Precomputed header bytes

src/Microsoft.AspNet.Server.Kestrel/Filter/FilteredStreamAdapter.cs

@@ -22,7 +22,7 @@ public FilteredStreamAdapter(
             IKestrelTrace logger)
         {
             SocketInput = new SocketInput(memory);
-            SocketOutput = new StreamSocketOutput(filteredStream);
+            SocketOutput = new StreamSocketOutput(filteredStream, memory);
 
             _log = logger;
             _filteredStream = filteredStream;

src/Microsoft.AspNet.Server.Kestrel/Filter/LibuvStream.cs

@@ -68,13 +68,29 @@ public override Task<int> ReadAsync(byte[] buffer, int offset, int count, Cancel
 
         public override void Write(byte[] buffer, int offset, int count)
         {
-            var segment = new ArraySegment<byte>(buffer, offset, count);
+            ArraySegment<byte> segment;
+            if (buffer != null)
+            {
+                segment = new ArraySegment<byte>(buffer, offset, count);
+            }
+            else
+            {
+                segment = default(ArraySegment<byte>);
+            }
             _output.Write(segment);
         }
 
         public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken token)
         {
-            var segment = new ArraySegment<byte>(buffer, offset, count);
+            ArraySegment<byte> segment;
+            if (buffer != null)
+            {
+                segment = new ArraySegment<byte>(buffer, offset, count);
+            }
+            else
+            {
+                segment = default(ArraySegment<byte>);
+            }
             return _output.WriteAsync(segment, cancellationToken: token);
         }
 

src/Microsoft.AspNet.Server.Kestrel/Filter/StreamSocketOutput.cs

@@ -13,10 +13,13 @@ namespace Microsoft.AspNet.Server.Kestrel.Filter
     public class StreamSocketOutput : ISocketOutput
     {
         private readonly Stream _outputStream;
+        private readonly MemoryPool2 _memory;
+        private MemoryPoolBlock2 _producingBlock;
 
-        public StreamSocketOutput(Stream outputStream)
+        public StreamSocketOutput(Stream outputStream, MemoryPool2 memory)
         {
             _outputStream = outputStream;
+            _memory = memory;
         }
 
         void ISocketOutput.Write(ArraySegment<byte> buffer, bool immediate)
@@ -30,5 +33,27 @@ Task ISocketOutput.WriteAsync(ArraySegment<byte> buffer, bool immediate, Cancell
             _outputStream.Write(buffer.Array, buffer.Offset, buffer.Count);
             return TaskUtilities.CompletedTask;
         }
+
+        public MemoryPoolIterator2 ProducingStart()
+        {
+            _producingBlock = _memory.Lease();
+            return new MemoryPoolIterator2(_producingBlock);
+        }
+
+        public void ProducingComplete(MemoryPoolIterator2 end, int count)
+        {
+            var block = _producingBlock;
+            while (block != end.Block)
+            {
+                _outputStream.Write(block.Data.Array, block.Data.Offset, block.Data.Count);
+
+                var returnBlock = block;
+                block = block.Next;
+                returnBlock.Pool?.Return(returnBlock);
+            }
+
+            _outputStream.Write(end.Block.Array, end.Block.Data.Offset, end.Index - end.Block.Data.Offset);
+            end.Block.Pool?.Return(end.Block);
+        }
     }
 }

src/Microsoft.AspNet.Server.Kestrel/Http/Connection.cs

@@ -42,7 +42,7 @@ public Connection(ListenerContext context, UvStreamHandle socket) : base(context
             _connectionId = Interlocked.Increment(ref _lastConnectionId);
 
             _rawSocketInput = new SocketInput(Memory2);
-            _rawSocketOutput = new SocketOutput(Thread, _socket, this, _connectionId, Log);
+            _rawSocketOutput = new SocketOutput(Thread, _socket, Memory2, this, _connectionId, Log);
         }
 
         public void Start()
@@ -116,7 +116,7 @@ public void Abort()
                 // called from a libuv thread.
                 ThreadPool.QueueUserWorkItem(state =>
                 {
-                    var connection = (Connection)this;
+                    var connection = (Connection)state;
                     connection._frame.Abort();
                 }, this);
             }

src/Microsoft.AspNet.Server.Kestrel/Http/DateHeaderValueManager.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Text;
 using System.Threading;
 using Microsoft.AspNet.Server.Kestrel.Infrastructure;
 
@@ -17,6 +18,9 @@ public class DateHeaderValueManager : IDisposable
         private readonly TimeSpan _timerInterval;
 
         private volatile string _dateValue;
+        private volatile bool _activeDateBytes;
+        private readonly byte[] _dateBytes0 = Encoding.ASCII.GetBytes("\r\nDate: DDD, dd mmm yyyy hh:mm:ss GMT");
+        private readonly byte[] _dateBytes1 = Encoding.ASCII.GetBytes("\r\nDate: DDD, dd mmm yyyy hh:mm:ss GMT");
         private object _timerLocker = new object();
         private bool _isDisposed = false;
         private bool _hadRequestsSinceLastTimerTick = false;
@@ -62,6 +66,12 @@ public virtual string GetDateHeaderValue()
             return _dateValue ?? _systemClock.UtcNow.ToString(Constants.RFC1123DateFormat);
         }
 
+        public byte[] GetDateHeaderValueBytes()
+        {
+            PumpTimer();
+            return _activeDateBytes ? _dateBytes0 : _dateBytes1;
+        }
+
         /// <summary>
         /// Releases all resources used by the current instance of <see cref="DateHeaderValueManager"/>.
         /// </summary>
@@ -92,6 +102,8 @@ private void PumpTimer()
                         // here as the timer won't fire until the timer interval has passed and we want a value assigned
                         // inline now to serve requests that occur in the meantime.
                         _dateValue = _systemClock.UtcNow.ToString(Constants.RFC1123DateFormat);
+                        Encoding.ASCII.GetBytes(_dateValue, 0, _dateValue.Length, !_activeDateBytes ? _dateBytes0 : _dateBytes1, "\r\nDate: ".Length);
+                        _activeDateBytes = !_activeDateBytes;
                         _dateValueTimer = new Timer(UpdateDateValue, state: null, dueTime: _timerInterval, period: _timerInterval);
                     }
                 }
@@ -105,6 +117,8 @@ private void UpdateDateValue(object state)
 
             // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.18 for required format of Date header
             _dateValue = now.ToString(Constants.RFC1123DateFormat);
+            Encoding.ASCII.GetBytes(_dateValue, 0, _dateValue.Length, !_activeDateBytes ? _dateBytes0 : _dateBytes1, "\r\nDate: ".Length);
+            _activeDateBytes = !_activeDateBytes;
 
             if (_hadRequestsSinceLastTimerTick)
             {