001    /*
002     * CDDL HEADER START
003     *
004     * The contents of this file are subject to the terms of the
005     * Common Development and Distribution License, Version 1.0 only
006     * (the "License").  You may not use this file except in compliance
007     * with the License.
008     *
009     * You can obtain a copy of the license at
010     * trunk/opends/resource/legal-notices/OpenDS.LICENSE
011     * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
012     * See the License for the specific language governing permissions
013     * and limitations under the License.
014     *
015     * When distributing Covered Code, include this CDDL HEADER in each
016     * file and include the License file at
017     * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
018     * add the following below this CDDL HEADER, with the fields enclosed
019     * by brackets "[]" replaced with your own identifying information:
020     *      Portions Copyright [yyyy] [name of copyright owner]
021     *
022     * CDDL HEADER END
023     *
024     *
025     *      Copyright 2006-2008 Sun Microsystems, Inc.
026     */
027    package org.opends.server.backends.jeb;
028    
029    import java.util.Comparator;
030    
031    /**
032     * A comparator for index modifications.
033     */
034    public class IndexModComparator implements Comparator<IndexMod>
035    {
036      /**
037       * The index key comparator.
038       */
039      private Comparator<byte[]> comparator;
040    
041      /**
042       * Indicates when true that the entry ID should also factor into the
043       * comparison, in addition to the index key.
044       */
045      private boolean compareID;
046    
047      /**
048       * Create a new comparator for index modifications.
049       * @param comparator The index key comparator.
050       * @param compareID Indicates when true that the entry ID should also factor
051       * into the comparison, in addition to the index key.
052       */
053      public IndexModComparator(Comparator<byte[]> comparator, boolean compareID)
054      {
055        this.comparator = comparator;
056        this.compareID = compareID;
057      }
058    
059      /**
060       * Compares its two arguments for order.  Returns a negative integer,
061       * zero, or a positive integer as the first argument is less than, equal
062       * to, or greater than the second.
063       *
064       * @param a the first object to be compared.
065       * @param b the second object to be compared.
066       * @return a negative integer, zero, or a positive integer as the
067       *         first argument is less than, equal to, or greater than the
068       *         second.
069       */
070      public int compare(IndexMod a, IndexMod b)
071      {
072        int r = comparator.compare(a.key, b.key);
073        if (compareID)
074        {
075          if (r == 0)
076          {
077            r = a.value.compareTo(b.value);
078          }
079        }
080        return r;
081      }
082    }