Clean up some of protocol abstractions (#2311)

* Clean up some of protocol abstractions
- Renamed PipeConnection to DuplexPipe
- Removed MemoryPool from ConnectionContext
- Work around value tuple issue on net471

benchmarks/Kestrel.Performance/Http1ConnectionParsingOverheadBenchmark.cs

@@ -23,7 +23,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         public void Setup()
         {
             var memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext
             {

benchmarks/Kestrel.Performance/Http1WritingBenchmark.cs

@@ -25,7 +25,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         private static readonly Func<object, Task> _psuedoAsyncTaskFunc = (obj) => _psuedoAsyncTask;
 
         private readonly TestHttp1Connection _http1Connection;
-        private (IDuplexPipe Transport, IDuplexPipe Application) _pair;
+        private DuplexPipe.DuplexPipePair _pair;
 
         private readonly byte[] _writeData;
 
@@ -95,7 +95,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         {
             using (var memoryPool = new MemoryPool())
             {
-                var pair = PipeFactory.CreateConnectionPair(memoryPool);
+                var pair = DuplexPipe.CreateConnectionPair(memoryPool);
                 _pair = pair;
 
                 var serviceContext = new ServiceContext

benchmarks/Kestrel.Performance/HttpProtocolFeatureCollection.cs

@@ -78,7 +78,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         public HttpProtocolFeatureCollection()
         {
             var memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext
             {

benchmarks/Kestrel.Performance/RequestParsingBenchmark.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         public void Setup()
         {
             var memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext
             {

benchmarks/Kestrel.Performance/ResponseHeaderCollectionBenchmark.cs

@@ -171,7 +171,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         public void Setup()
         {
             var memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext
             {

benchmarks/Kestrel.Performance/ResponseHeadersWritingBenchmark.cs

@@ -111,7 +111,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Performance
         public void Setup()
         {
             var memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(memoryPool);
 
             var serviceContext = new ServiceContext
             {

src/Kestrel.Core/Internal/ConnectionHandler.cs

@@ -36,10 +36,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
 
             // REVIEW: Unfortunately, we still need to use the service context to create the pipes since the settings
             // for the scheduler and limits are specified here
-            var inputOptions = GetInputPipeOptions(_serviceContext, connectionContext.MemoryPool, transportFeature.InputWriterScheduler);
+            var inputOptions = GetInputPipeOptions(_serviceContext, transportFeature.MemoryPool, transportFeature.InputWriterScheduler);
-            var outputOptions = GetOutputPipeOptions(_serviceContext, connectionContext.MemoryPool, transportFeature.OutputReaderScheduler);
+            var outputOptions = GetOutputPipeOptions(_serviceContext, transportFeature.MemoryPool, transportFeature.OutputReaderScheduler);
 
-            var pair = PipeFactory.CreateConnectionPair(inputOptions, outputOptions);
+            var pair = DuplexPipe.CreateConnectionPair(inputOptions, outputOptions);
 
             // Set the transport and connection id
             connectionContext.ConnectionId = CorrelationIdGenerator.GetNextId();

src/Kestrel.Core/Internal/HttpConnectionMiddleware.cs

@@ -44,7 +44,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
                 Protocols = _protocols,
                 ServiceContext = _serviceContext,
                 ConnectionFeatures = connectionContext.Features,
-                MemoryPool = connectionContext.MemoryPool,
+                MemoryPool = transportFeature.MemoryPool,
                 ConnectionAdapters = _connectionAdapters,
                 Transport = connectionContext.Transport,
                 Application = transportFeature.Application

src/Protocols.Abstractions/ConnectionContext.cs

@@ -1,8 +1,4 @@
-using System;
+using System.IO.Pipelines;
-using System.Buffers;
-using System.IO.Pipelines;
-using System.Threading;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http.Features;
 
 namespace Microsoft.AspNetCore.Protocols
@@ -14,7 +10,5 @@ namespace Microsoft.AspNetCore.Protocols
         public abstract IFeatureCollection Features { get; }
 
         public abstract IDuplexPipe Transport { get; set; }
-
-        public abstract MemoryPool MemoryPool { get; }
     }
 }

src/Protocols.Abstractions/DefaultConnectionContext.cs

@@ -28,8 +28,6 @@ namespace Microsoft.AspNetCore.Protocols
 
         public override IFeatureCollection Features => _features.Collection;
 
-        public override MemoryPool MemoryPool => ConnectionTransportFeature.MemoryPool;
-
         public override IDuplexPipe Transport
         {
             get => ConnectionTransportFeature.Transport;

src/Protocols.Abstractions/DuplexPipe.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Buffers;
+using System.Collections.Generic;
+using System.Text;
+
+namespace System.IO.Pipelines
+{
+    public class DuplexPipe : IDuplexPipe
+    {
+        public DuplexPipe(PipeReader reader, PipeWriter writer)
+        {
+            Input = reader;
+            Output = writer;
+        }
+
+        public PipeReader Input { get; }
+
+        public PipeWriter Output { get; }
+
+        public void Dispose()
+        {
+        }
+
+        public static DuplexPipePair CreateConnectionPair(MemoryPool memoryPool)
+        {
+            return CreateConnectionPair(new PipeOptions(memoryPool), new PipeOptions(memoryPool));
+        }
+
+        public static DuplexPipePair CreateConnectionPair(PipeOptions inputOptions, PipeOptions outputOptions)
+        {
+            var input = new Pipe(inputOptions);
+            var output = new Pipe(outputOptions);
+
+            var transportToApplication = new DuplexPipe(output.Reader, input.Writer);
+            var applicationToTransport = new DuplexPipe(input.Reader, output.Writer);
+
+            return new DuplexPipePair(applicationToTransport, transportToApplication);
+        }
+
+        // This class exists to work around issues with value tuple on .NET Framework
+        public readonly struct DuplexPipePair
+        {
+            public IDuplexPipe Transport { get; }
+            public IDuplexPipe Application { get; }
+
+            public DuplexPipePair(IDuplexPipe transport, IDuplexPipe application)
+            {
+                Transport = transport;
+                Application = application;
+            }
+        }
+    }
+}

