From c05c203c289ebc38dfbb7496199b6baad7d1bb75 Mon Sep 17 00:00:00 2001
From: Louis DeJardin <lodejard@microsoft.com>
Date: Wed, 16 Dec 2015 22:02:05 -0800
Subject: [PATCH] Adding example of what http context pooling might look like

---
 samples/SampleApp/PooledHttpContext.cs        | 54 +++++++++++++++
 samples/SampleApp/PooledHttpContextFactory.cs | 65 +++++++++++++++++++
 .../DefaultHttpRequest.cs                     |  2 +-
 .../DefaultHttpResponse.cs                    |  2 +-
 4 files changed, 121 insertions(+), 2 deletions(-)
 create mode 100644 samples/SampleApp/PooledHttpContext.cs
 create mode 100644 samples/SampleApp/PooledHttpContextFactory.cs

diff --git a/samples/SampleApp/PooledHttpContext.cs b/samples/SampleApp/PooledHttpContext.cs
new file mode 100644
index 0000000000..7736085eac
--- /dev/null
+++ b/samples/SampleApp/PooledHttpContext.cs
@@ -0,0 +1,54 @@
+// 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 Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Features;
+using Microsoft.AspNet.Http.Internal;
+
+namespace SampleApp
+{
+    public class PooledHttpContext : DefaultHttpContext
+    {
+        DefaultHttpRequest _pooledHttpRequest;
+        DefaultHttpResponse _pooledHttpResponse;
+
+        public PooledHttpContext(IFeatureCollection featureCollection) : 
+            base(featureCollection)
+        {
+        }
+
+        protected override HttpRequest InitializeHttpRequest()
+        {
+            if (_pooledHttpRequest != null)
+            {
+                _pooledHttpRequest.Initialize(this, Features);
+                return _pooledHttpRequest;
+            }
+
+            return new DefaultHttpRequest(this, Features);
+        }
+
+        protected override void UninitializeHttpRequest(HttpRequest instance)
+        {
+            _pooledHttpRequest = instance as DefaultHttpRequest;
+            _pooledHttpRequest?.Uninitialize();
+        }
+
+        protected override HttpResponse InitializeHttpResponse()
+        {
+            if (_pooledHttpResponse != null)
+            {
+                _pooledHttpResponse.Initialize(this, Features);
+                return _pooledHttpResponse;
+            }
+
+            return new DefaultHttpResponse(this, Features);
+        }
+
+        protected override void UninitializeHttpResponse(HttpResponse instance)
+        {
+            _pooledHttpResponse = instance as DefaultHttpResponse;
+            _pooledHttpResponse?.Uninitialize();
+        }
+    }
+}
\ No newline at end of file
diff --git a/samples/SampleApp/PooledHttpContextFactory.cs b/samples/SampleApp/PooledHttpContextFactory.cs
new file mode 100644
index 0000000000..62955d90f8
--- /dev/null
+++ b/samples/SampleApp/PooledHttpContextFactory.cs
@@ -0,0 +1,65 @@
+// 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.Collections.Generic;
+using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Features;
+
+namespace SampleApp
+{
+    public class PooledHttpContextFactory : IHttpContextFactory
+    {
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly Stack<PooledHttpContext> _pool = new Stack<PooledHttpContext>();
+
+        public PooledHttpContextFactory(IHttpContextAccessor httpContextAccessor)
+        {
+            _httpContextAccessor = httpContextAccessor;
+        }
+
+        public HttpContext Create(IFeatureCollection featureCollection)
+        {
+            PooledHttpContext httpContext = null;
+            lock (_pool)
+            {
+                if (_pool.Count != 0)
+                {
+                    httpContext = _pool.Pop();
+                }
+            }
+
+            if (httpContext == null)
+            {
+                httpContext = new PooledHttpContext(featureCollection);
+            }
+            else
+            {
+                httpContext.Initialize(featureCollection);
+            }
+
+            if (_httpContextAccessor != null)
+            {
+                _httpContextAccessor.HttpContext = httpContext;
+            }
+            return httpContext;
+        }
+
+        public void Dispose(HttpContext httpContext)
+        {
+            if (_httpContextAccessor != null)
+            {
+                _httpContextAccessor.HttpContext = null;
+            }
+
+            var pooled = httpContext as PooledHttpContext;
+            if (pooled != null)
+            {
+                pooled.Uninitialize();
+                lock (_pool)
+                {
+                    _pool.Push(pooled);
+                }
+            }
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.Http/DefaultHttpRequest.cs b/src/Microsoft.AspNet.Http/DefaultHttpRequest.cs
index e03f93c83c..f8890e7345 100644
--- a/src/Microsoft.AspNet.Http/DefaultHttpRequest.cs
+++ b/src/Microsoft.AspNet.Http/DefaultHttpRequest.cs
@@ -16,7 +16,7 @@ namespace Microsoft.AspNet.Http.Internal
         private HttpContext _context;
         private FeatureReferences<FeatureInterfaces> _features;
 
-        public DefaultHttpRequest(DefaultHttpContext context, IFeatureCollection features)
+        public DefaultHttpRequest(HttpContext context, IFeatureCollection features)
         {
             Initialize(context, features);
         }
diff --git a/src/Microsoft.AspNet.Http/DefaultHttpResponse.cs b/src/Microsoft.AspNet.Http/DefaultHttpResponse.cs
index 901e17cbfe..a9cb49cbdf 100644
--- a/src/Microsoft.AspNet.Http/DefaultHttpResponse.cs
+++ b/src/Microsoft.AspNet.Http/DefaultHttpResponse.cs
@@ -15,7 +15,7 @@ namespace Microsoft.AspNet.Http.Internal
         private HttpContext _context;
         private FeatureReferences<FeatureInterfaces> _features;
 
-        public DefaultHttpResponse(DefaultHttpContext context, IFeatureCollection features)
+        public DefaultHttpResponse(HttpContext context, IFeatureCollection features)
         {
             Initialize(context, features);
         }