Nuke RequestServicesContainer (inline instead)

src/Microsoft.AspNet.Hosting/Internal/RequestServicesContainer.cs

@@ -1,114 +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;
-using Microsoft.AspNet.Http;
-using Microsoft.Framework.DependencyInjection;
-
-namespace Microsoft.AspNet.Hosting.Internal
-{
-    public class RequestServicesContainer : IDisposable
-    {
-        public RequestServicesContainer(
-            HttpContext context,
-            IServiceScopeFactory scopeFactory,
-            IServiceProvider appServiceProvider)
-        {
-            if (scopeFactory == null)
-            {
-                throw new ArgumentNullException(nameof(scopeFactory));
-            }
-            if (context == null)
-            {
-                throw new ArgumentNullException(nameof(context));
-            }
-
-            Context = context;
-            PriorAppServices = context.ApplicationServices;
-            PriorRequestServices = context.RequestServices;
-
-            // Begin the scope
-            Scope = scopeFactory.CreateScope();
-
-            Context.ApplicationServices = appServiceProvider;
-            Context.RequestServices = Scope.ServiceProvider;
-        }
-
-        private HttpContext Context { get; set; }
-        private IServiceProvider PriorAppServices { get; set; }
-        private IServiceProvider PriorRequestServices { get; set; }
-        private IServiceScope Scope { get; set; }
-
-        // CONSIDER: this could be an extension method on HttpContext instead
-        public static RequestServicesContainer EnsureRequestServices(HttpContext httpContext, IServiceProvider services)
-        {
-            // All done if we already have a request services
-            if (httpContext.RequestServices != null)
-            {
-                return null;
-            }
-
-            var serviceProvider = httpContext.ApplicationServices ?? services;
-            if (serviceProvider == null)
-            {
-                throw new InvalidOperationException("TODO: services and httpContext.ApplicationServices are both null!");
-            }
-
-            // Matches constructor of RequestContainer
-            var rootServiceProvider = serviceProvider.GetRequiredService<IServiceProvider>();
-            var rootServiceScopeFactory = serviceProvider.GetRequiredService<IServiceScopeFactory>();
-
-            // Pre Scope setup
-            var priorApplicationServices = serviceProvider;
-            var priorRequestServices = serviceProvider;
-
-            var appServiceProvider = rootServiceProvider;
-            var appServiceScopeFactory = rootServiceScopeFactory;
-
-            if (priorApplicationServices != null &&
-                priorApplicationServices != appServiceProvider)
-            {
-                appServiceProvider = priorApplicationServices;
-                appServiceScopeFactory = priorApplicationServices.GetRequiredService<IServiceScopeFactory>();
-            }
-
-            // Creates the scope and does the service swaps
-            return new RequestServicesContainer(httpContext, appServiceScopeFactory, appServiceProvider);
-        }
-
-#region IDisposable Support
-        private bool disposedValue = false; // To detect redundant calls
-
-        protected virtual void Dispose(bool disposing)
-        {
-            if (!disposedValue)
-            {
-                if (disposing)
-                {
-                    Context.RequestServices = PriorRequestServices;
-                    Context.ApplicationServices = PriorAppServices;
-                }
-
-                if (Scope != null)
-                {
-                    Scope.Dispose();
-                    Scope = null;
-                }
-
-                Context = null;
-                PriorAppServices = null;
-                PriorRequestServices = null;
-
-                disposedValue = true;
-            }
-        }
-
-        // This code added to correctly implement the disposable pattern.
-        public void Dispose()
-        {
-            // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
-            Dispose(true);
-        }
-#endregion
-    }
-}

src/Microsoft.AspNet.Hosting/Internal/RequestServicesContainerMiddleware.cs

@@ -5,6 +5,8 @@ using System;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Http;
+using Microsoft.Framework.DependencyInjection;
+using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Hosting.Internal
 {
@@ -13,17 +15,40 @@ namespace Microsoft.AspNet.Hosting.Internal
         private readonly RequestDelegate _next;
         private readonly IServiceProvider _services;
 
