2 * Copyright © 2010 Codethink Limited
3 * Copyright © 2011 Canonical Limited
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 licence, 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 Public
16 * 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.
23 #include "gsettingsschema-internal.h"
24 #include "gsettings.h"
26 #include "gvdb/gvdb-reader.h"
34 * SECTION:gsettingsschema
35 * @short_description: introspecting and controlling the loading of
38 * The #GSettingsSchemaSource and #GSettingsSchema APIs provide a
39 * mechanism for advanced control over the loading of schemas and a
40 * mechanism for introspecting their content.
42 * Plugin loading systems that wish to provide plugins a way to access
43 * settings face the problem of how to make the schemas for these
44 * settings visible to GSettings. Typically, a plugin will want to ship
45 * the schema along with itself and it won't be installed into the
46 * standard system directories for schemas.
48 * #GSettingsSchemaSource provides a mechanism for dealing with this by
49 * allowing the creation of a new 'schema source' from which schemas can
50 * be acquired. This schema source can then become part of the metadata
51 * associated with the plugin and queried whenever the plugin requires
52 * access to some settings.
54 * Consider the following example:
60 * GSettingsSchemaSource *schema_source;
65 * initialise_plugin (const gchar *dir)
71 * plugin->schema_source =
72 * g_settings_new_schema_source_from_directory (dir,
73 * g_settings_schema_source_get_default (), FALSE, NULL);
83 * plugin_get_settings (Plugin *plugin,
84 * const gchar *schema_id)
86 * GSettingsSchema *schema;
88 * if (schema_id == NULL)
89 * schema_id = plugin->identifier;
91 * schema = g_settings_schema_source_lookup (plugin->schema_source,
96 * ... disable the plugin or abort, etc ...
99 * return g_settings_new_full (schema, NULL, NULL);
103 * The code above shows how hooks should be added to the code that
104 * initialises (or enables) the plugin to create the schema source and
105 * how an API can be added to the plugin system to provide a convenient
106 * way for the plugin to access its settings, using the schemas that it
109 * From the standpoint of the plugin, it would need to ensure that it
110 * ships a gschemas.compiled file as part of itself, and then simply do
115 * GSettings *settings;
118 * settings = plugin_get_settings (self, NULL);
119 * some_value = g_settings_get_int (settings, "some-value");
124 * It's also possible that the plugin system expects the schema source
125 * files (ie: .gschema.xml files) instead of a gschemas.compiled file.
126 * In that case, the plugin loading system must compile the schemas for
127 * itself before attempting to create the settings source.
135 * This is an opaque structure type. You may not access it directly.
139 struct _GSettingsSchema
141 const gchar
*gettext_domain
;
152 * G_TYPE_SETTINGS_SCHEMA_SOURCE:
154 * A boxed #GType corresponding to #GSettingsSchemaSource.
158 G_DEFINE_BOXED_TYPE (GSettingsSchemaSource
, g_settings_schema_source
, g_settings_schema_source_ref
, g_settings_schema_source_unref
)
161 * G_TYPE_SETTINGS_SCHEMA:
163 * A boxed #GType corresponding to #GSettingsSchema.
167 G_DEFINE_BOXED_TYPE (GSettingsSchema
, g_settings_schema
, g_settings_schema_ref
, g_settings_schema_unref
)
170 * GSettingsSchemaSource:
172 * This is an opaque structure type. You may not access it directly.
176 struct _GSettingsSchemaSource
178 GSettingsSchemaSource
*parent
;
184 static GSettingsSchemaSource
*schema_sources
;
187 prepend_schema_table (GvdbTable
*table
)
189 GSettingsSchemaSource
*source
;
191 /* we steal the reference from 'schema_sources' for our ->parent */
192 source
= g_slice_new (GSettingsSchemaSource
);
193 source
->parent
= schema_sources
;
194 source
->table
= table
;
195 source
->ref_count
= 1;
197 schema_sources
= source
;
201 * g_settings_schema_source_ref:
202 * @source: a #GSettingsSchemaSource
204 * Increase the reference count of @source, returning a new reference.
