1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright (C) 2006-2007 Red Hat, Inc.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
18 * Boston, MA 02111-1307, USA.
20 * Author: Alexander Larsson <alexl@redhat.com>
27 #include "giomodule.h"
28 #include "giomodule-priv.h"
29 #include "glocalfilemonitor.h"
30 #include "glocaldirectorymonitor.h"
31 #include "gnativevolumemonitor.h"
32 #include "gproxyresolver.h"
34 #include "gsettingsbackendinternal.h"
35 #include "gsocks4proxy.h"
36 #include "gsocks4aproxy.h"
37 #include "gsocks5proxy.h"
38 #include "gtlsbackend.h"
41 #include "gregistrysettingsbackend.h"
43 #include <glib/gstdio.h>
45 #undef G_DISABLE_DEPRECATED
48 #include "gdesktopappinfo.h"
53 * @short_description: Loadable GIO Modules
56 * Provides an interface and default functions for loading and unloading
57 * modules. This is used internally to make GIO extensible, but can also
58 * be used by others to implement module loading.
63 * SECTION:extensionpoints
64 * @short_description: Extension Points
66 * @see_also: <link linkend="extending-gio">Extending GIO</link>
68 * #GIOExtensionPoint provides a mechanism for modules to extend the
69 * functionality of the library or application that loaded it in an
72 * An extension point is identified by a name, and it may optionally
73 * require that any implementation must by of a certain type (or derived
74 * thereof). Use g_io_extension_point_register() to register an
75 * extension point, and g_io_extension_point_set_required_type() to
76 * set a required type.
78 * A module can implement an extension point by specifying the #GType
79 * that implements the functionality. Additionally, each implementation
80 * of an extension point has a name, and a priority. Use
81 * g_io_extension_point_implement() to implement an extension point.
84 * GIOExtensionPoint *ep;
86 * /* Register an extension point */
87 * ep = g_io_extension_point_register ("my-extension-point");
88 * g_io_extension_point_set_required_type (ep, MY_TYPE_EXAMPLE);
92 * /* Implement an extension point */
93 * G_DEFINE_TYPE (MyExampleImpl, my_example_impl, MY_TYPE_EXAMPLE);
94 * g_io_extension_point_implement ("my-extension-point",
95 * my_example_impl_get_type (),
100 * It is up to the code that registered the extension point how
101 * it uses the implementations that have been associated with it.
102 * Depending on the use case, it may use all implementations, or
103 * only the one with the highest priority, or pick a specific
106 * To avoid opening all modules just to find out what extension
107 * points they implement, GIO makes use of a caching mechanism,
108 * see <link linkend="gio-querymodules">gio-querymodules</link>.
109 * You are expected to run this command after installing a
112 * The <envar>GIO_EXTRA_MODULES</envar> environment variable can be
113 * used to specify additional directories to automatically load modules
114 * from. This environment variable has the same syntax as the
115 * <envar>PATH</envar>. If two modules have the same base name in different
116 * directories, then the latter one will be ignored. If additional
117 * directories are specified GIO will load modules from the built-in
124 * Represents a scope for loading IO modules. A scope can be used for blocking
125 * duplicate modules, or blocking a module you don't want to load.
127 * The scope can be used with g_io_modules_load_all_in_directory_with_scope()
128 * or g_io_modules_scan_all_in_directory_with_scope().
132 struct _GIOModuleScope {
133 GIOModuleScopeFlags flags;
134 GHashTable *basenames;
138 * g_io_module_scope_new:
139 * @flags: flags for the new scope
141 * Create a new scope for loading of IO modules. A scope can be used for
142 * blocking duplicate modules, or blocking a module you don't want to load.
