From 713cdaef5dc5e5fc114b47ae74614b12e08957ac Mon Sep 17 00:00:00 2001
From: RoosterDragon <RoosterDragon@outlook.com>
Date: Sun, 12 Nov 2017 12:06:16 +0000
Subject: [PATCH] Reduce allocations needed by ReplayConnection.

Packets from each chunk are now saved directly in an array, removing the overhead of a list. Additionally, a list is reused as a buffer for decoding packets into, preventing a new buffer from needing to be allocated for each chunk.
---
 OpenRA.Game/Network/ReplayConnection.cs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/OpenRA.Game/Network/ReplayConnection.cs b/OpenRA.Game/Network/ReplayConnection.cs
index 4a101d286e..2cc2176e26 100644
--- a/OpenRA.Game/Network/ReplayConnection.cs
+++ b/OpenRA.Game/Network/ReplayConnection.cs
@@ -22,7 +22,7 @@ namespace OpenRA.Network
 		class Chunk
 		{
 			public int Frame;
-			public List<Pair<int, byte[]>> Packets = new List<Pair<int, byte[]>>();
+			public Pair<int, byte[]>[] Packets;
 		}
 
 		Queue<Chunk> chunks = new Queue<Chunk>();
@@ -45,6 +45,8 @@ namespace OpenRA.Network
 			// to avoid issues with all immediate orders being resolved on the first tick.
 			using (var rs = File.OpenRead(replayFilename))
 			{
+				var packets = new List<Pair<int, byte[]>>();
+
 				var chunk = new Chunk();
 
 				while (rs.Position < rs.Length)
@@ -55,7 +57,7 @@ namespace OpenRA.Network
 					var packetLen = rs.ReadInt32();
 					var packet = rs.ReadBytes(packetLen);
 					var frame = BitConverter.ToInt32(packet, 0);
-					chunk.Packets.Add(Pair.New(client, packet));
+					packets.Add(Pair.New(client, packet));
 
 					if (frame != int.MaxValue &&
 						(!lastClientsFrame.ContainsKey(client) || frame > lastClientsFrame[client]))
@@ -81,6 +83,8 @@ namespace OpenRA.Network
 					{
 						// Regular order - finalize the chunk
 						chunk.Frame = frame;
+						chunk.Packets = packets.ToArray();
+						packets.Clear();
 						chunks.Enqueue(chunk);
 						chunk = new Chunk();