001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2012 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.duplications.detector;
021    
022    import java.util.Comparator;
023    
024    import org.sonar.duplications.index.ClonePart;
025    import org.sonar.duplications.utils.FastStringComparator;
026    
027    /**
028     * Allows to determine if ClonePart includes another ClonePart.
029     * Inclusion is the partial order, so in fact this class violates contracts of {@link Comparator},
030     * however it allows to use {@link org.sonar.duplications.utils.SortedListsUtils} for efficient filtering.
031     */
032    public final class ContainsInComparator implements Comparator<ClonePart> {
033    
034      /**
035       * Defines order by resourceId.
036       */
037      public static final Comparator<ClonePart> RESOURCE_ID_COMPARATOR = new Comparator<ClonePart>() {
038        public int compare(ClonePart o1, ClonePart o2) {
039          return FastStringComparator.INSTANCE.compare(o1.getResourceId(), o2.getResourceId());
040        }
041      };
042    
043      /**
044       * Defines order by resourceId and by unitStart.
045       */
046      public static final Comparator<ClonePart> CLONEPART_COMPARATOR = new Comparator<ClonePart>() {
047        public int compare(ClonePart o1, ClonePart o2) {
048          int c = RESOURCE_ID_COMPARATOR.compare(o1, o2);
049          if (c == 0) {
050            return o1.getUnitStart() - o2.getUnitStart();
051          }
052          return c;
053        }
054      };
055    
056      private final int l1, l2;
057    
058      /**
059       * Constructs new comparator for two parts with lengths {@code l1} and {@code l2} respectively.
060       */
061      public ContainsInComparator(int l1, int l2) {
062        this.l1 = l1;
063        this.l2 = l2;
064      }
065    
066      /**
067       * Compares two parts on inclusion.
068       * part1 includes part2 if {@code (part1.resourceId == part2.resourceId) && (part1.unitStart <= part2.unitStart) && (part2.unitEnd <= part1.unitEnd)}.
069       * 
070       * @return 0 if part1 includes part2,
071       *         1 if resourceId of part1 is greater than resourceId of part2 or if unitStart of part1 is greater than unitStart of part2,
072       *         -1 in all other cases
073       */
074      public int compare(ClonePart part1, ClonePart part2) {
075        int c = RESOURCE_ID_COMPARATOR.compare(part1, part2);
076        if (c == 0) {
077          if (part1.getUnitStart() <= part2.getUnitStart()) {
078            if (part2.getUnitStart() + l2 <= part1.getUnitStart() + l1) {
079              return 0; // part1 contains part2
080            } else {
081              return -1; // SortedListsUtils#contains should continue search
082            }
083          } else {
084            return 1; // unitStart of part1 is less than unitStart of part2 - SortedListsUtils#contains should stop search
085          }
086        } else {
087          return c;
088        }
089      }
090    
091    }