144 * Specify the %G_IO_MODULES_SCOPE_BLOCK_DUPLICATES flag to block modules
145 * which have the same base name as a module that has already been seen
148 * Returns: (transfer full): the new module scope
153 g_io_module_scope_new (GIOModuleScopeFlags flags)
155 GIOModuleScope *scope = g_new0 (GIOModuleScope, 1);
156 scope->flags = flags;
157 scope->basenames = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
162 * g_io_module_scope_free:
163 * @scope: a module loading scope
165 * Free a module scope.
170 g_io_module_scope_free (GIOModuleScope *scope)
174 g_hash_table_destroy (scope->basenames);
179 * g_io_module_scope_block:
180 * @scope: a module loading scope
182 * Block modules with the given base name from being loaded when this scope
183 * is used with g_io_modules_scan_all_in_directory_with_scope() or
184 * g_io_modules_load_all_in_directory_with_scope().
189 g_io_module_scope_block (GIOModuleScope *scope,
190 const gchar *basename)
194 g_return_if_fail (scope != NULL);
195 g_return_if_fail (basename != NULL);
197 key = g_strdup (basename);
198 g_hash_table_insert (scope->basenames, key, key);
202 _g_io_module_scope_contains (GIOModuleScope *scope,
203 const gchar *basename)
205 return g_hash_table_lookup (scope->basenames, basename) ? TRUE : FALSE;
209 GTypeModule parent_instance;
213 gboolean initialized; /* The module was loaded at least once */
215 void (* load) (GIOModule *module);
216 void (* unload) (GIOModule *module);
219 struct _GIOModuleClass
221 GTypeModuleClass parent_class;
225 static void g_io_module_finalize (GObject *object);
226 static gboolean g_io_module_load_module (GTypeModule *gmodule);
227 static void g_io_module_unload_module (GTypeModule *gmodule);
229 struct _GIOExtension {
235 struct _GIOExtensionPoint {
239 GList *lazy_load_modules;
242 static GHashTable *extension_points = NULL;
243 G_LOCK_DEFINE_STATIC(extension_points);
245 G_DEFINE_TYPE (GIOModule, g_io_module, G_TYPE_TYPE_MODULE);
248 g_io_module_class_init (GIOModuleClass *class)
250 GObjectClass *object_class = G_OBJECT_CLASS (class);
251 GTypeModuleClass *type_module_class = G_TYPE_MODULE_CLASS (class);
253 object_class->finalize = g_io_module_finalize;
255 type_module_class->load = g_io_module_load_module;
256 type_module_class->unload = g_io_module_unload_module;
260 g_io_module_init (GIOModule *module)
265 g_io_module_finalize (GObject *object)
267 GIOModule *module = G_IO_MODULE (object);
269 g_free (module->filename);
271 G_OBJECT_CLASS (g_io_module_parent_class)->finalize (object);
275 g_io_module_load_module (GTypeModule *gmodule)
277 GIOModule *module = G_IO_MODULE (gmodule);
279 if (!module->filename)
281 g_warning ("GIOModule path not set");
285 module->library = g_module_open (module->filename, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
287 if (!module->library)
289 g_printerr ("%s\n", g_module_error ());
293 /* Make sure that the loaded library contains the required methods */
294 if (! g_module_symbol (module->library,
296 (gpointer) &module->load) ||
297 ! g_module_symbol (module->library,
298 "g_io_module_unload",
299 (gpointer) &module->unload))
301 g_printerr ("%s\n", g_module_error ());
302 g_module_close (module->library);
307 /* Initialize the loaded module */
308 module->load (module);
309 module->initialized = TRUE;
315 g_io_module_unload_module (GTypeModule *gmodule)
317 GIOModule *module = G_IO_MODULE (gmodule);
319 module->unload (module);
321 g_module_close (module->library);
322 module->library = NULL;
325 module->unload = NULL;
330 * @filename: filename of the shared library module.
332 * Creates a new GIOModule that will load the specific
333 * shared library when in use.
