Reorganise FileFormats

OpenRA.FileFormats/Primitives/Cache.cs

@@ -0,0 +1,59 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007,2009,2010 Chris Forbes, Robert Pepperell, Matthew Bowra-Dean, Paul Chote, Alli Witheford.
+ * This file is part of OpenRA.
+ * 
+ *  OpenRA is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  OpenRA is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with OpenRA.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace OpenRA.FileFormats
+{
+	public class Cache<T, U> : IEnumerable<KeyValuePair<T, U>>
+	{
+		Dictionary<T, U> hax = new Dictionary<T, U>();
+		Func<T,U> loader;
+
+		public Cache(Func<T,U> loader)
+		{
+			if (loader == null)
+				throw new ArgumentNullException();
+
+			this.loader = loader;
+		}
+
+		public U this[T key]
+		{
+			get
+			{
+				U result;
+				if (!hax.TryGetValue(key, out result))
+					hax.Add(key, result = loader(key));
+
+				return result;
+			}
+		}
+
+		public IEnumerator<KeyValuePair<T, U>> GetEnumerator() { return hax.GetEnumerator(); }
+
+		IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
+
+		public IEnumerable<T> Keys { get { return hax.Keys; } }
+		public IEnumerable<U> Values { get { return hax.Values; } }
+	}
+}