001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.mapred;
020
021import java.io.DataInput;
022import java.io.IOException;
023
024import org.apache.hadoop.classification.InterfaceAudience;
025import org.apache.hadoop.classification.InterfaceStability;
026
027/**
028 * JobID represents the immutable and unique identifier for 
029 * the job. JobID consists of two parts. First part 
030 * represents the jobtracker identifier, so that jobID to jobtracker map 
031 * is defined. For cluster setup this string is the jobtracker 
032 * start time, for local setting, it is "local".
033 * Second part of the JobID is the job number. <br> 
034 * An example JobID is : 
035 * <code>job_200707121733_0003</code> , which represents the third job 
036 * running at the jobtracker started at <code>200707121733</code>. 
037 * <p>
038 * Applications should never construct or parse JobID strings, but rather 
039 * use appropriate constructors or {@link #forName(String)} method. 
040 * 
041 * @see TaskID
042 * @see TaskAttemptID
043 */
044@InterfaceAudience.Public
045@InterfaceStability.Stable
046public class JobID extends org.apache.hadoop.mapreduce.JobID {
047  /**
048   * Constructs a JobID object 
049   * @param jtIdentifier jobTracker identifier
050   * @param id job number
051   */
052  public JobID(String jtIdentifier, int id) {
053    super(jtIdentifier, id);
054  }
055  
056  public JobID() { }
057
058  /**
059   * Downgrade a new JobID to an old one
060   * @param old a new or old JobID
061   * @return either old or a new JobID build to match old
062   */
063  public static JobID downgrade(org.apache.hadoop.mapreduce.JobID old) {
064    if (old instanceof JobID) {
065      return (JobID) old;
066    } else {
067      return new JobID(old.getJtIdentifier(), old.getId());
068    }
069  }
070
071  @Deprecated
072  public static JobID read(DataInput in) throws IOException {
073    JobID jobId = new JobID();
074    jobId.readFields(in);
075    return jobId;
076  }
077
078  /** Construct a JobId object from given string 
079   * @return constructed JobId object or null if the given String is null
080   * @throws IllegalArgumentException if the given string is malformed
081   */
082  public static JobID forName(String str) throws IllegalArgumentException {
083    return (JobID) org.apache.hadoop.mapreduce.JobID.forName(str);
084  }
085  
086  /** 
087   * Returns a regex pattern which matches task IDs. Arguments can 
088   * be given null, in which case that part of the regex will be generic.  
089   * For example to obtain a regex matching <i>any job</i> 
090   * run on the jobtracker started at <i>200707121733</i>, we would use :
091   * <pre> 
092   * JobID.getTaskIDsPattern("200707121733", null);
093   * </pre>
094   * which will return :
095   * <pre> "job_200707121733_[0-9]*" </pre> 
096   * @param jtIdentifier jobTracker identifier, or null
097   * @param jobId job number, or null
098   * @return a regex pattern matching JobIDs
099   */
100  @Deprecated
101  public static String getJobIDsPattern(String jtIdentifier, Integer jobId) {
102    StringBuilder builder = new StringBuilder(JOB).append(SEPARATOR);
103    builder.append(getJobIDsPatternWOPrefix(jtIdentifier, jobId));
104    return builder.toString();
105  }
106  
107  @Deprecated
108  static StringBuilder getJobIDsPatternWOPrefix(String jtIdentifier,
109                                                Integer jobId) {
110    StringBuilder builder = new StringBuilder();
111    if (jtIdentifier != null) {
112      builder.append(jtIdentifier);
113    } else {
114      builder.append("[^").append(SEPARATOR).append("]*");
115    }
116    builder.append(SEPARATOR)
117      .append(jobId != null ? idFormat.format(jobId) : "[0-9]*");
118    return builder;
119  }
120
121}