335 * Returns: a #GIOModule from given @filename,
339 g_io_module_new (const gchar *filename)
343 g_return_val_if_fail (filename != NULL, NULL);
345 module = g_object_new (G_IO_TYPE_MODULE, NULL);
346 module->filename = g_strdup (filename);
352 is_valid_module_name (const gchar *basename,
353 GIOModuleScope *scope)
357 #if !defined(G_OS_WIN32) && !defined(G_WITH_CYGWIN)
358 if (!g_str_has_prefix (basename, "lib") ||
359 !g_str_has_suffix (basename, ".so"))
362 if (!g_str_has_suffix (basename, ".dll"))
369 result = _g_io_module_scope_contains (scope, basename) ? FALSE : TRUE;
370 if (result && (scope->flags & G_IO_MODULE_SCOPE_BLOCK_DUPLICATES))
371 g_io_module_scope_block (scope, basename);
379 * g_io_modules_scan_all_in_directory_with_scope:
380 * @dirname: pathname for a directory containing modules to scan.
381 * @scope: a scope to use when scanning the modules
383 * Scans all the modules in the specified directory, ensuring that
384 * any extension point implemented by a module is registered.
386 * This may not actually load and initialize all the types in each
387 * module, some modules may be lazily loaded and initialized when
388 * an extension point it implementes is used with e.g.
389 * g_io_extension_point_get_extensions() or
390 * g_io_extension_point_get_extension_by_name().
392 * If you need to guarantee that all types are loaded in all the modules,
393 * use g_io_modules_load_all_in_directory().
398 g_io_modules_scan_all_in_directory_with_scope (const char *dirname,
399 GIOModuleScope *scope)
409 if (!g_module_supported ())
412 dir = g_dir_open (dirname, 0, NULL);
416 filename = g_build_filename (dirname, "giomodule.cache", NULL);
418 cache = g_hash_table_new_full (g_str_hash, g_str_equal,
419 g_free, (GDestroyNotify)g_strfreev);
422 if (g_stat (filename, &statbuf) == 0 &&
423 g_file_get_contents (filename, &data, NULL, NULL))
428 /* Cache mtime is the time the cache file was created, any file
429 * that has a ctime before this was created then and not modified
430 * since then (userspace can't change ctime). Its possible to change
431 * the ctime forward without changing the file content, by e.g.
432 * chmoding the file, but this is uncommon and will only cause us
433 * to not use the cache so will not cause bugs.
435 cache_mtime = statbuf.st_mtime;
437 lines = g_strsplit (data, "\n", -1);
440 for (i = 0; lines[i] != NULL; i++)
442 char *line = lines[i];
445 char **extension_points;
450 colon = strchr (line, ':');
451 if (colon == NULL || line == colon)
452 continue; /* Invalid line, ignore */
454 *colon = 0; /* terminate filename */
455 file = g_strdup (line);
456 colon++; /* after colon */
458 while (g_ascii_isspace (*colon))
461 extension_points = g_strsplit (colon, ",", -1);
462 g_hash_table_insert (cache, file, extension_points);
467 while ((name = g_dir_read_name (dir)))
469 if (is_valid_module_name (name, scope))
471 GIOExtensionPoint *extension_point;
474 char **extension_points;
477 path = g_build_filename (dirname, name, NULL);
478 module = g_io_module_new (path);
480 extension_points = g_hash_table_lookup (cache, name);
481 if (extension_points != NULL &&
482 g_stat (path, &statbuf) == 0 &&
483 statbuf.st_ctime <= cache_mtime)
485 /* Lazy load/init the library when first required */
486 for (i = 0; extension_points[i] != NULL; i++)
489 g_io_extension_point_register (extension_points[i]);
490 extension_point->lazy_load_modules =
491 g_list_prepend (extension_point->lazy_load_modules,
497 /* Try to load and init types */
498 if (g_type_module_use (G_TYPE_MODULE (module)))
499 g_type_module_unuse (G_TYPE_MODULE (module)); /* Unload */
501 { /* Failure to load */
502 g_printerr ("Failed to load module: %s\n", path);
503 g_object_unref (module);
515 g_hash_table_destroy (cache);
521 * g_io_modules_scan_all_in_directory:
522 * @dirname: pathname for a directory containing modules to scan.