206 * Returns: a new reference to @source
210 GSettingsSchemaSource
*
211 g_settings_schema_source_ref (GSettingsSchemaSource
*source
)
213 g_atomic_int_inc (&source
->ref_count
);
219 * g_settings_schema_source_unref:
220 * @source: a #GSettingsSchemaSource
222 * Decrease the reference count of @source, possibly freeing it.
227 g_settings_schema_source_unref (GSettingsSchemaSource
*source
)
229 if (g_atomic_int_dec_and_test (&source
->ref_count
))
231 if (source
== schema_sources
)
232 g_error ("g_settings_schema_source_unref() called too many times on the default schema source");
235 g_settings_schema_source_unref (source
->parent
);
236 gvdb_table_unref (source
->table
);
238 g_slice_free (GSettingsSchemaSource
, source
);
243 * g_settings_schema_source_new_from_directory:
244 * @directory: the filename of a directory
245 * @parent: (allow-none): a #GSettingsSchemaSource, or %NULL
246 * @trusted: %TRUE, if the directory is trusted
247 * @error: a pointer to a #GError pointer set to %NULL, or %NULL
249 * Attempts to create a new schema source corresponding to the contents
250 * of the given directory.
252 * This function is not required for normal uses of #GSettings but it
253 * may be useful to authors of plugin management systems.
255 * The directory should contain a file called
256 * <filename>gschemas.compiled</filename> as produced by
257 * <command>glib-compile-schemas</command>.
259 * If @trusted is %TRUE then <filename>gschemas.compiled</filename> is
260 * trusted not to be corrupted. This assumption has a performance
261 * advantage, but can result in crashes or inconsistent behaviour in the
262 * case of a corrupted file. Generally, you should set @trusted to
263 * %TRUE for files installed by the system and to %FALSE for files in
264 * the home directory.
266 * If @parent is non-%NULL then there are two effects.
268 * First, if g_settings_schema_source_lookup() is called with the
269 * @recursive flag set to %TRUE and the schema can not be found in the
270 * source, the lookup will recurse to the parent.
272 * Second, any references to other schemas specified within this
273 * source (ie: <literal>child</literal> or <literal>extents</literal>)
274 * references may be resolved from the @parent.
276 * For this second reason, except in very unusual situations, the
277 * @parent should probably be given as the default schema source, as
278 * returned by g_settings_schema_source_get_default().
282 GSettingsSchemaSource
*
283 g_settings_schema_source_new_from_directory (const gchar
*directory
,
284 GSettingsSchemaSource
*parent
,
288 GSettingsSchemaSource
*source
;
292 filename
= g_build_filename (directory
, "gschemas.compiled", NULL
);
293 table
= gvdb_table_new (filename
, trusted
, error
);
299 source
= g_slice_new (GSettingsSchemaSource
);
300 source
->parent
= parent
? g_settings_schema_source_ref (parent
) : NULL
;
301 source
->table
= table
;
302 source
->ref_count
= 1;
308 initialise_schema_sources (void)
310 static gsize initialised
;
312 /* need a separate variable because 'schema_sources' may legitimately
313 * be null if we have zero valid schema sources
315 if G_UNLIKELY (g_once_init_enter (&initialised
))
317 const gchar
* const *dirs
;
321 /* iterate in reverse: count up, then count down */
322 dirs
= g_get_system_data_dirs ();
323 for (i
= 0; dirs
[i
]; i
++);
330 filename
= g_build_filename (dirs
[i
], "glib-2.0", "schemas", "gschemas.compiled", NULL
);
331 table
= gvdb_table_new (filename
, TRUE
, NULL
);
334 prepend_schema_table (table
);
339 if ((path
= g_getenv ("GSETTINGS_SCHEMA_DIR")) != NULL
)
344 filename
= g_build_filename (path
, "gschemas.compiled", NULL
);
345 table
= gvdb_table_new (filename
, TRUE
, NULL
);
348 prepend_schema_table (table
);
353 g_once_init_leave (&initialised
, TRUE
);
358 * g_settings_schema_source_get_default:
360 * Gets the default system schema source.
