propper buffering in place

Frameworks/MQTTnet.NetFramework/Implementations/MqttServerAdapter.cs

@@ -10,6 +10,7 @@ using MQTTnet.Core.Adapter;
 using MQTTnet.Core.Diagnostics;
 using MQTTnet.Core.Serializer;
 using MQTTnet.Core.Server;
+using MQTTnet.Core.Channel;
 
 namespace MQTTnet.Implementations
 {
@@ -86,7 +87,7 @@ namespace MQTTnet.Implementations
                 try
                 {
                     var clientSocket = await Task.Factory.FromAsync(_defaultEndpointSocket.BeginAccept, _defaultEndpointSocket.EndAccept, null).ConfigureAwait(false);
-                    var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, null), new MqttPacketSerializer());
+                    var clientAdapter = new MqttChannelCommunicationAdapter(new BufferedCommunicationChannel(new MqttTcpChannel(clientSocket, null)), new MqttPacketSerializer());
                     ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
                 }
                 catch (Exception exception) when (!(exception is ObjectDisposedException))

Frameworks/MQTTnet.NetFramework/Implementations/MqttTcpChannel.cs

@@ -93,17 +93,15 @@ namespace MQTTnet.Implementations
             }
         }
 
-        public async Task ReadAsync(byte[] buffer)
+        public async Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer)
         {
-            if (buffer == null) throw new ArgumentNullException(nameof(buffer));
-
             try
             {
                 var totalBytes = 0;
 
                 do
                 {
-                    var read = await _dataStream.ReadAsync(buffer, totalBytes, buffer.Length - totalBytes).ConfigureAwait(false);
+                    var read = await _dataStream.ReadAsync(buffer, totalBytes, length - totalBytes).ConfigureAwait(false);
                     if (read == 0)
                     {
                         throw new MqttCommunicationException(new SocketException((int)SocketError.Disconnecting));
@@ -111,7 +109,8 @@ namespace MQTTnet.Implementations
 
                     totalBytes += read;
                 }
-                while (totalBytes < buffer.Length);
+                while (totalBytes < length);
+                return new ArraySegment<byte>(buffer, 0, length);
             }
             catch (SocketException exception)
             {
@@ -143,5 +142,10 @@ namespace MQTTnet.Implementations
 
             return certificates;
         }
+
+        public int Peek()
+        {
+            return _socket.Available;
+        }
     }
 }

Frameworks/MQTTnet.NetFramework/Implementations/MqttWebSocketChannel.cs

@@ -11,9 +11,6 @@ namespace MQTTnet.Implementations
     public sealed class MqttWebSocketChannel : IMqttCommunicationChannel, IDisposable
     {
         private ClientWebSocket _webSocket = new ClientWebSocket();
-        private const int BufferSize = 4096;
-        private const int BufferAmplifier = 20;
-        private readonly byte[] WebSocketBuffer = new byte[BufferSize * BufferAmplifier];
         private int WebSocketBufferSize;
         private int WebSocketBufferOffset;
 
@@ -42,50 +39,39 @@ namespace MQTTnet.Implementations
             _webSocket?.Dispose();
         }
 
-        public Task ReadAsync(byte[] buffer)
+        public async Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer)
         {
-            return Task.WhenAll(ReadToBufferAsync(buffer));
+            await ReadToBufferAsync(length, buffer).ConfigureAwait(false);
+            
+            var result = new ArraySegment<byte>(buffer, WebSocketBufferOffset, length);
+            WebSocketBufferSize -= length;
+            WebSocketBufferOffset += length;
+            
+            return result;
         }
 
-        private async Task ReadToBufferAsync(byte[] buffer)
+        private async Task ReadToBufferAsync(int length, byte[] buffer)
         {
-            var temporaryBuffer = new byte[BufferSize];
-            var offset = 0;
+            if (WebSocketBufferSize > 0)
+            {
+                return;
+            }
 
-            while (_webSocket.State == WebSocketState.Open)
+            var offset = 0;
+            while (_webSocket.State == WebSocketState.Open && WebSocketBufferSize < length)
             {
-                if (WebSocketBufferSize == 0)
+                WebSocketReceiveResult response;
+                do
                 {
-                    WebSocketBufferOffset = 0;
-
-                    WebSocketReceiveResult response;
-                    do
-                    {
-                        response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(temporaryBuffer), CancellationToken.None).ConfigureAwait(false);
-
-                        temporaryBuffer.CopyTo(WebSocketBuffer, offset);
-                        offset += response.Count;
-                        temporaryBuffer = new byte[BufferSize];
-                    } while (!response.EndOfMessage);
+                    response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer, offset, buffer.Length - offset), CancellationToken.None).ConfigureAwait(false);
+                    offset += response.Count;
+                } while (!response.EndOfMessage);
 
