diff options
Diffstat (limited to 'engine')
| -rw-r--r-- | engine/dconf-engine.c | 84 |
1 files changed, 83 insertions, 1 deletions
diff --git a/engine/dconf-engine.c b/engine/dconf-engine.c index cbb2a00..6a1f247 100644 --- a/engine/dconf-engine.c +++ b/engine/dconf-engine.c @@ -24,6 +24,7 @@ #include "../common/dconf-enums.h" #include "../common/dconf-paths.h" +#include "../common/dconf-gvdb-utils.h" #include "../gvdb/gvdb-reader.h" #include <string.h> #include <stdlib.h> @@ -822,6 +823,54 @@ dconf_engine_list (DConfEngine *engine, return list; } +static gboolean +dconf_engine_dir_has_writable_contents (DConfEngine *engine, + const gchar *dir) +{ + DConfChangeset *database; + GHashTable *current_state; + + /* Read the on disk state */ + if (engine->n_sources == 0 || !engine->sources[0]->writable) + // If there are no writable sources, there won't be any pending writes either + return FALSE; + + dconf_engine_acquire_sources (engine); + database = dconf_gvdb_utils_changeset_from_table (engine->sources[0]->values); + dconf_engine_release_sources (engine); + + /* Apply pending and in_flight changes to the on disk state */ + dconf_engine_lock_queue (engine); + + if (engine->in_flight != NULL) + dconf_changeset_change (database, engine->in_flight); + + if (engine->pending != NULL) + { + /** + * We don't want to seal the pending changeset because it may still be changed, + * and sealing the changeset would be a side effect of passing engine->pending + * directly into dconf_changeset_change. + */ + DConfChangeset *changes = dconf_changeset_filter_changes (database, engine->pending); + if (changes != NULL) + { + dconf_changeset_change (database, changes); + dconf_changeset_unref (changes); + } + } + + dconf_engine_unlock_queue (engine); + + /* Check if there are writable contents at the given directory in the current state */ + current_state = dconf_gvdb_utils_table_from_changeset (database); + gboolean result = g_hash_table_contains (current_state, dir); + + g_hash_table_unref (current_state); + dconf_changeset_unref (database); + return result; +} + typedef void (* DConfEngineCallHandleCallback) (DConfEngine *engine, gpointer handle, GVariant *parameter, @@ -1129,6 +1178,34 @@ dconf_engine_prepare_change (DConfEngine *engine, */ static void dconf_engine_manage_queue (DConfEngine *engine); +/** + * a #DConfChangesetPredicate which determines whether the given path and + * value is already present in the given engine. "Already present" means + * that setting that path to that value would have no effect on the + * engine, including for directory resets. + */ +static gboolean +dconf_engine_path_has_value_predicate (const gchar *path, + GVariant *new_value, + gpointer user_data) +{ + DConfEngine *engine = user_data; + + // Path reset are handled specially + if (g_str_has_suffix (path, "/")) + return !dconf_engine_dir_has_writable_contents (engine, path); + + g_autoptr(GVariant) current_value = dconf_engine_read ( + engine, + DCONF_READ_USER_VALUE, + NULL, + path + ); + return ((current_value == NULL && new_value == NULL) || + (current_value != NULL && new_value != NULL && + g_variant_equal (current_value, new_value))); +} + static void dconf_engine_emit_changes (DConfEngine *engine, DConfChangeset *changeset, @@ -1274,6 +1351,10 @@ dconf_engine_change_fast (DConfEngine *engine, if (dconf_changeset_is_empty (changeset)) return TRUE; + gboolean has_no_effect = dconf_changeset_all (changeset, + dconf_engine_path_has_value_predicate, + engine); + if (!dconf_engine_changeset_changes_only_writable_keys (engine, changeset, error)) return FALSE; @@ -1298,7 +1379,8 @@ dconf_engine_change_fast (DConfEngine *engine, dconf_engine_unlock_queue (engine); /* Emit the signal after dropping the lock to avoid deadlock on re-entry. */ - dconf_engine_emit_changes (engine, changeset, origin_tag); + if (!has_no_effect) + dconf_engine_emit_changes (engine, changeset, origin_tag); return TRUE; } |