001    /*
002     * JBoss, Home of Professional Open Source.
003     * Copyright 2008, Red Hat Middleware LLC, and individual contributors
004     * as indicated by the @author tags. See the copyright.txt file in the
005     * distribution for a full listing of individual contributors. 
006     *
007     * This is free software; you can redistribute it and/or modify it
008     * under the terms of the GNU Lesser General Public License as
009     * published by the Free Software Foundation; either version 2.1 of
010     * the License, or (at your option) any later version.
011     *
012     * This software is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015     * Lesser General Public License for more details.
016     *
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this software; if not, write to the Free
019     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021     */
022    package org.jboss.dna.connector.federation.contribution;
023    
024    import java.util.Iterator;
025    import net.jcip.annotations.Immutable;
026    import org.jboss.dna.graph.Location;
027    import org.jboss.dna.graph.properties.DateTime;
028    
029    /**
030     * The record of a source contributing only two children to a node.
031     * 
032     * @author Randall Hauch
033     */
034    @Immutable
035    public class TwoChildContribution extends NonEmptyContribution {
036    
037        /**
038         * This is the first version of this class. See the documentation of MergePlan.serialVersionUID.
039         */
040        private static final long serialVersionUID = 1L;
041    
042        private final Location child1;
043        private final Location child2;
044    
045        /**
046         * Create a contribution of two children from the source with the supplied name.
047         * 
048         * @param sourceName the name of the source, which may not be null or blank
049         * @param locationInSource the path in the source for this contributed information; may not be null
050         * @param expirationTime the time (in UTC) after which this contribution should be considered expired, or null if there is no
051         *        expiration time
052         * @param child1 the first child contributed from the source; may not be null
053         * @param child2 the second child contributed from the source; may not be null
054         */
055        public TwoChildContribution( String sourceName,
056                                     Location locationInSource,
057                                     DateTime expirationTime,
058                                     Location child1,
059                                     Location child2 ) {
060            super(sourceName, locationInSource, expirationTime);
061            assert child1 != null;
062            assert child2 != null;
063            this.child1 = child1;
064            this.child2 = child2;
065            if (ContributionStatistics.RECORD) ContributionStatistics.record(0, 2);
066        }
067    
068        /**
069         * {@inheritDoc}
070         * 
071         * @see org.jboss.dna.connector.federation.contribution.Contribution#getChildren()
072         */
073        @Override
074        public Iterator<Location> getChildren() {
075            return new TwoValueIterator<Location>(child1, child2);
076        }
077    
078        /**
079         * {@inheritDoc}
080         * 
081         * @see org.jboss.dna.connector.federation.contribution.Contribution#getChildrenCount()
082         */
083        @Override
084        public int getChildrenCount() {
085            return 2;
086        }
087    
088    }