FileSourcePellet.java

/*
 * Copyright 2014 University of Southern California
 *
 * Licensed 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 edu.usc.pgroup.floe.examples.pellets;

import edu.usc.pgroup.floe.app.AppContext;
import edu.usc.pgroup.floe.app.Emitter;
import edu.usc.pgroup.floe.app.Tuple;
import edu.usc.pgroup.floe.app.pellets.PelletContext;
import edu.usc.pgroup.floe.app.pellets.StatelessPellet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.StreamTokenizer;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * @author kumbhare
 */
public class FileSourcePellet extends StatelessPellet {

    /**
     * the global logger instance.
     */
    private static final Logger LOGGER =
            LoggerFactory.getLogger(FileSourcePellet.class);

    /**
     * Path to the file to be used as source.
     */
    private final String path;

    /**
     * Interval between emitting words.
     */
    private final long interval;

    /**
     * Constructor.
     * @param filePath file path.
     * @param sleepTime interval between reading lines.
     * @param keyFieldName fieldname used to emit tuples.
     */
    public FileSourcePellet(final String keyFieldName, final String filePath,
                            final long sleepTime) {
        //super(keyFieldName);
        this.path = filePath;
        this.interval = sleepTime;
    }


    /**
     * The execute method which is called for each tuple. (stateless)
     *
     * @param t       input tuple received from the preceding pellet.
     * @param emitter An output emitter which may be used by the user to emmit
     */
    @Override
    public final void execute(final Tuple t, final Emitter emitter) {
        LOGGER.info("Executing file source pellet.");

        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new FileReader(path));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        StreamTokenizer tokenizer = new StreamTokenizer(reader);
        tokenizer.resetSyntax();
        final int wcs = 0x23;
        final int wce = 0xFF;
        final int wcss = 0x00;
        final int wcse = 0x20;
        tokenizer.wordChars(wcs, wce);
        tokenizer.whitespaceChars(wcss, wcse);
        tokenizer.quoteChar('"');

        List<String> list = new ArrayList<>();
        final int large = 100000;
        final int small = 6;
        Tuple ot = new Tuple();
        Integer id = 0;
        while (true) {

            ot.put("word", id.toString());
            emitter.emit(ot);
            id++;
            try {
                if (list.size() == 0) {
                    while (tokenizer.nextToken() != StreamTokenizer.TT_EOF) {
                        String w = tokenizer.sval;
                        if (w == null) {
                            continue;
                        }


                        ot.put("word", w);
                        LOGGER.info("Emmitting: {}", ot);
                        emitter.emit(ot);
                        if (interval > 0) {
                            Thread.sleep(interval);
                        }
                        list.add(w);
                    }
                    LOGGER.error("DONE FILE.");
                    /*for (int i = 0; i < large; i++) {
                        ot.put("word", "the");
                        for (int j = 0; j < small; j++) {
                            emitter.emit(ot);
                        }
                        if (interval > 0) {
                            Thread.sleep(interval);
                        }
                    }*/
                    //LOGGER.error("DONE THEs.");
                } else {
                    Iterator<String> iterator = list.iterator();
                    while (iterator.hasNext()) {

                        ot.put("word", iterator.next());
                        LOGGER.info("Emmitting: {}", ot);
                        emitter.emit(ot);

                        ot.put("word", "the");
                        LOGGER.info("Emmitting: {}", ot);
                        emitter.emit(ot);
                        emitter.emit(ot);

                        if (interval > 0) {
                            Thread.sleep(interval);
                        }
                    }
                }

                ot.put("word", id.toString());
                emitter.emit(ot);
                id++;
                if (id >= small) {
                    id = 0;
                }
                if (interval > 0) {
                    Thread.sleep(interval);
                }
            } catch (InterruptedException e) {
                LOGGER.error("Exception: {}", e);
                break;
            } catch (IOException e) {
                LOGGER.error("Exception: {}", e);
            }
        }
    }

    /**
     * The setup function is called once to let the pellet initialize.
     *
     * @param appContext    Application's context. Some data related to
     *                      application's deployment.
     * @param pelletContext Pellet instance context. Related to this
     */
    @Override
    public final void onStart(final AppContext appContext,
                            final PelletContext pelletContext) {

    }

    /**
     * The teardown function, called when the topology is killed.
     * Or when the Pellet instance is scaled down.
     */
    @Override
    public void teardown() {

    }

    /**
     * @return The names of the streams to be used later during emitting
     * messages.
     */
    @Override
    public final List<String> getOutputStreamNames() {
        return null;
    }
}