| /** |
| * 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 java.text.NumberFormat; |
| import java.util.EnumMap; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.io.WritableUtils; |
| |
| |
| /** |
| * 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 |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class TaskID extends org.apache.hadoop.mapred.ID { |
| protected static final String TASK = "task"; |
| protected static final NumberFormat idFormat = NumberFormat.getInstance(); |
| static { |
| idFormat.setGroupingUsed(false); |
| idFormat.setMinimumIntegerDigits(6); |
| } |
| |
| private JobID jobId; |
| private TaskType type; |
| |
| /** |
| * Constructs a TaskID object from given {@link JobID}. |
| * @param jobId JobID that this tip belongs to |
| * @param type the {@link TaskType} of the task |
| * @param id the tip number |
| */ |
| public TaskID(JobID jobId, TaskType type, int id) { |
| super(id); |
| if(jobId == null) { |
| throw new IllegalArgumentException("jobId cannot be null"); |
| } |
| this.jobId = jobId; |
| this.type = type; |
| } |
| |
| /** |
| * Constructs a TaskInProgressId object from given parts. |
| * @param jtIdentifier jobTracker identifier |
| * @param jobId job number |
| * @param type the TaskType |
| * @param id the tip number |
| */ |
| public TaskID(String jtIdentifier, int jobId, TaskType type, int id) { |
| this(new JobID(jtIdentifier, jobId), type, id); |
| } |
| |
| public TaskID() { |
| jobId = new JobID(); |
| } |
| |
| /** Returns the {@link JobID} object that this tip belongs to */ |
| public JobID getJobID() { |
| return jobId; |
| } |
| |
| /** |
| * Get the type of the task |
| */ |
| public TaskType getTaskType() { |
| return type; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!super.equals(o)) |
| return false; |
| |
| TaskID that = (TaskID)o; |
| return this.type == that.type && this.jobId.equals(that.jobId); |
| } |
| |
| /**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.type == that.type) { |
| return this.id - that.id; |
| } |
| else { |
| return this.type.compareTo(that.type); |
| } |
| } |
| else return jobComp; |
| } |
| @Override |
| public String toString() { |
| return appendTo(new StringBuilder(TASK)).toString(); |
| } |
| |
| /** |
| * Add the unique string to the given builder. |
| * @param builder the builder to append to |
| * @return the builder that was passed in |
| */ |
| protected StringBuilder appendTo(StringBuilder builder) { |
| return jobId.appendTo(builder). |
| append(SEPARATOR). |
| append(CharTaskTypeMaps.getRepresentingCharacter(type)). |
| append(SEPARATOR). |
| append(idFormat.format(id)); |
| } |
| |
| @Override |
| public int hashCode() { |
| return jobId.hashCode() * 524287 + id; |
| } |
| |
| @Override |
| public void readFields(DataInput in) throws IOException { |
| super.readFields(in); |
| jobId.readFields(in); |
| type = WritableUtils.readEnum(in, TaskType.class); |
| } |
| |
| @Override |
| public void write(DataOutput out) throws IOException { |
| super.write(out); |
| jobId.write(out); |
| WritableUtils.writeEnum(out, type); |
| } |
| |
| /** 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)) { |
| String type = parts[3]; |
| TaskType t = CharTaskTypeMaps.getTaskType(type.charAt(0)); |
| if(t != null) { |
| |
| return new org.apache.hadoop.mapred.TaskID(parts[1], |
| Integer.parseInt(parts[2]), |
| t, |
| Integer.parseInt(parts[4])); |
| } else throw new Exception(); |
| } |
| } |
| }catch (Exception ex) {//fall below |
| } |
| throw new IllegalArgumentException("TaskId string : " + str |
| + " is not properly formed"); |
| } |
| /** |
| * Gets the character representing the {@link TaskType} |
| * @param type the TaskType |
| * @return the character |
| */ |
| public static char getRepresentingCharacter(TaskType type) { |
| return CharTaskTypeMaps.getRepresentingCharacter(type); |
| } |
| /** |
| * Gets the {@link TaskType} corresponding to the character |
| * @param c the character |
| * @return the TaskType |
| */ |
| public static TaskType getTaskType(char c) { |
| return CharTaskTypeMaps.getTaskType(c); |
| } |
| |
| public static String getAllTaskTypes() { |
| return CharTaskTypeMaps.allTaskTypes; |
| } |
| |
| /** |
| * Maintains the mapping from the character representation of a task type to |
| * the enum class TaskType constants |
| */ |
| static class CharTaskTypeMaps { |
| private static EnumMap<TaskType, Character> typeToCharMap = |
| new EnumMap<TaskType,Character>(TaskType.class); |
| private static Map<Character, TaskType> charToTypeMap = |
| new HashMap<Character, TaskType>(); |
| static String allTaskTypes = "(m|r|s|c|t)"; |
| static { |
| setupTaskTypeToCharMapping(); |
| setupCharToTaskTypeMapping(); |
| } |
| |
| private static void setupTaskTypeToCharMapping() { |
| typeToCharMap.put(TaskType.MAP, 'm'); |
| typeToCharMap.put(TaskType.REDUCE, 'r'); |
| typeToCharMap.put(TaskType.JOB_SETUP, 's'); |
| typeToCharMap.put(TaskType.JOB_CLEANUP, 'c'); |
| typeToCharMap.put(TaskType.TASK_CLEANUP, 't'); |
| } |
| |
| private static void setupCharToTaskTypeMapping() { |
| charToTypeMap.put('m', TaskType.MAP); |
| charToTypeMap.put('r', TaskType.REDUCE); |
| charToTypeMap.put('s', TaskType.JOB_SETUP); |
| charToTypeMap.put('c', TaskType.JOB_CLEANUP); |
| charToTypeMap.put('t', TaskType.TASK_CLEANUP); |
| } |
| |
| static char getRepresentingCharacter(TaskType type) { |
| return typeToCharMap.get(type); |
| } |
| static TaskType getTaskType(char c) { |
| return charToTypeMap.get(c); |
| } |
| } |
| |
| } |