Implement IHttpBufferingFeature (#1391)

src/AspNetCoreModuleV2/InProcessRequestHandler/managedexports.cpp

@@ -86,6 +86,19 @@ Finished:
     return hr;
 }
 
+EXTERN_C __MIDL_DECLSPEC_DLLEXPORT
+HRESULT
+http_set_server_variable(
+    _In_ IN_PROCESS_HANDLER* pInProcessHandler,
+    _In_ PCSTR pszVariableName,
+    _In_ PCWSTR pszVariableValue
+)
+{
+    return pInProcessHandler
+        ->QueryHttpContext()
+        ->SetServerVariable(pszVariableName, pszVariableValue);
+}
+
 EXTERN_C __MIDL_DECLSPEC_DLLEXPORT
 HRESULT
 http_set_response_status_code(
@@ -400,6 +413,17 @@ http_cancel_io(
     return pInProcessHandler->QueryHttpContext()->CancelIo();
 }
 
+EXTERN_C __MIDL_DECLSPEC_DLLEXPORT
+HRESULT
+http_disable_buffering(
+    _In_ IN_PROCESS_HANDLER* pInProcessHandler
+)
+{
+    pInProcessHandler->QueryHttpContext()->GetResponse()->DisableBuffering();
+
+    return S_OK;
+}
+
 EXTERN_C __MIDL_DECLSPEC_DLLEXPORT
 HRESULT
 http_response_set_unknown_header(

src/Microsoft.AspNetCore.Server.IIS/Core/IISHttpContext.FeatureCollection.cs

@@ -23,7 +23,8 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
                                             IHttpUpgradeFeature,
                                             IHttpRequestLifetimeFeature,
                                             IHttpAuthenticationFeature,
-                                            IServerVariablesFeature
+                                            IServerVariablesFeature,
+                                            IHttpBufferingFeature
     {
         // NOTE: When feature interfaces are added to or removed from this HttpProtocol implementation,
         // then the list of `implementedFeatures` in the generated code project MUST also be updated.
@@ -202,7 +203,7 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
             {
                 if (string.IsNullOrEmpty(variableName))
                 {
-                    return null;
+                    throw new ArgumentException($"{nameof(variableName)} should be non-empty string");
                 }
 
                 // Synchronize access to native methods that might run in parallel with IO loops
@@ -211,6 +212,19 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
                     return NativeMethods.HttpTryGetServerVariable(_pInProcessHandler, variableName, out var value) ? value : null;
                 }
             }
+            set
+            {
+                if (string.IsNullOrEmpty(variableName))
+                {
+                    throw new ArgumentException($"{nameof(variableName)} should be non-empty string");
+                }
+
+                // Synchronize access to native methods that might run in parallel with IO loops
+                lock (_contextLock)
+                {
+                    NativeMethods.HttpSetServerVariable(_pInProcessHandler, variableName, value);
+                }
+            }
         }
 
         object IFeatureCollection.this[Type key]
@@ -284,5 +298,21 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
         {
             Abort();
         }
+
+        void IHttpBufferingFeature.DisableRequestBuffering()
+        {
+        }
+
+        void IHttpBufferingFeature.DisableResponseBuffering()
+        {
+            NativeMethods.HttpDisableBuffering(_pInProcessHandler);
+            DisableCompression();
+        }
+
+        private void DisableCompression()
+        {
+            var serverVariableFeature = (IServerVariablesFeature)this;
+            serverVariableFeature["IIS_EnableDynamicCompression"] = "0";
+        }
     }
 }

src/Microsoft.AspNetCore.Server.IIS/Core/IISHttpContext.Features.cs

@@ -27,6 +27,7 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
         private static readonly Type IHttpSendFileFeatureType = typeof(global::Microsoft.AspNetCore.Http.Features.IHttpSendFileFeature);
         private static readonly Type IISHttpContextType = typeof(IISHttpContext);
         private static readonly Type IServerVariablesFeature = typeof(global::Microsoft.AspNetCore.Http.Features.IServerVariablesFeature);
+        private static readonly Type IHttpBufferingFeature = typeof(global::Microsoft.AspNetCore.Http.Features.IHttpBufferingFeature);
 
