/*
 * JasperReports - Free Java Reporting Library.
 * Copyright (C) 2001 - 2016 TIBCO Software Inc. All rights reserved.
 * http://www.jaspersoft.com
 *
 * Unless you have purchased a commercial license agreement from Jaspersoft,
 * the following license terms apply:
 *
 * This program is part of JasperReports.
 *
 * JasperReports is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JasperReports 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with JasperReports. If not, see <http://www.gnu.org/licenses/>.
 */
package net.sf.jasperreports.engine.export.tabulator;

import java.util.TreeSet;

/**
 * @author Lucian Chirita (lucianc@users.sourceforge.net)
 */
public class EntryIndexes
{
	int seq;
	TreeSet<Integer> recycled;
	
	public EntryIndexes()
	{
	}
	
	public int next()
	{
		if (recycled != null)
		{
			Integer idx = recycled.pollFirst();
			if (idx != null)
			{
				return idx;
			}
		}
		
		int idx = seq;
		++seq;
		return idx;
	}
	
	public void recycle(int index)
	{
		if (recycled == null)
		{
			recycled = new TreeSet<Integer>();
		}
		
		boolean added = recycled.add(index);
		assert added;
	}
}