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.properties.DateTime;
027    import org.jboss.dna.graph.properties.Path;
028    import org.jboss.dna.graph.properties.Path.Segment;
029    
030    /**
031     * The record of a source contributing only a single child to a node.
032     * 
033     * @author Randall Hauch
034     */
035    @Immutable
036    public class OneChildContribution extends NonEmptyContribution {
037    
038        /**
039         * This is the first version of this class. See the documentation of MergePlan.serialVersionUID.
040         */
041        private static final long serialVersionUID = 1L;
042    
043        private final Segment child;
044    
045        /**
046         * Create a contribution of a single child 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 pathInSource 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 child the child contributed from the source; may not be null
053         */
054        public OneChildContribution( String sourceName,
055                                     Path pathInSource,
056                                     DateTime expirationTime,
057                                     Segment child ) {
058            super(sourceName, pathInSource, expirationTime);
059            assert child != null;
060            this.child = child;
061            if (ContributionStatistics.RECORD) ContributionStatistics.record(0, 1);
062        }
063    
064        /**
065         * {@inheritDoc}
066         * 
067         * @see org.jboss.dna.connector.federation.contribution.Contribution#getChildren()
068         */
069        @Override
070        public Iterator<Segment> getChildren() {
071            return new OneValueIterator<Segment>(child);
072        }
073    
074        /**
075         * {@inheritDoc}
076         * 
077         * @see org.jboss.dna.connector.federation.contribution.Contribution#getChildrenCount()
078         */
079        @Override
080        public int getChildrenCount() {
081            return 1;
082        }
083    
084    }