-                    WebSocketBufferSize = response.Count;
-                    if (response.MessageType == WebSocketMessageType.Close)
-                    {
-                        await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
-                    }
-
-                    Buffer.BlockCopy(WebSocketBuffer, 0, buffer, 0, buffer.Length);
-                    WebSocketBufferSize -= buffer.Length;
-                    WebSocketBufferOffset += buffer.Length;
-                }
-                else
+                WebSocketBufferSize = response.Count;
+                if (response.MessageType == WebSocketMessageType.Close)
                 {
-                    Buffer.BlockCopy(WebSocketBuffer, WebSocketBufferOffset, buffer, 0, buffer.Length);
-                    WebSocketBufferSize -= buffer.Length;
-                    WebSocketBufferOffset += buffer.Length;
+                    await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
                 }
-
-                return;
             }
         }
 
@@ -105,5 +91,10 @@ namespace MQTTnet.Implementations
                 throw new MqttCommunicationException(exception);
             }
         }
+
+        public int Peek()
+        {
+            return WebSocketBufferSize;
+        }
     }
 }

Frameworks/MQTTnet.NetFramework/MqttClientFactory.cs

@@ -22,7 +22,7 @@ namespace MQTTnet
             {
                 case MqttConnectionType.Tcp:
                 case MqttConnectionType.Tls:
-                    return new MqttTcpChannel();
+                    return new BufferedCommunicationChannel( new MqttTcpChannel() );
                 case MqttConnectionType.Ws:
                 case MqttConnectionType.Wss:
                     return new MqttWebSocketChannel();

Frameworks/MQTTnet.NetStandard/Implementations/MqttTcpChannel.cs

@@ -92,17 +92,15 @@ namespace MQTTnet.Implementations
             }
         }
 
-        public async Task ReadAsync(byte[] buffer)
+        public async Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer)
         {
-            if (buffer == null) throw new ArgumentNullException(nameof(buffer));
-
             try
             {
                 var totalBytes = 0;
 
                 do
                 {
-                    var read = await _dataStream.ReadAsync(buffer, totalBytes, buffer.Length - totalBytes).ConfigureAwait(false);
+                    var read = await _dataStream.ReadAsync(buffer, totalBytes, length - totalBytes).ConfigureAwait(false);
                     if (read == 0)
                     {
                         throw new MqttCommunicationException(new SocketException((int)SocketError.Disconnecting));
@@ -110,7 +108,8 @@ namespace MQTTnet.Implementations
 
                     totalBytes += read;
                 }
-                while (totalBytes < buffer.Length);
+                while (totalBytes < length);
+                return new ArraySegment<byte>(buffer, 0, length);
             }
             catch (SocketException exception)
             {
@@ -142,5 +141,10 @@ namespace MQTTnet.Implementations
 
             return certificates;
         }
+
+        public int Peek()
+        {
+            return _socket.Available;
+        }
     }
 }

Frameworks/MQTTnet.NetStandard/Implementations/MqttWebSocketChannel.cs

@@ -11,9 +11,6 @@ namespace MQTTnet.Implementations
     public sealed class MqttWebSocketChannel : IMqttCommunicationChannel, IDisposable
     {
         private ClientWebSocket _webSocket = new ClientWebSocket();
-        private const int BufferSize = 4096;
-        private const int BufferAmplifier = 20;
-        private readonly byte[] WebSocketBuffer = new byte[BufferSize * BufferAmplifier];
         private int WebSocketBufferSize;
         private int WebSocketBufferOffset;
 
@@ -42,50 +39,39 @@ namespace MQTTnet.Implementations
             _webSocket?.Dispose();
         }
 
-        public Task ReadAsync(byte[] buffer)
+        public async Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer)
         {
-            return Task.WhenAll(ReadToBufferAsync(buffer));
+            await ReadToBufferAsync(length, buffer).ConfigureAwait(false);
+
+            var result = new ArraySegment<byte>(buffer, WebSocketBufferOffset, length);
+            WebSocketBufferSize -= length;
+            WebSocketBufferOffset += length;
+
+            return result;
         }
 
-        private async Task ReadToBufferAsync(byte[] buffer)
+        private async Task ReadToBufferAsync(int length, byte[] buffer)
         {
-            var temporaryBuffer = new byte[BufferSize];
-            var offset = 0;
+            if (WebSocketBufferSize > 0)
+            {
+                return;
+            }
 
