scripts: add suspend-node.lua to replace m-node-suspension

... plus the necessary API for it to work

modules/module-lua-scripting/api.c

@@ -31,6 +31,21 @@ get_wp_export_core (lua_State *L)
   return lua_touserdata (L, -1);
 }
 
+/* GSource */
+
+static int
+source_destroy (lua_State *L)
+{
+  GSource *source = wplua_checkboxed (L, 1, G_TYPE_SOURCE);
+  g_source_destroy (source);
+  return 0;
+}
+
+static const luaL_Reg source_methods[] = {
+  { "destroy", source_destroy },
+  { NULL, NULL }
+};
+
 /* WpCore */
 
 static int
@@ -58,20 +73,24 @@ core_get_info (lua_State *L)
 static int
 core_idle_add (lua_State *L)
 {
+  GSource *source = NULL;
   luaL_checktype (L, 1, LUA_TFUNCTION);
-  wp_core_idle_add_closure (get_wp_core (L), NULL,
+  wp_core_idle_add_closure (get_wp_core (L), &source,
       wplua_function_to_closure (L, 1));
-  return 0;
+  wplua_pushboxed (L, G_TYPE_SOURCE, source);
+  return 1;
 }
 
 static int
 core_timeout_add (lua_State *L)
 {
+  GSource *source = NULL;
   lua_Integer timeout_ms = luaL_checkinteger (L, 1);
   luaL_checktype (L, 2, LUA_TFUNCTION);
-  wp_core_timeout_add_closure (get_wp_core (L), NULL, timeout_ms,
+  wp_core_timeout_add_closure (get_wp_core (L), &source, timeout_ms,
       wplua_function_to_closure (L, 2));
-  return 0;
+  wplua_pushboxed (L, G_TYPE_SOURCE, source);
+  return 1;
 }
 
 static void
@@ -800,7 +819,17 @@ node_new (lua_State *L)
   return 1;
 }
 
+static int
+node_send_command (lua_State *L)
+{
+  WpNode *node = wplua_checkobject (L, 1, WP_TYPE_NODE);
+  const char *command = luaL_checkstring (L, 2);
+  wp_node_send_command (node, command);
+  return 0;
+}
+
 static const luaL_Reg node_methods[] = {
+  { "send_command", node_send_command },
   { NULL, NULL }
 };
 
@@ -968,6 +997,8 @@ wp_lua_scripting_api_init (lua_State *L)
 
   wp_lua_scripting_pod_init (L);
 
+  wplua_register_type_methods (L, G_TYPE_SOURCE,
+      NULL, source_methods);
   wplua_register_type_methods (L, WP_TYPE_OBJECT,
       NULL, object_methods);
   wplua_register_type_methods (L, WP_TYPE_PROXY,

src/config/config.lua

@@ -57,7 +57,7 @@ load_module("si-standard-link")
 load_monitor("v4l2")
 
 -- Automatically suspends idle nodes after 3 seconds
-load_module("node-suspension")
+load_script("suspend-node.lua")
 
 -- Automatically sets device profiles to 'On'
 load_module("device-activation")

src/scripts/suspend-node.lua

@@ -0,0 +1,47 @@
+-- WirePlumber
+--
+-- Copyright © 2021 Collabora Ltd.
+--    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+--
+-- SPDX-License-Identifier: MIT
+
+om = ObjectManager {
+  Interest { type = "node",
+    Constraint { "media.class", "matches", "Audio/*" }
+  },
+  Interest { type = "node",
+    Constraint { "media.class", "matches", "Video/*" }
+  },
+}
+
+sources = {}
+
+om:connect("object-added", function (om, node)
+  node:connect("state-changed", function (node, old_state, cur_state)
+    -- Always clear the current source if any
+    local id = node["bound-id"]
+    if sources[id] then
+      sources[id]:destroy()
+      sources[id] = nil
+    end
+
+    -- Add a timeout source if idle for at least 3 seconds
+    if cur_state == "idle" then
+      sources[id] = Core.timeout_add(3000, function()
+        -- Suspend the node
+        Log.info(node, "was idle for a while; suspending ...")
+        node:send_command("Suspend")
+
+        -- Unref the source
+        sources[id] = nil
+
+        -- false (== G_SOURCE_REMOVE) destroys the source so that this
+        -- function does not get fired again after 3 seconds
+        return false
+      end)
+    end
+
+  end)
+end)
+
+om:activate()