Dynamic Window Size

LibSample/Program.cs

@@ -14,6 +14,7 @@ public static class Program
             new PacketProcessorExample(),
             new AesEncryptionTest(),
             new NtpTest(),
+            new ThroughputTest(),
         };
 
         static void Main(string[] args)

LibSample/ThroughputTest.cs

@@ -0,0 +1,259 @@
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using LiteNetLib;
+using LiteNetLib.Utils;
+
+namespace LibSample
+{
+    public class ThroughputTest : IExample
+    {
+        public const long TOTAL_BYTES = 1024L * 1024L * 16; // 256 MB
+        public const int SEND_CHUNK_SIZE = 1024 * 1024; // 1 MB
+        public const int SEND_CHUNK_COUNT = (int)(TOTAL_BYTES / SEND_CHUNK_SIZE);
+
+        public class Server : INetEventListener, IDisposable
+        {
+            public int ReliableReceived { get; private set; }
+            public bool HasCompleted { get; private set; }
+
+            readonly NetManager _server;
+
+            public TimeSpan TransferTime => _lastChunkReceiveTime - _peerConnectTime;
+
+            DateTime _peerConnectTime;
+            DateTime _lastChunkReceiveTime;
+
+            public NetStatistics Stats => _server.Statistics;
+
+            public Server(int latency, int jitter, int packetLoss)
+            {
+                _server = new NetManager(this)
+                {
+                    AutoRecycle = true,
+                    UpdateTime = 1,
+                    SimulatePacketLoss = true,
+                    SimulationPacketLossChance = packetLoss,
+                    SimulateLatency = true,
+                    SimulationMinLatency = latency,
+                    SimulationMaxLatency = latency + jitter,
+                    EnableStatistics = true,
+                    UnsyncedEvents = true
+                };
+                _server.Start(9050);
+            }
+
+            void INetEventListener.OnNetworkError(IPEndPoint endPoint, SocketError socketErrorCode)
+            {
+                Console.WriteLine($"Server: error: {socketErrorCode}");
+            }
+
+            void INetEventListener.OnNetworkLatencyUpdate(NetPeer peer, int latency)
+            {
+            }
+
+            public void OnConnectionRequest(ConnectionRequest request)
+            {
+                request.AcceptIfKey("ConnKey");
+            }
+
+            void INetEventListener.OnNetworkReceive(NetPeer peer, NetPacketReader reader, byte channelNumber, DeliveryMethod deliveryMethod)
+            {
+                if (++ReliableReceived == SEND_CHUNK_COUNT)
+                {
+                    _lastChunkReceiveTime = DateTime.UtcNow;
+                    HasCompleted = true;
+                }
+            }
+
+            void INetEventListener.OnNetworkReceiveUnconnected(IPEndPoint remoteEndPoint, NetPacketReader reader,
+                UnconnectedMessageType messageType)
+            {
+            }
+
+            void INetEventListener.OnPeerConnected(NetPeer peer)
+            {
+                Console.WriteLine($"Server: client connected: {peer}");
+
+                _peerConnectTime = DateTime.UtcNow;
+            }
+
+            void INetEventListener.OnPeerDisconnected(NetPeer peer, DisconnectInfo disconnectInfo)
+            {
+                Console.WriteLine($"Server: client disconnected: {disconnectInfo.Reason}");
+            }
+
+            public void Dispose()
+            {
+                _server.Stop();
+            }
+        }
+
+        public class Client : INetEventListener, IDisposable
+        {
+            public int ReliableSent;
+
+            public bool HasCompleted { get; private set; }
+            public bool IsRunning => _peer.ConnectionState == ConnectionState.Connected;
+
+            readonly NetManager _client;
+            NetPeer _peer;
+
+            public NetStatistics Stats => _client.Statistics;
+
+            public Client(int latency, int jitter, int packetLoss)
+            {
+                _client = new NetManager(this)
+                {
+                    UnsyncedEvents = true,
+                    AutoRecycle = true,
+                    SimulatePacketLoss = true,
+                    SimulationPacketLossChance = packetLoss,
+                    SimulateLatency = true,
+                    SimulationMinLatency = latency,
+                    SimulationMaxLatency = latency + jitter,
+                    EnableStatistics = true
+                };
+                _client.Start();
+            }
+
+            public void SendReliable(byte[] data)
+            {
+                _peer.Send(data, DeliveryMethod.ReliableOrdered);
