From fc49d6943a2927a6ddba468d68ff04811571c3b3 Mon Sep 17 00:00:00 2001
From: Vapre <vapre@hotmail.com>
Date: Tue, 5 Jan 2021 00:08:04 +0100
Subject: [PATCH] OrderIO performance improvement

OrderIO, ToOrderList, skip if frame is empty,
which occurs often each client each frame.
---
 OpenRA.Game/Network/OrderIO.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/OpenRA.Game/Network/OrderIO.cs b/OpenRA.Game/Network/OrderIO.cs
index ce69dc76e9..4d4f7e82b4 100644
--- a/OpenRA.Game/Network/OrderIO.cs
+++ b/OpenRA.Game/Network/OrderIO.cs
@@ -16,8 +16,14 @@ namespace OpenRA.Network
 {
 	public static class OrderIO
 	{
+		static readonly List<Order> EmptyOrderList = new List<Order>(0);
+
 		public static List<Order> ToOrderList(this byte[] bytes, World world)
 		{
+			// PERF: Skip empty order frames, often per client each frame
+			if (bytes.Length == 4)
+				return EmptyOrderList;
+
 			var ms = new MemoryStream(bytes, 4, bytes.Length - 4);
 			var reader = new BinaryReader(ms);
 			var ret = new List<Order>();