001/**
002 * Copyright (c) 2012, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.storm.bolt;
031
032import java.util.Map;
033
034import backtype.storm.task.OutputCollector;
035import backtype.storm.task.TopologyContext;
036import backtype.storm.topology.IBasicBolt;
037import backtype.storm.topology.OutputFieldsDeclarer;
038import backtype.storm.topology.base.BaseRichBolt;
039import backtype.storm.tuple.Fields;
040import backtype.storm.tuple.Tuple;
041import backtype.storm.tuple.Values;
042
043/**
044 * A simple Storm {@link IBasicBolt} whose purpose is to increment a count on
045 * the reciept of a tuple followed by an emit of the same tuple.
046 *
047 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
048 *
049 */
050public class CountingEmittingBolt extends BaseRichBolt {
051        private static final long serialVersionUID = -2567619894656997375L;
052        private Fields fields;
053        private int count;
054        private OutputCollector collector;
055
056        /**
057         * @param fields
058         *            the fields to expect and emit
059         */
060        public CountingEmittingBolt(Fields fields) {
061                this.fields = new Fields(fields.toList());
062                count = 0;
063        }
064
065        @Override
066        public void declareOutputFields(OutputFieldsDeclarer declarer) {
067                declarer.declare(fields);
068        }
069
070        @Override
071        public void prepare(@SuppressWarnings("rawtypes") Map stormConf, TopologyContext context, OutputCollector collector) {
072                this.collector = collector;
073        }
074
075        @Override
076        public void execute(Tuple input) {
077                final Object[] values = new Object[this.fields.size()];
078                count++;
079                for (int i = 0; i < values.length; i++) {
080                        values[i] = input.getValueByField(this.fields.get(i)).toString();
081                }
082                collector.emit(input, new Values(values));
083                collector.ack(input);
084                System.out.println(String.format("Seen: %s", count));
085        }
086
087}