org.apache.hadoop.mapreduce.TaskAttemptID Maven / Gradle / Ivy
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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
* 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.mapreduce;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* TaskAttemptID represents the immutable and unique identifier for
* a task attempt. Each task attempt is one particular instance of a Map or
* Reduce Task identified by its TaskID.
*
* TaskAttemptID consists of 2 parts. First part is the
* {@link TaskID}, that this TaskAttemptID belongs to.
* Second part is the task attempt number.
* An example TaskAttemptID is :
* attempt_200707121733_0003_m_000005_0 , which represents the
* zeroth task attempt for the fifth map task in the third job
* running at the jobtracker started at 200707121733.
*
* Applications should never construct or parse TaskAttemptID strings
* , but rather use appropriate constructors or {@link #forName(String)}
* method.
*
* @see JobID
* @see TaskID
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class TaskAttemptID extends org.apache.hadoop.mapred.ID {
protected static final String ATTEMPT = "attempt";
private TaskID taskId;
/**
* Constructs a TaskAttemptID object from given {@link TaskID}.
* @param taskId TaskID that this task belongs to
* @param id the task attempt number
*/
public TaskAttemptID(TaskID taskId, int id) {
super(id);
if(taskId == null) {
throw new IllegalArgumentException("taskId cannot be null");
}
this.taskId = taskId;
}
/**
* Constructs a TaskId object from given parts.
* @param jtIdentifier jobTracker identifier
* @param jobId job number
* @param type the TaskType
* @param taskId taskId number
* @param id the task attempt number
*/
public TaskAttemptID(String jtIdentifier, int jobId, TaskType type,
int taskId, int id) {
this(new TaskID(jtIdentifier, jobId, type, taskId), id);
}
/**
* Constructs a TaskId object from given parts.
* @param jtIdentifier jobTracker identifier
* @param jobId job number
* @param isMap whether the tip is a map
* @param taskId taskId number
* @param id the task attempt number
*/
@Deprecated
public TaskAttemptID(String jtIdentifier, int jobId, boolean isMap,
int taskId, int id) {
this(new TaskID(jtIdentifier, jobId, isMap, taskId), id);
}
public TaskAttemptID() {
taskId = new TaskID();
}
/** Returns the {@link JobID} object that this task attempt belongs to */
public JobID getJobID() {
return taskId.getJobID();
}
/** Returns the {@link TaskID} object that this task attempt belongs to */
public TaskID getTaskID() {
return taskId;
}
/**Returns whether this TaskID is a map ID */
@Deprecated
public boolean isMap() {
return taskId.isMap();
}
/**Returns the TaskType of the TaskAttemptID */
public TaskType getTaskType() {
return taskId.getTaskType();
}
@Override
public boolean equals(Object o) {
if (!super.equals(o))
return false;
TaskAttemptID that = (TaskAttemptID)o;
return this.taskId.equals(that.taskId);
}
/**
* Add the unique string to the StringBuilder
* @param builder the builder to append ot
* @return the builder that was passed in.
*/
protected StringBuilder appendTo(StringBuilder builder) {
return taskId.appendTo(builder).append(SEPARATOR).append(id);
}
@Override
public void readFields(DataInput in) throws IOException {
super.readFields(in);
taskId.readFields(in);
}
@Override
public void write(DataOutput out) throws IOException {
super.write(out);
taskId.write(out);
}
@Override
public int hashCode() {
return taskId.hashCode() * 5 + id;
}
/**Compare TaskIds by first tipIds, then by task numbers. */
@Override
public int compareTo(ID o) {
TaskAttemptID that = (TaskAttemptID)o;
int tipComp = this.taskId.compareTo(that.taskId);
if(tipComp == 0) {
return this.id - that.id;
}
else return tipComp;
}
@Override
public String toString() {
return appendTo(new StringBuilder(ATTEMPT)).toString();
}
/** Construct a TaskAttemptID object from given string
* @return constructed TaskAttemptID object or null if the given String is null
* @throws IllegalArgumentException if the given string is malformed
*/
public static TaskAttemptID forName(String str
) throws IllegalArgumentException {
if(str == null)
return null;
String exceptionMsg = null;
try {
String[] parts = str.split(Character.toString(SEPARATOR));
if(parts.length == 6) {
if(parts[0].equals(ATTEMPT)) {
String type = parts[3];
TaskType t = TaskID.getTaskType(type.charAt(0));
if(t != null) {
return new org.apache.hadoop.mapred.TaskAttemptID
(parts[1],
Integer.parseInt(parts[2]),
t, Integer.parseInt(parts[4]),
Integer.parseInt(parts[5]));
} else
exceptionMsg = "Bad TaskType identifier. TaskAttemptId string : "
+ str + " is not properly formed.";
}
}
} catch (Exception ex) {
//fall below
}
if (exceptionMsg == null) {
exceptionMsg = "TaskAttemptId string : " + str
+ " is not properly formed";
}
throw new IllegalArgumentException(exceptionMsg);
}
}