1 /**
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements.  See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership.  The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License.  You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 package org.apache.hadoop.mapreduce;
19 
20 import org.apache.hadoop.classification.InterfaceAudience;
21 import org.apache.hadoop.classification.InterfaceStability;
22 import org.apache.hadoop.mapreduce.counters.Limits;
23 import org.apache.hadoop.mapreduce.counters.GenericCounter;
24 import org.apache.hadoop.mapreduce.counters.AbstractCounterGroup;
25 import org.apache.hadoop.mapreduce.counters.CounterGroupBase;
26 import org.apache.hadoop.mapreduce.counters.FileSystemCounterGroup;
27 import org.apache.hadoop.mapreduce.counters.AbstractCounters;
28 import org.apache.hadoop.mapreduce.counters.CounterGroupFactory;
29 import org.apache.hadoop.mapreduce.counters.FrameworkCounterGroup;
30 
31 /**
32  * <p><code>Counters</code> holds per job/task counters, defined either by the
33  * Map-Reduce framework or applications. Each <code>Counter</code> can be of
34  * any {@link Enum} type.</p>
35  *
36  * <p><code>Counters</code> are bunched into {@link CounterGroup}s, each
37  * comprising of counters from a particular <code>Enum</code> class.
38  */
39 @InterfaceAudience.Public
40 @InterfaceStability.Stable
41 public class Counters extends AbstractCounters<Counter, CounterGroup> {
42 
43   // Mix framework group implementation into CounterGroup interface
44   private static class FrameworkGroupImpl<T extends Enum<T>>
45       extends FrameworkCounterGroup<T, Counter> implements CounterGroup {
46 
FrameworkGroupImpl(Class<T> cls)47     FrameworkGroupImpl(Class<T> cls) {
48       super(cls);
49     }
50 
51     @Override
newCounter(T key)52     protected FrameworkCounter<T> newCounter(T key) {
53       return new FrameworkCounter<T>(key, getName());
54     }
55 
56     @Override
getUnderlyingGroup()57     public CounterGroupBase<Counter> getUnderlyingGroup() {
58       return this;
59     }
60   }
61 
62   // Mix generic group implementation into CounterGroup interface
63   // and provide some mandatory group factory methods.
64   private static class GenericGroup extends AbstractCounterGroup<Counter>
65       implements CounterGroup {
66 
GenericGroup(String name, String displayName, Limits limits)67     GenericGroup(String name, String displayName, Limits limits) {
68       super(name, displayName, limits);
69     }
70 
71     @Override
newCounter(String name, String displayName, long value)72     protected Counter newCounter(String name, String displayName, long value) {
73       return new GenericCounter(name, displayName, value);
74     }
75 
76     @Override
newCounter()77     protected Counter newCounter() {
78       return new GenericCounter();
79     }
80 
81     @Override
getUnderlyingGroup()82     public CounterGroupBase<Counter> getUnderlyingGroup() {
83       return this;
84     }
85   }
86 
87   // Mix file system group implementation into the CounterGroup interface
88   private static class FileSystemGroup extends FileSystemCounterGroup<Counter>
89       implements CounterGroup {
90 
91     @Override
newCounter(String scheme, FileSystemCounter key)92     protected Counter newCounter(String scheme, FileSystemCounter key) {
93       return new FSCounter(scheme, key);
94     }
95 
96     @Override
getUnderlyingGroup()97     public CounterGroupBase<Counter> getUnderlyingGroup() {
98       return this;
99     }
100   }
101 
102   /**
103    * Provide factory methods for counter group factory implementation.
104    * See also the GroupFactory in
105    *  {@link org.apache.hadoop.mapred.Counters mapred.Counters}
106    */
107   private static class GroupFactory
108       extends CounterGroupFactory<Counter, CounterGroup> {
109 
110     @Override
111     protected <T extends Enum<T>>
112     FrameworkGroupFactory<CounterGroup>
newFrameworkGroupFactory(final Class<T> cls)113         newFrameworkGroupFactory(final Class<T> cls) {
114       return new FrameworkGroupFactory<CounterGroup>() {
115         @Override public CounterGroup newGroup(String name) {
116           return new FrameworkGroupImpl<T>(cls); // impl in this package
117         }
118       };
119     }
120 
121     @Override
newGenericGroup(String name, String displayName, Limits limits)122     protected CounterGroup newGenericGroup(String name, String displayName,
123                                            Limits limits) {
124       return new GenericGroup(name, displayName, limits);
125     }
126 
127     @Override
newFileSystemGroup()128     protected CounterGroup newFileSystemGroup() {
129       return new FileSystemGroup();
130     }
131   }
132 
133   private static final GroupFactory groupFactory = new GroupFactory();
134 
135   /**
136    * Default constructor
137    */
138   public Counters() {
139     super(groupFactory);
140   }
141 
142   /**
143    * Construct the Counters object from the another counters object
144    * @param <C> the type of counter
145    * @param <G> the type of counter group
146    * @param counters the old counters object
147    */
148   public <C extends Counter, G extends CounterGroupBase<C>>
149   Counters(AbstractCounters<C, G> counters) {
150     super(counters, groupFactory);
151   }
152 }
153