org.apache.streams.twitter.provider.TwitterStreamProcessor.java Source code

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Here is the source code for org.apache.streams.twitter.provider.TwitterStreamProcessor.java

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/*
 * 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
 *
 *   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.streams.twitter.provider;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.common.collect.Lists;
import com.twitter.hbc.core.processor.StringDelimitedProcessor;
import org.apache.streams.core.StreamsDatum;
import org.apache.streams.twitter.converter.StreamsTwitterMapper;
import org.apache.streams.util.ComponentUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 *
 */
public class TwitterStreamProcessor extends StringDelimitedProcessor {

    private static final Logger LOGGER = LoggerFactory.getLogger(TwitterStreamProcessor.class);
    private static final int DEFAULT_POOL_SIZE = 5;

    private final TwitterStreamProvider provider;
    private final ExecutorService service;

    public TwitterStreamProcessor(TwitterStreamProvider provider) {
        this(provider, DEFAULT_POOL_SIZE);
    }

    public TwitterStreamProcessor(TwitterStreamProvider provider, int poolSize) {
        //We are only going to use the Hosebird processor to manage the extraction of the tweets from the Stream
        super(null);
        service = Executors.newFixedThreadPool(poolSize);
        this.provider = provider;
    }

    @Override
    public boolean process() throws IOException, InterruptedException {
        String msg = null;
        do {
            msg = this.processNextMessage();
            if (msg == null) {
                Thread.sleep(10);
            }
        } while (msg == null);

        //Deserializing to an ObjectNode can take time.  Parallelize the task to improve throughput
        return provider.addDatum(service.submit(new StreamDeserializer(msg)));
    }

    public void cleanUp() {
        ComponentUtils.shutdownExecutor(service, 1, 30);
    }

    protected static class StreamDeserializer implements Callable<List<StreamsDatum>> {

        protected static final ObjectMapper mapper = StreamsTwitterMapper.getInstance();

        protected String item;

        public StreamDeserializer(String item) {
            this.item = item;
        }

        @Override
        public List<StreamsDatum> call() throws Exception {
            if (item != null) {
                ObjectNode objectNode = (ObjectNode) mapper.readTree(item);
                StreamsDatum rawDatum = new StreamsDatum(objectNode);
                return Lists.newArrayList(rawDatum);
            }
            return Lists.newArrayList();
        }
    }
}