1 files changed, 184 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.Core/Messaging/CachedDirectWebResponse.cs b/src/DotNetOpenAuth.Core/Messaging/CachedDirectWebResponse.cs
new file mode 100644
index 0000000..2f3a1d9
--- /dev/null
+++ b/src/DotNetOpenAuth.Core/Messaging/CachedDirectWebResponse.cs
@@ -0,0 +1,184 @@
+//-----------------------------------------------------------------------
+// <copyright file="CachedDirectWebResponse.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.Messaging {
+	using System;
+	using System.Diagnostics;
+	using System.Diagnostics.CodeAnalysis;
+	using System.Diagnostics.Contracts;
+	using System.IO;
+	using System.Net;
+	using System.Text;
+
+	/// <summary>
+	/// Cached details on the response from a direct web request to a remote party.
+	/// </summary>
+	[ContractVerification(true)]
+	[DebuggerDisplay("{Status} {ContentType.MediaType}, length: {ResponseStream.Length}")]
+	internal class CachedDirectWebResponse : IncomingWebResponse {
+		/// <summary>
+		/// A seekable, repeatable response stream.
+		/// </summary>
+		private MemoryStream responseStream;
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="CachedDirectWebResponse"/> class.
+		/// </summary>
+		internal CachedDirectWebResponse() {
+		}
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="CachedDirectWebResponse"/> class.
+		/// </summary>
+		/// <param name="requestUri">The request URI.</param>
+		/// <param name="response">The response.</param>
+		/// <param name="maximumBytesToRead">The maximum bytes to read.</param>
+		internal CachedDirectWebResponse(Uri requestUri, HttpWebResponse response, int maximumBytesToRead)
+			: base(requestUri, response) {
+			Requires.NotNull(requestUri, "requestUri");
+			Requires.NotNull(response, "response");
+			this.responseStream = CacheNetworkStreamAndClose(response, maximumBytesToRead);
+
+			// BUGBUG: if the response was exactly maximumBytesToRead, we'll incorrectly believe it was truncated.
+			this.ResponseTruncated = this.responseStream.Length == maximumBytesToRead;
+		}
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="CachedDirectWebResponse"/> class.
+		/// </summary>
+		/// <param name="requestUri">The request URI.</param>
+		/// <param name="responseUri">The final URI to respond to the request.</param>
+		/// <param name="headers">The headers.</param>
+		/// <param name="statusCode">The status code.</param>
+		/// <param name="contentType">Type of the content.</param>
+		/// <param name="contentEncoding">The content encoding.</param>
+		/// <param name="responseStream">The response stream.</param>
+		internal CachedDirectWebResponse(Uri requestUri, Uri responseUri, WebHeaderCollection headers, HttpStatusCode statusCode, string contentType, string contentEncoding, MemoryStream responseStream)
+			: base(requestUri, responseUri, headers, statusCode, contentType, contentEncoding) {
+			Requires.NotNull(requestUri, "requestUri");
+			Requires.NotNull(responseStream, "responseStream");
+			this.responseStream = responseStream;
+		}
+
+		/// <summary>
+		/// Gets a value indicating whether the cached response stream was
+		/// truncated to a maximum allowable length.
+		/// </summary>
+		public bool ResponseTruncated { get; private set; }
+
+		/// <summary>
+		/// Gets the body of the HTTP response.
+		/// </summary>
+		public override Stream ResponseStream {
+			get { return this.responseStream; }
+		}
+
+		/// <summary>
+		/// Gets or sets the cached response stream.
+		/// </summary>
+		internal MemoryStream CachedResponseStream {
+			get { return this.responseStream; }
+			set { this.responseStream = value; }
+		}
+
+		/// <summary>
+		/// Creates a text reader for the response stream.
