org.apache.hadoop.mapreduce
Class CounterGroup

java.lang.Object
  org.apache.hadoop.mapreduce.CounterGroup

All Implemented Interfaces:

Iterable<Counter>, Writable

public class CounterGroup
extends Object
implements Writable, Iterable<Counter>

A group of Counters that logically belong together. Typically, it is an Enum subclass and the counters are the values.

Constructor Summary

protected	CounterGroup(String name)
protected	CounterGroup(String name, String displayName)

Method Summary

boolean	equals(Object genericRight)
Counter	findCounter(String counterName)
protected Counter	findCounter(String counterName, String displayName) Internal to find a counter in a group.
String	getDisplayName() Get the display name of the group.
String	getName() Get the internal name of the group
int	hashCode()
void	incrAllCounters(CounterGroup rightGroup)
Iterator<Counter>	iterator()
void	readFields(DataInput in) Deserialize the fields of this object from in.
int	size() Returns the number of counters in this group.
void	write(DataOutput out) Serialize the fields of this object to out.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CounterGroup

protected CounterGroup(String name)

CounterGroup

protected CounterGroup(String name,
                       String displayName)

Method Detail

getName

public String getName()

Get the internal name of the group

Returns:

the internal name

getDisplayName

public String getDisplayName()

Get the display name of the group.

Returns:

the human readable name

findCounter

protected Counter findCounter(String counterName,
                              String displayName)

Internal to find a counter in a group.

Parameters:

counterName - the name of the counter

displayName - the display name of the counter

Returns:

the counter that was found or added

findCounter

public Counter findCounter(String counterName)

iterator

public Iterator<Counter> iterator()

Specified by:

iterator in interface Iterable<Counter>

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Serialize the fields of this object to out.

Specified by:

write in interface Writable

Parameters:

out - DataOuput to serialize this object into.

Throws:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Parameters:

in - DataInput to deseriablize this object from.

Throws:

IOException

size

public int size()

Returns the number of counters in this group.

equals

public boolean equals(Object genericRight)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

incrAllCounters

public void incrAllCounters(CounterGroup rightGroup)