+                ReliableSent++;
+            }
+
+            public void Connect()
+            {
+                _peer = _client.Connect("localhost", 9050, "ConnKey");
+            }
+
+            void INetEventListener.OnNetworkError(IPEndPoint endPoint, SocketError socketErrorCode)
+            {
+                Console.WriteLine($"Client: error: {socketErrorCode}");
+            }
+
+            void INetEventListener.OnNetworkLatencyUpdate(NetPeer peer, int latency)
+            {
+            }
+
+            public void OnConnectionRequest(ConnectionRequest request)
+            {
+                request.RejectForce();
+            }
+
+            void INetEventListener.OnNetworkReceive(NetPeer peer, NetPacketReader reader, byte channelNumber, DeliveryMethod deliveryMethod)
+            {
+
+            }
+
+            void INetEventListener.OnNetworkReceiveUnconnected(IPEndPoint remoteEndPoint, NetPacketReader reader,
+                UnconnectedMessageType messageType)
+            {
+            }
+
+            void INetEventListener.OnPeerConnected(NetPeer peer)
+            {
+                Task.Run(() =>
+                {
+                    var data = new byte[SEND_CHUNK_SIZE];
+                    var r = new Random();
+
+                    for (int i = 0; i < SEND_CHUNK_COUNT; i++)
+                    {
+                        r.NextBytes(data);
+                        SendReliable(data);
+                    }
+
+                    HasCompleted = true;
+                });
+            }
+
+            void INetEventListener.OnPeerDisconnected(NetPeer peer, DisconnectInfo disconnectInfo)
+            {
+                Console.WriteLine($"Client: Disconnected {disconnectInfo.Reason}");
+            }
+
+            public void Dispose()
+            {
+                _client.Stop();
+            }
+        }
+
+        public void Run()
+        {
+            Console.WriteLine("Testing Throughput...");
+
+            int[] packetLossValues = new int[] { 0, 1, 2, 5, 10 };
+            int[] latencies = new int[] { 5, 10, 20, 40, 60, 80, 100, 150, 200, 300 };
+
+            Dictionary<int, List<TimeSpan>> resultGroups = new Dictionary<int, List<TimeSpan>>();
+
+            foreach (var packetLoss in packetLossValues)
+            {
+                var results = new List<TimeSpan>();
+
+                resultGroups.Add(packetLoss, results);
+
+                foreach (var latency in latencies)
+                {
+                    var jitter = Math.Max(1, (int)Math.Round(latency / 5f));
+
+                    var serverThread = new Thread(() => StartServer(latency, jitter, packetLoss, results));
+                    serverThread.Start();
+
+                    var clientThread = new Thread(() => StartClient(latency, jitter, packetLoss));
+                    clientThread.Start();
+
+                    Console.WriteLine($"Processing, latency: {latency} ms, jitter: {jitter}, packet loss: {packetLoss} %...");
+
+                    serverThread.Join();
+                    clientThread.Join();
+                }
+            }
+
+            foreach (var resultGroup in resultGroups)
+            {
+                Console.WriteLine($"Results for packet loss: {resultGroup.Key} %");
+
+                for (int i = 0; i < latencies.Length; i++)
+                {
+                    var bytesPerSec = TOTAL_BYTES / resultGroup.Value[i].TotalSeconds;
+                    Console.WriteLine($"\t{latencies[i]} ms -> {resultGroup.Value[i]}\t{bytesPerSec / 1024:F2} kB/s");
+                }
+            }
+        }
+
+        static void StartServer(int latency, int jitter, int packetLoss, List<TimeSpan> results)
+        {
+            using (Server s = new Server(latency, jitter, packetLoss))
+            {
+                while (!s.HasCompleted)
+                    Thread.Sleep(100);
+
+                Console.WriteLine("SERVER RECEIVED -> Reliable: " + s.ReliableReceived + " in " + s.TransferTime);
+                Console.WriteLine("SERVER STATS:\n" + s.Stats);
+
+                results.Add(s.TransferTime);
+            }
+        }
+
+        static void StartClient(int latency, int jitter, int packetLoss)
+        {
+            using (Client c = new Client(latency, jitter, packetLoss))
+            {
+                c.Connect();
+
+                while (!c.HasCompleted || c.IsRunning)
+                    Thread.Sleep(100);
+
+                Console.WriteLine("CLIENT SENT -> Reliable: " + c.ReliableSent);
+                Console.WriteLine("CLIENT STATS:\n" + c.Stats);
+            }
+        }
+    }
+}

