default-nodes: fallback to priority.driver if priority.session is not set

See #642

src/scripts/default-nodes/find-best-default-node.lua

@@ -6,6 +6,8 @@
 
 log = Log.open_topic ("s-default-nodes")
 
+nutils = require ("node-utils")
+
 SimpleEventHook {
   name = "default-nodes/find-best-default-node",
   interests = {
@@ -25,8 +27,7 @@ SimpleEventHook {
 
     for _, node_props in ipairs (available_nodes) do
       -- Highest priority node wins
-      local priority = node_props ["priority.session"]
+      local priority = nutils.get_session_priority (node_props)
-      priority = math.tointeger (priority) or 0
 
       if priority > selected_prio or selected_node == nil then
         selected_prio = priority

src/scripts/default-nodes/find-selected-default-node.lua

@@ -13,6 +13,8 @@
 
 log = Log.open_topic ("s-default-nodes")
 
+nutils = require ("node-utils")
+
 SimpleEventHook {
   name = "default-nodes/find-selected-default-node",
   interests = {
@@ -47,8 +49,7 @@ SimpleEventHook {
 
     for _, node_props in ipairs (available_nodes) do
       local name = node_props ["node.name"]
-      local priority = node_props ["priority.session"]
+      local priority = nutils.get_session_priority (node_props)
-      priority = math.tointeger (priority) or 0
 
       if current_configured_node == name then
         priority = 30000 + priority

src/scripts/default-nodes/state-default-nodes.lua

@@ -12,6 +12,8 @@
 
 log = Log.open_topic ("s-default-nodes")
 
+nutils = require ("node-utils")
+
 -- the state storage
 state = nil
 state_table = nil
@@ -42,8 +44,7 @@ find_stored_default_node_hook = SimpleEventHook {
 
       for i, v in ipairs (stored) do
         if name == v then
-          local priority = node_props ["priority.session"]
+          local priority = nutils.get_session_priority (node_props)
-          priority = math.tointeger (priority) or 0
           priority = priority + 20001 - i
 
           if priority > selected_prio then

src/scripts/lib/node-utils.lua

@@ -0,0 +1,18 @@
+-- WirePlumber
+--
+-- Copyright © 2024 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+
+local module = {}
+
+function module.get_session_priority (node_props)
+  local priority = node_props ["priority.session"]
+  -- fallback to driver priority if session priority is not set
+  if not priority then
+    priority = node_props ["priority.driver"]
+  end
+  return math.tointeger (priority) or 0
+end
+
+return module