Reorganise FileFormats

OpenRA.FileFormats/Primitives/PriorityQueue.cs

@@ -0,0 +1,113 @@
+#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.Generic;
+
+namespace OpenRA.FileFormats
+{
+	public class PriorityQueue<T>
+			where T : IComparable<T>
+	{
+		List<T[]> items = new List<T[]>();
+		int level, index;
+
+		public PriorityQueue()
+		{
+			items.Add(new T[1]);
+		}
+
+		public void Add(T item)
+		{
+			int addLevel = level;
+			int addIndex = index;
+
+			while (addLevel >= 1 && Above(addLevel, addIndex).CompareTo(item) > 0)
+			{
+				items[addLevel][addIndex] = Above(addLevel, addIndex);
+				--addLevel;
+				addIndex >>= 1;
+			}
+
+			items[addLevel][addIndex] = item;
+
+			if (++index >= (1 << level))
+			{
+				index = 0;
+				if (items.Count <= ++level)
+					items.Add(new T[1 << level]);
+			}
+		}
+
+		public bool Empty { get { return (level == 0); } }
+
+		T At(int level, int index) { return items[level][index]; }
+		T Above(int level, int index) { return items[level - 1][index >> 1]; }
+
+		T Last()
+		{
+			int lastLevel = level;
+			int lastIndex = index;
+
+			if (--lastIndex < 0)
+				lastIndex = (1 << --lastLevel) - 1;
+
+			return At(lastLevel, lastIndex);
+		}
+
+		public T Pop()
+		{
+			if (level == 0 && index == 0)
+				throw new InvalidOperationException("Attempting to pop empty PriorityQueue");
+
+			T ret = At(0, 0);
+			BubbleInto(0, 0, Last());
+			if (--index < 0)
+				index = (1 << --level) - 1;
+
+			return ret;
+		}
+
+		void BubbleInto(int intoLevel, int intoIndex, T val)
+		{
+			int downLevel = intoLevel + 1;
+			int downIndex = intoIndex << 1;
+
+			if (downLevel > level || (downLevel == level && downIndex >= index))
+			{
+				items[intoLevel][intoIndex] = val;
+				return;
+			}
+
+			if (downLevel <= level && downIndex < index - 1 &&
+				At(downLevel, downIndex).CompareTo(At(downLevel, downIndex + 1)) >= 0)
+				++downIndex;
+
+			if (val.CompareTo(At(downLevel, downIndex)) <= 0)
+			{
+				items[intoLevel][intoIndex] = val;
+				return;
+			}
+
+			items[intoLevel][intoIndex] = At(downLevel, downIndex);
+			BubbleInto(downLevel, downIndex, val);
+		}
+	}
+}