-            while (_webSocket.State == WebSocketState.Open)
+            var offset = 0;
+            while (_webSocket.State == WebSocketState.Open && WebSocketBufferSize < length)
             {
-                if (WebSocketBufferSize == 0)
+                WebSocketReceiveResult response;
+                do
                 {
-                    WebSocketBufferOffset = 0;
-
-                    WebSocketReceiveResult response;
-                    do
-                    {
-                        response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(temporaryBuffer), CancellationToken.None).ConfigureAwait(false);
+                    response = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer, offset, buffer.Length - offset), CancellationToken.None).ConfigureAwait(false);
+                    offset += response.Count;
+                } while (!response.EndOfMessage);
 
-                        temporaryBuffer.CopyTo(WebSocketBuffer, offset);
-                        offset += response.Count;
-                        temporaryBuffer = new byte[BufferSize];
-                    } while (!response.EndOfMessage);
-
-                    WebSocketBufferSize = response.Count;
-                    if (response.MessageType == WebSocketMessageType.Close)
-                    {
-                        await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
-                    }
-
-                    Buffer.BlockCopy(WebSocketBuffer, 0, buffer, 0, buffer.Length);
-                    WebSocketBufferSize -= buffer.Length;
-                    WebSocketBufferOffset += buffer.Length;
-                }
-                else
+                WebSocketBufferSize = response.Count;
+                if (response.MessageType == WebSocketMessageType.Close)
                 {
-                    Buffer.BlockCopy(WebSocketBuffer, WebSocketBufferOffset, buffer, 0, buffer.Length);
-                    WebSocketBufferSize -= buffer.Length;
-                    WebSocketBufferOffset += buffer.Length;
+                    await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, string.Empty, CancellationToken.None).ConfigureAwait(false);
                 }
-
-                return;
             }
         }
 
@@ -105,5 +91,10 @@ namespace MQTTnet.Implementations
                 throw new MqttCommunicationException(exception);
             }
         }
+
+        public int Peek()
+        {
+            return WebSocketBufferSize;
+        }
     }
 }

MQTTnet.Core/Channel/BufferConstants.cs

@@ -0,0 +1,7 @@
+namespace MQTTnet.Core.Channel
+{
+    public static class BufferConstants
+    {
+        public const int Size = 4096 * 20;
+    }
+}

MQTTnet.Core/Channel/BufferedCommunicationChannel.cs

@@ -0,0 +1,77 @@
+using System.Threading.Tasks;
+using MQTTnet.Core.Client;
+using System;
+
+namespace MQTTnet.Core.Channel
+{
+    public class BufferedCommunicationChannel : IMqttCommunicationChannel
+    {
+        private IMqttCommunicationChannel _inner { get; }
+        private int _bufferSize = 0;
+        private int _bufferOffset = 0;
+
+        public BufferedCommunicationChannel(IMqttCommunicationChannel inner)
+        {
+            _inner = inner;
+        }
+
+        public Task ConnectAsync(MqttClientOptions options)
+        {
+            return _inner.ConnectAsync(options);
+        }
+
+        public Task DisconnectAsync()
+        {
+            return _inner.DisconnectAsync();
+        }
+
+        public int Peek()
+        {
+            return _inner.Peek();
+        }
+
+        public async Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer)
+        {
+            //read from buffer
+            if (_bufferSize > 0)
+            {
+                return ReadFomBuffer(length, buffer);
+            }
+
+            var available = _inner.Peek();
+            // if there are less or equal bytes available then requested then just read em
+            if (available <= length)
+            {
+                return await _inner.ReadAsync(length, buffer);
+            }
+
+            //if more bytes are available than requested do buffer them to reduce calls to network buffers
+            await WriteToBuffer(available, buffer).ConfigureAwait(false);
+            return ReadFomBuffer(length, buffer);
+        }
+
+        private async Task WriteToBuffer(int available, byte[] buffer)
+        {
+            await _inner.ReadAsync(available, buffer).ConfigureAwait(false);
+            _bufferSize = available;
+            _bufferOffset = 0;
+        }
+
+        private ArraySegment<byte> ReadFomBuffer(int length, byte[] buffer)
+        {
+            var result = new ArraySegment<byte>(buffer, _bufferOffset, length);
+            _bufferSize -= length;
+            _bufferOffset += length;
+
+            if (_bufferSize < 0)
+            {
+            }
+            return result;
+        }
+
+        public Task WriteAsync(byte[] buffer)
+        {
+            return _inner.WriteAsync(buffer);
+        }
+    }
+}

