001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.mapreduce;
019
020import org.apache.hadoop.classification.InterfaceAudience;
021import org.apache.hadoop.classification.InterfaceStability;
022import org.apache.hadoop.mapreduce.counters.Limits;
023import org.apache.hadoop.mapreduce.counters.GenericCounter;
024import org.apache.hadoop.mapreduce.counters.AbstractCounterGroup;
025import org.apache.hadoop.mapreduce.counters.CounterGroupBase;
026import org.apache.hadoop.mapreduce.counters.FileSystemCounterGroup;
027import org.apache.hadoop.mapreduce.counters.AbstractCounters;
028import org.apache.hadoop.mapreduce.counters.CounterGroupFactory;
029import org.apache.hadoop.mapreduce.counters.FrameworkCounterGroup;
030
031/**
032 * <p><code>Counters</code> holds per job/task counters, defined either by the
033 * Map-Reduce framework or applications. Each <code>Counter</code> can be of
034 * any {@link Enum} type.</p>
035 *
036 * <p><code>Counters</code> are bunched into {@link CounterGroup}s, each
037 * comprising of counters from a particular <code>Enum</code> class.
038 */
039@InterfaceAudience.Public
040@InterfaceStability.Stable
041public class Counters extends AbstractCounters<Counter, CounterGroup> {
042
043  // Mix framework group implementation into CounterGroup interface
044  private static class FrameworkGroupImpl<T extends Enum<T>>
045      extends FrameworkCounterGroup<T, Counter> implements CounterGroup {
046
047    FrameworkGroupImpl(Class<T> cls) {
048      super(cls);
049    }
050
051    @Override
052    protected FrameworkCounter<T> newCounter(T key) {
053      return new FrameworkCounter<T>(key, getName());
054    }
055
056    @Override
057    public CounterGroupBase<Counter> getUnderlyingGroup() {
058      return this;
059    }
060  }
061
062  // Mix generic group implementation into CounterGroup interface
063  // and provide some mandatory group factory methods.
064  private static class GenericGroup extends AbstractCounterGroup<Counter>
065      implements CounterGroup {
066
067    GenericGroup(String name, String displayName, Limits limits) {
068      super(name, displayName, limits);
069    }
070
071    @Override
072    protected Counter newCounter(String name, String displayName, long value) {
073      return new GenericCounter(name, displayName, value);
074    }
075
076    @Override
077    protected Counter newCounter() {
078      return new GenericCounter();
079    }
080
081    @Override
082    public CounterGroupBase<Counter> getUnderlyingGroup() {
083      return this;
084    }
085  }
086
087  // Mix file system group implementation into the CounterGroup interface
088  private static class FileSystemGroup extends FileSystemCounterGroup<Counter>
089      implements CounterGroup {
090
091    @Override
092    protected Counter newCounter(String scheme, FileSystemCounter key) {
093      return new FSCounter(scheme, key);
094    }
095
096    @Override
097    public CounterGroupBase<Counter> getUnderlyingGroup() {
098      return this;
099    }
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>
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
122    protected CounterGroup newGenericGroup(String name, String displayName,
123                                           Limits limits) {
124      return new GenericGroup(name, displayName, limits);
125    }
126
127    @Override
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}