tez-runtime-library/src/main/java/org/apache/tez/runtime/library/processor/SleepProcessor.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.tez.runtime.library.processor;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tez.runtime.api.Event;
import org.apache.tez.runtime.api.LogicalIOProcessor;
import org.apache.tez.runtime.api.LogicalInput;
import org.apache.tez.runtime.api.LogicalOutput;
import org.apache.tez.runtime.api.TezProcessorContext;

import java.util.List;
import java.util.Map;

/**
 * A simple sleep processor implementation that sleeps for the configured
 * time in milliseconds.
 *
 * @see SleepProcessorConfig for configuring the SleepProcessor
 */
public class SleepProcessor implements LogicalIOProcessor {

  private static final Log LOG = LogFactory.getLog(SleepProcessor.class);

  private int timeToSleepMS;

  @Override
  public void initialize(TezProcessorContext processorContext)
    throws Exception {
    if (processorContext.getUserPayload() == null) {
      LOG.info("No processor user payload specified"
        + ", using default timeToSleep of 1 ms");
      timeToSleepMS = 1;
    } else {
      SleepProcessorConfig cfg =
        new SleepProcessorConfig();
      cfg.fromUserPayload(processorContext.getUserPayload());
      timeToSleepMS = cfg.getTimeToSleepMS();
    }
    LOG.info("Initialized SleepProcessor, timeToSleepMS=" + timeToSleepMS);
  }

  @Override
  public void run(Map<String, LogicalInput> inputs,
                  Map<String, LogicalOutput> outputs) throws Exception {
    LOG.info("Running the Sleep Processor, sleeping for "
      + timeToSleepMS + " ms");
    for (LogicalInput input : inputs.values()) {
      input.start();
    }
    for (LogicalOutput output : outputs.values()) {
      output.start();
    }
    try {
      Thread.sleep(timeToSleepMS);
    } catch (InterruptedException ie) {
      // ignore
    }
  }

  @Override
  public void handleEvents(List<Event> processorEvents) {
    // Nothing to do
  }

  @Override
  public void close() throws Exception {
    // Nothing to cleanup
  }

  /**
   * Configuration for the Sleep Processor.
   * Only configuration option is time to sleep in milliseconds.
   */
  public static class SleepProcessorConfig {
    private int timeToSleepMS;

    public SleepProcessorConfig() {
    }

    /**
     * @param timeToSleepMS Time to sleep in milliseconds
     */
    public SleepProcessorConfig (int timeToSleepMS) {
      this.timeToSleepMS = timeToSleepMS;
    }

    public byte[] toUserPayload() {
      return Integer.toString(timeToSleepMS).getBytes();
    }

    public void fromUserPayload(byte[] userPayload) {
      timeToSleepMS = Integer.valueOf(new String(userPayload)).intValue();
    }

    public int getTimeToSleepMS() {
      return timeToSleepMS;
    }
  }
}