524 * Scans all the modules in the specified directory, ensuring that
525 * any extension point implemented by a module is registered.
527 * This may not actually load and initialize all the types in each
528 * module, some modules may be lazily loaded and initialized when
529 * an extension point it implementes is used with e.g.
530 * g_io_extension_point_get_extensions() or
531 * g_io_extension_point_get_extension_by_name().
533 * If you need to guarantee that all types are loaded in all the modules,
534 * use g_io_modules_load_all_in_directory().
539 g_io_modules_scan_all_in_directory (const char *dirname)
541 g_io_modules_scan_all_in_directory_with_scope (dirname, NULL);
545 * g_io_modules_load_all_in_directory_with_scope:
546 * @dirname: pathname for a directory containing modules to load.
547 * @scope: a scope to use when scanning the modules.
549 * Loads all the modules in the specified directory.
551 * If don't require all modules to be initialized (and thus registering
552 * all gtypes) then you can use g_io_modules_scan_all_in_directory()
553 * which allows delayed/lazy loading of modules.
555 * Returns: (element-type GIOModule) (transfer full): a list of #GIOModules loaded
556 * from the directory,
557 * All the modules are loaded into memory, if you want to
558 * unload them (enabling on-demand loading) you must call
559 * g_type_module_unuse() on all the modules. Free the list
560 * with g_list_free().
565 g_io_modules_load_all_in_directory_with_scope (const char *dirname,
566 GIOModuleScope *scope)
572 if (!g_module_supported ())
575 dir = g_dir_open (dirname, 0, NULL);
580 while ((name = g_dir_read_name (dir)))
582 if (is_valid_module_name (name, scope))
587 path = g_build_filename (dirname, name, NULL);
588 module = g_io_module_new (path);
590 if (!g_type_module_use (G_TYPE_MODULE (module)))
592 g_printerr ("Failed to load module: %s\n", path);
593 g_object_unref (module);
600 modules = g_list_prepend (modules, module);
610 * g_io_modules_load_all_in_directory:
611 * @dirname: pathname for a directory containing modules to load.
613 * Loads all the modules in the specified directory.
615 * If don't require all modules to be initialized (and thus registering
616 * all gtypes) then you can use g_io_modules_scan_all_in_directory()
617 * which allows delayed/lazy loading of modules.
619 * Returns: (element-type GIOModule) (transfer full): a list of #GIOModules loaded
620 * from the directory,
621 * All the modules are loaded into memory, if you want to
622 * unload them (enabling on-demand loading) you must call
623 * g_type_module_unuse() on all the modules. Free the list
624 * with g_list_free().
