UpdateTableStreamExample.java

/*
    BeepBeep, an event stream processor
    Copyright (C) 2008-2018 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 plots;

import ca.uqac.lif.cep.Connector;
import static ca.uqac.lif.cep.Connector.TOP;
import static ca.uqac.lif.cep.Connector.BOTTOM;
import static ca.uqac.lif.cep.Connector.OUTPUT;
import ca.uqac.lif.cep.io.Print;
import ca.uqac.lif.cep.mtnp.UpdateTable;
import ca.uqac.lif.cep.mtnp.UpdateTableStream;
import ca.uqac.lif.cep.tmf.Pump;
import ca.uqac.lif.cep.tmf.QueueSource;

/**
 * Update a table from two streams of numbers.
 * This example generates dummy (x,y) pairs of numbers, accumulates them
 * into a table, and prints the table made from these numbers.
 * @author Sylvain Hallé
 * @difficulty Easy
 */
public class UpdateTableStreamExample
{

    public static void main(String[] args) throws InterruptedException
    {
        /// We create two streams of numbers
        QueueSource src1 = new QueueSource().setEvents(1, 2, 3, 4, 5);
        QueueSource src2 = new QueueSource().setEvents(2, 3, 5, 7, 4);

        /* These x-stream and y-stream are then pushed into an
         * {@link UpdateTableStream} processor. We instantiate this processor,
         * telling it to create an empty {@link Table} object with two
         * columns, called "x" and "y". */
        UpdateTable table = new UpdateTableStream("x", "y");
        
        /* This creates a processor with two input streams, one for the "x"
         * values, and the other for the "y" values. Each pair of values from
         * the x and y streams is used to append a new line to the (initially
         * empty) table. We connect the two
         * outputs of the random processor to these two inputs. */
        Connector.connect(src1, OUTPUT, table, TOP);
        Connector.connect(src2, OUTPUT, table, BOTTOM);
        
        /* We print the contents of the resulting table. */
        Pump pump = new Pump();
        Print print = new Print().setSeparator("\n");
        Connector.connect(table, pump, print);

        /* Ready to start the pump! */
        pump.turn(4);
        ///
    }
}