+		/// </summary>
+		/// <returns>The text reader, initialized for the proper encoding.</returns>
+		public override StreamReader GetResponseReader() {
+			this.ResponseStream.Seek(0, SeekOrigin.Begin);
+			string contentEncoding = this.Headers[HttpResponseHeader.ContentEncoding];
+			Encoding encoding = null;
+			if (!string.IsNullOrEmpty(contentEncoding)) {
+				try {
+					encoding = Encoding.GetEncoding(contentEncoding);
+				} catch (ArgumentException ex) {
+					Logger.Messaging.ErrorFormat("Encoding.GetEncoding(\"{0}\") threw ArgumentException: {1}", contentEncoding, ex);
+				}
+			}
+
+			return encoding != null ? new StreamReader(this.ResponseStream, encoding) : new StreamReader(this.ResponseStream);
+		}
+
+		/// <summary>
+		/// Gets the body of the response as a string.
+		/// </summary>
+		/// <returns>The entire body of the response.</returns>
+		internal string GetResponseString() {
+			if (this.ResponseStream != null) {
+				string value = this.GetResponseReader().ReadToEnd();
+				this.ResponseStream.Seek(0, SeekOrigin.Begin);
+				return value;
+			} else {
+				return null;
+			}
+		}
+
+		/// <summary>
+		/// Gets an offline snapshot version of this instance.
+		/// </summary>
+		/// <param name="maximumBytesToCache">The maximum bytes from the response stream to cache.</param>
+		/// <returns>A snapshot version of this instance.</returns>
+		/// <remarks>
+		/// If this instance is a <see cref="NetworkDirectWebResponse"/> creating a snapshot
+		/// will automatically close and dispose of the underlying response stream.
+		/// If this instance is a <see cref="CachedDirectWebResponse"/>, the result will
+		/// be the self same instance.
+		/// </remarks>
+		internal override CachedDirectWebResponse GetSnapshot(int maximumBytesToCache) {
+			return this;
+		}
+
+		/// <summary>
+		/// Sets the response to some string, encoded as UTF-8.
+		/// </summary>
+		/// <param name="body">The string to set the response to.</param>
+		internal void SetResponse(string body) {
+			if (body == null) {
+				this.responseStream = null;
+				return;
+			}
+
+			Encoding encoding = Encoding.UTF8;
+			this.Headers[HttpResponseHeader.ContentEncoding] = encoding.HeaderName;
+			this.responseStream = new MemoryStream();
+			StreamWriter writer = new StreamWriter(this.ResponseStream, encoding);
+			writer.Write(body);
+			writer.Flush();
+			this.ResponseStream.Seek(0, SeekOrigin.Begin);
+		}
+
+		/// <summary>
+		/// Caches the network stream and closes it if it is open.
+		/// </summary>
+		/// <param name="response">The response whose stream is to be cloned.</param>
+		/// <param name="maximumBytesToRead">The maximum bytes to cache.</param>
+		/// <returns>The seekable Stream instance that contains a copy of what was returned in the HTTP response.</returns>
+		[SuppressMessage("Microsoft.Globalization", "CA1303:Do not pass literals as localized parameters", MessageId = "System.Diagnostics.Contracts.__ContractsRuntime.Assume(System.Boolean,System.String,System.String)", Justification = "No localization required.")]
+		private static MemoryStream CacheNetworkStreamAndClose(HttpWebResponse response, int maximumBytesToRead) {
+			Requires.NotNull(response, "response");
+			Contract.Ensures(Contract.Result<MemoryStream>() != null);
+
+			// Now read and cache the network stream
+			Stream networkStream = response.GetResponseStream();
+			MemoryStream cachedStream = new MemoryStream(response.ContentLength < 0 ? 4 * 1024 : Math.Min((int)response.ContentLength, maximumBytesToRead));
+			try {
+				Contract.Assume(networkStream.CanRead, "HttpWebResponse.GetResponseStream() always returns a readable stream."); // CC missing
+				Contract.Assume(cachedStream.CanWrite, "This is a MemoryStream -- it's always writable."); // CC missing
+				networkStream.CopyTo(cachedStream);
+				cachedStream.Seek(0, SeekOrigin.Begin);
+
+				networkStream.Dispose();
+				response.Close();
+
+				return cachedStream;
+			} catch {
+				cachedStream.Dispose();
+				throw;
+			}
+		}
+	}
+}