         private object _currentIHttpRequestFeature;
         private object _currentIHttpResponseFeature;
@@ -41,14 +42,12 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
         private object _currentIResponseCookiesFeature;
         private object _currentIItemsFeature;
         private object _currentITlsConnectionFeature;
-        private object _currentIHttpMaxRequestBodySizeFeature;
-        private object _currentIHttpMinRequestBodyDataRateFeature;
-        private object _currentIHttpMinResponseDataRateFeature;
         private object _currentIHttpWebSocketFeature;
         private object _currentISessionFeature;
         private object _currentIHttpBodyControlFeature;
         private object _currentIHttpSendFileFeature;
         private object _currentIServerVariablesFeature;
+        private object _currentIHttpBufferingFeature;
 
         private void Initialize()
         {
@@ -58,12 +57,10 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
             _currentIHttpRequestIdentifierFeature = this;
             _currentIHttpRequestLifetimeFeature = this;
             _currentIHttpConnectionFeature = this;
-            _currentIHttpMaxRequestBodySizeFeature = this;
-            _currentIHttpMinRequestBodyDataRateFeature = this;
-            _currentIHttpMinResponseDataRateFeature = this;
             _currentIHttpBodyControlFeature = this;
             _currentIHttpAuthenticationFeature = this;
             _currentIServerVariablesFeature = this;
+            _currentIHttpBufferingFeature = this;
         }
 
         internal object FastFeatureGet(Type key)
@@ -142,7 +139,11 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
             }
             if (key == IServerVariablesFeature)
             {
-                return this;
+                return _currentIServerVariablesFeature;
+            }
+            if (key == IHttpBufferingFeature)
+            {
+                return _currentIHttpBufferingFeature;
             }
 
             return ExtraFeatureGet(key);
@@ -242,6 +243,11 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
                 _currentIServerVariablesFeature = feature;
                 return;
             }
+            if (key == IHttpBufferingFeature)
+            {
+                _currentIHttpBufferingFeature = feature;
+                return;
+            }
             if (key == IISHttpContextType)
             {
                 throw new InvalidOperationException("Cannot set IISHttpContext in feature collection");
@@ -323,6 +329,10 @@ namespace Microsoft.AspNetCore.Server.IIS.Core
             {
                 yield return new KeyValuePair<Type, object>(IServerVariablesFeature, _currentIServerVariablesFeature as global::Microsoft.AspNetCore.Http.Features.IServerVariablesFeature);
             }
+            if (_currentIHttpBufferingFeature != null)
+            {
+                yield return new KeyValuePair<Type, object>(IHttpBufferingFeature, _currentIHttpBufferingFeature as global::Microsoft.AspNetCore.Http.Features.IHttpBufferingFeature);
+            }
 
             if (MaybeExtra != null)
             {

src/Microsoft.AspNetCore.Server.IIS/IServerVariableFeature.cs

@@ -15,10 +15,10 @@ namespace Microsoft.AspNetCore.Http.Features
     public interface IServerVariablesFeature
     {
         /// <summary>
-        /// Gets the value of a server variable for the current request.
+        /// Gets or sets the value of a server variable for the current request.
         /// </summary>
         /// <param name="variableName">The variable name</param>
         /// <returns>May return null or empty if the variable does not exist or is not set.</returns>
-        string this[string variableName] { get; }
+        string this[string variableName] { get; set; }
     }
 }

src/Microsoft.AspNetCore.Server.IIS/NativeMethods.cs

@@ -76,6 +76,9 @@ namespace Microsoft.AspNetCore.Server.IIS
         [DllImport(AspNetCoreModuleDll)]
         private static extern int http_stop_incoming_requests(IntPtr pInProcessApplication);
 
+        [DllImport(AspNetCoreModuleDll)]
+        private static extern int http_disable_buffering(IntPtr pInProcessApplication);
+
         [DllImport(AspNetCoreModuleDll, CharSet = CharSet.Ansi)]
         private static extern int http_set_response_status_code(IntPtr pInProcessHandler, ushort statusCode, string pszReason);
 
@@ -97,6 +100,12 @@ namespace Microsoft.AspNetCore.Server.IIS
             [MarshalAs(UnmanagedType.LPStr)] string variableName,
             [MarshalAs(UnmanagedType.BStr)] out string value);
 
