001/*
002 * #%L
003 * Netarchivesuite - harvester
004 * %%
005 * Copyright (C) 2005 - 2014 The Royal Danish Library, the Danish State and University Library,
006 *             the National Library of France and the Austrian National Library.
007 * %%
008 * This program is free software: you can redistribute it and/or modify
009 * it under the terms of the GNU Lesser General Public License as
010 * published by the Free Software Foundation, either version 2.1 of the
011 * License, or (at your option) any later version.
012 * 
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Lesser Public License for more details.
017 * 
018 * You should have received a copy of the GNU General Lesser Public
019 * License along with this program.  If not, see
020 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
021 * #L%
022 */
023package dk.netarkivet.harvester.harvesting.frontier;
024
025import java.util.Comparator;
026
027/**
028 * This class implements a natural order on {@link FrontierReportLine}. Comparisons are made : - first by decreasing
029 * values of totalEnqueues - secondly by domain name (string natural order)
030 */
031public class FrontierReportLineNaturalOrder implements Comparator<FrontierReportLineOrderKey> {
032
033    private static final FrontierReportLineNaturalOrder order = new FrontierReportLineNaturalOrder();
034
035    @Override
036    public int compare(FrontierReportLineOrderKey k1, FrontierReportLineOrderKey k2) {
037        int sizeComp = Long.valueOf(k1.getQueueSize()).compareTo(k2.getQueueSize());
038        if (sizeComp == 0) {
039            return k1.getQueueId().compareTo(k2.getQueueId());
040        }
041        return -sizeComp;
042    }
043
044    /**
045     * Returns the singleton instance of this class.
046     *
047     * @return the singleton instance of this class.
048     */
049    public static FrontierReportLineNaturalOrder getInstance() {
050        return order;
051    }
052
053}