MQTTnet.Core/Channel/IMqttCommunicationChannel.cs

@@ -1,5 +1,6 @@
 using System.Threading.Tasks;
 using MQTTnet.Core.Client;
+using System;
 
 namespace MQTTnet.Core.Channel
 {
@@ -11,6 +12,11 @@ namespace MQTTnet.Core.Channel
 
         Task WriteAsync(byte[] buffer);
 
-        Task ReadAsync(byte[] buffer);
+        /// <summary>
+        /// get the currently available number of bytes without reading them
+        /// </summary>
+        int Peek();
+
+        Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer);
     }
 }

MQTTnet.Core/Serializer/MqttPacketReader.cs

@@ -49,13 +49,13 @@ namespace MQTTnet.Core.Serializer
             return ReadBytes(_header.BodyLength - (int)BaseStream.Position);
         }
 
-        public static async Task<MqttPacketHeader> ReadHeaderFromSourceAsync(IMqttCommunicationChannel source)
+        public static async Task<MqttPacketHeader> ReadHeaderFromSourceAsync(IMqttCommunicationChannel source, byte[] buffer)
         {
-            var fixedHeader = await ReadStreamByteAsync(source).ConfigureAwait(false);
+            var fixedHeader = await ReadStreamByteAsync(source, buffer).ConfigureAwait(false);
             var byteReader = new ByteReader(fixedHeader);
             byteReader.Read(4);
             var controlPacketType = (MqttControlPacketType)byteReader.Read(4);
-            var bodyLength = await ReadBodyLengthFromSourceAsync(source).ConfigureAwait(false);
+            var bodyLength = await ReadBodyLengthFromSourceAsync(source, buffer).ConfigureAwait(false);
 
             return new MqttPacketHeader()
             {
@@ -65,18 +65,17 @@ namespace MQTTnet.Core.Serializer
             };
         }
 
-        private static async Task<byte> ReadStreamByteAsync(IMqttCommunicationChannel source)
+        private static async Task<byte> ReadStreamByteAsync(IMqttCommunicationChannel source, byte[] readBuffer)
         {
-            var buffer = new byte[1];
-            await ReadFromSourceAsync(source, buffer).ConfigureAwait(false);
-            return buffer[0];
+            var result = await ReadFromSourceAsync(source, 1, readBuffer).ConfigureAwait(false);
+            return result.Array[result.Offset];
         }
 
-        public static async Task ReadFromSourceAsync(IMqttCommunicationChannel source, byte[] buffer)
+        public static async Task<ArraySegment<byte>> ReadFromSourceAsync(IMqttCommunicationChannel source, int length, byte[] buffer)
         {
             try
             {
-                await source.ReadAsync(buffer);
+                return await source.ReadAsync(length, buffer);
             }
             catch (Exception exception)
             {
@@ -84,7 +83,7 @@ namespace MQTTnet.Core.Serializer
             }
         }
         
-        private static async Task<int> ReadBodyLengthFromSourceAsync(IMqttCommunicationChannel source)
+        private static async Task<int> ReadBodyLengthFromSourceAsync(IMqttCommunicationChannel source, byte[] buffer)
         {
             // Alorithm taken from http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html.
             var multiplier = 1;
@@ -92,7 +91,7 @@ namespace MQTTnet.Core.Serializer
             byte encodedByte;
             do
             {
-                encodedByte = await ReadStreamByteAsync(source).ConfigureAwait(false);
+                encodedByte = await ReadStreamByteAsync(source, buffer).ConfigureAwait(false);
                 value += (encodedByte & 127) * multiplier;
                 multiplier *= 128;
                 if (multiplier > 128 * 128 * 128)

MQTTnet.Core/Serializer/MqttPacketSerializer.cs

@@ -17,6 +17,7 @@ namespace MQTTnet.Core.Serializer
         private static byte[] ProtocolVersionV310Name { get; } = Encoding.UTF8.GetBytes("MQIs");
 
         public MqttProtocolVersion ProtocolVersion { get; set; } = MqttProtocolVersion.V311;
+        private byte[] _readBuffer = new byte[BufferConstants.Size]; 
 
         public async Task SerializeAsync(MqttBasePacket packet, IMqttCommunicationChannel destination)
         {
@@ -115,17 +116,13 @@ namespace MQTTnet.Core.Serializer
         public async Task<MqttBasePacket> DeserializeAsync(IMqttCommunicationChannel source)
         {
             if (source == null) throw new ArgumentNullException(nameof(source));
-            
-            var header = await MqttPacketReader.ReadHeaderFromSourceAsync(source).ConfigureAwait(false);
 
