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.plugins.core.timemachine.tracking;
021    
022    /**
023     * Wraps a {@link Sequence} to assign hash codes to elements.
024     */
025    public final class HashedSequence<S extends Sequence> implements Sequence {
026    
027      final S base;
028      final int[] hashes;
029    
030      public static <S extends Sequence> HashedSequence<S> wrap(S base, SequenceComparator<S> cmp) {
031        int size = base.length();
032        int[] hashes = new int[size];
033        for (int i = 0; i < size; i++) {
034          hashes[i] = cmp.hash(base, i);
035        }
036        return new HashedSequence<S>(base, hashes);
037      }
038    
039      private HashedSequence(S base, int[] hashes) {
040        this.base = base;
041        this.hashes = hashes;
042      }
043    
044      public int length() {
045        return base.length();
046      }
047    
048    }