627 g_io_modules_load_all_in_directory (const char *dirname)
629 return g_io_modules_load_all_in_directory_with_scope (dirname, NULL);
632 G_LOCK_DEFINE_STATIC (registered_extensions);
633 G_LOCK_DEFINE_STATIC (loaded_dirs);
635 extern GType _g_fen_directory_monitor_get_type (void);
636 extern GType _g_fen_file_monitor_get_type (void);
637 extern GType _g_inotify_directory_monitor_get_type (void);
638 extern GType _g_inotify_file_monitor_get_type (void);
639 extern GType _g_unix_volume_monitor_get_type (void);
640 extern GType _g_local_vfs_get_type (void);
642 extern GType _g_win32_volume_monitor_get_type (void);
643 extern GType g_win32_directory_monitor_get_type (void);
644 extern GType _g_winhttp_vfs_get_type (void);
646 extern GType _g_dummy_proxy_resolver_get_type (void);
647 extern GType _g_dummy_tls_backend_get_type (void);
649 #ifdef G_PLATFORM_WIN32
653 static HMODULE gio_dll = NULL;
658 DllMain (HINSTANCE hinstDLL,
662 if (fdwReason == DLL_PROCESS_ATTACH)
670 #undef GIO_MODULE_DIR
672 /* GIO_MODULE_DIR is used only in code called just once,
673 * so no problem leaking this
675 #define GIO_MODULE_DIR \
676 g_build_filename (g_win32_get_package_installation_directory_of_module (gio_dll), \
683 _g_io_modules_ensure_extension_points_registered (void)
685 static gboolean registered_extensions = FALSE;
686 GIOExtensionPoint *ep;
688 G_LOCK (registered_extensions);
690 if (!registered_extensions)
692 registered_extensions = TRUE;
695 #if !GLIB_CHECK_VERSION (3, 0, 0)
696 ep = g_io_extension_point_register (G_DESKTOP_APP_INFO_LOOKUP_EXTENSION_POINT_NAME);
697 g_io_extension_point_set_required_type (ep, G_TYPE_DESKTOP_APP_INFO_LOOKUP);
701 ep = g_io_extension_point_register (G_LOCAL_DIRECTORY_MONITOR_EXTENSION_POINT_NAME);
702 g_io_extension_point_set_required_type (ep, G_TYPE_LOCAL_DIRECTORY_MONITOR);
704 ep = g_io_extension_point_register (G_LOCAL_FILE_MONITOR_EXTENSION_POINT_NAME);
705 g_io_extension_point_set_required_type (ep, G_TYPE_LOCAL_FILE_MONITOR);
707 ep = g_io_extension_point_register (G_VOLUME_MONITOR_EXTENSION_POINT_NAME);
708 g_io_extension_point_set_required_type (ep, G_TYPE_VOLUME_MONITOR);
710 ep = g_io_extension_point_register (G_NATIVE_VOLUME_MONITOR_EXTENSION_POINT_NAME);
711 g_io_extension_point_set_required_type (ep, G_TYPE_NATIVE_VOLUME_MONITOR);
713 ep = g_io_extension_point_register (G_VFS_EXTENSION_POINT_NAME);
714 g_io_extension_point_set_required_type (ep, G_TYPE_VFS);
716 ep = g_io_extension_point_register ("gsettings-backend");
717 g_io_extension_point_set_required_type (ep, G_TYPE_OBJECT);
719 ep = g_io_extension_point_register (G_PROXY_RESOLVER_EXTENSION_POINT_NAME);
720 g_io_extension_point_set_required_type (ep, G_TYPE_PROXY_RESOLVER);
722 ep = g_io_extension_point_register (G_PROXY_EXTENSION_POINT_NAME);
723 g_io_extension_point_set_required_type (ep, G_TYPE_PROXY);
725 ep = g_io_extension_point_register (G_TLS_BACKEND_EXTENSION_POINT_NAME);
726 g_io_extension_point_set_required_type (ep, G_TYPE_TLS_BACKEND);
729 G_UNLOCK (registered_extensions);
733 _g_io_modules_ensure_loaded (void)
735 static gboolean loaded_dirs = FALSE;
736 const char *module_path;
737 GIOModuleScope *scope;
739 _g_io_modules_ensure_extension_points_registered ();
741 G_LOCK (loaded_dirs);
746 scope = g_io_module_scope_new (G_IO_MODULE_SCOPE_BLOCK_DUPLICATES);
748 /* First load any overrides, extras */
749 module_path = g_getenv ("GIO_EXTRA_MODULES");
755 paths = g_strsplit (module_path, ":", 0);
757 for (i = 0; paths[i] != NULL; i++)
759 g_io_modules_scan_all_in_directory_with_scope (paths[i], scope);
765 /* Then load the compiled in path */
766 g_io_modules_scan_all_in_directory_with_scope (GIO_MODULE_DIR, scope);
768 g_io_module_scope_free (scope);
770 /* Initialize types from built-in "modules" */
771 g_null_settings_backend_get_type ();
772 g_memory_settings_backend_get_type ();
773 #if defined(HAVE_SYS_INOTIFY_H) || defined(HAVE_LINUX_INOTIFY_H)
774 _g_inotify_directory_monitor_get_type ();
775 _g_inotify_file_monitor_get_type ();
777 #if defined(HAVE_FEN)
778 _g_fen_directory_monitor_get_type ();
779 _g_fen_file_monitor_get_type ();
782 _g_win32_volume_monitor_get_type ();
783 g_win32_directory_monitor_get_type ();
784 g_registry_backend_get_type ();
787 _g_unix_volume_monitor_get_type ();
790 _g_winhttp_vfs_get_type ();
792 _g_local_vfs_get_type ();
793 _g_dummy_proxy_resolver_get_type ();
794 _g_socks4a_proxy_get_type ();
795 _g_socks4_proxy_get_type ();
796 _g_socks5_proxy_get_type ();
797 _g_dummy_tls_backend_get_type ();
800 G_UNLOCK (loaded_dirs);
804 g_io_extension_point_free (GIOExtensionPoint *ep)
811 * g_io_extension_point_register:
812 * @name: The name of the extension point
814 * Registers an extension point.