362 * This function is not required for normal uses of #GSettings but it
363 * may be useful to authors of plugin management systems or to those who
364 * want to introspect the content of schemas.
366 * If no schemas are installed, %NULL will be returned.
368 * The returned source may actually consist of multiple schema sources
369 * from different directories, depending on which directories were given
370 * in <envar>XDG_DATA_DIRS</envar> and
371 * <envar>GSETTINGS_SCHEMA_DIR</envar>. For this reason, all lookups
372 * performed against the default source should probably be done
375 * Returns: (transfer none): the default schema source
379 GSettingsSchemaSource
*
380 g_settings_schema_source_get_default (void)
382 initialise_schema_sources ();
384 return schema_sources
;
388 * g_settings_schema_source_lookup:
389 * @source: a #GSettingsSchemaSource
390 * @schema_id: a schema ID
391 * @recursive: %TRUE if the lookup should be recursive
393 * Looks up a schema with the identifier @schema_id in @source.
395 * This function is not required for normal uses of #GSettings but it
396 * may be useful to authors of plugin management systems or to those who
397 * want to introspect the content of schemas.
399 * If the schema isn't found directly in @source and @recursive is %TRUE
400 * then the parent sources will also be checked.
402 * If the schema isn't found, %NULL is returned.
404 * Returns: (transfer full): a new #GSettingsSchema
409 g_settings_schema_source_lookup (GSettingsSchemaSource
*source
,
410 const gchar
*schema_id
,
413 GSettingsSchema
*schema
;
416 g_return_val_if_fail (source
!= NULL
, NULL
);
417 g_return_val_if_fail (schema_id
!= NULL
, NULL
);
419 table
= gvdb_table_get_table (source
->table
, schema_id
);
421 if (table
== NULL
&& recursive
)
422 for (source
= source
->parent
; source
; source
= source
->parent
)
423 if ((table
= gvdb_table_get_table (source
->table
, schema_id
)))
429 schema
= g_slice_new0 (GSettingsSchema
);
430 schema
->ref_count
= 1;
431 schema
->id
= g_strdup (schema_id
);
432 schema
->table
= table
;
433 schema
->path
= g_settings_schema_get_string (schema
, ".path");
434 schema
->gettext_domain
= g_settings_schema_get_string (schema
, ".gettext-domain");
436 if (schema
->gettext_domain
)
437 bind_textdomain_codeset (schema
->gettext_domain
, "UTF-8");
443 steal_item (gpointer key
,
447 gchar
***ptr
= user_data
;
449 *(*ptr
)++ = (gchar
*) key
;
454 static const gchar
* const *non_relocatable_schema_list
;
455 static const gchar
* const *relocatable_schema_list
;
456 static gsize schema_lists_initialised
;
459 ensure_schema_lists (void)
461 if (g_once_init_enter (&schema_lists_initialised
))
463 GSettingsSchemaSource
*source
;
464 GHashTable
*single
, *reloc
;
469 initialise_schema_sources ();
471 /* We use hash tables to avoid duplicate listings for schemas that
472 * appear in more than one file.
474 single
= g_hash_table_new_full (g_str_hash
, g_str_equal
, g_free
, NULL
);
475 reloc
= g_hash_table_new_full (g_str_hash
, g_str_equal
, g_free
, NULL
);
477 for (source
= schema_sources
; source
; source
= source
->parent
)
479 list
= gvdb_table_list (source
->table
, "");
481 g_assert (list
!= NULL
);
483 for (i
= 0; list
[i
]; i
++)
485 if (!g_hash_table_lookup (single
, list
[i
]) &&
486 !g_hash_table_lookup (reloc
, list
[i
]))
490 table
= gvdb_table_get_table (source
->table
, list
[i
]);
491 g_assert (table
!= NULL
);
493 if (gvdb_table_has_value (table
, ".path"))
494 g_hash_table_insert (single
, g_strdup (list
[i
]), NULL
);
496 g_hash_table_insert (reloc
, g_strdup (list
[i
]), NULL
);
498 gvdb_table_unref (table
);
505 ptr
= g_new (const gchar
*, g_hash_table_size (single
) + 1);
506 non_relocatable_schema_list
= ptr
;
507 g_hash_table_foreach_steal (single
, steal_item
, &ptr
);
508 g_hash_table_unref (single
);
511 ptr
= g_new (const gchar
*, g_hash_table_size (reloc
) + 1);
512 relocatable_schema_list
= ptr
;
513 g_hash_table_foreach_steal (reloc
, steal_item
, &ptr
);
514 g_hash_table_unref (reloc
);
517 g_once_init_leave (&schema_lists_initialised
, TRUE
);
522 * g_settings_list_schemas:
524 * Gets a list of the #GSettings schemas installed on the system. The
525 * returned list is exactly the list of schemas for which you may call
526 * g_settings_new() without adverse effects.