-        public RequestServicesContainerMiddleware(RequestDelegate next, IServiceProvider services)
+        public RequestServicesContainerMiddleware([NotNull] RequestDelegate next, [NotNull] IServiceProvider services)
         {
             _services = services;
             _next = next;
         }
 
-        public async Task Invoke(HttpContext httpContext)
+        public async Task Invoke([NotNull] HttpContext httpContext)
         {
-            using (var container = RequestServicesContainer.EnsureRequestServices(httpContext, _services))
+            // All done if there request services is set
+            if (httpContext.RequestServices != null)
             {
                 await _next.Invoke(httpContext);
+                return;
+            }
+
+            var priorApplicationServices = httpContext.ApplicationServices;
+            var serviceProvider = priorApplicationServices ?? _services;
+            var scopeFactory = serviceProvider.GetRequiredService<IServiceScopeFactory>();
+
+            try
+            {
+                // Creates the scope and temporarily swap services
+                using (var scope = scopeFactory.CreateScope())
+                {
+                    httpContext.ApplicationServices = serviceProvider;
+                    httpContext.RequestServices = scope.ServiceProvider;
+
+                    await _next.Invoke(httpContext);
+                }
+            }
+            finally
+            {
+                httpContext.RequestServices = null;
+                httpContext.ApplicationServices = priorApplicationServices;
             }
         }
     }

test/Microsoft.AspNet.Hosting.Tests/HostingEngineTests.cs

@@ -8,6 +8,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.FeatureModel;
 using Microsoft.AspNet.Hosting.Builder;
+using Microsoft.AspNet.Hosting.Fakes;
 using Microsoft.AspNet.Hosting.Internal;
 using Microsoft.AspNet.Hosting.Server;
 using Microsoft.AspNet.Hosting.Startup;

test/Microsoft.AspNet.TestHost.Tests/TestServerTests.cs

@@ -8,6 +8,7 @@ using System.Net.Http;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Hosting;
+using Microsoft.AspNet.Hosting.Startup;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.Configuration;
 using Microsoft.Framework.DependencyInjection;
@@ -55,10 +56,60 @@ namespace Microsoft.AspNet.TestHost
             Assert.Equal("RequestServices:True", result);
         }
 
+        public class TestService { }
+
+        public class TestRequestServiceMiddleware
+        {
+            private RequestDelegate _next;
+
+            public TestRequestServiceMiddleware(RequestDelegate next)
+            {
+                _next = next;
+            }
+
+            public Task Invoke(HttpContext httpContext)
+            {
+                var services = new ServiceCollection();
+                services.AddTransient<TestService>();
+                httpContext.RequestServices = services.BuildServiceProvider();
+
+                return _next.Invoke(httpContext);
+            }
+        }
+
+        public class RequestServicesFilter : IStartupFilter
+        {
+            public Action<IApplicationBuilder> Configure(IApplicationBuilder app, Action<IApplicationBuilder> next)
+            {
+                return builder =>
+                {
+                    app.UseMiddleware<TestRequestServiceMiddleware>();
+                    next(builder);
+                };
+            }
+        }
+
+        [Fact]
+        public async Task ExistingRequestServicesWillNotBeReplaced()
+        {
+            var server = TestServer.Create(app =>
+            {
+                app.Run(context =>
+                {
+                    var service = context.RequestServices.GetService<TestService>();
+                    return context.Response.WriteAsync("Found:" + (service != null));
+                });
+            },
+            services => services.AddTransient<IStartupFilter, RequestServicesFilter>());
+            string result = await server.CreateClient().GetStringAsync("/path");
+            Assert.Equal("Found:True", result);
+        }
+
+
         [Fact]
         public async Task CanAccessLogger()
         {
-            TestServer server = TestServer.Create(app =>
+            var server = TestServer.Create(app =>
             {
                 app.Run(context =>
                 {