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
019 package org.apache.hadoop.mapreduce;
020
021 import java.io.DataInput;
022 import java.io.DataOutput;
023 import java.io.IOException;
024 import java.text.NumberFormat;
025
026 import org.apache.hadoop.classification.InterfaceAudience;
027 import org.apache.hadoop.classification.InterfaceStability;
028 import org.apache.hadoop.io.Text;
029
030 /**
031 * JobID represents the immutable and unique identifier for
032 * the job. JobID consists of two parts. First part
033 * represents the jobtracker identifier, so that jobID to jobtracker map
034 * is defined. For cluster setup this string is the jobtracker
035 * start time, for local setting, it is "local" and a random number.
036 * Second part of the JobID is the job number. <br>
037 * An example JobID is :
038 * <code>job_200707121733_0003</code> , which represents the third job
039 * running at the jobtracker started at <code>200707121733</code>.
040 * <p>
041 * Applications should never construct or parse JobID strings, but rather
042 * use appropriate constructors or {@link #forName(String)} method.
043 *
044 * @see TaskID
045 * @see TaskAttemptID
046 */
047 @InterfaceAudience.Public
048 @InterfaceStability.Stable
049 public class JobID extends org.apache.hadoop.mapred.ID
050 implements Comparable<ID> {
051 protected static final String JOB = "job";
052
053 // Jobid regex for various tools and framework components
054 public static final String JOBID_REGEX =
055 JOB + SEPARATOR + "[0-9]+" + SEPARATOR + "[0-9]+";
056
057 private final Text jtIdentifier;
058
059 protected static final NumberFormat idFormat = NumberFormat.getInstance();
060 static {
061 idFormat.setGroupingUsed(false);
062 idFormat.setMinimumIntegerDigits(4);
063 }
064
065 /**
066 * Constructs a JobID object
067 * @param jtIdentifier jobTracker identifier
068 * @param id job number
069 */
070 public JobID(String jtIdentifier, int id) {
071 super(id);
072 this.jtIdentifier = new Text(jtIdentifier);
073 }
074
075 public JobID() {
076 jtIdentifier = new Text();
077 }
078
079 public String getJtIdentifier() {
080 return jtIdentifier.toString();
081 }
082
083 @Override
084 public boolean equals(Object o) {
085 if (!super.equals(o))
086 return false;
087
088 JobID that = (JobID)o;
089 return this.jtIdentifier.equals(that.jtIdentifier);
090 }
091
092 /**Compare JobIds by first jtIdentifiers, then by job numbers*/
093 @Override
094 public int compareTo(ID o) {
095 JobID that = (JobID)o;
096 int jtComp = this.jtIdentifier.compareTo(that.jtIdentifier);
097 if(jtComp == 0) {
098 return this.id - that.id;
099 }
100 else return jtComp;
101 }
102
103 /**
104 * Add the stuff after the "job" prefix to the given builder. This is useful,
105 * because the sub-ids use this substring at the start of their string.
106 * @param builder the builder to append to
107 * @return the builder that was passed in
108 */
109 public StringBuilder appendTo(StringBuilder builder) {
110 builder.append(SEPARATOR);
111 builder.append(jtIdentifier);
112 builder.append(SEPARATOR);
113 builder.append(idFormat.format(id));
114 return builder;
115 }
116
117 @Override
118 public int hashCode() {
119 return jtIdentifier.hashCode() + id;
120 }
121
122 @Override
123 public String toString() {
124 return appendTo(new StringBuilder(JOB)).toString();
125 }
126
127 @Override
128 public void readFields(DataInput in) throws IOException {
129 super.readFields(in);
130 this.jtIdentifier.readFields(in);
131 }
132
133 @Override
134 public void write(DataOutput out) throws IOException {
135 super.write(out);
136 jtIdentifier.write(out);
137 }
138
139 /** Construct a JobId object from given string
140 * @return constructed JobId object or null if the given String is null
141 * @throws IllegalArgumentException if the given string is malformed
142 */
143 public static JobID forName(String str) throws IllegalArgumentException {
144 if(str == null)
145 return null;
146 try {
147 String[] parts = str.split("_");
148 if(parts.length == 3) {
149 if(parts[0].equals(JOB)) {
150 return new org.apache.hadoop.mapred.JobID(parts[1],
151 Integer.parseInt(parts[2]));
152 }
153 }
154 }catch (Exception ex) {//fall below
155 }
156 throw new IllegalArgumentException("JobId string : " + str
157 + " is not properly formed");
158 }
159
160 }