xref: /OpenGrok/opengrok-indexer/src/main/java/org/opengrok/indexer/search/context/PhraseHighlightComparator.java (revision 5d9f3aa0ca3da3a714233f987fa732f62c0965f6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * See LICENSE.txt included in this distribution for the specific
9  * language governing permissions and limitations under the License.
10  *
11  * When distributing Covered Code, include this CDDL HEADER in each
12  * file and include the License file at LICENSE.txt.
13  * If applicable, add the following below this CDDL HEADER, with the
14  * fields enclosed by brackets "[]" replaced with your own identifying
15  * information: Portions Copyright [yyyy] [name of copyright owner]
16  *
17  * CDDL HEADER END
18  */
19 
20 /*
21  * Copyright (c) 2018, Chris Fraire <cfraire@me.com>.
22  */
23 package org.opengrok.indexer.search.context;
24 
25 import java.util.Comparator;
26 
27 /**
28  * Represents a {@link Comparator} for {@link PhraseHighlight}.
29  */
30 public class PhraseHighlightComparator implements Comparator<PhraseHighlight> {
31 
32     public static final PhraseHighlightComparator INSTANCE = new PhraseHighlightComparator();
33 
34     /**
35      * Compares two {@link PhraseHighlight} instances for order by first
36      * comparing using {@link Integer#compare(int, int)} the
37      * {@link PhraseHighlight#lineStart} values of {@code o1} and {@code o2} and
38      * subsequently, if identical, comparing the {@link PhraseHighlight#lineEnd}
39      * values of {@code o2} and {@code o1} (i.e. inverted).
40      * <p>The ordering allows to iterate through a collection afterward and
41      * easily subsume where necessary a {@link PhraseHighlight} instance into
42      * its immediate predecessor.
43      * @param o1 a required instance
44      * @param o2 a required instance
45      * @return a negative integer, zero, or a positive integer as the first
46      * argument is less than, equal to, or greater than the second
47      */
48     @Override
compare(PhraseHighlight o1, PhraseHighlight o2)49     public int compare(PhraseHighlight o1, PhraseHighlight o2) {
50         int cmp;
51         if (o1.getLineStart() < 0) {
52             if (o2.getLineStart() >= 0) {
53                 return -1;
54             }
55             cmp = 0;
56         } else if (o2.getLineStart() < 0) {
57             return 1;
58         } else {
59             cmp = Integer.compare(o1.getLineStart(), o2.getLineStart());
60         }
61         if (cmp != 0) {
62             return cmp;
63         }
64         cmp = Integer.compare(o2.getLineEnd(), o1.getLineEnd());
65         return cmp;
66     }
67 
68     /** Private to enforce singleton. */
PhraseHighlightComparator()69     private PhraseHighlightComparator() {
70     }
71 }
72