PipingBinaryWait.java

/*
    BeepBeep, an event stream processor
    Copyright (C) 2008-2016 Sylvain Hallé

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package basic;

import java.util.Queue;

import ca.uqac.lif.cep.Adder;
import ca.uqac.lif.cep.Connector;
import ca.uqac.lif.cep.Pullable;
import ca.uqac.lif.cep.UtilityMethods;
import ca.uqac.lif.cep.tmf.QueueSource;

/**
 * Pipe processors together using the {@link ca.uqac.lif.cep.Connector Connector}
 * object.
 * The chain of processors in this example is almost identical to
 * {@link PipingBinary}, and can be represented graphically as:
 * <p>
 * <img src="./doc-files/basic/PipingBinaryWait.png" alt="Processor graph">
 * <p>
 * The difference is that the first queue source has been replaced by a
 * "slow" queue source, that waits 5 seconds before outputting an event.
 * @see PipingBinary
 * @author Sylvain Hallé
 * @difficulty Easy
 */
public class PipingBinaryWait
{
    public static void main (String[] args)
    {
        ///
        SlowQueueSource source1 = new SlowQueueSource();
        source1.setEvents(2, 7, 1, 8, 3);
        QueueSource source2 = new QueueSource();
        source2.setEvents(3, 1, 4, 1, 6);
        Adder add = new Adder();
        Connector.connect(source1, 0, add, 0);
        Connector.connect(source2, 0, add, 1);
        Pullable p = add.getPullableOutput();
        for (int i = 0; i < 5; i++)
        {
            float x = (Float) p.pull();
            System.out.println("The event is: " + x);
        }
        ///
    }
    
    /**
     * A queue source object that waits 5 seconds before outputting
     * each event.
     */
    public static class SlowQueueSource extends QueueSource
    {
        @Override
        public boolean compute(Object[] inputs, Queue<Object[]> outputs)
        {
            UtilityMethods.pause(5000);
            return super.compute(inputs, outputs);
        }
    }
}