+        [DllImport(AspNetCoreModuleDll)]
+        private static extern int http_set_server_variable(
+            IntPtr pInProcessHandler,
+            [MarshalAs(UnmanagedType.LPStr)] string variableName,
+            [MarshalAs(UnmanagedType.LPWStr)] string value);
+
         [DllImport(AspNetCoreModuleDll)]
         private static extern unsafe int http_websockets_read_bytes(
             IntPtr pInProcessHandler,
@@ -176,6 +185,11 @@ namespace Microsoft.AspNetCore.Server.IIS
             Validate(http_stop_incoming_requests(pInProcessApplication));
         }
 
+        public static void HttpDisableBuffering(IntPtr pInProcessApplication)
+        {
+            Validate(http_disable_buffering(pInProcessApplication));
+        }
+
         public static void HttpSetResponseStatusCode(IntPtr pInProcessHandler, ushort statusCode, string pszReason)
         {
             Validate(http_set_response_status_code(pInProcessHandler, statusCode, pszReason));
@@ -208,6 +222,11 @@ namespace Microsoft.AspNetCore.Server.IIS
             return http_get_server_variable(pInProcessHandler, variableName, out value) == 0;
         }
 
+        public static void HttpSetServerVariable(IntPtr pInProcessHandler, string variableName, string value)
+        {
+            Validate(http_set_server_variable(pInProcessHandler, variableName, value));
+        }
+
         public static unsafe int HttpWebsocketsReadBytes(
             IntPtr pInProcessHandler,
             byte* pvBuffer,

src/Microsoft.AspNetCore.Server.IntegrationTesting.IIS/IISDeploymentParameterExtensions.cs

@@ -80,5 +80,31 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting.IIS
                     aspNetCoreElement.SetAttributeValue("arguments", transformation((string)aspNetCoreElement.Attribute("arguments"), contentRoot));
                 });
         }
+
+        public static void EnableModule(this IISDeploymentParameters parameters, string moduleName, string modulePath)
+        {
+            if (parameters.ServerType == ServerType.IIS)
+            {
+                modulePath = modulePath.Replace("%IIS_BIN%", "%windir%\\System32\\inetsrv");
+            }
+
+            parameters.ServerConfigActionList.Add(
+                (element, _) => {
+                    var webServerElement = element
+                        .RequiredElement("system.webServer");
+
+                    webServerElement
+                        .RequiredElement("globalModules")
+                        .GetOrAdd("add", "name", moduleName)
+                        .SetAttributeValue("image", modulePath);
+
+                    (webServerElement.Element("modules") ??
+                     element
+                         .Element("location")
+                         .RequiredElement("system.webServer")
+                         .RequiredElement("modules"))
+                        .GetOrAdd("add", "name", moduleName);
+                });
+        }
     }
 }

