[120] | 1 | /** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 3 | * or more contributor license agreements. See the NOTICE file |
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| 4 | * distributed with this work for additional information |
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| 5 | * regarding copyright ownership. The ASF licenses this file |
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| 6 | * to you under the Apache License, Version 2.0 (the |
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| 7 | * "License"); you may not use this file except in compliance |
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| 8 | * with the License. You may obtain a copy of the License at |
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| 9 | * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 11 | * |
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| 12 | * Unless required by applicable law or agreed to in writing, software |
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| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 15 | * See the License for the specific language governing permissions and |
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| 16 | * limitations under the License. |
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| 17 | */ |
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| 18 | |
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| 19 | package org.apache.hadoop.mapreduce; |
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| 20 | |
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| 21 | import java.io.DataInput; |
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| 22 | import java.io.DataOutput; |
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| 23 | import java.io.IOException; |
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| 24 | |
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| 25 | import org.apache.hadoop.io.WritableComparable; |
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| 26 | |
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| 27 | /** |
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| 28 | * A general identifier, which internally stores the id |
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| 29 | * as an integer. This is the super class of {@link JobID}, |
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| 30 | * {@link TaskID} and {@link TaskAttemptID}. |
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| 31 | * |
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| 32 | * @see JobID |
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| 33 | * @see TaskID |
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| 34 | * @see TaskAttemptID |
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| 35 | */ |
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| 36 | public abstract class ID implements WritableComparable<ID> { |
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| 37 | protected static final char SEPARATOR = '_'; |
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| 38 | protected int id; |
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| 39 | |
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| 40 | /** constructs an ID object from the given int */ |
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| 41 | public ID(int id) { |
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| 42 | this.id = id; |
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| 43 | } |
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| 44 | |
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| 45 | protected ID() { |
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| 46 | } |
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| 47 | |
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| 48 | /** returns the int which represents the identifier */ |
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| 49 | public int getId() { |
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| 50 | return id; |
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| 51 | } |
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| 52 | |
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| 53 | @Override |
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| 54 | public String toString() { |
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| 55 | return String.valueOf(id); |
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| 56 | } |
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| 57 | |
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| 58 | @Override |
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| 59 | public int hashCode() { |
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| 60 | return Integer.valueOf(id).hashCode(); |
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| 61 | } |
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| 62 | |
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| 63 | @Override |
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| 64 | public boolean equals(Object o) { |
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| 65 | if (this == o) |
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| 66 | return true; |
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| 67 | if(o == null) |
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| 68 | return false; |
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| 69 | if (o.getClass() == this.getClass()) { |
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| 70 | ID that = (ID) o; |
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| 71 | return this.id == that.id; |
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| 72 | } |
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| 73 | else |
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| 74 | return false; |
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| 75 | } |
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| 76 | |
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| 77 | /** Compare IDs by associated numbers */ |
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| 78 | public int compareTo(ID that) { |
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| 79 | return this.id - that.id; |
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| 80 | } |
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| 81 | |
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| 82 | public void readFields(DataInput in) throws IOException { |
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| 83 | this.id = in.readInt(); |
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| 84 | } |
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| 85 | |
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| 86 | public void write(DataOutput out) throws IOException { |
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| 87 | out.writeInt(id); |
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| 88 | } |
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| 89 | |
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| 90 | } |
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