Refactoring

Build/MQTTnet.nuspec

@@ -11,6 +11,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker).</description>
     <releaseNotes> * [Client] Added new overloads for the message builder.
+* [Core] Performance optimizations (thanks to @	israellot)
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2018</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 

Frameworks/MQTTnet.NetStandard/Adapter/MqttChannelAdapter.cs

@@ -1,9 +1,6 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Net.Sockets;
-using System.Runtime.ExceptionServices;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
@@ -53,14 +50,13 @@ namespace MQTTnet.Adapter
 
         public async Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, MqttBasePacket[] packets)
         {
-            for(var i=0;i<packets.Length;i++)
+            foreach (var packet in packets)
             {
-                await SendPacketsAsync(timeout, cancellationToken, packets[i]).ConfigureAwait(false);
+                await SendPacketsAsync(timeout, cancellationToken, packet).ConfigureAwait(false);
             }
-
         }
 
-        public Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, MqttBasePacket packet)
+        private Task SendPacketsAsync(TimeSpan timeout, CancellationToken cancellationToken, MqttBasePacket packet)
         {
             ThrowIfDisposed();
 
@@ -75,21 +71,23 @@ namespace MQTTnet.Adapter
                 {
                     return;
                 }
-                                
+                
-
                 _logger.Verbose<MqttChannelAdapter>("TX >>> {0} [Timeout={1}]", packet, timeout);
 
                 var packetData = PacketSerializer.Serialize(packet);
+
                 if (cancellationToken.IsCancellationRequested)
                 {
                     return;
                 }
+
                 await _channel.SendStream.WriteAsync(
                     packetData.Array,
                     packetData.Offset,
-                    (int)packetData.Count,
+                    packetData.Count,
                     cancellationToken).ConfigureAwait(false);
 
+                await _channel.SendStream.FlushAsync(cancellationToken).ConfigureAwait(false);
             });
         }
 
@@ -113,12 +111,11 @@ namespace MQTTnet.Adapter
                         {
                             receivedMqttPacket = await ReceiveAsync(_channel.ReceiveStream, linkedCts.Token).ConfigureAwait(false);
                         }
-                        catch(OperationCanceledException ex)
+                        catch (OperationCanceledException ex)
                         {
-                            //check if  timed out
+                            var timedOut = linkedCts.IsCancellationRequested && !cancellationToken.IsCancellationRequested;
-                            if(linkedCts.IsCancellationRequested && !cancellationToken.IsCancellationRequested)
+                            if (timedOut)
                             {
-                                //only timeout token was cancelled
                                 throw new MqttCommunicationTimedOutException(ex);
                             }
                             else

Frameworks/MQTTnet.NetStandard/Implementations/MqttTcpChannel.cs

@@ -14,7 +14,7 @@ namespace MQTTnet.Implementations
 {
     public sealed class MqttTcpChannel : IMqttChannel
     {
-#if NET452 || NET461
+#if NET452 || NET461 || NETSTANDARD2_0
         // ReSharper disable once MemberCanBePrivate.Global
         // ReSharper disable once AutoPropertyCanBeMadeGetOnly.Global
         public static int BufferSize { get; set; } = 4096 * 20; // Can be changed for fine tuning by library user.
@@ -60,7 +60,6 @@ namespace MQTTnet.Implementations
             if (_socket == null)
             {
                 _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
-                
             }
 
 #if NET452 || NET461
@@ -212,8 +211,8 @@ namespace MQTTnet.Implementations
             {
                 stream = new NetworkStream(_socket, true);
             }
-            
+
-#if NET452 || NET461
+#if NET452 || NET461 || NETSTANDARD2_0
             SendStream = new BufferedStream(stream, _bufferSize);
             ReceiveStream = new BufferedStream(stream, _bufferSize);
 #else

Frameworks/MQTTnet.NetStandard/Implementations/MqttTcpServerAdapter.cs

@@ -38,8 +38,7 @@ namespace MQTTnet.Implementations
 
             if (options.DefaultEndpointOptions.IsEnabled)
             {
-                _defaultEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp);
+                _defaultEndpointSocket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
-                _defaultEndpointSocket.NoDelay = true;
 
                 _defaultEndpointSocket.Bind(new IPEndPoint(options.DefaultEndpointOptions.BoundIPAddress, options.GetDefaultEndpointPort()));
                 _defaultEndpointSocket.Listen(options.ConnectionBacklog);
@@ -80,7 +79,7 @@ namespace MQTTnet.Implementations
             _defaultEndpointSocket = null;
 