816 * Returns: (transfer none): the new #GIOExtensionPoint. This object is
817 * owned by GIO and should not be freed.
820 g_io_extension_point_register (const char *name)
822 GIOExtensionPoint *ep;
824 G_LOCK (extension_points);
825 if (extension_points == NULL)
826 extension_points = g_hash_table_new_full (g_str_hash,
829 (GDestroyNotify)g_io_extension_point_free);
831 ep = g_hash_table_lookup (extension_points, name);
834 G_UNLOCK (extension_points);
838 ep = g_new0 (GIOExtensionPoint, 1);
839 ep->name = g_strdup (name);
841 g_hash_table_insert (extension_points, ep->name, ep);
843 G_UNLOCK (extension_points);
849 * g_io_extension_point_lookup:
850 * @name: the name of the extension point
852 * Looks up an existing extension point.
854 * Returns: (transfer none): the #GIOExtensionPoint, or %NULL if there
855 * is no registered extension point with the given name.
858 g_io_extension_point_lookup (const char *name)
860 GIOExtensionPoint *ep;
862 G_LOCK (extension_points);
864 if (extension_points != NULL)
865 ep = g_hash_table_lookup (extension_points, name);
867 G_UNLOCK (extension_points);
874 * g_io_extension_point_set_required_type:
875 * @extension_point: a #GIOExtensionPoint
876 * @type: the #GType to require
878 * Sets the required type for @extension_point to @type.
879 * All implementations must henceforth have this type.
882 g_io_extension_point_set_required_type (GIOExtensionPoint *extension_point,
885 extension_point->required_type = type;
889 * g_io_extension_point_get_required_type:
890 * @extension_point: a #GIOExtensionPoint
892 * Gets the required type for @extension_point.
894 * Returns: the #GType that all implementations must have,
895 * or #G_TYPE_INVALID if the extension point has no required type
898 g_io_extension_point_get_required_type (GIOExtensionPoint *extension_point)
900 return extension_point->required_type;
904 lazy_load_modules (GIOExtensionPoint *extension_point)
909 for (l = extension_point->lazy_load_modules; l != NULL; l = l->next)
913 if (!module->initialized)
915 if (g_type_module_use (G_TYPE_MODULE (module)))
916 g_type_module_unuse (G_TYPE_MODULE (module)); /* Unload */
918 g_printerr ("Failed to load module: %s\n",
925 * g_io_extension_point_get_extensions:
926 * @extension_point: a #GIOExtensionPoint
928 * Gets a list of all extensions that implement this extension point.
929 * The list is sorted by priority, beginning with the highest priority.
