From 389e27e46055a95648efe48a512614fc4f8ff08e Mon Sep 17 00:00:00 2001
From: Chris Ross <Tratcher@Outlook.com>
Date: Wed, 29 Oct 2014 16:32:50 -0700
Subject: [PATCH] #134 - Add HeadersSent api.

---
 src/Microsoft.AspNet.Http/HttpResponse.cs        |  3 ++-
 .../IHttpResponseFeature.cs                      |  1 +
 .../OwinFeatureCollection.cs                     | 16 ++++++++++++++++
 .../DefaultHttpResponse.cs                       |  5 +++++
 .../DefaultHttpResponseFeature.cs                |  5 +++++
 5 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/Microsoft.AspNet.Http/HttpResponse.cs b/src/Microsoft.AspNet.Http/HttpResponse.cs
index 010d159ab8..d0156b4ee9 100644
--- a/src/Microsoft.AspNet.Http/HttpResponse.cs
+++ b/src/Microsoft.AspNet.Http/HttpResponse.cs
@@ -5,7 +5,6 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Security.Claims;
-using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Security;
 
 namespace Microsoft.AspNet.Http
@@ -24,6 +23,8 @@ namespace Microsoft.AspNet.Http
 
         public abstract IResponseCookies Cookies { get; }
 
+        public abstract bool HeadersSent { get; }
+
         public abstract void OnSendingHeaders(Action<object> callback, object state);
 
         public virtual void Redirect(string location)
diff --git a/src/Microsoft.AspNet.HttpFeature/IHttpResponseFeature.cs b/src/Microsoft.AspNet.HttpFeature/IHttpResponseFeature.cs
index cf322f6747..aa7603be03 100644
--- a/src/Microsoft.AspNet.HttpFeature/IHttpResponseFeature.cs
+++ b/src/Microsoft.AspNet.HttpFeature/IHttpResponseFeature.cs
@@ -15,6 +15,7 @@ namespace Microsoft.AspNet.HttpFeature
         string ReasonPhrase { get; set; }
         IDictionary<string, string[]> Headers { get; set; }
         Stream Body { get; set; }
+        bool HeadersSent { get; }
         void OnSendingHeaders(Action<object> callback, object state);
     }
 }
diff --git a/src/Microsoft.AspNet.Owin/OwinFeatureCollection.cs b/src/Microsoft.AspNet.Owin/OwinFeatureCollection.cs
index 7478a81e68..23ca6df7bf 100644
--- a/src/Microsoft.AspNet.Owin/OwinFeatureCollection.cs
+++ b/src/Microsoft.AspNet.Owin/OwinFeatureCollection.cs
@@ -35,11 +35,22 @@ namespace Microsoft.AspNet.Owin
         IOwinEnvironmentFeature
     {
         public IDictionary<string, object> Environment { get; set; }
+        private bool _headersSent;
 
         public OwinFeatureCollection(IDictionary<string, object> environment)
         {
             Environment = environment;
             SupportsWebSockets = true;
+
+            var register = Prop<Action<Action<object>, object>>(OwinConstants.CommonKeys.OnSendingHeaders);
+            if (register != null)
+            {
+                register(state =>
+                {
+                    var collection = (OwinFeatureCollection)state;
+                    collection._headersSent = true;
+                }, this);
+            }
         }
 
         T Prop<T>(string key)
@@ -129,6 +140,11 @@ namespace Microsoft.AspNet.Owin
             set { Prop(OwinConstants.ResponseBody, value); }
         }
 
+        bool IHttpResponseFeature.HeadersSent
+        {
+            get { return _headersSent; }
+        }
+
         void IHttpResponseFeature.OnSendingHeaders(Action<object> callback, object state)
         {
             var register = Prop<Action<Action<object>, object>>(OwinConstants.CommonKeys.OnSendingHeaders);
diff --git a/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponse.cs b/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponse.cs
index 3b50493b58..03841751ec 100644
--- a/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponse.cs
+++ b/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponse.cs
@@ -105,6 +105,11 @@ namespace Microsoft.AspNet.PipelineCore
             get { return ResponseCookiesFeature.Cookies; }
         }
 
+        public override bool HeadersSent
+        {
+            get { return HttpResponseFeature.HeadersSent; }
+        }
+
         public override void OnSendingHeaders(Action<object> callback, object state)
         {
             HttpResponseFeature.OnSendingHeaders(callback, state);
diff --git a/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponseFeature.cs b/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponseFeature.cs
index 819ff17421..c3b933bb8a 100644
--- a/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponseFeature.cs
+++ b/src/Microsoft.AspNet.PipelineCore/DefaultHttpResponseFeature.cs
@@ -25,6 +25,11 @@ namespace Microsoft.AspNet.PipelineCore
 
         public Stream Body { get; set; }
 
+        public bool HeadersSent
+        {
+            get { return false; }
+        }
+
         public void OnSendingHeaders(Action<object> callback, object state)
         {
             throw new NotSupportedException();