Use System.Buffers

src/Microsoft.AspNetCore.Http/BufferingHelper.cs

@@ -9,7 +9,7 @@ namespace Microsoft.AspNetCore.Http.Internal
 {
     public static class BufferingHelper
     {
-        internal const int DefaultBufferThreshold = 1024 * 30;
+        internal const int DefaultBufferThreshold = 32768;
 
         private readonly static Func<string> _getTempDirectory = () => TempDirectory;
 

src/Microsoft.AspNetCore.Http/project.json

@@ -13,7 +13,8 @@
   "dependencies": {
     "Microsoft.AspNetCore.Http.Abstractions": "1.0.0-*",
     "Microsoft.AspNetCore.WebUtilities": "1.0.0-*",
-    "Microsoft.Net.Http.Headers": "1.0.0-*"
+    "Microsoft.Net.Http.Headers": "1.0.0-*",
+    "System.Buffers": "4.0.0-*"
   },
   "frameworks": {
     "net451": {},

src/Microsoft.AspNetCore.Owin/WebSockets/OwinWebSocketAdapter.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.Buffers;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -126,11 +127,18 @@ public override async Task CloseAsync(WebSocketCloseStatus closeStatus, string s
                 await CloseOutputAsync(closeStatus, statusDescription, cancellationToken);
             }
 
-            byte[] buffer = new byte[1024];
-            while (State == WebSocketState.CloseSent)
+            var buffer = ArrayPool<byte>.Shared.Rent(1024);
+            try
             {
-                // Drain until close received
-                await ReceiveAsync(new ArraySegment<byte>(buffer), cancellationToken);
+                while (State == WebSocketState.CloseSent)
+                {
+                    // Drain until close received
+                    await ReceiveAsync(new ArraySegment<byte>(buffer), cancellationToken);
+                }
+            }
+            finally
+            {
+                ArrayPool<byte>.Shared.Return(buffer);
             }
         }
 

src/Microsoft.AspNetCore.WebUtilities/BufferedReadStream.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.Buffers;
 using System.IO;
 using System.Text;
 using System.Threading;
@@ -16,19 +17,26 @@ internal class BufferedReadStream : Stream
 
         private readonly Stream _inner;
         private readonly byte[] _buffer;
+        private readonly ArrayPool<byte> _bytePool;
         private int _bufferOffset = 0;
         private int _bufferCount = 0;
         private bool _disposed;
 
         public BufferedReadStream(Stream inner, int bufferSize)
+            : this(inner, bufferSize, ArrayPool<byte>.Shared)
+        {
+        }
+
+        public BufferedReadStream(Stream inner, int bufferSize, ArrayPool<byte> bytePool)
         {
             if (inner == null)
             {
                 throw new ArgumentNullException(nameof(inner));
             }
 
             _inner = inner;
-            _buffer = new byte[bufferSize];
+            _bytePool = bytePool;
+            _buffer = bytePool.Rent(bufferSize);
         }
 
         public ArraySegment<byte> BufferedData
@@ -128,10 +136,15 @@ public override void SetLength(long value)
 
         protected override void Dispose(bool disposing)
         {
-            _disposed = true;
-            if (disposing)
+            if (!_disposed)
             {
-                _inner.Dispose();
+                _disposed = true;
+                _bytePool.Return(_buffer);
+
+                if (disposing)
+                {
+                    _inner.Dispose();
+                }
             }
         }
 

src/Microsoft.AspNetCore.WebUtilities/FileBufferingReadStream.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.Buffers;
 using System.Diagnostics;
 using System.IO;
 using System.Threading;
@@ -17,11 +18,14 @@ namespace Microsoft.AspNetCore.WebUtilities
     public class FileBufferingReadStream : Stream
     {
         private readonly Stream _inner;
+        private readonly ArrayPool<byte> _bytePool;
         private readonly int _memoryThreshold;
         private string _tempFileDirectory;
         private readonly Func<string> _tempFileDirectoryAccessor;
 
-        private Stream _buffer = new MemoryStream(); // TODO: We could have a more efficiently expanding buffer stream.
+        private Stream _buffer;
+        private byte[] _rentedBuffer;
+        private int _readIntoBuffer = 0;
         private bool _inMemory = true;
         private bool _completelyBuffered;
 
@@ -32,6 +36,15 @@ public FileBufferingReadStream(
             Stream inner,
             int memoryThreshold,
             Func<string> tempFileDirectoryAccessor)
+            : this(inner, memoryThreshold, tempFileDirectoryAccessor, ArrayPool<byte>.Shared)
+        {
+        }
+
+        public FileBufferingReadStream(
+            Stream inner,
+            int memoryThreshold,
+            Func<string> tempFileDirectoryAccessor,
+            ArrayPool<byte> bytePool)
         {
             if (inner == null)
             {
@@ -43,13 +56,33 @@ public FileBufferingReadStream(
                 throw new ArgumentNullException(nameof(tempFileDirectoryAccessor));
             }
 