test/Common.FunctionalTests/Inprocess/CompressionTests.cs

@@ -0,0 +1,96 @@
+// 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;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Testing.xunit;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
+{
+    [Collection(IISCompressionSiteCollection.Name)]
+    public class CompressionTests : FixtureLoggedTest
+    {
+        private readonly IISCompressionSiteFixture _fixture;
+
+        public CompressionTests(IISCompressionSiteFixture fixture): base(fixture)
+        {
+            _fixture = fixture;
+        }
+
+        [ConditionalTheory]
+        [RequiresIIS(IISCapability.DynamicCompression)]
+        [InlineData(true)]
+        [InlineData(false)]
+        public async Task BufferingDisabled(bool compression)
+        {
+            using (var connection = _fixture.CreateTestConnection())
+            {
+                var requestLength = 0;
+                var messages = new List<string>();
+                for (var i = 1; i < 100; i++)
+                {
+                    var message = i + Environment.NewLine;
+                    requestLength += message.Length;
+                    messages.Add(message);
+                }
+
+                await connection.Send(
+                    "POST /ReadAndWriteEchoLinesNoBuffering HTTP/1.1",
+                    $"Content-Length: {requestLength}",
+                    "Accept-Encoding: " + (compression ? "gzip": "identity"),
+                    "Response-Content-Type: text/event-stream",
+                    "Host: localhost",
+                    "Connection: close",
+                    "",
+                    "");
+
+                await connection.Receive(
+                    "HTTP/1.1 200 OK",
+                    "");
+                await connection.ReceiveHeaders();
+
+                foreach (var message in messages)
+                {
+                    await connection.Send(message);
+                    await connection.ReceiveChunk(message);
+                }
+
+                await connection.Send("\r\n");
+                await connection.ReceiveChunk("");
+                await connection.WaitForConnectionClose();
+            }
+        }
+
+        [ConditionalFact]
+        [RequiresIIS(IISCapability.DynamicCompression)]
+        public async Task DynamicResponsesAreCompressed()
+        {
+            var handler = new HttpClientHandler
+            {
+                AutomaticDecompression = DecompressionMethods.GZip
+            };
+            var client = new HttpClient(handler)
+            {
+                BaseAddress = _fixture.Client.BaseAddress,
+            };
+            client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("gzip"));
+            client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("identity", 0));
+            client.DefaultRequestHeaders.Add("Response-Content-Type", "text/event-stream");
+            var messages = "Message1\r\nMessage2\r\n";
+
+            // Send messages with terminator
+            var response = await client.PostAsync("ReadAndWriteEchoLines", new StringContent(messages + "\r\n"));
+            Assert.Equal(messages, await response.Content.ReadAsStringAsync());
+            Assert.True(response.Content.Headers.TryGetValues("Content-Type", out var contentTypes));
+            Assert.Single(contentTypes, "text/event-stream");
+            // Not the cleanest check but I wasn't able to figure out other way to check
+            // that response was compressed
+            Assert.Contains("gzip", response.Content.GetType().FullName, StringComparison.OrdinalIgnoreCase);
+        }
+    }
+}

test/Common.FunctionalTests/Inprocess/ServerVariablesTest.cs

@@ -34,6 +34,12 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
             Assert.Equal("THIS_VAR_IS_UNDEFINED: (null)", await _fixture.Client.GetStringAsync("/ServerVariable?q=THIS_VAR_IS_UNDEFINED"));
         }
 
+        [ConditionalFact]
+        public async Task CanSetAndReadVariable()
+        {
+            Assert.Equal("ROUNDTRIP: 1", await _fixture.Client.GetStringAsync("/ServerVariable?v=1&q=ROUNDTRIP"));
+        }
+
         [ConditionalFact]
         public async Task BasePathIsNotPrefixedBySlashSlashQuestionMark()
         {

test/Common.FunctionalTests/Utilities/IISCapability.cs

@@ -12,6 +12,7 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
         Websockets = 1,
         WindowsAuthentication = 2,
         PoolEnvironmentVariables = 4,
-        ShutdownToken = 8
+        ShutdownToken = 8,
+        DynamicCompression = 16
     }
 }

test/Common.FunctionalTests/Utilities/IISCompressionSiteCollection.cs

@@ -0,0 +1,13 @@
+// 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 Xunit;
+
+namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
+{
+    [CollectionDefinition(Name)]
+    public class IISCompressionSiteCollection : ICollectionFixture<IISCompressionSiteFixture>
+    {
+        public const string Name = nameof(IISCompressionSiteCollection);
+    }
+}

test/Common.FunctionalTests/Utilities/IISCompressionSiteFixture.cs

@@ -0,0 +1,44 @@
+// 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;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading;
+using Microsoft.AspNetCore.Server.IntegrationTesting;
+using Microsoft.AspNetCore.Server.IntegrationTesting.IIS;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Testing;
+
+namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
+{
+    public class IISCompressionSiteFixture : IISTestSiteFixture
+    {
+        public IISCompressionSiteFixture() : base(Configure)
+        {
+        }
+
+        private static void Configure(IISDeploymentParameters deploymentParameters)
+        {
+            // Enable dynamic compression
+            deploymentParameters.ServerConfigActionList.Add(
+                (element, _) => {
+                    var webServerElement = element
+                        .RequiredElement("system.webServer");
+
+                    webServerElement
+                        .GetOrAdd("urlCompression")
+                        .SetAttributeValue("doDynamicCompression", "true");
+
+                    webServerElement
+                        .GetOrAdd("httpCompression")
+                        .GetOrAdd("dynamicTypes")
+                        .GetOrAdd("add", "mimeType", "text/*")
+                        .SetAttributeValue("enabled", "true");
+
+                });
+
+            deploymentParameters.EnableModule("DynamicCompressionModule", "%IIS_BIN%\\compdyn.dll");
+        }
+    }
+}