             _tlsCertificate = null;
-            
+
             _tlsEndpointSocket?.Dispose();
             _tlsEndpointSocket = null;
 
@@ -104,7 +103,8 @@ namespace MQTTnet.Implementations
 #else
                     var clientSocket = await _defaultEndpointSocket.AcceptAsync().ConfigureAwait(false);
 #endif
-                    clientSocket.NoDelay=true;
+                    clientSocket.NoDelay = true;
+
                     var clientAdapter = new MqttChannelAdapter(new MqttTcpChannel(clientSocket, null), new MqttPacketSerializer(), _logger);
                     ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
                 }
@@ -139,7 +139,7 @@ namespace MQTTnet.Implementations
 
                     var sslStream = new SslStream(new NetworkStream(clientSocket));
                     await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false).ConfigureAwait(false);
-                    
+
                     var clientAdapter = new MqttChannelAdapter(new MqttTcpChannel(clientSocket, sslStream), new MqttPacketSerializer(), _logger);
                     ClientAccepted?.Invoke(this, new MqttServerAdapterClientAcceptedEventArgs(clientAdapter));
                 }

Frameworks/MQTTnet.NetStandard/Serializer/MqttPacketSerializer.cs

@@ -2,7 +2,6 @@
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -23,29 +22,28 @@ namespace MQTTnet.Serializer
             using (var stream = new MemoryStream(128))
             using (var writer = new MqttPacketWriter(stream))
             {
-                //leave enough head space for max header (fixed + 4 variable remaining lenght)
+                // Leave enough head space for max header size (fixed + 4 variable remaining length)
                 stream.Position = 5;
 
                 var fixedHeader = SerializePacket(packet, writer);
 
-                var remainingLength = MqttPacketWriter.GetRemainingLength((int)stream.Length-5);
+                var remainingLength = MqttPacketWriter.GetRemainingLength((int)stream.Length - 5);
 
                 var headerSize = remainingLength.Length + 1;
                 var headerOffset = 5 - headerSize;
 
-                //position curson on correct offset on beginining of array
+                // Position cursor on correct offset on beginining of array (has leading 0x0)
                 stream.Position = headerOffset;
-                
+
-                //write header
                 writer.Write(fixedHeader);
-                writer.Write(remainingLength,0,remainingLength.Length);
+                writer.Write(remainingLength, 0, remainingLength.Length);
-                                
+
 #if NET461 || NET452 || NETSTANDARD2_0
                 var buffer = stream.GetBuffer();
 #else
                 var buffer = stream.ToArray();
 #endif
-                return new ArraySegment<byte>(buffer, headerOffset, (int)stream.Length- headerOffset);
+                return new ArraySegment<byte>(buffer, headerOffset, (int)stream.Length - headerOffset);
             }
         }
 
@@ -300,7 +298,7 @@ namespace MQTTnet.Serializer
 
             return packet;
         }
-        
+
         private static void ValidateConnectPacket(MqttConnectPacket packet)
         {
             if (packet == null) throw new ArgumentNullException(nameof(packet));

Frameworks/MQTTnet.NetStandard/Serializer/MqttPacketWriter.cs

@@ -60,11 +60,11 @@ namespace MQTTnet.Serializer
         {
             if (length <= 0)
             {
-                return new [] { (byte)0 };
+                return new[] { (byte)0 };
             }
 
             var bytes = new byte[4];
-            int arraySize = 0;
+            var offset = 0;
 
             // Alorithm taken from http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html.
             var x = length;
@@ -77,12 +77,12 @@ namespace MQTTnet.Serializer
                     encodedByte = encodedByte | 128;
                 }
 
-                bytes[arraySize] = (byte)encodedByte;
+                bytes[offset] = (byte)encodedByte;
 
-                arraySize++;
+                offset++;
             } while (x > 0);
 
-            return bytes.Take(arraySize).ToArray();
+            return bytes.Take(offset).ToArray();
         }
     }
 }

Tests/MQTTnet.TestApp.NetCore/PerformanceTest.cs

@@ -44,7 +44,7 @@ namespace MQTTnet.TestApp.NetCore
 
                 try
                 {
-                    await client.ConnectAsync(options);
+                    await client.ConnectAsync(options).ConfigureAwait(false);
                 }
                 catch (Exception exception)
                 {
@@ -165,7 +165,7 @@ namespace MQTTnet.TestApp.NetCore
                 Console.WriteLine("Press any key to exit.");
                 Console.ReadLine();
 
-                await mqttServer.StopAsync();
+                await mqttServer.StopAsync().ConfigureAwait(false);
             }
             catch (Exception e)
             {