Combine BufferWriter and CountingBufferWriter

benchmarkapps/PlatformBenchmarks/BenchmarkApplication.cs

@@ -78,7 +78,7 @@ namespace PlatformBenchmarks
         }
         private static void PlainText(PipeWriter pipeWriter)
         {
-            var writer = new CountingBufferWriter<PipeWriter>(pipeWriter);
+            var writer = new BufferWriter<PipeWriter>(pipeWriter);
             // HTTP 1.1 OK
             writer.Write(_http11OK);
 
@@ -105,7 +105,7 @@ namespace PlatformBenchmarks
 
         private static void Json(PipeWriter pipeWriter)
         {
-            var writer = new CountingBufferWriter<PipeWriter>(pipeWriter);
+            var writer = new BufferWriter<PipeWriter>(pipeWriter);
 
             // HTTP 1.1 OK
             writer.Write(_http11OK);
@@ -134,7 +134,7 @@ namespace PlatformBenchmarks
 
         private static void Default(PipeWriter pipeWriter)
         {
-            var writer = new CountingBufferWriter<PipeWriter>(pipeWriter);
+            var writer = new BufferWriter<PipeWriter>(pipeWriter);
 
             // HTTP 1.1 OK
             writer.Write(_http11OK);

src/Kestrel.Core/Internal/BufferWriter.cs

@@ -1,25 +1,27 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Copyright (c) .NET Foundation. All rights reserved.
-// The .NET Foundation licenses this file to you under the MIT license.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-// See the LICENSE file in the project root for more information.
 
 using System.Runtime.CompilerServices;
 
 namespace System.Buffers
 {
-    internal ref struct BufferWriter<T> where T: IBufferWriter<byte>
+    internal ref struct BufferWriter<T> where T : IBufferWriter<byte>
     {
         private T _output;
         private Span<byte> _span;
         private int _buffered;
+        private long _bytesCommitted;
 
         public BufferWriter(T output)
         {
             _buffered = 0;
+            _bytesCommitted = 0;
             _output = output;
             _span = output.GetSpan();
         }
 
         public Span<byte> Span => _span;
+        public long BytesCommitted => _bytesCommitted;
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Commit()
@@ -27,6 +29,7 @@ namespace System.Buffers
             var buffered = _buffered;
             if (buffered > 0)
             {
+                _bytesCommitted += buffered;
                 _buffered = 0;
                 _output.Advance(buffered);
             }

src/Kestrel.Core/Internal/Http/ChunkWriter.cs

@@ -48,14 +48,14 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return new ArraySegment<byte>(bytes, offset, 10 - offset);
         }
 
-        internal static int WriteBeginChunkBytes(ref CountingBufferWriter<PipeWriter> start, int dataCount)
+        internal static int WriteBeginChunkBytes(ref BufferWriter<PipeWriter> start, int dataCount)
         {
             var chunkSegment = BeginChunkBytes(dataCount);
             start.Write(new ReadOnlySpan<byte>(chunkSegment.Array, chunkSegment.Offset, chunkSegment.Count));
             return chunkSegment.Count;
         }
 
-        internal static void WriteEndChunkBytes(ref CountingBufferWriter<PipeWriter> start)
+        internal static void WriteEndChunkBytes(ref BufferWriter<PipeWriter> start)
         {
             start.Write(new ReadOnlySpan<byte>(_endChunkBytes.Array, _endChunkBytes.Offset, _endChunkBytes.Count));
         }