test/Common.FunctionalTests/Utilities/IISTestSiteFixture.cs

@@ -14,40 +14,36 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
 {
     public class IISTestSiteFixture : IDisposable
     {
-        private readonly ApplicationDeployer _deployer;
-        private readonly ForwardingProvider _forwardingProvider;
+        private ApplicationDeployer _deployer;
+        private ILoggerFactory _loggerFactory;
+        private ForwardingProvider _forwardingProvider;
+        private IISDeploymentResult _deploymentResult;
+        private readonly Action<IISDeploymentParameters> _configure;
 
-        public IISTestSiteFixture()
+        public IISTestSiteFixture() : this(_ => { })
         {
-            var logging = AssemblyTestLog.ForAssembly(typeof(IISTestSiteFixture).Assembly);
-
-            var deploymentParameters = new IISDeploymentParameters(Helpers.GetInProcessTestSitesPath(),
-                DeployerSelector.ServerType,
-                RuntimeFlavor.CoreClr,
-                RuntimeArchitecture.x64)
-            {
-                TargetFramework = Tfm.NetCoreApp22,
-                AncmVersion = AncmVersion.AspNetCoreModuleV2,
-                HostingModel = HostingModel.InProcess,
-                PublishApplicationBeforeDeployment = true,
-            };
-
-            _forwardingProvider = new ForwardingProvider();
-            var loggerFactory = logging.CreateLoggerFactory(null, nameof(IISTestSiteFixture));
-            loggerFactory.AddProvider(_forwardingProvider);
-
-            _deployer = IISApplicationDeployerFactory.Create(deploymentParameters, loggerFactory);
-
-            DeploymentResult = (IISDeploymentResult)_deployer.DeployAsync().Result;
-            Client = DeploymentResult.HttpClient;
-            BaseUri = DeploymentResult.ApplicationBaseUri;
-            ShutdownToken = DeploymentResult.HostShutdownToken;
         }
 
-        public string BaseUri { get; }
-        public HttpClient Client { get; }
-        public CancellationToken ShutdownToken { get; }
-        public IISDeploymentResult DeploymentResult { get; }
+        public IISTestSiteFixture(Action<IISDeploymentParameters> configure)
+        {
+            var logging = AssemblyTestLog.ForAssembly(typeof(IISTestSiteFixture).Assembly);
+            _loggerFactory = logging.CreateLoggerFactory(null, nameof(IISTestSiteFixture));
+
+            _forwardingProvider = new ForwardingProvider();
+            _loggerFactory.AddProvider(_forwardingProvider);
+
+            _configure = configure;
+        }
+
+        public HttpClient Client => DeploymentResult.HttpClient;
+        public IISDeploymentResult DeploymentResult
+        {
+            get
+            {
+                EnsureInitialized();
+                return _deploymentResult;
+            }
+        }
 
         public TestConnection CreateTestConnection()
         {
@@ -56,7 +52,7 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
 
         public void Dispose()
         {
-            _deployer.Dispose();
+            _deployer?.Dispose();
         }
 
         public void Attach(LoggedTest test)
@@ -79,6 +75,30 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
             _forwardingProvider.LoggerFactory = null;
         }
 
