[Fixes #429] FileResult

1) Implemented FilePathResult to efficiently return files from disk.
2) Implemented FileStreamResult to return content from a stream.
3) Implemented FileContentResult to return content from a byte array.

Author: javiercn

Mvc.sln

@@ -82,6 +82,8 @@ Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "UrlHelperWebSite", "test\We
 EndProject
 Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "ApiExplorerWebSite", "test\WebSites\ApiExplorerWebSite\ApiExplorerWebSite.kproj", "{61061528-071E-424E-965A-07BCC2F02672}"
 EndProject
+Project("{8BB2217D-0F2D-49D1-97BC-3654ED321F3B}") = "FilesWebSite", "test\WebSites\FilesWebSite\FilesWebSite.kproj", "{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -412,6 +414,16 @@ Global
 		{A192E504-2881-41DC-90D1-B7F1DD1134E8}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{A192E504-2881-41DC-90D1-B7F1DD1134E8}.Release|Mixed Platforms.Build.0 = Release|Any CPU
 		{A192E504-2881-41DC-90D1-B7F1DD1134E8}.Release|x86.ActiveCfg = Release|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Release|Mixed Platforms.Build.0 = Release|Any CPU
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3}.Release|x86.ActiveCfg = Release|Any CPU
 		{61061528-071E-424E-965A-07BCC2F02672}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{61061528-071E-424E-965A-07BCC2F02672}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{61061528-071E-424E-965A-07BCC2F02672}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
@@ -460,6 +472,7 @@ Global
 		{1976AC4A-FEA4-4587-A158-D9F79736D2B6} = {16703B76-C9F7-4C75-AE6C-53D92E308E3C}
 		{96107AC0-18E2-474D-BAB4-2FFF2185FBCD} = {16703B76-C9F7-4C75-AE6C-53D92E308E3C}
 		{A192E504-2881-41DC-90D1-B7F1DD1134E8} = {16703B76-C9F7-4C75-AE6C-53D92E308E3C}
+		{0EF9860B-10D7-452F-B0F4-A405B88BEBB3} = {16703B76-C9F7-4C75-AE6C-53D92E308E3C}
 		{61061528-071E-424E-965A-07BCC2F02672} = {16703B76-C9F7-4C75-AE6C-53D92E308E3C}
 	EndGlobalSection
 EndGlobal

samples/MvcSample.Web/HomeController.cs

@@ -34,6 +34,16 @@ public ActionResult NotFound()
             return HttpNotFound();
         }
 
+        public ActionResult SendFileFromDisk()
+        {
+            return File("sample.txt", "text/plain");
+        }
+
+        public ActionResult SendFileFromDiskWithName()
+        {
+            return File("sample.txt", "text/plain", "sample-file.txt");
+        }
+
         public bool IsDefaultNameSpace()
         {
             var namespaceToken = ActionContext.RouteData.DataTokens["NameSpace"] as string;

samples/MvcSample.Web/sample.txt

@@ -0,0 +1 @@
+This is a sample file returned from a controller

src/Microsoft.AspNet.Mvc.Core/ActionResults/FileContentResult.cs

@@ -0,0 +1,41 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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.Threading;
+using System.Threading.Tasks;
+using Microsoft.AspNet.Http;
+
+namespace Microsoft.AspNet.Mvc
+{
+    /// <summary>
+    /// Represents an <see cref="ActionResult"/> that when executed will
+    /// write a binary file to the response.
+    /// </summary>
+    public class FileContentResult : FileResult
+    {
+        /// <summary>
+        /// Creates a new <see cref="FileContentResult"/> instance with
+        /// the provided <paramref name="fileContents"/> and the
+        /// provided <paramref name="contentType"/>.
+        /// </summary>
+        /// <param name="fileContents">The bytes that represent the file contents.</param>
+        /// <param name="contentType">The Content-Type header of the response.</param>
+        public FileContentResult([NotNull] byte[] fileContents, string contentType)
+            : base(contentType)
+        {
+            FileContents = fileContents;
+        }
+
+        /// <summary>
+        /// Gets the file contents.
+        /// </summary>
+        public byte[] FileContents { get; private set; }
+
+        /// <inheritdoc />
+        protected override Task WriteFileAsync(HttpResponse response, CancellationToken cancellation)
+        {
+            return response.Body.WriteAsync(FileContents, 0, FileContents.Length, cancellation);
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Core/ActionResults/FilePathResult.cs

@@ -0,0 +1,84 @@
+// Copyright (c) Microsoft Open Technologies, Inc. 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.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.AspNet.Http;
+using Microsoft.AspNet.HttpFeature;
+using Microsoft.AspNet.Mvc.Core;
+
+namespace Microsoft.AspNet.Mvc
+{
+    /// <summary>
+    /// Represents an <see cref="ActionResult"/> that when executed will
+    /// write a file from disk to the response using mechanisms provided
+    /// by the host.
+    /// </summary>
+    public class FilePathResult : FileResult
+    {
+        private const int DefaultBufferSize = 0x1000;
+
+        /// <summary>
+        /// Creates a new <see cref="FilePathResult"/> instance with
+        /// the provided <paramref name="fileName"/> and the
+        /// provided <paramref name="contentType"/>.
+        /// </summary>
+        /// <param name="fileName">The path to the file. The path must be an absolute
+        /// path. Relative and virtual paths are not supported.</param>
+        /// <param name="contentType">The Content-Type header of the response.</param>
+        public FilePathResult([NotNull] string fileName, [NotNull] string contentType)
+            : base(contentType)
+        {
+            if (!Path.IsPathRooted(fileName))
+            {
+                var message = Resources.FormatFileResult_InvalidPathType_RelativeOrVirtualPath(fileName);
+                throw new ArgumentException(message, "fileName");
+            }
+
+            FileName = fileName;
+        }
+
+        /// <summary>
+        /// Gets the path to the file that will be sent back as the response.
+        /// </summary>
+        public string FileName { get; private set; }
+
+        /// <inheritdoc />
+        protected async override Task WriteFileAsync(HttpResponse response, CancellationToken cancellation)
+        {
+            var sendFile = response.HttpContext.GetFeature<IHttpSendFileFeature>();
+            if (sendFile != null)
+            {
+                await sendFile.SendFileAsync(
+                    FileName,
+                    offset: 0,
+                    length: null,
+                    cancellation: cancellation);
+            }
+            else
+            {
+                await CopyStreamToResponse(FileName, response, cancellation);
+            }
+        }
+
+        private static async Task CopyStreamToResponse(
+            string fileName,
+            HttpResponse response,
+            CancellationToken cancellation)
+        {
+            var fileStream = new FileStream(
+                fileName, FileMode.Open,
+                FileAccess.Read,
+                FileShare.ReadWrite,
+                DefaultBufferSize,
+                FileOptions.Asynchronous | FileOptions.SequentialScan);
+
+            using (fileStream)
+            {
+                await fileStream.CopyToAsync(response.Body, DefaultBufferSize, cancellation);
+            }
+        }
+    }
+}