LiteNetLib/BaseChannel.cs

@@ -6,7 +6,7 @@ namespace LiteNetLib
     internal abstract class BaseChannel
     {
         protected readonly NetPeer Peer;
-        protected readonly Queue<NetPacket> OutgoingQueue = new Queue<NetPacket>(NetConstants.DefaultWindowSize);
+        protected readonly Queue<NetPacket> OutgoingQueue = new Queue<NetPacket>(NetConstants.MaximumWindowSize);
         private int _isAddedToPeerChannelSendQueue;
 
         public int PacketsInQueue => OutgoingQueue.Count;

LiteNetLib/NetConstants.cs

@@ -38,7 +38,9 @@ public enum DeliveryMethod : byte
     public static class NetConstants
     {
         //can be tuned
-        public const int DefaultWindowSize = 64;
+        public const int MinimumWindowSize = 8;
+        public const int MaximumWindowSize = 512;
+        public const int StartingDynamicWindowSize = 64;
         public const int SocketBufferSize = 1024 * 1024; //1mb
         public const int SocketTTL = 255;
 

LiteNetLib/NetPeer.cs

@@ -5,6 +5,7 @@
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using System.Net;
 using System.Threading;
 using LiteNetLib.Utils;
@@ -81,6 +82,8 @@ private set
             }
         }
 
+        internal bool HasUnsentData => _mergeCount > 0;
+
         //Channels
         private readonly Queue<NetPacket> _unreliableChannel;
         private readonly ConcurrentQueue<BaseChannel> _channelSendQueue;
@@ -302,6 +305,27 @@ private void OverrideMtu(int mtuValue)
             _finishMtu = true;
         }
 
+        public void SetDynamicWindowSize(int size)
+        {
+            foreach (var channel in _channels)
+                if (channel is ReliableChannel reliableChannel)
+                    reliableChannel.CurrentDynamicWindowSize = size;
+        }
+
+        public int TotalReliablePacketsInFlight
+        {
+            get
+            {
+                int count = 0;
+
+                foreach (var channel in _channels)
+                    if (channel is ReliableChannel reliableChannel)
+                        count += reliableChannel.CurrentPacketsInFlight;
+
+                return count;
+            }
+        }
+
         /// <summary>
         /// Returns packets count in queue for reliable channel
         /// </summary>
@@ -1277,10 +1301,19 @@ private void SendMerged()
             _mergeCount = 0;
         }
 
-        internal void SendUserData(NetPacket packet)
+        internal int ComputeMergedPacketSize(NetPacket packet) => NetConstants.HeaderSize + packet.Size + 2;
+
+        internal bool CanMerge(NetPacket packet)
+        {
+            int mergedPacketSize = ComputeMergedPacketSize(packet);
+
+            return _mergePos + mergedPacketSize <= _mtu;
+        }
+
+        internal bool SendUserData(NetPacket packet)
         {
             packet.ConnectionNumber = _connectNum;
-            int mergedPacketSize = NetConstants.HeaderSize + packet.Size + 2;
+            int mergedPacketSize = ComputeMergedPacketSize(packet);
             const int sizeTreshold = 20;
             if (mergedPacketSize + sizeTreshold >= _mtu)
             {
@@ -1293,16 +1326,23 @@ internal void SendUserData(NetPacket packet)
                     Statistics.AddBytesSent(bytesSent);
                 }
 
-                return;
+                return true;
             }
-            if (_mergePos + mergedPacketSize > _mtu)
+
+            bool packetWasSent = false;
+            if (!CanMerge(packet))
+            {
                 SendMerged();
+                packetWasSent = true;
+            }
 
             FastBitConverter.GetBytes(_mergeData.RawData, _mergePos + NetConstants.HeaderSize, (ushort)packet.Size);
             Buffer.BlockCopy(packet.RawData, 0, _mergeData.RawData, _mergePos + NetConstants.HeaderSize + 2, packet.Size);
             _mergePos += packet.Size + 2;
             _mergeCount++;
             //DebugWriteForce("Merged: " + _mergePos + "/" + (_mtu - 2) + ", count: " + _mergeCount);
+
+            return packetWasSent;
         }
 
         internal void Update(int deltaTime)