src/Kestrel.Core/Internal/Http/CountingBufferWriter.cs

@@ -1,99 +0,0 @@
-
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Runtime.CompilerServices;
-
-namespace System.Buffers
-{
-    // TODO: Once this is public, update the actual CountingBufferWriter in the Common repo,
-    // and go back to using that.
-    internal ref struct CountingBufferWriter<T> where T: IBufferWriter<byte>
-    {
-        private T _output;
-        private Span<byte> _span;
-        private int _buffered;
-        private long _bytesCommitted;
-
-        public CountingBufferWriter(T output)
-        {
-            _buffered = 0;
-            _bytesCommitted = 0;
-            _output = output;
-            _span = output.GetSpan();
-        }
-
-        public Span<byte> Span => _span;
-        public long BytesCommitted => _bytesCommitted;
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Commit()
-        {
-            var buffered = _buffered;
-            if (buffered > 0)
-            {
-                _bytesCommitted += buffered;
-                _buffered = 0;
-                _output.Advance(buffered);
-            }
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Advance(int count)
-        {
-            _buffered += count;
-            _span = _span.Slice(count);
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Write(ReadOnlySpan<byte> source)
-        {
-            if (_span.Length >= source.Length)
-            {
-                source.CopyTo(_span);
-                Advance(source.Length);
-            }
-            else
-            {
-                WriteMultiBuffer(source);
-            }
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Ensure(int count = 1)
-        {
-            if (_span.Length < count)
-            {
-                EnsureMore(count);
-            }
-        }
-
-        [MethodImpl(MethodImplOptions.NoInlining)]
-        private void EnsureMore(int count = 0)
-        {
-            if (_buffered > 0)
-            {
-                Commit();
-            }
-
-            _output.GetMemory(count);
-            _span = _output.GetSpan();
-        }
-
-        private void WriteMultiBuffer(ReadOnlySpan<byte> source)
-        {
-            while (source.Length > 0)
-            {
-                if (_span.Length == 0)
-                {
-                    EnsureMore();
-                }
-
-                var writable = Math.Min(source.Length, _span.Length);
-                source.Slice(0, writable).CopyTo(_span);
-                source = source.Slice(writable);
-                Advance(writable);
-            }
-        }
-    }
-}

src/Kestrel.Core/Internal/Http/Http1OutputProducer.cs

@@ -128,7 +128,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
 
                 var buffer = _pipeWriter;
-                var writer = new CountingBufferWriter<PipeWriter>(buffer);
+                var writer = new BufferWriter<PipeWriter>(buffer);
 
                 writer.Write(_bytesHttpVersion11);
                 var statusBytes = ReasonPhrases.ToStatusBytes(statusCode, reasonPhrase);
@@ -210,7 +210,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                 }
 
                 writableBuffer = _pipeWriter;
-                var writer = new CountingBufferWriter<PipeWriter>(writableBuffer);
+                var writer = new BufferWriter<PipeWriter>(writableBuffer);
                 if (buffer.Length > 0)
                 {
                     writer.Write(buffer);

src/Kestrel.Core/Internal/Http/HttpHeaders.Generated.cs

@@ -7765,7 +7765,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return true;
         }
         
-        internal void CopyToFast(ref CountingBufferWriter<PipeWriter> output)
+        internal void CopyToFast(ref BufferWriter<PipeWriter> output)
         {
             var tempBits = _bits | (_contentLength.HasValue ? -9223372036854775808L : 0);
             

src/Kestrel.Core/Internal/Http/HttpProtocol.cs

@@ -936,7 +936,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             var bytesWritten = 0L;
             if (buffer.Length > 0)
             {
-                var writer = new CountingBufferWriter<PipeWriter>(writableBuffer);
+                var writer = new BufferWriter<PipeWriter>(writableBuffer);
 
                 ChunkWriter.WriteBeginChunkBytes(ref writer, buffer.Length);
                 writer.Write(buffer.Span);

src/Kestrel.Core/Internal/Http/HttpResponseHeaders.cs

@@ -27,7 +27,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return GetEnumerator();
         }
 
-        internal void CopyTo(ref CountingBufferWriter<PipeWriter> buffer)
+        internal void CopyTo(ref BufferWriter<PipeWriter> buffer)
         {
             CopyToFast(ref buffer);
             if (MaybeUnknown != null)

src/Kestrel.Core/Internal/Http/PipelineExtensions.cs

@@ -40,7 +40,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return result;
         }
 
-        internal static unsafe void WriteAsciiNoValidation(ref this CountingBufferWriter<PipeWriter> buffer, string data)
+        internal static unsafe void WriteAsciiNoValidation(ref this BufferWriter<PipeWriter> buffer, string data)
         {
             if (string.IsNullOrEmpty(data))
             {
@@ -69,7 +69,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        internal static unsafe void WriteNumeric(ref this CountingBufferWriter<PipeWriter> buffer, ulong number)
+        internal static unsafe void WriteNumeric(ref this BufferWriter<PipeWriter> buffer, ulong number)
         {
             const byte AsciiDigitStart = (byte)'0';
 
@@ -119,7 +119,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
-        private static void WriteNumericMultiWrite(ref this CountingBufferWriter<PipeWriter> buffer, ulong number)
+        private static void WriteNumericMultiWrite(ref this BufferWriter<PipeWriter> buffer, ulong number)
         {
             const byte AsciiDigitStart = (byte)'0';
 
