1230 static void
1231 enumerator_free (Enumerator *e)
1232 {
1233   gint i;
1234
1235   for (i = 0; i < e->depth; i++)
1236     {
1237       if (e->enumerators[i])
1238         g_object_unref (e->enumerators[i]);
1239       if (e->children[i])
1240         g_object_unref (e->children[i]);
1241     }
1242
1243   g_free (e->enumerators);
1244   g_free (e->children);
1245   g_strfreev (e->components);
1246   if (e->case_components)
1247     g_strfreev (e->case_components);
1248   g_free (e->path);
1249   g_free (e);
1250 }
1251
1252 static gboolean
1253 matchlet_match (TreeMatchlet *matchlet,
1254                 GFile        *root)
1255 {
1256   GFile *file;
1257   GFileInfo *info;
1258   gboolean result;
1259   const gchar *attrs;
1260   Enumerator *e;
1261   GList *l;
1262
1263   e = enumerator_new (root, matchlet->path, !matchlet->match_case);
1264
1265   do
1266     {
1267       file = enumerator_next (e);
1268       if (!file)
1269         {
1270           enumerator_free (e);
1271           return FALSE;
1272         }
1273
1274       if (matchlet->mimetype)
1275         attrs = G_FILE_ATTRIBUTE_STANDARD_TYPE ","
1276                 G_FILE_ATTRIBUTE_ACCESS_CAN_EXECUTE ","
1277                 G_FILE_ATTRIBUTE_STANDARD_CONTENT_TYPE;
1278       else
1279         attrs = G_FILE_ATTRIBUTE_STANDARD_TYPE ","
1280                 G_FILE_ATTRIBUTE_ACCESS_CAN_EXECUTE;
1281       info = g_file_query_info (file,
1282                                 attrs,
1283                                 G_FILE_QUERY_INFO_NONE,
1284                                 NULL,
1285                                 NULL);
1286       if (info)
1287         {
1288           result = TRUE;
1289
1290           if (matchlet->type != G_FILE_TYPE_UNKNOWN &&
1291               g_file_info_get_file_type (info) != matchlet->type)
1292             result = FALSE;
1293
1294           if (matchlet->executable &&
1295               !g_file_info_get_attribute_boolean (info, G_FILE_ATTRIBUTE_ACCESS_CAN_EXECUTE))
1296             result = FALSE;
1297         }
1298       else
1299         result = FALSE;
1300
1301       if (result && matchlet->non_empty)
1302         {
1303           GFileEnumerator *child_enum;
1304           GFileInfo *child_info;
1305
1306           child_enum = g_file_enumerate_children (file,
1307                                                   G_FILE_ATTRIBUTE_STANDARD_NAME,
1308                                                   G_FILE_QUERY_INFO_NONE,
1309                                                   NULL,
1310                                                   NULL);
1311
1312           if (child_enum)
1313             {
1314               child_info = g_file_enumerator_next_file (child_enum, NULL, NULL);
1315               if (child_info)
1316                 g_object_unref (child_info);
1317               else
1318                 result = FALSE;
1319               g_object_unref (child_enum);
1320             }
1321           else
1322             result = FALSE;
1323         }
1324
1325       if (result && matchlet->mimetype)
1326         {
1327           if (strcmp (matchlet->mimetype, g_file_info_get_content_type (info)) != 0)
1328             result = FALSE;
1329         }
1330
1331       g_object_unref (info);
1332       g_object_unref (file);
1333     }
1334   while (!result);
1335
1336   enumerator_free (e);
1337
1338   if (!matchlet->matches)
1339     return TRUE;
1340
1341   for (l = matchlet->matches; l; l = l->next)
1342     {
1343       TreeMatchlet *submatchlet;
1344
1345       submatchlet = l->data;
1346       if (matchlet_match (submatchlet, root))
1347         return TRUE;
1348     }
1349
1350   return FALSE;
1351 }
1352
1353 static void
1354 match_match (TreeMatch    *match,
1355              GFile        *root,
1356              GPtrArray    *types)
1357 {
1358   GList *l;
1359
1360   for (l = match->matches; l; l = l->next)
1361     {
1362       TreeMatchlet *matchlet = l->data;
1363       if (matchlet_match (matchlet, root))
1364         {
1365           g_ptr_array_add (types, g_strdup (match->contenttype));
1366           break;
1367         }
1368     }
1369 }
1370
1371 /**
1372  * g_content_type_guess_for_tree:
1373  * @root: the root of the tree to guess a type for
1374  *
1375  * Tries to guess the type of the tree with root @root, by
1376  * looking at the files it contains. The result is an array
1377  * of content types, with the best guess coming first.
1378  *
1379  * The types returned all have the form x-content/foo, e.g.
1380  * x-content/audio-cdda (for audio CDs) or x-content/image-dcf
1381  * (for a camera memory card). See the <ulink url="http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec">shared-mime-info</ulink>
1382  * specification for more on x-content types.
1383  *
1384  * This function is useful in the implementation of
1385  * g_mount_guess_content_type().
1386  *
1387  * Returns: (transfer full) (array zero-terminated=1): an %NULL-terminated
1388  *     array of zero or more content types. Free with g_strfreev()
1389  *
1390  * Since: 2.18
1391  */
1392 gchar **
1393 g_content_type_guess_for_tree (GFile *root)
1394 {
1395   GPtrArray *types;
1396   GList *l;
1397
1398   types = g_ptr_array_new ();
1399
1400   G_LOCK (gio_treemagic);
1401
1402   tree_magic_init ();
1403   for (l = tree_matches; l; l = l->next)
1404     {
1405       TreeMatch *match = l->data;
1406       match_match (match, root, types);
1407     }
1408
1409   G_UNLOCK (gio_treemagic);
1410
1411   g_ptr_array_add (types, NULL);
1412
1413   return (gchar **)g_ptr_array_free (types, FALSE);
1414 }