mapreduce/src/contrib/mumak/src/java/org/apache/hadoop/mapred/SimulatorJobCache.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.hadoop.mapred;

import java.util.HashMap;
import java.util.Map;

import org.apache.hadoop.mapred.JobID;
import org.apache.hadoop.tools.rumen.JobStory;

/**
 * A static ({@link JobID}, {@link JobStory}) mapping, used by {@link JobClient}
 * and {@link JobTracker} for job submission.
 */
public class SimulatorJobCache {
  private static Map<JobID, JobStory> submittedJobs = new HashMap<JobID, JobStory>();

  /**
   * Put ({@link JobID}, {@link JobStory}) into the mapping.
   * @param jobId id of the job.
   * @param job {@link JobStory} object of the job.
   */
  public static void put(JobID jobId, JobStory job) {
    submittedJobs.put(jobId, job);
  }
  
  /**
   * Get the job identified by {@link JobID} and remove it from the mapping.
   * @param jobId id of the job.
   * @return {@link JobStory} object of the job.
   */
  public static JobStory get(JobID jobId) {
    return submittedJobs.remove(jobId);
  }
  
  /**
   * Check the job at the head of queue, without removing it from the mapping.
   * @param jobId id of the job.
   * @return {@link JobStory} object of the job.
   */
  public static JobStory peek(JobID jobId) {
    return submittedJobs.get(jobId);
  }
}