modules: re-implement the simple policy module using WpPolicy

modules/module-simple-policy.c

@@ -0,0 +1,136 @@
+/* WirePlumber
+ *
+ * Copyright © 2019 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <wp/wp.h>
+
+struct _WpSimplePolicy
+{
+  WpPolicy parent;
+};
+
+G_DECLARE_FINAL_TYPE (WpSimplePolicy, simple_policy, WP, SIMPLE_POLICY, WpPolicy)
+G_DEFINE_TYPE (WpSimplePolicy, simple_policy, WP_TYPE_POLICY)
+
+static void
+simple_policy_init (WpSimplePolicy *self)
+{
+}
+
+static gboolean
+simple_policy_handle_endpoint (WpPolicy *policy, WpEndpoint *ep)
+{
+  const char *media_class = NULL;
+  GVariantDict d;
+  g_autoptr (GVariant) props = NULL;
+  g_autoptr (WpCore) core = NULL;
+  g_autoptr (WpEndpoint) target = NULL;
+  g_autoptr (GError) error = NULL;
+  guint32 stream_id;
+
+  /* TODO: For now we only accept audio output clients */
+  media_class = wp_endpoint_get_media_class(ep);
+  if (!g_str_equal (media_class, "Stream/Output/Audio"))
+    return FALSE;
+
+  /* Locate the target endpoint */
+  g_variant_dict_init (&d, NULL);
+  g_variant_dict_insert (&d, "action", "s", "link");
+  g_variant_dict_insert (&d, "media.class", "s", "Audio/Sink");
+  /* TODO: more properties are needed here */
+  props = g_variant_dict_end (&d);
+
+  core = wp_policy_get_core (policy);
+  target = wp_policy_find_endpoint (core, props, &stream_id);
+  if (!target) {
+    g_warning ("Could not find an Audio/Sink target endpoint\n");
+    /* TODO: we should kill the client, otherwise it's going to hang waiting */
+    return FALSE;
+  }
+
+  /* Link the client with the target */
+  if (!wp_endpoint_link_new (core, ep, 0, target, stream_id, &error)) {
+    g_warning ("Could not link endpoints: %s\n", error->message);
+  } else {
+    g_info ("Sucessfully linked '%s' to '%s'\n", wp_endpoint_get_name (ep),
+        wp_endpoint_get_name (target));
+  }
+
+  return TRUE;
+}
+
+static WpEndpoint *
+simple_policy_find_endpoint (WpPolicy *policy, GVariant *props,
+    guint32 *stream_id)
+{
+  g_autoptr (WpCore) core = NULL;
+  g_autoptr (GPtrArray) ptr_array = NULL;
+  const char *media_class = NULL;
+  WpEndpoint *ep;
+  int i;
+
+  core = wp_policy_get_core (policy);
+
+  /* Get all the endpoints with the specific media class*/
+  g_variant_lookup (props, "media.class", "&s", &media_class);
+  ptr_array = wp_endpoint_find (core, media_class);
+  if (!ptr_array)
+    return NULL;
+
+  /* TODO: for now we statically return the first stream
+   * we should be looking into the media.role eventually */
+  *stream_id = 0;
+
+  /* Find and return the "selected" endpoint */
+  /* FIXME: fix the endpoint API, this is terrible */
+  for (i = 0; i < ptr_array->len; i++) {
+    ep = g_ptr_array_index (ptr_array, i);
+    GVariantIter iter;
+    g_autoptr (GVariant) controls = NULL;
+    g_autoptr (GVariant) value = NULL;
+    const gchar *name;
+    guint id;
+
+    controls = wp_endpoint_list_controls (ep);
+    g_variant_iter_init (&iter, controls);
+    while ((value = g_variant_iter_next_value (&iter))) {
+      if (!g_variant_lookup (value, "name", "&s", &name)
+          || !g_str_equal (name, "selected")) {
+        g_variant_unref (value);
+        continue;
+      }
+      g_variant_lookup (value, "id", "u", &id);
+      g_variant_unref (value);
+    }
+
+    value = wp_endpoint_get_control_value (ep, id);
+    if (value && g_variant_get_boolean (value))
+      return g_object_ref (ep);
+  }
+
+  /* If not found, return the first endpoint */
+  ep = (ptr_array->len > 1) ? g_ptr_array_index (ptr_array, 0) : NULL;
+  return g_object_ref (ep);
+}
+
+static void
+simple_policy_class_init (WpSimplePolicyClass *klass)
+{
+  WpPolicyClass *policy_class = (WpPolicyClass *) klass;
+
+  policy_class->handle_endpoint = simple_policy_handle_endpoint;
+  policy_class->find_endpoint = simple_policy_find_endpoint;
+}
+
+void
+wireplumber__module_init (WpModule * module, WpCore * core, GVariant * args)
+{
+  WpPolicy *p = g_object_new (simple_policy_get_type (),
+      "rank", WP_POLICY_RANK_UPSTREAM,
+      NULL);
+  wp_policy_register (p, core);
+}