[player] Sort devices and autoselect based on priority

src/outputs.c

@@ -315,6 +315,11 @@ outputs_metadata_free(struct output_metadata *omd)
     }
 }
 
+int
+outputs_priority(struct output_device *device)
+{
+  return outputs[device->type]->priority;
+}
 
 const char *
 outputs_name(enum output_types type)

src/outputs.h

@@ -147,7 +147,6 @@ struct output_definition
 
   // Priority to give this output when autoselecting an output, 1 is highest
   // 1 = highest priority, 0 = don't autoselect
-  // TODO Not implemented yet
   int priority;
 
   // Set to 1 if the output initialization failed
@@ -240,6 +239,9 @@ outputs_metadata_prune(uint64_t rtptime);
 void
 outputs_metadata_free(struct output_metadata *omd);
 
+int
+outputs_priority(struct output_device *device);
+
 const char *
 outputs_name(enum output_types type);
 

src/player.c

@@ -1567,6 +1567,40 @@ player_playback_cb(int fd, short what, void *arg)
 }
 
 /* Helpers */
+static void
+device_list_sort(void)
+{
+  struct output_device *device;
+  struct output_device *next;
+  struct output_device *prev;
+  int swaps;
+
+  // Swap sorting since even the most inefficient sorting should do fine here
+  do
+    {
+      swaps = 0;
+      prev = NULL;
+      for (device = dev_list; device && device->next; device = device->next)
+	{
+	  next = device->next;
+	  if ( (outputs_priority(device) > outputs_priority(next)) ||
+	       (outputs_priority(device) == outputs_priority(next) && strcasecmp(device->name, next->name) > 0) )
+	    {
+	      if (device == dev_list)
+		dev_list = next;
+	      if (prev)
+		prev->next = next;
+
+	      device->next = next->next;
+	      next->next = device;
+	      swaps++;
+	    }
+	  prev = device;
+	}
+    }
+  while (swaps > 0);
+}
+
 static void
 device_remove(struct output_device *remove)
 {
@@ -1693,6 +1727,8 @@ device_add(struct player_command *cmd)
       outputs_device_free(add);
     }
 
+  device_list_sort();
+
   return 0;
 }
 
@@ -2396,8 +2432,9 @@ playback_start_item(struct player_command *cmd, struct queue_item *qii)
   if ((cmd->output_requests_pending == 0) && (output_sessions == 0))
     for (device = dev_list; device; device = device->next)
       {
-        if (!device->session)
+	if ((outputs_priority(device) == 0) || device->session)
-	  {
+	  continue;
+
 	speaker_select_output(device);
 	ret = outputs_device_start(device, device_restart_cb, last_rtptime + AIRTUNES_V2_PACKET_SAMPLES);
 	if (ret < 0)
@@ -2411,7 +2448,6 @@ playback_start_item(struct player_command *cmd, struct queue_item *qii)
 	cmd->output_requests_pending++;
 	break;
       }
-      }
 
   /* No luck finding valid output */
   if ((cmd->output_requests_pending == 0) && (output_sessions == 0))