+            _bytePool = bytePool;
+            if (memoryThreshold < 1024 * 1024)
+            {
+                _rentedBuffer = bytePool.Rent(memoryThreshold);
+                _buffer = new MemoryStream(_rentedBuffer);
+            }
+            else
+            {
+                _buffer = new MemoryStream();
+            }
+
             _inner = inner;
             _memoryThreshold = memoryThreshold;
             _tempFileDirectoryAccessor = tempFileDirectoryAccessor;
         }
 
         // TODO: allow for an optional buffer size limit to prevent filling hard disks. 1gb?
         public FileBufferingReadStream(Stream inner, int memoryThreshold, string tempFileDirectory)
+            : this(inner, memoryThreshold, tempFileDirectory, ArrayPool<byte>.Shared)
+        {
+        }
+
+        public FileBufferingReadStream(
+            Stream inner,
+            int memoryThreshold,
+            string tempFileDirectory,
+            ArrayPool<byte> bytePool)
         {
             if (inner == null)
             {
@@ -61,6 +94,17 @@ public FileBufferingReadStream(Stream inner, int memoryThreshold, string tempFil
                 throw new ArgumentNullException(nameof(tempFileDirectory));
             }
 
+            _bytePool = bytePool;
+            if (memoryThreshold < 1024 * 1024)
+            {
+                _rentedBuffer = bytePool.Rent(memoryThreshold);
+                _buffer = new MemoryStream(_rentedBuffer);
+            }
+            else
+            {
+                _buffer = new MemoryStream();
+            }
+
             _inner = inner;
             _memoryThreshold = memoryThreshold;
             _tempFileDirectory = tempFileDirectory;
@@ -135,22 +179,27 @@ private Stream CreateTempFile()
         public override int Read(byte[] buffer, int offset, int count)
         {
             ThrowIfDisposed();
-            if (_buffer.Position < _buffer.Length || _completelyBuffered)
+            if (_buffer.Position < _readIntoBuffer || _completelyBuffered)
             {
                 // Just read from the buffer
-                return _buffer.Read(buffer, offset, (int)Math.Min(count, _buffer.Length - _buffer.Position));
+                return _buffer.Read(buffer, offset, (int)Math.Min(count, _readIntoBuffer - _buffer.Position));
             }
 
             int read = _inner.Read(buffer, offset, count);
 
-            if (_inMemory && _buffer.Length + read > _memoryThreshold)
+            if (_inMemory && _readIntoBuffer + read > _memoryThreshold)
             {
-                var oldBuffer = _buffer;
-                _buffer = CreateTempFile();
                 _inMemory = false;
-                oldBuffer.Position = 0;
-                oldBuffer.CopyTo(_buffer, 1024 * 16);
+                checked
+                {
+                    int length = _readIntoBuffer;
+                    _buffer = CreateTempFile();
+                    _buffer.Write(_rentedBuffer, 0, length);
+                    _bytePool.Return(_rentedBuffer);
+                    _rentedBuffer = null;
+                }
             }
+            _readIntoBuffer += read;
 
             if (read > 0)
             {
@@ -206,22 +255,27 @@ public override int EndRead(IAsyncResult asyncResult)
         public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             ThrowIfDisposed();
-            if (_buffer.Position < _buffer.Length || _completelyBuffered)
+            if (_buffer.Position < _readIntoBuffer || _completelyBuffered)
             {
                 // Just read from the buffer
-                return await _buffer.ReadAsync(buffer, offset, (int)Math.Min(count, _buffer.Length - _buffer.Position), cancellationToken);
+                return await _buffer.ReadAsync(buffer, offset, (int)Math.Min(count, _readIntoBuffer - _buffer.Position), cancellationToken);
             }
 
             int read = await _inner.ReadAsync(buffer, offset, count, cancellationToken);
 
-            if (_inMemory && _buffer.Length + read > _memoryThreshold)
+            if (_inMemory && _readIntoBuffer + read > _memoryThreshold)
             {
-                var oldBuffer = _buffer;
-                _buffer = CreateTempFile();
                 _inMemory = false;
-                oldBuffer.Position = 0;
-                await oldBuffer.CopyToAsync(_buffer, 1024 * 16, cancellationToken);
+                checked
+                {
+                    int length = _readIntoBuffer;
+                    _buffer = CreateTempFile();
+                    await _buffer.WriteAsync(_rentedBuffer, 0, length, cancellationToken);
+                    _bytePool.Return(_rentedBuffer);
+                    _rentedBuffer = null;
+                }
             }
+            _readIntoBuffer += read;
 
             if (read > 0)
             {
@@ -270,6 +324,11 @@ protected override void Dispose(bool disposing)
             if (!_disposed)
             {
                 _disposed = true;
+                if (_rentedBuffer != null)
+                {
+                    _bytePool.Return(_rentedBuffer);
+                }
+
                 if (disposing)
                 {
                     _buffer.Dispose();
@@ -285,4 +344,4 @@ private void ThrowIfDisposed()
             }
         }
     }
-}
+}