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 */
020package org.sonar.plugins.core.timemachine.tracking;
021
022/**
023 * Wraps a {@link Sequence} to assign hash codes to elements.
024 */
025public 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}