1 files changed, 217 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.Core/Messaging/Reflection/MessageDescriptionCollection.cs b/src/DotNetOpenAuth.Core/Messaging/Reflection/MessageDescriptionCollection.cs
new file mode 100644
index 0000000..79ef172
--- /dev/null
+++ b/src/DotNetOpenAuth.Core/Messaging/Reflection/MessageDescriptionCollection.cs
@@ -0,0 +1,217 @@
+//-----------------------------------------------------------------------
+// <copyright file="MessageDescriptionCollection.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.Messaging.Reflection {
+	using System;
+	using System.Collections.Generic;
+	using System.Diagnostics.CodeAnalysis;
+	using System.Diagnostics.Contracts;
+
+	/// <summary>
+	/// A cache of <see cref="MessageDescription"/> instances.
+	/// </summary>
+	[ContractVerification(true)]
+	internal class MessageDescriptionCollection : IEnumerable<MessageDescription> {
+		/// <summary>
+		/// A dictionary of reflected message types and the generated reflection information.
+		/// </summary>
+		private readonly Dictionary<MessageTypeAndVersion, MessageDescription> reflectedMessageTypes = new Dictionary<MessageTypeAndVersion, MessageDescription>();
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="MessageDescriptionCollection"/> class.
+		/// </summary>
+		internal MessageDescriptionCollection() {
+		}
+
+		#region IEnumerable<MessageDescription> Members
+
+		/// <summary>
+		/// Returns an enumerator that iterates through a collection.
+		/// </summary>
+		/// <returns>
+		/// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
+		/// </returns>
+		public IEnumerator<MessageDescription> GetEnumerator() {
+			return this.reflectedMessageTypes.Values.GetEnumerator();
+		}
+
+		#endregion
+
+		#region IEnumerable Members
+
+		/// <summary>
+		/// Returns an enumerator that iterates through a collection.
+		/// </summary>
+		/// <returns>
+		/// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
+		/// </returns>
+		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() {
+			return this.reflectedMessageTypes.Values.GetEnumerator();
+		}
+
+		#endregion
+
+		/// <summary>
+		/// Gets a <see cref="MessageDescription"/> instance prepared for the
+		/// given message type.
+		/// </summary>
+		/// <param name="messageType">A type that implements <see cref="IMessage"/>.</param>
+		/// <param name="messageVersion">The protocol version of the message.</param>
+		/// <returns>A <see cref="MessageDescription"/> instance.</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.")]
+		[Pure]
+		internal MessageDescription Get(Type messageType, Version messageVersion) {
+			Requires.NotNullSubtype<IMessage>(messageType, "messageType");
+			Requires.NotNull(messageVersion, "messageVersion");
+			Contract.Ensures(Contract.Result<MessageDescription>() != null);
+
+			MessageTypeAndVersion key = new MessageTypeAndVersion(messageType, messageVersion);
+
+			MessageDescription result;
+			if (!this.reflectedMessageTypes.TryGetValue(key, out result)) {
+				lock (this.reflectedMessageTypes) {
+					if (!this.reflectedMessageTypes.TryGetValue(key, out result)) {
+						this.reflectedMessageTypes[key] = result = new MessageDescription(messageType, messageVersion);
+					}
+				}
+			}
+
+			Contract.Assume(result != null, "We should never assign null values to this dictionary.");
+			return result;
+		}
+
+		/// <summary>
+		/// Gets a <see cref="MessageDescription"/> instance prepared for the
+		/// given message type.
+		/// </summary>
+		/// <param name="message">The message for which a <see cref="MessageDescription"/> should be obtained.</param>
+		/// <returns>
+		/// A <see cref="MessageDescription"/> instance.
+		/// </returns>
+		[Pure]
+		internal MessageDescription Get(IMessage message) {
+			Requires.NotNull(message, "message");
+			Contract.Ensures(Contract.Result<MessageDescription>() != null);
+			return this.Get(message.GetType(), message.Version);
+		}
+
+		/// <summary>
+		/// Gets the dictionary that provides read/write access to a message.