+        private void EnsureInitialized()
+        {
+            if (_deployer != null)
+            {
+                return;
+            }
+
+            var deploymentParameters = new IISDeploymentParameters(Helpers.GetInProcessTestSitesPath(),
+                DeployerSelector.ServerType,
+                RuntimeFlavor.CoreClr,
+                RuntimeArchitecture.x64)
+            {
+                TargetFramework = Tfm.NetCoreApp22,
+                AncmVersion = AncmVersion.AspNetCoreModuleV2,
+                HostingModel = HostingModel.InProcess,
+                PublishApplicationBeforeDeployment = true,
+            };
+
+            _configure(deploymentParameters);
+
+            _deployer = IISApplicationDeployerFactory.Create(deploymentParameters, _loggerFactory);
+            _deploymentResult = (IISDeploymentResult)_deployer.DeployAsync().Result;
+        }
+
         private class ForwardingProvider : ILoggerProvider
         {
             private readonly List<ForwardingLogger> _loggers = new List<ForwardingLogger>();

test/Common.Tests/Utilities/TestConnections.cs

@@ -24,7 +24,6 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
         private readonly bool _ownsSocket;
         private readonly Socket _socket;
         private readonly NetworkStream _stream;
-        private readonly StreamReader _reader;
 
         public TestConnection(int port)
             : this(port, AddressFamily.InterNetwork)
@@ -46,13 +45,10 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
             _ownsSocket = ownsSocket;
             _socket = socket;
             _stream = new NetworkStream(_socket, ownsSocket: false);
-            _reader = new StreamReader(_stream, Encoding.ASCII);
         }
 
         public Socket Socket => _socket;
 
-        public StreamReader Reader => _reader;
-
         public void Dispose()
         {
             _stream.Dispose();
@@ -79,50 +75,96 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
             await _stream.FlushAsync().ConfigureAwait(false);
         }
 
+        public async Task<int> ReadCharAsync()
+        {
+            var bytes = new byte[1];
+            return (await _stream.ReadAsync(bytes, 0, 1) == 1) ? bytes[0] : -1;
+        }
+
+        public async Task<string> ReadLineAsync()
+        {
+            var builder = new StringBuilder();
+            var current = await ReadCharAsync();
+            while (current != '\r')
+            {
+                builder.Append((char)current);
+                current = await ReadCharAsync();
+            }
+
+            // Consume \n
+            await ReadCharAsync();
+
+            return builder.ToString();
+        }
+
+        public async Task<Memory<byte>> ReceiveChunk()
+        {
+            var length = int.Parse(await ReadLineAsync(), System.Globalization.NumberStyles.HexNumber);
+
+            var bytes = await Receive(length);
+
+            await ReadLineAsync();
+
+            return bytes;
+        }
+
+        public async Task ReceiveChunk(string expected)
+        {
+            Assert.Equal(expected, Encoding.ASCII.GetString((await ReceiveChunk()).Span));
+        }
+
         public async Task Receive(params string[] lines)
         {
             var expected = string.Join("\r\n", lines);
-            var actual = new char[expected.Length];
-            var offset = 0;
+            var actual = await Receive(expected.Length);
 
+            Assert.Equal(expected, Encoding.ASCII.GetString(actual.Span));
+        }
+
+        private async Task<Memory<byte>> Receive(int length)
+        {
+            var actual = new byte[length];
+            int offset = 0;
             try
             {
-                while (offset < expected.Length)
+                while (offset < length)
                 {
-                    var data = new byte[expected.Length];
-                    var task = _reader.ReadAsync(actual, offset, actual.Length - offset);
+                    var task = _stream.ReadAsync(actual, offset, actual.Length - offset);
                     if (!Debugger.IsAttached)
                     {
                         task = task.TimeoutAfter(Timeout);
                     }
+
                     var count = await task.ConfigureAwait(false);
                     if (count == 0)
                     {
                         break;
                     }
+
                     offset += count;
                 }
             }
             catch (TimeoutException ex) when (offset != 0)
             {
-                throw new TimeoutException($"Did not receive a complete response within {Timeout}.{Environment.NewLine}{Environment.NewLine}" +
-                    $"Expected:{Environment.NewLine}{expected}{Environment.NewLine}{Environment.NewLine}" +
-                    $"Actual:{Environment.NewLine}{new string(actual, 0, offset)}{Environment.NewLine}",
+                throw new TimeoutException(
+                    $"Did not receive a complete response within {Timeout}.{Environment.NewLine}{Environment.NewLine}" +
+                    $"Expected:{Environment.NewLine}{length} bytes of data{Environment.NewLine}{Environment.NewLine}" +
+                    $"Actual:{Environment.NewLine}{Encoding.ASCII.GetString(actual, 0, offset)}{Environment.NewLine}",
                     ex);
             }
 