@@ -140,7 +140,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
-        private unsafe static void WriteAsciiMultiWrite(ref this CountingBufferWriter<PipeWriter> buffer, string data)
+        private unsafe static void WriteAsciiMultiWrite(ref this BufferWriter<PipeWriter> buffer, string data)
         {
             var remaining = data.Length;
 

test/Kestrel.Core.Tests/BufferWriterTests.cs

@@ -4,7 +4,6 @@
 using System.Buffers;
 using System.Collections.Generic;
 using System.Linq;
-using System.Threading.Tasks;
 using Xunit;
 
 namespace System.IO.Pipelines.Tests
@@ -73,15 +72,20 @@ namespace System.IO.Pipelines.Tests
         [InlineData(1, 2)]
         [InlineData(2, 1)]
         [InlineData(1, 1)]
-        public void CanWriteWithOffsetAndLenght(int offset, int length)
+        public void CanWriteWithOffsetAndLength(int offset, int length)
         {
             BufferWriter<PipeWriter> writer = new BufferWriter<PipeWriter>(Pipe.Writer);
             var array = new byte[] { 1, 2, 3 };
 
             writer.Write(new Span<byte>(array, offset, length));
+
+            Assert.Equal(0, writer.BytesCommitted);
+
             writer.Commit();
 
+            Assert.Equal(length, writer.BytesCommitted);
             Assert.Equal(array.Skip(offset).Take(length).ToArray(), Read());
+            Assert.Equal(length, writer.BytesCommitted);
         }
 
         [Fact]
@@ -94,6 +98,7 @@ namespace System.IO.Pipelines.Tests
             writer.Write(new Span<byte>(array, 0, array.Length));
             writer.Commit();
 
+            Assert.Equal(0, writer.BytesCommitted);
             Assert.Equal(array, Read());
         }
 
@@ -105,6 +110,7 @@ namespace System.IO.Pipelines.Tests
             writer.Write(new byte[] { 1, 2, 3 });
             writer.Commit();
 
+            Assert.Equal(3, writer.BytesCommitted);
             Assert.Equal(new byte[] { 1, 2, 3 }, Read());
         }
 
@@ -118,6 +124,7 @@ namespace System.IO.Pipelines.Tests
             writer.Write(new byte[] { 3 });
             writer.Commit();
 
+            Assert.Equal(3, writer.BytesCommitted);
             Assert.Equal(new byte[] { 1, 2, 3 }, Read());
         }
 
@@ -133,6 +140,7 @@ namespace System.IO.Pipelines.Tests
             writer.Write(expectedBytes);
             writer.Commit();
 
+            Assert.Equal(expectedBytes.LongLength, writer.BytesCommitted);
             Assert.Equal(expectedBytes, Read());
         }
 
@@ -142,6 +150,7 @@ namespace System.IO.Pipelines.Tests
             BufferWriter<PipeWriter> writer = new BufferWriter<PipeWriter>(Pipe.Writer);
             writer.Ensure(10);
             Assert.True(writer.Span.Length > 10);
+            Assert.Equal(0, writer.BytesCommitted);
             Assert.Equal(new byte[] { }, Read());
         }
 
@@ -164,6 +173,7 @@ namespace System.IO.Pipelines.Tests
             writer.Write(new byte[] { 1, 2, 3 });
             writer.Commit();
 
+            Assert.Equal(3, writer.BytesCommitted);
             Assert.Equal(initialLength - 3, writer.Span.Length);
             Assert.Equal(Pipe.Writer.GetMemory().Length, writer.Span.Length);
             Assert.Equal(new byte[] { 1, 2, 3 }, Read());
@@ -175,49 +185,17 @@ namespace System.IO.Pipelines.Tests
         [InlineData(500)]
         [InlineData(5000)]
         [InlineData(50000)]
-        public async Task WriteLargeDataBinary(int length)
+        public void WriteLargeDataBinary(int length)
         {
             var data = new byte[length];
             new Random(length).NextBytes(data);
-            PipeWriter output = Pipe.Writer;
-            output.Write(data);
-            await output.FlushAsync();
 