528 * This function does not list the schemas that do not provide their own
529 * paths (ie: schemas for which you must use
530 * g_settings_new_with_path()). See
531 * g_settings_list_relocatable_schemas() for that.
533 * Returns: (element-type utf8) (transfer none): a list of #GSettings
534 * schemas that are available. The list must not be modified or
539 const gchar
* const *
540 g_settings_list_schemas (void)
542 ensure_schema_lists ();
544 return non_relocatable_schema_list
;
548 * g_settings_list_relocatable_schemas:
550 * Gets a list of the relocatable #GSettings schemas installed on the
551 * system. These are schemas that do not provide their own path. It is
552 * usual to instantiate these schemas directly, but if you want to you
553 * can use g_settings_new_with_path() to specify the path.
555 * The output of this function, taken together with the output of
556 * g_settings_list_schemas() represents the complete list of all
559 * Returns: (element-type utf8) (transfer none): a list of relocatable
560 * #GSettings schemas that are available. The list must not be
565 const gchar
* const *
566 g_settings_list_relocatable_schemas (void)
568 ensure_schema_lists ();
570 return relocatable_schema_list
;
574 * g_settings_schema_ref:
575 * @schema: a #GSettingsSchema
577 * Increase the reference count of @schema, returning a new reference.
579 * Returns: a new reference to @schema
584 g_settings_schema_ref (GSettingsSchema
*schema
)
586 g_atomic_int_inc (&schema
->ref_count
);
592 * g_settings_schema_unref:
593 * @schema: a #GSettingsSchema
595 * Decrease the reference count of @schema, possibly freeing it.
600 g_settings_schema_unref (GSettingsSchema
*schema
)
602 if (g_atomic_int_dec_and_test (&schema
->ref_count
))
604 gvdb_table_unref (schema
->table
);
605 g_free (schema
->items
);
608 g_slice_free (GSettingsSchema
, schema
);
613 g_settings_schema_get_string (GSettingsSchema
*schema
,
616 const gchar
*result
= NULL
;
619 if ((value
= gvdb_table_get_raw_value (schema
->table
, key
)))
621 result
= g_variant_get_string (value
, NULL
);
622 g_variant_unref (value
);
629 g_settings_schema_get_value (GSettingsSchema
*schema
,
635 value
= gvdb_table_get_raw_value (schema
->table
, key
);
637 if G_UNLIKELY (value
== NULL
)
638 g_error ("Settings schema '%s' does not contain a key named '%s'", schema
->id
, key
);
640 iter
= g_variant_iter_new (value
);
641 g_variant_unref (value
);
647 * g_settings_schema_get_path:
648 * @schema: a #GSettingsSchema
650 * Gets the path associated with @schema, or %NULL.
652 * Schemas may be single-instance or relocatable. Single-instance
653 * schemas correspond to exactly one set of keys in the backend
654 * database: those located at the path returned by this function.
656 * Relocatable schemas can be referenced by other schemas and can
657 * threfore describe multiple sets of keys at different locations. For
658 * relocatable schemas, this function will return %NULL.
