| /** |
| * 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.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.text.NumberFormat; |
| |
| /** |
| * TaskID represents the immutable and unique identifier for |
| * a Map or Reduce Task. Each TaskID encompasses multiple attempts made to |
| * execute the Map or Reduce Task, each of which are uniquely indentified by |
| * their TaskAttemptID. |
| * |
| * TaskID consists of 3 parts. First part is the {@link JobID}, that this |
| * TaskInProgress belongs to. Second part of the TaskID is either 'm' or 'r' |
| * representing whether the task is a map task or a reduce task. |
| * And the third part is the task number. <br> |
| * An example TaskID is : |
| * <code>task_200707121733_0003_m_000005</code> , which represents the |
| * fifth map task in the third job running at the jobtracker |
| * started at <code>200707121733</code>. |
| * <p> |
| * Applications should never construct or parse TaskID strings |
| * , but rather use appropriate constructors or {@link #forName(String)} |
| * method. |
| * |
| * @see JobID |
| * @see TaskAttemptID |
| */ |
| public class TaskID extends ID { |
| private static final String TASK = "task"; |
| private static char UNDERSCORE = '_'; |
| private static NumberFormat idFormat = NumberFormat.getInstance(); |
| static { |
| idFormat.setGroupingUsed(false); |
| idFormat.setMinimumIntegerDigits(6); |
| } |
| |
| private JobID jobId; |
| private boolean isMap; |
| |
| /** |
| * Constructs a TaskID object from given {@link JobID}. |
| * @param jobId JobID that this tip belongs to |
| * @param isMap whether the tip is a map |
| * @param id the tip number |
| */ |
| public TaskID(JobID jobId, boolean isMap, int id) { |
| super(id); |
| if(jobId == null) { |
| throw new IllegalArgumentException("jobId cannot be null"); |
| } |
| this.jobId = jobId; |
| this.isMap = isMap; |
| } |
| |
| /** |
| * Constructs a TaskInProgressId object from given parts. |
| * @param jtIdentifier jobTracker identifier |
| * @param jobId job number |
| * @param isMap whether the tip is a map |
| * @param id the tip number |
| */ |
| public TaskID(String jtIdentifier, int jobId, boolean isMap, int id) { |
| this(new JobID(jtIdentifier, jobId), isMap, id); |
| } |
| |
| private TaskID() { } |
| |
| /** Returns the {@link JobID} object that this tip belongs to */ |
| public JobID getJobID() { |
| return jobId; |
| } |
| |
| /**Returns whether this TaskID is a map ID */ |
| public boolean isMap() { |
| return isMap; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if(o == null) |
| return false; |
| if(o.getClass().equals(TaskID.class)) { |
| TaskID that = (TaskID)o; |
| return this.id==that.id |
| && this.isMap == that.isMap |
| && this.jobId.equals(that.jobId); |
| } |
| else return false; |
| } |
| |
| /**Compare TaskInProgressIds by first jobIds, then by tip numbers. Reduces are |
| * defined as greater then maps.*/ |
| @Override |
| public int compareTo(ID o) { |
| TaskID that = (TaskID)o; |
| int jobComp = this.jobId.compareTo(that.jobId); |
| if(jobComp == 0) { |
| if(this.isMap == that.isMap) { |
| return this.id - that.id; |
| } |
| else return this.isMap ? -1 : 1; |
| } |
| else return jobComp; |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder builder = new StringBuilder(); |
| return builder.append(TASK).append(UNDERSCORE) |
| .append(toStringWOPrefix()).toString(); |
| } |
| |
| StringBuilder toStringWOPrefix() { |
| StringBuilder builder = new StringBuilder(); |
| builder.append(jobId.toStringWOPrefix()) |
| .append(isMap ? "_m_" : "_r_"); |
| return builder.append(idFormat.format(id)); |
| } |
| |
| @Override |
| public int hashCode() { |
| return toStringWOPrefix().toString().hashCode(); |
| } |
| |
| @Override |
| public void readFields(DataInput in) throws IOException { |
| super.readFields(in); |
| this.jobId = JobID.read(in); |
| this.isMap = in.readBoolean(); |
| } |
| |
| @Override |
| public void write(DataOutput out) throws IOException { |
| super.write(out); |
| jobId.write(out); |
| out.writeBoolean(isMap); |
| } |
| |
| public static TaskID read(DataInput in) throws IOException { |
| TaskID tipId = new TaskID(); |
| tipId.readFields(in); |
| return tipId; |
| } |
| |
| /** Construct a TaskID object from given string |
| * @return constructed TaskID object or null if the given String is null |
| * @throws IllegalArgumentException if the given string is malformed |
| */ |
| public static TaskID forName(String str) |
| throws IllegalArgumentException { |
| if(str == null) |
| return null; |
| try { |
| String[] parts = str.split("_"); |
| if(parts.length == 5) { |
| if(parts[0].equals(TASK)) { |
| boolean isMap = false; |
| if(parts[3].equals("m")) isMap = true; |
| else if(parts[3].equals("r")) isMap = false; |
| else throw new Exception(); |
| return new TaskID(parts[1], Integer.parseInt(parts[2]), |
| isMap, Integer.parseInt(parts[4])); |
| } |
| } |
| }catch (Exception ex) {//fall below |
| } |
| throw new IllegalArgumentException("TaskId string : " + str |
| + " is not properly formed"); |
| } |
| |
| /** |
| * Returns a regex pattern which matches task IDs. Arguments can |
| * be given null, in which case that part of the regex will be generic. |
| * For example to obtain a regex matching <i>the first map task</i> |
| * of <i>any jobtracker</i>, of <i>any job</i>, we would use : |
| * <pre> |
| * TaskID.getTaskIDsPattern(null, null, true, 1); |
| * </pre> |
| * which will return : |
| * <pre> "task_[^_]*_[0-9]*_m_000001*" </pre> |
| * @param jtIdentifier jobTracker identifier, or null |
| * @param jobId job number, or null |
| * @param isMap whether the tip is a map, or null |
| * @param taskId taskId number, or null |
| * @return a regex pattern matching TaskIDs |
| */ |
| public static String getTaskIDsPattern(String jtIdentifier, Integer jobId |
| , Boolean isMap, Integer taskId) { |
| StringBuilder builder = new StringBuilder(TASK).append(UNDERSCORE) |
| .append(getTaskIDsPatternWOPrefix(jtIdentifier, jobId, isMap, taskId)); |
| return builder.toString(); |
| } |
| |
| static StringBuilder getTaskIDsPatternWOPrefix(String jtIdentifier |
| , Integer jobId, Boolean isMap, Integer taskId) { |
| StringBuilder builder = new StringBuilder(); |
| builder.append(JobID.getJobIDsPatternWOPrefix(jtIdentifier, jobId)) |
| .append(UNDERSCORE) |
| .append(isMap != null ? (isMap ? "m" : "r") : "(m|r)").append(UNDERSCORE) |
| .append(taskId != null ? idFormat.format(taskId) : "[0-9]*"); |
| return builder; |
| } |
| |
| } |