+		/// </summary>
+		/// <param name="message">The message.</param>
+		/// <returns>The dictionary.</returns>
+		[Pure]
+		internal MessageDictionary GetAccessor(IMessage message) {
+			Requires.NotNull(message, "message");
+			return this.GetAccessor(message, false);
+		}
+
+		/// <summary>
+		/// Gets the dictionary that provides read/write access to a message.
+		/// </summary>
+		/// <param name="message">The message.</param>
+		/// <param name="getOriginalValues">A value indicating whether this message dictionary will retrieve original values instead of normalized ones.</param>
+		/// <returns>The dictionary.</returns>
+		[Pure]
+		internal MessageDictionary GetAccessor(IMessage message, bool getOriginalValues) {
+			Requires.NotNull(message, "message");
+			return this.Get(message).GetDictionary(message, getOriginalValues);
+		}
+
+		/// <summary>
+		/// A struct used as the key to bundle message type and version.
+		/// </summary>
+		[ContractVerification(true)]
+		private struct MessageTypeAndVersion {
+			/// <summary>
+			/// Backing store for the <see cref="Type"/> property.
+			/// </summary>
+			private readonly Type type;
+
+			/// <summary>
+			/// Backing store for the <see cref="Version"/> property.
+			/// </summary>
+			private readonly Version version;
+
+			/// <summary>
+			/// Initializes a new instance of the <see cref="MessageTypeAndVersion"/> struct.
+			/// </summary>
+			/// <param name="messageType">Type of the message.</param>
+			/// <param name="messageVersion">The message version.</param>
+			internal MessageTypeAndVersion(Type messageType, Version messageVersion) {
+				Requires.NotNull(messageType, "messageType");
+				Requires.NotNull(messageVersion, "messageVersion");
+
+				this.type = messageType;
+				this.version = messageVersion;
+			}
+
+			/// <summary>
+			/// Gets the message type.
+			/// </summary>
+			[SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Justification = "Exposes basic identity on the type.")]
+			internal Type Type {
+				get { return this.type; }
+			}
+
+			/// <summary>
+			/// Gets the message version.
+			/// </summary>
+			[SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Justification = "Exposes basic identity on the type.")]
+			internal Version Version {
+				get { return this.version; }
+			}
+
+			/// <summary>
+			/// Implements the operator ==.
+			/// </summary>
+			/// <param name="first">The first object to compare.</param>
+			/// <param name="second">The second object to compare.</param>
+			/// <returns>The result of the operator.</returns>
+			public static bool operator ==(MessageTypeAndVersion first, MessageTypeAndVersion second) {
+				// structs cannot be null, so this is safe
+				return first.Equals(second);
+			}
+
+			/// <summary>
+			/// Implements the operator !=.
+			/// </summary>
+			/// <param name="first">The first object to compare.</param>
+			/// <param name="second">The second object to compare.</param>
+			/// <returns>The result of the operator.</returns>
+			public static bool operator !=(MessageTypeAndVersion first, MessageTypeAndVersion second) {
+				// structs cannot be null, so this is safe
+				return !first.Equals(second);
+			}
+
+			/// <summary>
+			/// Indicates whether this instance and a specified object are equal.
+			/// </summary>
+			/// <param name="obj">Another object to compare to.</param>
+			/// <returns>
+			/// true if <paramref name="obj"/> and this instance are the same type and represent the same value; otherwise, false.
+			/// </returns>
+			public override bool Equals(object obj) {
+				if (obj is MessageTypeAndVersion) {
+					MessageTypeAndVersion other = (MessageTypeAndVersion)obj;
+					return this.type == other.type && this.version == other.version;
+				} else {
+					return false;
+				}
+			}
+
+			/// <summary>
+			/// Returns the hash code for this instance.
+			/// </summary>
+			/// <returns>
+			/// A 32-bit signed integer that is the hash code for this instance.
+			/// </returns>
+			public override int GetHashCode() {
+				return this.type.GetHashCode();
+			}
+		}
+	}
+}