/* * Copyright © 2010 Codethink Limited * Copyright © 2011 Canonical Limited * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the licence, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include "config.h" #include "gsettingsschema-internal.h" #include "gsettings.h" #include "gvdb/gvdb-reader.h" #include "strinfo.c" #include #include #include /** * SECTION:gsettingsschema * @short_description: introspecting and controlling the loading of * GSettings schemas * * The #GSettingsSchemaSource and #GSettingsSchema APIs provide a * mechanism for advanced control over the loading of schemas and a * mechanism for introspecting their content. * * Plugin loading systems that wish to provide plugins a way to access * settings face the problem of how to make the schemas for these * settings visible to GSettings. Typically, a plugin will want to ship * the schema along with itself and it won't be installed into the * standard system directories for schemas. * * #GSettingsSchemaSource provides a mechanism for dealing with this by * allowing the creation of a new 'schema source' from which schemas can * be acquired. This schema source can then become part of the metadata * associated with the plugin and queried whenever the plugin requires * access to some settings. * * Consider the following example: * * |[ * typedef struct * { * ... * GSettingsSchemaSource *schema_source; * ... * } Plugin; * * Plugin * * initialise_plugin (const gchar *dir) * { * Plugin *plugin; * * ... * * plugin->schema_source = * g_settings_new_schema_source_from_directory (dir, * g_settings_schema_source_get_default (), FALSE, NULL); * * ... * * return plugin; * } * * ... * * GSettings * * plugin_get_settings (Plugin *plugin, * const gchar *schema_id) * { * GSettingsSchema *schema; * * if (schema_id == NULL) * schema_id = plugin->identifier; * * schema = g_settings_schema_source_lookup (plugin->schema_source, * schema_id, FALSE); * * if (schema == NULL) * { * ... disable the plugin or abort, etc ... * } * * return g_settings_new_full (schema, NULL, NULL); * } * ]| * * The code above shows how hooks should be added to the code that * initialises (or enables) the plugin to create the schema source and * how an API can be added to the plugin system to provide a convenient * way for the plugin to access its settings, using the schemas that it * ships. * * From the standpoint of the plugin, it would need to ensure that it * ships a gschemas.compiled file as part of itself, and then simply do * the following: * * |[ * { * GSettings *settings; * gint some_value; * * settings = plugin_get_settings (self, NULL); * some_value = g_settings_get_int (settings, "some-value"); * ... * } * ]| * * It's also possible that the plugin system expects the schema source * files (ie: .gschema.xml files) instead of a gschemas.compiled file. * In that case, the plugin loading system must compile the schemas for * itself before attempting to create the settings source. * * Since: 2.32 **/ /** * GSettingsSchema: * * This is an opaque structure type. You may not access it directly. * * Since: 2.32 **/ struct _GSettingsSchema { const gchar *gettext_domain; const gchar *path; GQuark *items; gint n_items; GvdbTable *table; gchar *id; gint ref_count; }; /** * G_TYPE_SETTINGS_SCHEMA_SOURCE: * * A boxed #GType corresponding to #GSettingsSchemaSource. * * Since: 2.32 **/ G_DEFINE_BOXED_TYPE (GSettingsSchemaSource, g_settings_schema_source, g_settings_schema_source_ref, g_settings_schema_source_unref) /** * G_TYPE_SETTINGS_SCHEMA: * * A boxed #GType corresponding to #GSettingsSchema. * * Since: 2.32 **/ G_DEFINE_BOXED_TYPE (GSettingsSchema, g_settings_schema, g_settings_schema_ref, g_settings_schema_unref) /** * GSettingsSchemaSource: * * This is an opaque structure type. You may not access it directly. * * Since: 2.32 **/ struct _GSettingsSchemaSource { GSettingsSchemaSource *parent; GvdbTable *table; gint ref_count; }; static GSettingsSchemaSource *schema_sources; static void prepend_schema_table (GvdbTable *table) { GSettingsSchemaSource *source; /* we steal the reference from 'schema_sources' for our ->parent */ source = g_slice_new (GSettingsSchemaSource); source->parent = schema_sources; source->table = table; source->ref_count = 1; schema_sources = source; } /** * g_settings_schema_source_ref: * @source: a #GSettingsSchemaSource * * Increase the reference count of @source, returning a new reference. * * Returns: a new reference to @source * * Since: 2.32 **/ GSettingsSchemaSource * g_settings_schema_source_ref (GSettingsSchemaSource *source) { g_atomic_int_inc (&source->ref_count); return source; } /** * g_settings_schema_source_unref: * @source: a #GSettingsSchemaSource * * Decrease the reference count of @source, possibly freeing it. * * Since: 2.32 **/ void g_settings_schema_source_unref (GSettingsSchemaSource *source) { if (g_atomic_int_dec_and_test (&source->ref_count)) { if (source == schema_sources) g_error ("g_settings_schema_source_unref() called too many times on the default schema source"); if (source->parent) g_settings_schema_source_unref (source->parent); gvdb_table_unref (source->table); g_slice_free (GSettingsSchemaSource, source); } } /** * g_settings_schema_source_new_from_directory: * @directory: the filename of a directory * @parent: (allow-none): a #GSettingsSchemaSource, or %NULL * @trusted: %TRUE, if the directory is trusted * @error: a pointer to a #GError pointer set to %NULL, or %NULL * * Attempts to create a new schema source corresponding to the contents * of the given directory. * * This function is not required for normal uses of #GSettings but it * may be useful to authors of plugin management systems. * * The directory should contain a file called * gschemas.compiled as produced by * glib-compile-schemas. * * If @trusted is %TRUE then gschemas.compiled is * trusted not to be corrupted. This assumption has a performance * advantage, but can result in crashes or inconsistent behaviour in the * case of a corrupted file. Generally, you should set @trusted to * %TRUE for files installed by the system and to %FALSE for files in * the home directory. * * If @parent is non-%NULL then there are two effects. * * First, if g_settings_schema_source_lookup() is called with the * @recursive flag set to %TRUE and the schema can not be found in the * source, the lookup will recurse to the parent. * * Second, any references to other schemas specified within this * source (ie: child or extends) * references may be resolved from the @parent. * * For this second reason, except in very unusual situations, the * @parent should probably be given as the default schema source, as * returned by g_settings_schema_source_get_default(). * * Since: 2.32 **/ GSettingsSchemaSource * g_settings_schema_source_new_from_directory (const gchar *directory, GSettingsSchemaSource *parent, gboolean trusted, GError **error) { GSettingsSchemaSource *source; GvdbTable *table; gchar *filename; filename = g_build_filename (directory, "gschemas.compiled", NULL); table = gvdb_table_new (filename, trusted, error); g_free (filename); if (table == NULL) return NULL; source = g_slice_new (GSettingsSchemaSource); source->parent = parent ? g_settings_schema_source_ref (parent) : NULL; source->table = table; source->ref_count = 1; return source; } static void initialise_schema_sources (void) { static gsize initialised; /* need a separate variable because 'schema_sources' may legitimately * be null if we have zero valid schema sources */ if G_UNLIKELY (g_once_init_enter (&initialised)) { const gchar * const *dirs; const gchar *path; gint i; /* iterate in reverse: count up, then count down */ dirs = g_get_system_data_dirs (); for (i = 0; dirs[i]; i++); while (i--) { gchar *filename; GvdbTable *table; filename = g_build_filename (dirs[i], "glib-2.0", "schemas", "gschemas.compiled", NULL); table = gvdb_table_new (filename, TRUE, NULL); if (table != NULL) prepend_schema_table (table); g_free (filename); } if ((path = g_getenv ("GSETTINGS_SCHEMA_DIR")) != NULL) { gchar *filename; GvdbTable *table; filename = g_build_filename (path, "gschemas.compiled", NULL); table = gvdb_table_new (filename, TRUE, NULL); if (table != NULL) prepend_schema_table (table); g_free (filename); } g_once_init_leave (&initialised, TRUE); } } /** * g_settings_schema_source_get_default: * * Gets the default system schema source. * * This function is not required for normal uses of #GSettings but it * may be useful to authors of plugin management systems or to those who * want to introspect the content of schemas. * * If no schemas are installed, %NULL will be returned. * * The returned source may actually consist of multiple schema sources * from different directories, depending on which directories were given * in XDG_DATA_DIRS and * GSETTINGS_SCHEMA_DIR. For this reason, all lookups * performed against the default source should probably be done * recursively. * * Returns: (transfer none): the default schema source * * Since: 2.32 **/ GSettingsSchemaSource * g_settings_schema_source_get_default (void) { initialise_schema_sources (); return schema_sources; } /** * g_settings_schema_source_lookup: * @source: a #GSettingsSchemaSource * @schema_id: a schema ID * @recursive: %TRUE if the lookup should be recursive * * Looks up a schema with the identifier @schema_id in @source. * * This function is not required for normal uses of #GSettings but it * may be useful to authors of plugin management systems or to those who * want to introspect the content of schemas. * * If the schema isn't found directly in @source and @recursive is %TRUE * then the parent sources will also be checked. * * If the schema isn't found, %NULL is returned. * * Returns: (transfer full): a new #GSettingsSchema * * Since: 2.32 **/ GSettingsSchema * g_settings_schema_source_lookup (GSettingsSchemaSource *source, const gchar *schema_id, gboolean recursive) { GSettingsSchema *schema; GvdbTable *table; g_return_val_if_fail (source != NULL, NULL); g_return_val_if_fail (schema_id != NULL, NULL); table = gvdb_table_get_table (source->table, schema_id); if (table == NULL && recursive) for (source = source->parent; source; source = source->parent) if ((table = gvdb_table_get_table (source->table, schema_id))) break; if (table == NULL) return NULL; schema = g_slice_new0 (GSettingsSchema); schema->ref_count = 1; schema->id = g_strdup (schema_id); schema->table = table; schema->path = g_settings_schema_get_string (schema, ".path"); schema->gettext_domain = g_settings_schema_get_string (schema, ".gettext-domain"); if (schema->gettext_domain) bind_textdomain_codeset (schema->gettext_domain, "UTF-8"); return schema; } static gboolean steal_item (gpointer key, gpointer value, gpointer user_data) { gchar ***ptr = user_data; *(*ptr)++ = (gchar *) key; return TRUE; } static const gchar * const *non_relocatable_schema_list; static const gchar * const *relocatable_schema_list; static gsize schema_lists_initialised; static void ensure_schema_lists (void) { if (g_once_init_enter (&schema_lists_initialised)) { GSettingsSchemaSource *source; GHashTable *single, *reloc; const gchar **ptr; gchar **list; gint i; initialise_schema_sources (); /* We use hash tables to avoid duplicate listings for schemas that * appear in more than one file. */ single = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL); reloc = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL); for (source = schema_sources; source; source = source->parent) { list = gvdb_table_list (source->table, ""); /* empty schema cache file? */ if (list == NULL) continue; for (i = 0; list[i]; i++) { if (!g_hash_table_lookup (single, list[i]) && !g_hash_table_lookup (reloc, list[i])) { GvdbTable *table; table = gvdb_table_get_table (source->table, list[i]); g_assert (table != NULL); if (gvdb_table_has_value (table, ".path")) g_hash_table_insert (single, g_strdup (list[i]), NULL); else g_hash_table_insert (reloc, g_strdup (list[i]), NULL); gvdb_table_unref (table); } } g_strfreev (list); } ptr = g_new (const gchar *, g_hash_table_size (single) + 1); non_relocatable_schema_list = ptr; g_hash_table_foreach_steal (single, steal_item, &ptr); g_hash_table_unref (single); *ptr = NULL; ptr = g_new (const gchar *, g_hash_table_size (reloc) + 1); relocatable_schema_list = ptr; g_hash_table_foreach_steal (reloc, steal_item, &ptr); g_hash_table_unref (reloc); *ptr = NULL; g_once_init_leave (&schema_lists_initialised, TRUE); } } /** * g_settings_list_schemas: * * Gets a list of the #GSettings schemas installed on the system. The * returned list is exactly the list of schemas for which you may call * g_settings_new() without adverse effects. * * This function does not list the schemas that do not provide their own * paths (ie: schemas for which you must use * g_settings_new_with_path()). See * g_settings_list_relocatable_schemas() for that. * * Returns: (element-type utf8) (transfer none): a list of #GSettings * schemas that are available. The list must not be modified or * freed. * * Since: 2.26 **/ const gchar * const * g_settings_list_schemas (void) { ensure_schema_lists (); return non_relocatable_schema_list; } /** * g_settings_list_relocatable_schemas: * * Gets a list of the relocatable #GSettings schemas installed on the * system. These are schemas that do not provide their own path. It is * usual to instantiate these schemas directly, but if you want to you * can use g_settings_new_with_path() to specify the path. * * The output of this function, taken together with the output of * g_settings_list_schemas() represents the complete list of all * installed schemas. * * Returns: (element-type utf8) (transfer none): a list of relocatable * #GSettings schemas that are available. The list must not be * modified or freed. * * Since: 2.28 **/ const gchar * const * g_settings_list_relocatable_schemas (void) { ensure_schema_lists (); return relocatable_schema_list; } /** * g_settings_schema_ref: * @schema: a #GSettingsSchema * * Increase the reference count of @schema, returning a new reference. * * Returns: a new reference to @schema * * Since: 2.32 **/ GSettingsSchema * g_settings_schema_ref (GSettingsSchema *schema) { g_atomic_int_inc (&schema->ref_count); return schema; } /** * g_settings_schema_unref: * @schema: a #GSettingsSchema * * Decrease the reference count of @schema, possibly freeing it. * * Since: 2.32 **/ void g_settings_schema_unref (GSettingsSchema *schema) { if (g_atomic_int_dec_and_test (&schema->ref_count)) { gvdb_table_unref (schema->table); g_free (schema->items); g_free (schema->id); g_slice_free (GSettingsSchema, schema); } } const gchar * g_settings_schema_get_string (GSettingsSchema *schema, const gchar *key) { const gchar *result = NULL; GVariant *value; if ((value = gvdb_table_get_raw_value (schema->table, key))) { result = g_variant_get_string (value, NULL); g_variant_unref (value); } return result; } GVariantIter * g_settings_schema_get_value (GSettingsSchema *schema, const gchar *key) { GVariantIter *iter; GVariant *value; value = gvdb_table_get_raw_value (schema->table, key); if G_UNLIKELY (value == NULL || !g_variant_is_of_type (value, G_VARIANT_TYPE_TUPLE)) g_error ("Settings schema '%s' does not contain a key named '%s'", schema->id, key); iter = g_variant_iter_new (value); g_variant_unref (value); return iter; } /** * g_settings_schema_get_path: * @schema: a #GSettingsSchema * * Gets the path associated with @schema, or %NULL. * * Schemas may be single-instance or relocatable. Single-instance * schemas correspond to exactly one set of keys in the backend * database: those located at the path returned by this function. * * Relocatable schemas can be referenced by other schemas and can * threfore describe multiple sets of keys at different locations. For * relocatable schemas, this function will return %NULL. * * Returns: (transfer none): the path of the schema, or %NULL * * Since: 2.32 **/ const gchar * g_settings_schema_get_path (GSettingsSchema *schema) { return schema->path; } const gchar * g_settings_schema_get_gettext_domain (GSettingsSchema *schema) { return schema->gettext_domain; } gboolean g_settings_schema_has_key (GSettingsSchema *schema, const gchar *key) { return gvdb_table_has_value (schema->table, key); } const GQuark * g_settings_schema_list (GSettingsSchema *schema, gint *n_items) { gint i, j; if (schema->items == NULL) { gchar **list; gint len; list = gvdb_table_list (schema->table, ""); len = list ? g_strv_length (list) : 0; schema->items = g_new (GQuark, len); j = 0; for (i = 0; i < len; i++) if (list[i][0] != '.') schema->items[j++] = g_quark_from_string (list[i]); schema->n_items = j; g_strfreev (list); } *n_items = schema->n_items; return schema->items; } /** * g_settings_schema_get_id: * @schema: a #GSettingsSchema * * Get the ID of @schema. * * Returns: (transfer none): the ID **/ const gchar * g_settings_schema_get_id (GSettingsSchema *schema) { return schema->id; } static inline void endian_fixup (GVariant **value) { #if G_BYTE_ORDER == G_BIG_ENDIAN GVariant *tmp; tmp = g_variant_byteswap (*value); g_variant_unref (*value); *value = tmp; #endif } void g_settings_schema_key_init (GSettingsSchemaKey *key, GSettingsSchema *schema, const gchar *name) { GVariantIter *iter; GVariant *data; guchar code; memset (key, 0, sizeof *key); iter = g_settings_schema_get_value (schema, name); key->schema = g_settings_schema_ref (schema); key->default_value = g_variant_iter_next_value (iter); endian_fixup (&key->default_value); key->type = g_variant_get_type (key->default_value); key->name = g_intern_string (name); while (g_variant_iter_next (iter, "(y*)", &code, &data)) { switch (code) { case 'l': /* translation requested */ g_variant_get (data, "(y&s)", &key->lc_char, &key->unparsed); break; case 'e': /* enumerated types... */ key->is_enum = TRUE; goto choice; case 'f': /* flags... */ key->is_flags = TRUE; goto choice; choice: case 'c': /* ..., choices, aliases */ key->strinfo = g_variant_get_fixed_array (data, &key->strinfo_length, sizeof (guint32)); break; case 'r': g_variant_get (data, "(**)", &key->minimum, &key->maximum); endian_fixup (&key->minimum); endian_fixup (&key->maximum); break; default: g_warning ("unknown schema extension '%c'", code); break; } g_variant_unref (data); } g_variant_iter_free (iter); } void g_settings_schema_key_clear (GSettingsSchemaKey *key) { if (key->minimum) g_variant_unref (key->minimum); if (key->maximum) g_variant_unref (key->maximum); g_variant_unref (key->default_value); g_settings_schema_unref (key->schema); } gboolean g_settings_schema_key_type_check (GSettingsSchemaKey *key, GVariant *value) { g_return_val_if_fail (value != NULL, FALSE); return g_variant_is_of_type (value, key->type); } gboolean g_settings_schema_key_range_check (GSettingsSchemaKey *key, GVariant *value) { if (key->minimum == NULL && key->strinfo == NULL) return TRUE; if (g_variant_is_container (value)) { gboolean ok = TRUE; GVariantIter iter; GVariant *child; g_variant_iter_init (&iter, value); while (ok && (child = g_variant_iter_next_value (&iter))) { ok = g_settings_schema_key_range_check (key, child); g_variant_unref (child); } return ok; } if (key->minimum) { return g_variant_compare (key->minimum, value) <= 0 && g_variant_compare (value, key->maximum) <= 0; } return strinfo_is_string_valid (key->strinfo, key->strinfo_length, g_variant_get_string (value, NULL)); } GVariant * g_settings_schema_key_range_fixup (GSettingsSchemaKey *key, GVariant *value) { const gchar *target; if (g_settings_schema_key_range_check (key, value)) return g_variant_ref (value); if (key->strinfo == NULL) return NULL; if (g_variant_is_container (value)) { GVariantBuilder builder; GVariantIter iter; GVariant *child; g_variant_iter_init (&iter, value); g_variant_builder_init (&builder, g_variant_get_type (value)); while ((child = g_variant_iter_next_value (&iter))) { GVariant *fixed; fixed = g_settings_schema_key_range_fixup (key, child); g_variant_unref (child); if (fixed == NULL) { g_variant_builder_clear (&builder); return NULL; } g_variant_builder_add_value (&builder, fixed); g_variant_unref (fixed); } return g_variant_ref_sink (g_variant_builder_end (&builder)); } target = strinfo_string_from_alias (key->strinfo, key->strinfo_length, g_variant_get_string (value, NULL)); return target ? g_variant_ref_sink (g_variant_new_string (target)) : NULL; } GVariant * g_settings_schema_key_get_translated_default (GSettingsSchemaKey *key) { const gchar *translated; GError *error = NULL; const gchar *domain; GVariant *value; domain = g_settings_schema_get_gettext_domain (key->schema); if (key->lc_char == '\0') /* translation not requested for this key */ return NULL; if (key->lc_char == 't') translated = g_dcgettext (domain, key->unparsed, LC_TIME); else translated = g_dgettext (domain, key->unparsed); if (translated == key->unparsed) /* the default value was not translated */ return NULL; /* try to parse the translation of the unparsed default */ value = g_variant_parse (key->type, translated, NULL, NULL, &error); if (value == NULL) { g_warning ("Failed to parse translated string '%s' for " "key '%s' in schema '%s': %s", key->unparsed, key->name, g_settings_schema_get_id (key->schema), error->message); g_warning ("Using untranslated default instead."); g_error_free (error); } else if (!g_settings_schema_key_range_check (key, value)) { g_warning ("Translated default '%s' for key '%s' in schema '%s' " "is outside of valid range", key->unparsed, key->name, g_settings_schema_get_id (key->schema)); g_variant_unref (value); value = NULL; } return value; } gint g_settings_schema_key_to_enum (GSettingsSchemaKey *key, GVariant *value) { gboolean it_worked; guint result; it_worked = strinfo_enum_from_string (key->strinfo, key->strinfo_length, g_variant_get_string (value, NULL), &result); /* 'value' can only come from the backend after being filtered for validity, * from the translation after being filtered for validity, or from the schema * itself (which the schema compiler checks for validity). If this assertion * fails then it's really a bug in GSettings or the schema compiler... */ g_assert (it_worked); return result; } GVariant * g_settings_schema_key_from_enum (GSettingsSchemaKey *key, gint value) { const gchar *string; string = strinfo_string_from_enum (key->strinfo, key->strinfo_length, value); if (string == NULL) return NULL; return g_variant_new_string (string); } guint g_settings_schema_key_to_flags (GSettingsSchemaKey *key, GVariant *value) { GVariantIter iter; const gchar *flag; guint result; result = 0; g_variant_iter_init (&iter, value); while (g_variant_iter_next (&iter, "&s", &flag)) { gboolean it_worked; guint flag_value; it_worked = strinfo_enum_from_string (key->strinfo, key->strinfo_length, flag, &flag_value); /* as in g_settings_to_enum() */ g_assert (it_worked); result |= flag_value; } return result; } GVariant * g_settings_schema_key_from_flags (GSettingsSchemaKey *key, guint value) { GVariantBuilder builder; gint i; g_variant_builder_init (&builder, G_VARIANT_TYPE ("as")); for (i = 0; i < 32; i++) if (value & (1u << i)) { const gchar *string; string = strinfo_string_from_enum (key->strinfo, key->strinfo_length, 1u << i); if (string == NULL) { g_variant_builder_clear (&builder); return NULL; } g_variant_builder_add (&builder, "s", string); } return g_variant_builder_end (&builder); }