m-settings: split out the WpSettings instance loading to a new built-in component

When running multi-instance setups or when clients like wpctl want to
access the WpSettings instance, it makes no sense to load the entire
module-settings, which will also create sm-settings metadata instances.

lib/wp/private/internal-comp-loader.c

@@ -598,7 +598,7 @@ ensure_no_media_session_task_idle (GTask * task)
 }
 
 static void
-ensure_no_media_session (GTask * task, WpCore * core)
+ensure_no_media_session (GTask * task, WpCore * core, WpSpaJson * args)
 {
   WpObjectManager *om = wp_object_manager_new ();
 
@@ -619,7 +619,7 @@ ensure_no_media_session (GTask * task, WpCore * core)
 }
 
 static void
-load_export_core (GTask * task, WpCore * core)
+load_export_core (GTask * task, WpCore * core, WpSpaJson * args)
 {
   g_autofree gchar *export_core_name = NULL;
   g_autoptr (WpCore) export_core = NULL;
@@ -641,12 +641,48 @@ load_export_core (GTask * task, WpCore * core)
   g_task_return_pointer (task, g_steal_pointer (&export_core), g_object_unref);
 }
 
+static void
+on_settings_ready (WpSettings *s, GAsyncResult *res, gpointer data)
+{
+  GTask *task = G_TASK (data);
+  g_autoptr (GError) error = NULL;
+
+  if (!wp_object_activate_finish (WP_OBJECT (s), res, &error)) {
+    g_task_return_new_error (task,
+        WP_DOMAIN_LIBRARY, WP_LIBRARY_ERROR_OPERATION_FAILED,
+        "failed to activate settings instance: %s", error->message);
+    return;
+  }
+
+  g_task_return_pointer (task, NULL, NULL);
+}
+
+static void
+load_settings_instance (GTask * task, WpCore * core, WpSpaJson * args)
+{
+  g_autofree gchar *metadata_name = NULL;
+  if (args)
+    wp_spa_json_object_get (args, "metadata.name", "s", &metadata_name, NULL);
+  if (!metadata_name)
+    metadata_name = g_strdup ("sm-settings");
+
+  wp_info_object (core, "loading settings instance '%s'...", metadata_name);
+
+  g_autoptr (WpSettings) settings = wp_settings_get_instance (core,
+      metadata_name);
+
+  wp_object_activate_closure (WP_OBJECT (settings), WP_OBJECT_FEATURES_ALL, NULL,
+      g_cclosure_new (G_CALLBACK (on_settings_ready), g_object_ref (task),
+          (GClosureNotify) g_object_unref));
+}
+
 static const struct {
   const gchar * name;
-  void (*load) (GTask *, WpCore *);
+  void (*load) (GTask *, WpCore *, WpSpaJson *);
 } builtin_components[] = {
   { "ensure-no-media-session", ensure_no_media_session },
   { "export-core", load_export_core },
+  { "settings-instance", load_settings_instance },
 };
 
 /*** WpInternalCompLoader ***/
@@ -796,7 +832,7 @@ wp_internal_comp_loader_load (WpComponentLoader * self, WpCore * core,
     else if (g_str_equal (type, "built-in")) {
       for (guint i = 0; i < G_N_ELEMENTS (builtin_components); i++) {
         if (g_str_equal (component, builtin_components[i].name)) {
-          builtin_components[i].load (task, core);
+          builtin_components[i].load (task, core, args);
           return;
         }
       }

modules/module-settings.c

@@ -141,22 +141,6 @@ is_persistent_settings_enabled (WpProperties *settings) {
   return res;
 }
 
-static void
-on_settings_ready (WpSettings *s, GAsyncResult *res, gpointer data)
-{
-  WpSettingsPlugin *self = WP_SETTINGS_PLUGIN (data);
-  g_autoptr (GError) error = NULL;
-
-  wp_info_object (self, "wpsettings object ready");
-
-  if (!wp_object_activate_finish (WP_OBJECT (s), res, &error)) {
-    wp_debug_object (self, "wpsettings activation failed: %s", error->message);
-    return;
-  }
-
-  wp_object_update_features (WP_OBJECT (self), WP_PLUGIN_FEATURE_ENABLED, 0);
-}
-
 static void
 on_metadata_activated (WpMetadata * m, GAsyncResult * res, gpointer user_data)
 {
@@ -215,12 +199,7 @@ on_metadata_activated (WpMetadata * m, GAsyncResult * res, gpointer user_data)
   g_signal_connect_object (m, "changed", G_CALLBACK (on_metadata_changed),
       self, 0);
 
-  g_autoptr (WpSettings) settings = wp_settings_get_instance (core,
-      self->metadata_name);
-
-  wp_object_activate (WP_OBJECT (settings), WP_OBJECT_FEATURES_ALL, NULL,
-    (GAsyncReadyCallback) on_settings_ready, self);
-
+  wp_object_update_features (WP_OBJECT (self), WP_PLUGIN_FEATURE_ENABLED, 0);
 }
 
 static void
@@ -310,7 +289,7 @@ wireplumber__module_init (WpCore * core, WpSpaJson * args, GError ** error)
 {
   g_autofree gchar *metadata_name = NULL;
   if (args)
-    wp_spa_json_object_get (args, "metadata-name", "s", &metadata_name, NULL);
+    wp_spa_json_object_get (args, "metadata.name", "s", &metadata_name, NULL);
 
   return G_OBJECT (g_object_new (wp_settings_plugin_get_type (),
       "name", "settings",

src/config/wireplumber.conf

@@ -70,6 +70,7 @@ wireplumber.profiles = {
 
   main = {
     check.no-media-session = required
+    metadata.sm-settings = required
     support.settings = required
     support.log-settings = required
     metadata.sm-objects = required
@@ -150,9 +151,18 @@ wireplumber.components = [
     requires = [ pw.client-node ]
   }
 
-  ## Settings provider
+  ## Provides the "sm-settings" metadata object
   {
     name = libwireplumber-module-settings, type = module
+    arguments = { metadata.name = sm-settings }
+    provides = metadata.sm-settings
+  }
+
+  ## Activates a global WpSettings instance, providing settings from
+  ## the sm-settings metadata object
+  {
+    name = settings-instance, type = built-in
+    arguments = { metadata.name = sm-settings }
     provides = support.settings
   }