/**
* 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 org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.mapreduce.counters.Limits;
import org.apache.hadoop.mapreduce.counters.GenericCounter;
import org.apache.hadoop.mapreduce.counters.AbstractCounterGroup;
import org.apache.hadoop.mapreduce.counters.CounterGroupBase;
import org.apache.hadoop.mapreduce.counters.FileSystemCounterGroup;
import org.apache.hadoop.mapreduce.counters.AbstractCounters;
import org.apache.hadoop.mapreduce.counters.CounterGroupFactory;
import org.apache.hadoop.mapreduce.counters.FrameworkCounterGroup;
/**
* <p><code>Counters</code> holds per job/task counters, defined either by the
* Map-Reduce framework or applications. Each <code>Counter</code> can be of
* any {@link Enum} type.</p>
*
* <p><code>Counters</code> are bunched into {@link CounterGroup}s, each
* comprising of counters from a particular <code>Enum</code> class.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class Counters extends AbstractCounters<Counter, CounterGroup> {
// Mix framework group implementation into CounterGroup interface
private static class FrameworkGroupImpl<T extends Enum<T>>
extends FrameworkCounterGroup<T, Counter> implements CounterGroup {
FrameworkGroupImpl(Class<T> cls) {
super(cls);
}
@Override
protected FrameworkCounter<T> newCounter(T key) {
return new FrameworkCounter<T>(key, getName());
}
@Override
public CounterGroupBase<Counter> getUnderlyingGroup() {
return this;
}
}
// Mix generic group implementation into CounterGroup interface
// and provide some mandatory group factory methods.
private static class GenericGroup extends AbstractCounterGroup<Counter>
implements CounterGroup {
GenericGroup(String name, String displayName, Limits limits) {
super(name, displayName, limits);
}
@Override
protected Counter newCounter(String name, String displayName, long value) {
return new GenericCounter(name, displayName, value);
}
@Override
protected Counter newCounter() {
return new GenericCounter();
}
@Override
public CounterGroupBase<Counter> getUnderlyingGroup() {
return this;
}
}
// Mix file system group implementation into the CounterGroup interface
private static class FileSystemGroup extends FileSystemCounterGroup<Counter>
implements CounterGroup {
@Override
protected Counter newCounter(String scheme, FileSystemCounter key) {
return new FSCounter(scheme, key);
}
@Override
public CounterGroupBase<Counter> getUnderlyingGroup() {
return this;
}
}
/**
* Provide factory methods for counter group factory implementation.
* See also the GroupFactory in
* {@link org.apache.hadoop.mapred.Counters mapred.Counters}
*/
private static class GroupFactory
extends CounterGroupFactory<Counter, CounterGroup> {
@Override
protected <T extends Enum<T>>
FrameworkGroupFactory<CounterGroup>
newFrameworkGroupFactory(final Class<T> cls) {
return new FrameworkGroupFactory<CounterGroup>() {
@Override public CounterGroup newGroup(String name) {
return new FrameworkGroupImpl<T>(cls); // impl in this package
}
};
}
@Override
protected CounterGroup newGenericGroup(String name, String displayName,
Limits limits) {
return new GenericGroup(name, displayName, limits);
}
@Override
protected CounterGroup newFileSystemGroup() {
return new FileSystemGroup();
}
}
private static final GroupFactory groupFactory = new GroupFactory();
/**
* Default constructor
*/
public Counters() {
super(groupFactory);
}
/**
* Construct the Counters object from the another counters object
* @param <C> the type of counter
* @param <G> the type of counter group
* @param counters the old counters object
*/
public <C extends Counter, G extends CounterGroupBase<C>>
Counters(AbstractCounters<C, G> counters) {
super(counters, groupFactory);
}
}