-            Assert.Equal(expected, new string(actual, 0, offset));
+            return actual.AsMemory(0, offset);
         }
 
         public async Task ReceiveStartsWith(string prefix, int maxLineLength = 1024)
         {
-            var actual = new char[maxLineLength];
+            var actual = new byte[maxLineLength];
             var offset = 0;
 
             while (offset < maxLineLength)
             {
                 // Read one char at a time so we don't read past the end of the line.
-                var task = _reader.ReadAsync(actual, offset, 1);
+                var task = _stream.ReadAsync(actual, offset, 1);
                 if (!Debugger.IsAttached)
                 {
                     Assert.True(task.Wait(4000), "timeout");
@@ -142,7 +184,7 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
                 }
             }
 
-            var actualLine = new string(actual, 0, offset);
+            var actualLine = Encoding.ASCII.GetString(actual, 0, offset);
             Assert.StartsWith(prefix, actualLine);
         }
 
@@ -152,7 +194,7 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
             string line;
             do
             {
-                line = await _reader.ReadLineAsync();
+                line = await ReadLineAsync();
                 headers.Add(line);
             } while (line != "");
 
@@ -190,7 +232,7 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
             else
             {
                 tcs.SetException(new IOException(
-                    $"Expected connection close, received data instead: \"{_reader.CurrentEncoding.GetString(e.Buffer, 0, e.BytesTransferred)}\""));
+                    $"Expected connection close, received data instead: \"{Encoding.ASCII.GetString(e.Buffer, 0, e.BytesTransferred)}\""));
             }
         }
 

test/IIS.FunctionalTests/RequiresIISAttribute.cs

@@ -18,12 +18,10 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
         private static readonly bool _isMetStatic;
         private static readonly string _skipReasonStatic;
 
-        private readonly bool _isMet;
-        private readonly string _skipReason;
-
         private static readonly bool _websocketsAvailable;
         private static readonly bool _windowsAuthAvailable;
         private static readonly bool _poolEnvironmentVariablesAvailable;
+        private static readonly bool _dynamicCompressionAvailable;
 
         static RequiresIISAttribute()
         {
@@ -84,6 +82,8 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
 
             _windowsAuthAvailable = File.Exists(Path.Combine(Environment.SystemDirectory, "inetsrv", "authsspi.dll"));
 
+            _dynamicCompressionAvailable = File.Exists(Path.Combine(Environment.SystemDirectory, "inetsrv", "compdyn.dll"));
+
             var iisRegistryKey = Registry.LocalMachine.OpenSubKey(@"Software\Microsoft\InetStp", writable: false);
             if (iisRegistryKey == null)
             {
@@ -98,47 +98,56 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
             }
         }
 
-        public RequiresIISAttribute() 
+        public RequiresIISAttribute()
             : this (IISCapability.None) { }
 
         public RequiresIISAttribute(IISCapability capabilities)
         {
-            _isMet = _isMetStatic;
-            _skipReason = _skipReasonStatic;
+            IsMet = _isMetStatic;
+            SkipReason = _skipReasonStatic;
             if (capabilities.HasFlag(IISCapability.Websockets))
             {
-                _isMet &= _websocketsAvailable;
+                IsMet &= _websocketsAvailable;
                 if (!_websocketsAvailable)
                 {
-                    _skipReason += "The machine does not have IIS websockets installed.";
+                    SkipReason += "The machine does not have IIS websockets installed.";
                 }
             }
             if (capabilities.HasFlag(IISCapability.WindowsAuthentication))
             {
-                _isMet &= _windowsAuthAvailable;
+                IsMet &= _windowsAuthAvailable;
 
                 if (!_windowsAuthAvailable)
                 {
-                    _skipReason += "The machine does not have IIS windows authentication installed.";
+                    SkipReason += "The machine does not have IIS windows authentication installed.";
                 }
             }
             if (capabilities.HasFlag(IISCapability.PoolEnvironmentVariables))
             {
-                _isMet &= _poolEnvironmentVariablesAvailable;
+                IsMet &= _poolEnvironmentVariablesAvailable;
                 if (!_poolEnvironmentVariablesAvailable)
                 {
-                    _skipReason += "The machine does allow for setting environment variables on application pools.";
+                    SkipReason += "The machine does allow for setting environment variables on application pools.";
                 }
             }
 