931 * Returns: (element-type GIOExtension) (transfer none): a #GList of
932 * #GIOExtension<!-- -->s. The list is owned by GIO and should not be
936 g_io_extension_point_get_extensions (GIOExtensionPoint *extension_point)
938 lazy_load_modules (extension_point);
939 return extension_point->extensions;
943 * g_io_extension_point_get_extension_by_name:
944 * @extension_point: a #GIOExtensionPoint
945 * @name: the name of the extension to get
947 * Finds a #GIOExtension for an extension point by name.
949 * Returns: (transfer none): the #GIOExtension for @extension_point that has the
950 * given name, or %NULL if there is no extension with that name
953 g_io_extension_point_get_extension_by_name (GIOExtensionPoint *extension_point,
958 lazy_load_modules (extension_point);
959 for (l = extension_point->extensions; l != NULL; l = l->next)
961 GIOExtension *e = l->data;
963 if (e->name != NULL &&
964 strcmp (e->name, name) == 0)
972 extension_prio_compare (gconstpointer a,
975 const GIOExtension *extension_a = a, *extension_b = b;
977 if (extension_a->priority > extension_b->priority)
980 if (extension_b->priority > extension_a->priority)
987 * g_io_extension_point_implement:
988 * @extension_point_name: the name of the extension point
989 * @type: the #GType to register as extension
990 * @extension_name: the name for the extension
991 * @priority: the priority for the extension
993 * Registers @type as extension for the extension point with name
994 * @extension_point_name.
996 * If @type has already been registered as an extension for this
997 * extension point, the existing #GIOExtension object is returned.
999 * Returns: (transfer none): a #GIOExtension object for #GType
1002 g_io_extension_point_implement (const char *extension_point_name,
1004 const char *extension_name,
1007 GIOExtensionPoint *extension_point;
1008 GIOExtension *extension;
1011 g_return_val_if_fail (extension_point_name != NULL, NULL);
1013 extension_point = g_io_extension_point_lookup (extension_point_name);
1014 if (extension_point == NULL)
1016 g_warning ("Tried to implement non-registered extension point %s", extension_point_name);
1020 if (extension_point->required_type != 0 &&
1021 !g_type_is_a (type, extension_point->required_type))
1023 g_warning ("Tried to register an extension of the type %s to extension point %s. "
1024 "Expected type is %s.",
1026 extension_point_name,
1027 g_type_name (extension_point->required_type));
1031 /* It's safe to register the same type multiple times */
1032 for (l = extension_point->extensions; l != NULL; l = l->next)
1034 extension = l->data;
1035 if (extension->type == type)
1039 extension = g_slice_new0 (GIOExtension);
1040 extension->type = type;
1041 extension->name = g_strdup (extension_name);
1042 extension->priority = priority;
1044 extension_point->extensions = g_list_insert_sorted (extension_point->extensions,
1045 extension, extension_prio_compare);
1051 * g_io_extension_ref_class:
1052 * @extension: a #GIOExtension
1054 * Gets a reference to the class for the type that is
1055 * associated with @extension.
1057 * Returns: (transfer full): the #GTypeClass for the type of @extension
1060 g_io_extension_ref_class (GIOExtension *extension)
1062 return g_type_class_ref (extension->type);
1066 * g_io_extension_get_type:
1067 * @extension: a #GIOExtension
1069 * Gets the type associated with @extension.
1071 * Returns: the type of @extension
1074 g_io_extension_get_type (GIOExtension *extension)
1076 return extension->type;
1080 * g_io_extension_get_name:
1081 * @extension: a #GIOExtension
1083 * Gets the name under which @extension was registered.
1085 * Note that the same type may be registered as extension
1086 * for multiple extension points, under different names.
1088 * Returns: the name of @extension.
1091 g_io_extension_get_name (GIOExtension *extension)
1093 return extension->name;
1097 * g_io_extension_get_priority:
1098 * @extension: a #GIOExtension
1100 * Gets the priority with which @extension was registered.
1102 * Returns: the priority of @extension
1105 g_io_extension_get_priority (GIOExtension *extension)
1107 return extension->priority;