660 * Returns: (transfer none): the path of the schema, or %NULL
665 g_settings_schema_get_path (GSettingsSchema
*schema
)
671 g_settings_schema_get_gettext_domain (GSettingsSchema
*schema
)
673 return schema
->gettext_domain
;
677 g_settings_schema_has_key (GSettingsSchema
*schema
,
680 return gvdb_table_has_value (schema
->table
, key
);
684 g_settings_schema_list (GSettingsSchema
*schema
,
689 if (schema
->items
== NULL
)
694 list
= gvdb_table_list (schema
->table
, "");
695 len
= list
? g_strv_length (list
) : 0;
697 schema
->items
= g_new (GQuark
, len
);
700 for (i
= 0; i
< len
; i
++)
701 if (list
[i
][0] != '.')
702 schema
->items
[j
++] = g_quark_from_string (list
[i
]);
708 *n_items
= schema
->n_items
;
709 return schema
->items
;
713 * g_settings_schema_get_id:
714 * @schema: a #GSettingsSchema
716 * Get the ID of @schema.
718 * Returns: (transfer none): the ID
721 g_settings_schema_get_id (GSettingsSchema
*schema
)
727 endian_fixup (GVariant
**value
)
729 #if G_BYTE_ORDER == G_BIG_ENDIAN
732 tmp
= g_variant_byteswap (*value
);
733 g_variant_unref (*value
);
739 g_settings_schema_key_init (GSettingsSchemaKey
*key
,
740 GSettingsSchema
*schema
,
747 memset (key
, 0, sizeof *key
);
749 iter
= g_settings_schema_get_value (schema
, name
);
751 key
->schema
= g_settings_schema_ref (schema
);
752 key
->default_value
= g_variant_iter_next_value (iter
);
753 endian_fixup (&key
->default_value
);
754 key
->type
= g_variant_get_type (key
->default_value
);
755 key
->name
= g_intern_string (name
);
757 while (g_variant_iter_next (iter
, "(y*)", &code
, &data
))
762 /* translation requested */
763 g_variant_get (data
, "(y&s)", &key
->lc_char
, &key
->unparsed
);
767 /* enumerated types... */
773 key
->is_flags
= TRUE
;
777 /* ..., choices, aliases */
778 key
->strinfo
= g_variant_get_fixed_array (data
, &key
->strinfo_length
, sizeof (guint32
));
782 g_variant_get (data
, "(**)", &key
->minimum
, &key
->maximum
);
783 endian_fixup (&key
->minimum
);
784 endian_fixup (&key
->maximum
);
788 g_warning ("unknown schema extension '%c'", code
);
792 g_variant_unref (data
);
795 g_variant_iter_free (iter
);
799 g_settings_schema_key_clear (GSettingsSchemaKey
*key
)
802 g_variant_unref (key
->minimum
);
805 g_variant_unref (key
->maximum
);
807 g_variant_unref (key
->default_value
);
809 g_settings_schema_unref (key
->schema
);
813 g_settings_schema_key_type_check (GSettingsSchemaKey
*key
,
816 g_return_val_if_fail (value
!= NULL
, FALSE
);
818 return g_variant_is_of_type (value
, key
->type
);
822 g_settings_schema_key_range_check (GSettingsSchemaKey
*key
,
825 if (key
->minimum
== NULL
&& key
->strinfo
== NULL
)
828 if (g_variant_is_container (value
))
834 g_variant_iter_init (&iter
, value
);
835 while (ok
&& (child
= g_variant_iter_next_value (&iter
)))
837 ok
= g_settings_schema_key_range_check (key
, child
);
838 g_variant_unref (child
);
846 return g_variant_compare (key
->minimum
, value
) <= 0 &&
847 g_variant_compare (value
, key
->maximum
) <= 0;
850 return strinfo_is_string_valid (key
->strinfo
, key
->strinfo_length
,
851 g_variant_get_string (value
, NULL
));
855 g_settings_schema_key_range_fixup (GSettingsSchemaKey
*key
,
860 if (g_settings_schema_key_range_check (key
, value
))
861 return g_variant_ref (value
);
863 if (key
->strinfo
== NULL
)
866 if (g_variant_is_container (value
))
868 GVariantBuilder builder
;
872 g_variant_iter_init (&iter
