subprojects/s4-example/src/main/java/org/apache/s4/example/model/MaximizerPE.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.s4.example.model;

import org.apache.s4.base.Event;
import org.apache.s4.core.App;
import org.apache.s4.core.ProcessingElement;
import org.apache.s4.core.Stream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

final public class MaximizerPE extends ProcessingElement {

    private static final Logger logger = LoggerFactory.getLogger(MaximizerPE.class);

    private int numClasses;
    private Stream<ObsEvent> assignmentStream;
    private int numEventsReceived = 0;
    private float maxLogProb = -Float.MAX_VALUE;
    private int hypID;

    public MaximizerPE(App app) {
        super(app);
    }

    public void setAssignmentStream(Stream<ObsEvent> stream) {
        assignmentStream = stream;
    }

    /**
     * @return the numClasses
     */
    public int getNumClasses() {
        return numClasses;
    }

    /**
     * @param numClasses
     *            the numClasses to set
     */
    public void setNumClasses(int numClasses) {
        this.numClasses = numClasses;
    }

    public void onEvent(Event event) {

        ObsEvent inEvent = (ObsEvent) event;
        float[] obs = inEvent.getObsVector();

        if (inEvent.getProb() > maxLogProb) {
            maxLogProb = inEvent.getProb();
            hypID = inEvent.getHypId();
        }

        if (++numEventsReceived == numClasses) {

            /* Got all the distances. Send class id with minimum distance. */
            ObsEvent outEvent = new ObsEvent(inEvent.getIndex(), obs, maxLogProb, inEvent.getClassId(), hypID, false);

            logger.trace("IN: " + inEvent.toString());
            logger.trace("OUT: " + outEvent.toString());

            assignmentStream.put(outEvent);

            /* This PE instance is no longer needed. */
            close();
        }

    }

    @Override
    protected void onRemove() {
        // TODO Auto-generated method stub

    }

    @Override
    protected void onCreate() {
        // TODO Auto-generated method stub

    }

}