perf: avoid allocation with message structs (#939)

* avoid allocation with message structs * Use ternary operator instead of if * Explain witchcraft
MirageNet · Jul 29, 2019 · 7c7c910 · 7c7c910
1 parent b4077c1
commit 7c7c910
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/Assets/Mirror/Runtime/NetworkMessage.cs b/Assets/Mirror/Runtime/NetworkMessage.cs
@@ -8,7 +8,11 @@ public struct NetworkMessage
 
         public TMsg ReadMessage<TMsg>() where TMsg : IMessageBase, new()
         {
-            TMsg msg = new TMsg();
+            // Normally I would just do:
+            // TMsg msg = new TMsg();
+            // but mono calls an expensive method Activator.CreateInstance
+            // For value types this is unnecesary,  just use the default value
+            TMsg msg = typeof(TMsg).IsValueType ? default(TMsg) : new TMsg();
             msg.Deserialize(reader);
             return msg;
         }