-            var body = new byte[header.BodyLength];
-            if (header.BodyLength > 0)
-            {
-                await MqttPacketReader.ReadFromSourceAsync(source, body).ConfigureAwait(false);
-            }
+            var header = await MqttPacketReader.ReadHeaderFromSourceAsync(source, _readBuffer).ConfigureAwait(false);
 
-            using (var mqttPacketReader = new MqttPacketReader(new MemoryStream(body), header))
-            {                
+            var body = await GetBody(source, header).ConfigureAwait(false);
+
+            using (var mqttPacketReader = new MqttPacketReader(body, header))
+            {
                 switch (header.ControlPacketType)
                 {
                     case MqttControlPacketType.Connect:
@@ -221,6 +218,17 @@ namespace MQTTnet.Core.Serializer
             }
         }
 
+        private async Task<MemoryStream> GetBody(IMqttCommunicationChannel source, MqttPacketHeader header)
+        {
+            if (header.BodyLength > 0)
+            {
+                var segment = await MqttPacketReader.ReadFromSourceAsync(source, header.BodyLength, _readBuffer).ConfigureAwait(false);
+                return new MemoryStream(segment.Array, segment.Offset, segment.Count);
+            }
+
+            return new MemoryStream();
+        }
+
         private static MqttBasePacket DeserializeUnsubscribe(MqttPacketReader reader)
         {
             var packet = new MqttUnsubscribePacket

Tests/MQTTnet.Core.Tests/MqttPacketSerializerTests.cs

@@ -418,15 +418,21 @@ namespace MQTTnet.Core.Tests
                 return _stream.WriteAsync(buffer, 0, buffer.Length);
             }
 
-            public Task ReadAsync(byte[] buffer)
+            public async Task<ArraySegment<byte>> ReadAsync(int length, byte[] buffer)
             {
-                return _stream.ReadAsync(buffer, 0, buffer.Length);
+                await _stream.ReadAsync(buffer, 0, length);
+                return new ArraySegment<byte>(buffer, 0, length);
             }
 
             public byte[] ToArray()
             {
                 return _stream.ToArray();
             }
+
+            public int Peek()
+            {
+                return (int)_stream.Length - (int)_stream.Position;
+            }
         }
 
         private static void SerializeAndCompare(MqttBasePacket packet, string expectedBase64Value, MqttProtocolVersion protocolVersion = MqttProtocolVersion.V311)

Tests/MQTTnet.TestApp.NetFramework/PerformanceTest.cs

@@ -29,7 +29,8 @@ namespace MQTTnet.TestApp.NetFramework
                 {
                     Server = "localhost",
                     ClientId = "XYZ",
-                    CleanSession = true
+                    CleanSession = true,
+                    DefaultCommunicationTimeout = TimeSpan.FromMinutes(10)
                 };
 
                 var client = new MqttClientFactory().CreateMqttClient(options);
@@ -128,7 +129,8 @@ namespace MQTTnet.TestApp.NetFramework
                         }
 
                         return MqttConnectReturnCode.ConnectionAccepted;
-                    }
+                    },
+                    DefaultCommunicationTimeout = TimeSpan.FromMinutes(10)
                 };
                 
                 var mqttServer = new MqttServerFactory().CreateMqttServer(options);

Tests/MQTTnet.TestApp.NetFramework/Program.cs

@@ -20,18 +20,18 @@ namespace MQTTnet.TestApp.NetFramework
             Console.WriteLine("1 = Start client");
             Console.WriteLine("2 = Start server");
             Console.WriteLine("3 = Start performance test");
-            var pressedKey = Console.ReadKey(true);
-            if (pressedKey.Key == ConsoleKey.D1)
-            {
-                Task.Run(() => RunClientAsync(args));
-                Thread.Sleep(Timeout.Infinite);
-            }
-            else if (pressedKey.Key == ConsoleKey.D2)
-            {
-                Task.Run(() => RunServerAsync(args));
-                Thread.Sleep(Timeout.Infinite);
-            }
-            else if (pressedKey.Key == ConsoleKey.D3)
+            //var pressedKey = Console.ReadKey(true);
+            //if (pressedKey.Key == ConsoleKey.D1)
+            //{
+            //    Task.Run(() => RunClientAsync(args));
+            //    Thread.Sleep(Timeout.Infinite);
+            //}
+            //else if (pressedKey.Key == ConsoleKey.D2)
+            //{
+            //    Task.Run(() => RunServerAsync(args));
+            //    Thread.Sleep(Timeout.Infinite);
+            //}
+            //else if (pressedKey.Key == ConsoleKey.D3)
             {
                 Task.Run(() => PerformanceTest.RunAsync());
                 Thread.Sleep(Timeout.Infinite);