001/*
002 * #%L
003 * Netarchivesuite - common
004 * %%
005 * Copyright (C) 2005 - 2014 The Royal Danish Library, the Danish State and University Library,
006 *             the National Library of France and the Austrian National Library.
007 * %%
008 * This program is free software: you can redistribute it and/or modify
009 * it under the terms of the GNU Lesser General Public License as
010 * published by the Free Software Foundation, either version 2.1 of the
011 * License, or (at your option) any later version.
012 * 
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Lesser Public License for more details.
017 * 
018 * You should have received a copy of the GNU General Lesser Public
019 * License along with this program.  If not, see
020 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
021 * #L%
022 */
023package dk.netarkivet.common.distribute.indexserver;
024
025import java.io.File;
026
027import dk.netarkivet.common.exceptions.ArgumentNotValid;
028
029/**
030 * An immutable pair if an index and the set this is an index for.
031 *
032 * @param <I> The type of set, this is an index for.
033 */
034public class Index<I> {
035
036    /** The file containing the index over the set. */
037    private final File indexFile;
038    /** The set this is an index for. */
039    private final I indexSet;
040
041    /**
042     * Initialise the set.
043     *
044     * @param indexFile The index file.
045     * @param indexSet The set this is an index for. Can be null TODO Should the indexSet be allowed to be null?
046     * @throws ArgumentNotValid if indexFile is null.
047     */
048    public Index(File indexFile, I indexSet) {
049        ArgumentNotValid.checkNotNull(indexFile, "File indexFile");
050        this.indexFile = indexFile;
051        this.indexSet = indexSet;
052    }
053
054    /**
055     * Get the index file.
056     *
057     * @return The index file.
058     */
059    public File getIndexFile() {
060        return indexFile;
061    }
062
063    /**
064     * Get the set this is an index for.
065     *
066     * @return The set this is an index for.
067     */
068    public I getIndexSet() {
069        return indexSet;
070    }
071
072}