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.graph.sequencers;
023    
024    import java.io.InputStream;
025    
026    /**
027     * The interface for a DNA sequencer that processes a property as a stream to extract information from the content and store in
028     * the repository.
029     * <p>
030     * Implementations must provide a no-argument constructor.
031     * </p>
032     * 
033     * @author Randall Hauch
034     * @author John Verhaeg
035     */
036    public interface StreamSequencer {
037    
038        /**
039         * Sequence the data found in the supplied stream, placing the output information into the supplied map.
040         * <p>
041         * JBoss DNA's SequencingService determines the sequencers that should be executed by monitoring the changes to one or more
042         * workspaces that it is monitoring. Changes in those workspaces are aggregated and used to determine which sequencers should
043         * be called. If the sequencer implements this interface, then this method is called with the property that is to be sequenced
044         * along with the interface used to register the output. The framework takes care of all the rest.
045         * </p>
046         * 
047         * @param stream the stream with the data to be sequenced; never <code>null</code>
048         * @param output the output from the sequencing operation; never <code>null</code>
049         * @param context the context for the sequencing operation; never <code>null</code>
050         */
051        void sequence( InputStream stream,
052                       SequencerOutput output,
053                       SequencerContext context );
054    }