1 files changed, 127 insertions, 0 deletions
diff --git a/src/DotNetOpenAuth.OpenId/OpenId/RelyingParty/Associations.cs b/src/DotNetOpenAuth.OpenId/OpenId/RelyingParty/Associations.cs
new file mode 100644
index 0000000..b171bec
--- /dev/null
+++ b/src/DotNetOpenAuth.OpenId/OpenId/RelyingParty/Associations.cs
@@ -0,0 +1,127 @@
+//-----------------------------------------------------------------------
+// <copyright file="Associations.cs" company="Andrew Arnott">
+//     Copyright (c) Andrew Arnott. All rights reserved.
+// </copyright>
+//-----------------------------------------------------------------------
+
+namespace DotNetOpenAuth.OpenId.RelyingParty {
+	using System;
+	using System.Collections.Generic;
+	using System.Collections.ObjectModel;
+	using System.Diagnostics;
+	using System.Diagnostics.CodeAnalysis;
+	using System.Diagnostics.Contracts;
+	using System.Linq;
+	using DotNetOpenAuth.Messaging;
+
+	/// <summary>
+	/// A dictionary of handle/Association pairs.
+	/// </summary>
+	/// <remarks>
+	/// Each method is locked, even if it is only one line, so that they are thread safe
+	/// against each other, particularly the ones that enumerate over the list, since they
+	/// can break if the collection is changed by another thread during enumeration.
+	/// </remarks>
+	[DebuggerDisplay("Count = {assocs.Count}")]
+	[ContractVerification(true)]
+	internal class Associations {
+		/// <summary>
+		/// The lookup table where keys are the association handles and values are the associations themselves.
+		/// </summary>
+		[DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
+		private readonly KeyedCollection<string, Association> associations = new KeyedCollectionDelegate<string, Association>(assoc => assoc.Handle);
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="Associations"/> class.
+		/// </summary>
+		public Associations() {
+		}
+
+		/// <summary>
+		/// Gets the <see cref="Association"/>s ordered in order of descending issue date
+		/// (most recently issued comes first).  An empty sequence if no valid associations exist.
+		/// </summary>
+		/// <remarks>
+		/// This property is used by relying parties that are initiating authentication requests.
+		/// It does not apply to Providers, which always need a specific association by handle.
+		/// </remarks>
+		public IEnumerable<Association> Best {
+			get {
+				Contract.Ensures(Contract.Result<IEnumerable<Association>>() != null);
+
+				lock (this.associations) {
+					return this.associations.OrderByDescending(assoc => assoc.Issued);
+				}
+			}
+		}
+
+		/// <summary>
+		/// Stores an <see cref="Association"/> in the collection.
+		/// </summary>
+		/// <param name="association">The association to add to the collection.</param>
+		public void Set(Association association) {
+			Contract.Requires<ArgumentNullException>(association != null);
+			Contract.Ensures(this.Get(association.Handle) == association);
+			lock (this.associations) {
+				this.associations.Remove(association.Handle); // just in case one already exists.
+				this.associations.Add(association);
+			}
+
+			Contract.Assume(this.Get(association.Handle) == association);
+		}
+
+		/// <summary>
+		/// Returns the <see cref="Association"/> with the given handle.  Null if not found.
+		/// </summary>
+		/// <param name="handle">The handle to the required association.</param>
+		/// <returns>The desired association, or null if none with the given handle could be found.</returns>
+		[Pure]
+		public Association Get(string handle) {
+			Contract.Requires<ArgumentException>(!string.IsNullOrEmpty(handle));
+
+			lock (this.associations) {
+				if (this.associations.Contains(handle)) {
+					return this.associations[handle];
+				} else {
+					return null;
+				}
+			}
+		}
+
+		/// <summary>
+		/// Removes the <see cref="Association"/> with the given handle.
+		/// </summary>
+		/// <param name="handle">The handle to the required association.</param>
+		/// <returns>Whether an <see cref="Association"/> with the given handle was in the collection for removal.</returns>
+		public bool Remove(string handle) {
+			Contract.Requires<ArgumentException>(!string.IsNullOrEmpty(handle));
+			lock (this.associations) {
+				return this.associations.Remove(handle);
+			}
+		}
+
+		/// <summary>
+		/// Removes all expired associations from the collection.
+		/// </summary>
+		public void ClearExpired() {
+			lock (this.associations) {
+				var expireds = this.associations.Where(assoc => assoc.IsExpired).ToList();
+				foreach (Association assoc in expireds) {
+					this.associations.Remove(assoc.Handle);
+				}
+			}
+		}
+
+#if CONTRACTS_FULL
+		/// <summary>
+		/// Verifies conditions that should be true for any valid state of this object.
+		/// </summary>
+		[SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Justification = "Called by code contracts.")]
+		[SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Justification = "Called by code contracts.")]
+		[ContractInvariantMethod]
+		private void ObjectInvariant() {
+			Contract.Invariant(this.associations != null);
+		}
+#endif
+	}
+}