-            ReadResult result = await Pipe.Reader.ReadAsync();
+            BufferWriter<PipeWriter> writer = new BufferWriter<PipeWriter>(Pipe.Writer);
-            ReadOnlySequence<byte> input = result.Buffer;
+            writer.Write(data);
-            Assert.Equal(data, input.ToArray());
+            writer.Commit();
-            Pipe.Reader.AdvanceTo(input.End);
-        }
 
-        [Fact]
+            Assert.Equal(length, writer.BytesCommitted);
-        public async Task CanWriteNothingToBuffer()
+            Assert.Equal(data, Read());
-        {
-            PipeWriter buffer = Pipe.Writer;
-            buffer.GetMemory(0);
-            buffer.Advance(0); // doing nothing, the hard way
-            await buffer.FlushAsync();
-        }
-
-        [Fact]
-        public void EmptyWriteDoesNotThrow()
-        {
-            Pipe.Writer.Write(new byte[0]);
-        }
-
-        [Fact]
-        public void ThrowsOnAdvanceOverMemorySize()
-        {
-            Memory<byte> buffer = Pipe.Writer.GetMemory(1);
-            var exception = Assert.Throws<InvalidOperationException>(() => Pipe.Writer.Advance(buffer.Length + 1));
-            Assert.Equal("Can't advance past buffer size.", exception.Message);
-        }
-
-        [Fact]
-        public void ThrowsOnAdvanceWithNoMemory()
-        {
-            PipeWriter buffer = Pipe.Writer;
-            var exception = Assert.Throws<InvalidOperationException>(() => buffer.Advance(1));
-            Assert.Equal("No writing operation. Make sure GetMemory() was called.", exception.Message);
         }
     }
 }

test/Kestrel.Core.Tests/PipelineExtensionTests.cs

@@ -36,7 +36,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void WritesNumericToAscii(ulong number)
         {
             var writerBuffer = _pipe.Writer;
-            var writer = new CountingBufferWriter<PipeWriter>(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             writer.WriteNumeric(number);
             writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
@@ -54,7 +54,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void WritesNumericAcrossSpanBoundaries(int gapSize)
         {
             var writerBuffer = _pipe.Writer;
-            var writer = new CountingBufferWriter<PipeWriter>(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             // almost fill up the first block
             var spacer = new byte[writer.Span.Length - gapSize];
             writer.Write(spacer);
@@ -85,7 +85,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public void EncodesAsAscii(string input, byte[] expected)
         {
             var pipeWriter = _pipe.Writer;
-            var writer = new CountingBufferWriter<PipeWriter>(pipeWriter);
+            var writer = new BufferWriter<PipeWriter>(pipeWriter);
             writer.WriteAsciiNoValidation(input);
             writer.Commit();
             pipeWriter.FlushAsync().GetAwaiter().GetResult();
@@ -115,7 +115,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             // WriteAscii doesn't validate if characters are in the ASCII range
             // but it shouldn't produce more than one byte per character
             var writerBuffer = _pipe.Writer;
-            var writer = new CountingBufferWriter<PipeWriter>(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             writer.WriteAsciiNoValidation(input);
             writer.Commit();
             writerBuffer.FlushAsync().GetAwaiter().GetResult();
@@ -129,7 +129,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             const byte maxAscii = 0x7f;
             var writerBuffer = _pipe.Writer;
-            var writer = new CountingBufferWriter<PipeWriter>(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             for (var i = 0; i < maxAscii; i++)
             {
                 writer.WriteAsciiNoValidation(new string((char)i, 1));
@@ -159,7 +159,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             var testString = new string(' ', stringLength);
             var writerBuffer = _pipe.Writer;
-            var writer = new CountingBufferWriter<PipeWriter>(writerBuffer);
+            var writer = new BufferWriter<PipeWriter>(writerBuffer);
             // almost fill up the first block
             var spacer = new byte[writer.Span.Length - gapSize];
             writer.Write(spacer);

tools/CodeGenerator/KnownHeaders.cs

@@ -548,7 +548,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             return true;
         }}
         {(loop.ClassName == "HttpResponseHeaders" ? $@"
-        internal void CopyToFast(ref CountingBufferWriter<PipeWriter> output)
+        internal void CopyToFast(ref BufferWriter<PipeWriter> output)
         {{
             var tempBits = _bits | (_contentLength.HasValue ? {1L << 63}L : 0);
             {Each(loop.Headers.Where(header => header.Identifier != "ContentLength").OrderBy(h => !h.PrimaryHeader), header => $@"