src/Protocols.Abstractions/PipeConnection.cs

@@ -1,23 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace System.IO.Pipelines
-{
-    public class PipeConnection : IDuplexPipe
-    {
-        public PipeConnection(PipeReader reader, PipeWriter writer)
-        {
-            Input = reader;
-            Output = writer;
-        }
-
-        public PipeReader Input { get; }
-
-        public PipeWriter Output { get; }
-
-        public void Dispose()
-        {
-        }
-    }
-}

src/Protocols.Abstractions/PipeFactoryExtensions.cs

@@ -1,23 +0,0 @@
-using System.Buffers;
-
-namespace System.IO.Pipelines
-{
-    public static class PipeFactory
-    {
-        public static (IDuplexPipe Transport, IDuplexPipe Application) CreateConnectionPair(MemoryPool memoryPool)
-        {
-            return CreateConnectionPair(new PipeOptions(memoryPool), new PipeOptions(memoryPool));
-        }
-
-        public static (IDuplexPipe Transport, IDuplexPipe Application) CreateConnectionPair(PipeOptions inputOptions, PipeOptions outputOptions)
-        {
-            var input = new Pipe(inputOptions);
-            var output = new Pipe(outputOptions);
-
-            var transportToApplication = new PipeConnection(output.Reader, input.Writer);
-            var applicationToTransport = new PipeConnection(input.Reader, output.Writer);
-
-            return (applicationToTransport, transportToApplication);
-        }
-    }
-}

test/Kestrel.Core.Tests/Http1ConnectionTests.cs

@@ -41,7 +41,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public Http1ConnectionTests()
         {
             _pipelineFactory = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(_pipelineFactory);
+            var pair = DuplexPipe.CreateConnectionPair(_pipelineFactory);
 
             _transport = pair.Transport;
             _application = pair.Application;

test/Kestrel.Core.Tests/Http2ConnectionTests.cs

@@ -94,7 +94,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         private static readonly byte[] _maxData = Encoding.ASCII.GetBytes(new string('a', Http2Frame.MinAllowedMaxFrameSize));
 
         private readonly MemoryPool _memoryPool = new MemoryPool();
-        private readonly (IDuplexPipe Transport, IDuplexPipe Application) _pair;
+        private readonly DuplexPipe.DuplexPipePair _pair;
         private readonly TestApplicationErrorLogger _logger;
         private readonly Http2ConnectionContext _connectionContext;
         private readonly Http2Connection _connection;
@@ -122,7 +122,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
 
         public Http2ConnectionTests()
         {
-            _pair = PipeFactory.CreateConnectionPair(_memoryPool);
+            _pair = DuplexPipe.CreateConnectionPair(_memoryPool);
 
             _noopApplication = context => Task.CompletedTask;
 

test/Kestrel.Core.Tests/HttpConnectionTests.cs

@@ -25,7 +25,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public HttpConnectionTests()
         {
             _memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(_memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
 
             _httpConnectionContext = new HttpConnectionContext
             {

test/Kestrel.Core.Tests/HttpResponseHeadersTests.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             using (var memoryPool = new MemoryPool())
             {
-                var pair = PipeFactory.CreateConnectionPair(memoryPool);
+                var pair = DuplexPipe.CreateConnectionPair(memoryPool);
                 var http1ConnectionContext = new Http1ConnectionContext
                 {
                     ServiceContext = new TestServiceContext(),

test/Kestrel.Core.Tests/TestInput.cs

@@ -20,7 +20,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         public TestInput()
         {
             _memoryPool = new MemoryPool();
-            var pair = PipeFactory.CreateConnectionPair(_memoryPool);
+            var pair = DuplexPipe.CreateConnectionPair(_memoryPool);
             Transport = pair.Transport;
             Application = pair.Application;
 

test/Kestrel.Transport.Libuv.Tests/LibuvOutputConsumerTests.cs

@@ -695,7 +695,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests
 
         private Http1OutputProducer CreateOutputProducer(PipeOptions pipeOptions, CancellationTokenSource cts = null)
         {
-            var pair = PipeFactory.CreateConnectionPair(pipeOptions, pipeOptions);
+            var pair = DuplexPipe.CreateConnectionPair(pipeOptions, pipeOptions);
 
             var logger = new TestApplicationErrorLogger();
             var serviceContext = new TestServiceContext

test/Kestrel.Transport.Libuv.Tests/TestHelpers/MockConnectionHandler.cs

@@ -20,13 +20,13 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Tests.TestHelpers
         {
             var connectionContext = new DefaultConnectionContext(features);
 
-            Input = new Pipe(InputOptions(connectionContext.MemoryPool));
-            Output = new Pipe(OutputOptions(connectionContext.MemoryPool));
-
             var feature = connectionContext.Features.Get<IConnectionTransportFeature>();
 
-            connectionContext.Transport = new PipeConnection(Input.Reader, Output.Writer);
+            Input = new Pipe(InputOptions(feature.MemoryPool));
-            feature.Application = new PipeConnection(Output.Reader, Input.Writer);
+            Output = new Pipe(OutputOptions(feature.MemoryPool));
+
+            connectionContext.Transport = new DuplexPipe(Input.Reader, Output.Writer);
+            feature.Application = new DuplexPipe(Output.Reader, Input.Writer);
         }
 
         public Pipe Input { get; private set; }