SortValueCachedComparator.java

/**
 * OrbisGIS is a java GIS application dedicated to research in GIScience.
 * OrbisGIS is developed by the GIS group of the DECIDE team of the 
 * Lab-STICC CNRS laboratory, see <http://www.lab-sticc.fr/>.
 *
 * The GIS group of the DECIDE team is located at :
 *
 * Laboratoire Lab-STICC – CNRS UMR 6285
 * Equipe DECIDE
 * UNIVERSITÉ DE BRETAGNE-SUD
 * Institut Universitaire de Technologie de Vannes
 * 8, Rue Montaigne - BP 561 56017 Vannes Cedex
 * 
 * OrbisGIS is distributed under GPL 3 license.
 *
 * Copyright (C) 2007-2014 CNRS (IRSTV FR CNRS 2488)
 * Copyright (C) 2015-2017 CNRS (Lab-STICC UMR CNRS 6285)
 *
 * This file is part of OrbisGIS.
 *
 * OrbisGIS 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.
 *
 * OrbisGIS 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
 * OrbisGIS. If not, see <http://www.gnu.org/licenses/>.
 *
 * For more information, please consult: <http://www.orbisgis.org/>
 * or contact directly:
 * info_at_ orbisgis.org
 */
package org.orbisgis.corejdbc;

import java.util.Comparator;

/**
 *
 * A comparator with pre-loaded values,
 * does not require primary key but require more memory
 * @author Nicolas Fortin
 */
public class SortValueCachedComparator implements Comparator<Integer> {

        private Comparable<Object>[] values;

        public SortValueCachedComparator(Comparable<Object>[] values) {
                this.values = values;
        }
        
        @Override
        public int compare(Integer t, Integer t1) {
                final Comparable<Object> left = values[t-1];
                final Comparable<Object> right = values[t1-1];
                if (right == null) {
                    return (left == null) ? t.compareTo(t1) : 1;
                } else if (left == null) {
                    return -1;
                }
                int res = left.compareTo(right);
                if(res==0) {
                        res = t.compareTo(t1); //TreeSet remove duplicates
                }
                return res;
        }        
}