, value
);
873 g_variant_builder_init (&builder
, g_variant_get_type (value
));
875 while ((child
= g_variant_iter_next_value (&iter
)))
879 fixed
= g_settings_schema_key_range_fixup (key
, child
);
880 g_variant_unref (child
);
884 g_variant_builder_clear (&builder
);
888 g_variant_builder_add_value (&builder
, fixed
);
889 g_variant_unref (fixed
);
892 return g_variant_ref_sink (g_variant_builder_end (&builder
));
895 target
= strinfo_string_from_alias (key
->strinfo
, key
->strinfo_length
,
896 g_variant_get_string (value
, NULL
));
897 return target
? g_variant_ref_sink (g_variant_new_string (target
)) : NULL
;
902 g_settings_schema_key_get_translated_default (GSettingsSchemaKey
*key
)
904 const gchar
*translated
;
905 GError
*error
= NULL
;
909 domain
= g_settings_schema_get_gettext_domain (key
->schema
);
911 if (key
->lc_char
== '\0')
912 /* translation not requested for this key */
915 if (key
->lc_char
== 't')
916 translated
= g_dcgettext (domain
, key
->unparsed
, LC_TIME
);
918 translated
= g_dgettext (domain
, key
->unparsed
);
920 if (translated
== key
->unparsed
)
921 /* the default value was not translated */
924 /* try to parse the translation of the unparsed default */
925 value
= g_variant_parse (key
->type
, translated
, NULL
, NULL
, &error
);
929 g_warning ("Failed to parse translated string `%s' for "
930 "key `%s' in schema `%s': %s", key
->unparsed
, key
->name
,
931 g_settings_schema_get_id (key
->schema
), error
->message
);
932 g_warning ("Using untranslated default instead.");
933 g_error_free (error
);
936 else if (!g_settings_schema_key_range_check (key
, value
))
938 g_warning ("Translated default `%s' for key `%s' in schema `%s' "
939 "is outside of valid range", key
->unparsed
, key
->name
,
940 g_settings_schema_get_id (key
->schema
));
941 g_variant_unref (value
);
949 g_settings_schema_key_to_enum (GSettingsSchemaKey
*key
,
955 it_worked
= strinfo_enum_from_string (key
->strinfo
, key
->strinfo_length
,
956 g_variant_get_string (value
, NULL
),
959 /* 'value' can only come from the backend after being filtered for validity,
960 * from the translation after being filtered for validity, or from the schema
961 * itself (which the schema compiler checks for validity). If this assertion
962 * fails then it's really a bug in GSettings or the schema compiler...
964 g_assert (it_worked
);
970 g_settings_schema_key_from_enum (GSettingsSchemaKey
*key
,
975 string
= strinfo_string_from_enum (key
->strinfo
, key
->strinfo_length
, value
);
980 return g_variant_new_string (string
);
984 g_settings_schema_key_to_flags (GSettingsSchemaKey
*key
,
992 g_variant_iter_init (&iter
, value
);
993 while (g_variant_iter_next (&iter
, "&s", &flag
))
998 it_worked
= strinfo_enum_from_string (key
->strinfo
, key
->strinfo_length
, flag
, &flag_value
);
999 /* as in g_settings_to_enum() */
1000 g_assert (it_worked
);
1002 result
|= flag_value
;
1009 g_settings_schema_key_from_flags (GSettingsSchemaKey
*key
,
1012 GVariantBuilder builder
;
1015 g_variant_builder_init (&builder
, G_VARIANT_TYPE ("as"));
1017 for (i
= 0; i
< 32; i
++)
1018 if (value
& (1u << i
))
1020 const gchar
*string
;
1022 string
= strinfo_string_from_enum (key
->strinfo
, key
->strinfo_length
, 1u << i
);
1026 g_variant_builder_clear (&builder
);
1030 g_variant_builder_add (&builder
, "s", string
);
1033 return g_variant_builder_end (&builder
);