             if (capabilities.HasFlag(IISCapability.ShutdownToken))
             {
-                _isMet = false;
-                _skipReason += "https://github.com/aspnet/IISIntegration/issues/1074";
+                IsMet = false;
+                SkipReason += "https://github.com/aspnet/IISIntegration/issues/1074";
+            }
+
+            if (capabilities.HasFlag(IISCapability.DynamicCompression))
+            {
+                IsMet &= _dynamicCompressionAvailable;
+                if (!_dynamicCompressionAvailable)
+                {
+                    SkipReason += "The machine does not have IIS dynamic compression installed.";
+                }
             }
         }
 
-        public bool IsMet => _isMet;
-        public string SkipReason => _skipReason;
+        public bool IsMet { get; }
+        public string SkipReason { get; }
     }
 }

test/IISExpress.FunctionalTests/InProcess/WebSocketTests.cs

@@ -20,7 +20,7 @@ namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
 
         public WebSocketsTests(IISTestSiteFixture fixture)
         {
-            _webSocketUri = fixture.BaseUri.Replace("http:", "ws:");
+            _webSocketUri = fixture.DeploymentResult.ApplicationBaseUri.Replace("http:", "ws:");
         }
 
         [ConditionalFact]

test/WebSites/InProcessWebSite/Startup.cs

@@ -30,7 +30,13 @@ namespace TestSite
         private async Task ServerVariable(HttpContext ctx)
         {
             var varName = ctx.Request.Query["q"];
-            await ctx.Response.WriteAsync($"{varName}: {ctx.GetIISServerVariable(varName) ?? "(null)"}");
+            var newValue = ctx.Request.Query["v"];
+            var feature = ctx.Features.Get<IServerVariablesFeature>();
+            if (newValue.Count != 0)
+            {
+                feature[varName] = newValue;
+            }
+            await ctx.Response.WriteAsync($"{varName}: {feature[varName] ?? "(null)"}");
         }
 
         private async Task AuthenticationAnonymous(HttpContext ctx)
@@ -321,6 +327,11 @@ namespace TestSite
 
         private async Task ReadAndWriteEchoLines(HttpContext ctx)
         {
+            if (ctx.Request.Headers.TryGetValue("Response-Content-Type", out var contentType))
+            {
+                ctx.Response.ContentType = contentType;
+            }
+
             //Send headers
             await ctx.Response.Body.FlushAsync();
 
@@ -337,6 +348,31 @@ namespace TestSite
             }
         }
 
+        private async Task ReadAndWriteEchoLinesNoBuffering(HttpContext ctx)
+        {
+            var feature = ctx.Features.Get<IHttpBufferingFeature>();
+            feature.DisableResponseBuffering();
+
+            if (ctx.Request.Headers.TryGetValue("Response-Content-Type", out var contentType))
+            {
+                ctx.Response.ContentType = contentType;
+            }
+
+            //Send headers
+            await ctx.Response.Body.FlushAsync();
+
+            var reader = new StreamReader(ctx.Request.Body);
+            while (!reader.EndOfStream)
+            {
+                var line = await reader.ReadLineAsync();
+                if (line == "")
+                {
+                    return;
+                }
+                await ctx.Response.WriteAsync(line + Environment.NewLine);
+            }
+        }
+
         private async Task ReadPartialBody(HttpContext ctx)
         {
             var data = new byte[5];
@@ -631,10 +667,11 @@ namespace TestSite
             // executed on background thread while request thread calls GetServerVariable
             // concurrent native calls may cause native object corruption
 
+            var serverVariableFeature = ctx.Features.Get<IServerVariablesFeature>();
             await ctx.Response.WriteAsync("Response Begin");
             for (int i = 0; i < 1000; i++)
             {
-                await ctx.Response.WriteAsync(ctx.GetIISServerVariable("REMOTE_PORT"));
+                await ctx.Response.WriteAsync(serverVariableFeature["REMOTE_PORT"]);
                 await ctx.Response.Body.FlushAsync();
             }
             await ctx.Response.WriteAsync("Response End");