Promote IFormFile extension methods

src/Microsoft.AspNet.Http.Abstractions/IFormFile.cs

@@ -2,6 +2,8 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Http
 {
@@ -10,18 +12,52 @@ namespace Microsoft.AspNet.Http
     /// </summary>
     public interface IFormFile
     {
+        /// <summary>
+        /// Gets the raw Content-Type header of the uploaded file.
+        /// </summary>
         string ContentType { get; }
 
+        /// <summary>
+        /// Gets the raw Content-Disposition header of the uploaded file.
+        /// </summary>
         string ContentDisposition { get; }
 
+        /// <summary>
+        /// Gets the header dictionary of the uploaded file.
+        /// </summary>
         IHeaderDictionary Headers { get; }
 
+        /// <summary>
+        /// Gets the file length in bytes.
+        /// </summary>
         long Length { get; }
 
+        /// <summary>
+        /// Gets the name from the Content-Disposition header.
+        /// </summary>
         string Name { get; }
 
+        /// <summary>
+        /// Gets the file name from the Content-Disposition header.
+        /// </summary>
         string FileName { get; }
 
+        /// <summary>
+        /// Opens the request stream for reading the uploaded file.
+        /// </summary>
         Stream OpenReadStream();
+
+        /// <summary>
+        /// Saves the contents of the uploaded file.
+        /// </summary>
+        /// <param name="path">The path of the file to create.</param>
+        void SaveAs(string path);
+
+        /// <summary>
+        /// Asynchronously saves the contents of the uploaded file.
+        /// </summary>
+        /// <param name="path">The path of the file to create.</param>
+        /// <param name="cancellationToken"></param>
+        Task SaveAsAsync(string path, CancellationToken cancellationToken = default(CancellationToken));
     }
-}
+}

src/Microsoft.AspNet.Http/Features/FormFile.cs

@@ -2,12 +2,17 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.AspNet.Http.Internal;
 
 namespace Microsoft.AspNet.Http.Features.Internal
 {
     public class FormFile : IFormFile
     {
+        // Stream.CopyTo method uses 80KB as the default buffer size.
+        private const int DefaultBufferSize = 80 * 1024;
+
         private readonly Stream _baseStream;
         private readonly long _baseStreamOffset;
 
@@ -20,29 +25,77 @@ public FormFile(Stream baseStream, long baseStreamOffset, long length, string na
             FileName = fileName;
         }
 
+        /// <summary>
+        /// Gets the raw Content-Disposition header of the uploaded file.
+        /// </summary>
         public string ContentDisposition
         {
             get { return Headers["Content-Disposition"]; }
             set { Headers["Content-Disposition"] = value; }
         }
 
+        /// <summary>
+        /// Gets the raw Content-Type header of the uploaded file.
+        /// </summary>
         public string ContentType
         {
             get { return Headers["Content-Type"]; }
             set { Headers["Content-Type"] = value; }
         }
 
+        /// <summary>
+        /// Gets the header dictionary of the uploaded file.
+        /// </summary>
         public IHeaderDictionary Headers { get; set; }
 
+        /// <summary>
+        /// Gets the file length in bytes.
+        /// </summary>
         public long Length { get; }
 
+        /// <summary>
+        /// Gets the name from the Content-Disposition header.
+        /// </summary>
         public string Name { get; }
 
+        /// <summary>
+        /// Gets the file name from the Content-Disposition header.
+        /// </summary>
         public string FileName { get; }
 
+        /// <summary>
+        /// Opens the request stream for reading the uploaded file.
+        /// </summary>
         public Stream OpenReadStream()
         {
             return new ReferenceReadStream(_baseStream, _baseStreamOffset, Length);
         }
+
+        /// <summary>
+        /// Saves the contents of the uploaded file.
+        /// </summary>
+        /// <param name="path">The path of the file to create.</param>
+        public void SaveAs(string path)
+        {
+            using (var fileStream = File.Create(path, DefaultBufferSize))
+            {
+                var inputStream = OpenReadStream();
+                inputStream.CopyTo(fileStream, DefaultBufferSize);
+            }
+        }
+
+        /// <summary>
+        /// Asynchronously saves the contents of the uploaded file.
+        /// </summary>
+        /// <param name="path">The path of the file to create.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task SaveAsAsync(string path, CancellationToken cancellationToken = default(CancellationToken))
+        {
+            using (var fileStream = File.Create(path, DefaultBufferSize, FileOptions.Asynchronous))
+            {
+                var inputStream = OpenReadStream();
+                await inputStream.CopyToAsync(fileStream, DefaultBufferSize, cancellationToken);
+            }
+        }
     }
-}
+}