com.cloudera.crunch.lib
Class Aggregate.TopKFn<K,V>

java.lang.Object
  com.cloudera.crunch.DoFn<Pair<K,V>,Pair<Boolean,Pair<K,V>>>
      com.cloudera.crunch.lib.Aggregate.TopKFn<K,V>

All Implemented Interfaces:

Serializable

Enclosing class:

Aggregate

public static class Aggregate.TopKFn<K,V>
extends DoFn<Pair<K,V>,Pair<Boolean,Pair<K,V>>>

See Also:

Serialized Form

Constructor Summary

Aggregate.TopKFn(int limit, boolean ascending)

Method Summary

void	cleanup(Emitter<Pair<Boolean,Pair<K,V>>> emitter) Called during the cleanup of the MapReduce job this DoFn is associated with.
void	initialize() Called during the setup of the MapReduce job this DoFn is associated with.
void	process(Pair<K,V> input, Emitter<Pair<Boolean,Pair<K,V>>> emitter) Processes the records from a PCollection.

Methods inherited from class com.cloudera.crunch.DoFn

configure, getConfiguration, getCounter, getCounter, getStatus, getTaskAttemptID, progress, scaleFactor, setConfigurationForTest, setContext, setStatus

Methods inherited from class java.lang.Object

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

Constructor Detail

Aggregate.TopKFn

public Aggregate.TopKFn(int limit,
                        boolean ascending)

Method Detail

initialize

public void initialize()

Description copied from class: DoFn

Called during the setup of the MapReduce job this DoFn is associated with. Subclasses may override this method to do appropriate initialization.

Overrides:

initialize in class DoFn<Pair<K,V>,Pair<Boolean,Pair<K,V>>>

process

public void process(Pair<K,V> input,
                    Emitter<Pair<Boolean,Pair<K,V>>> emitter)

Description copied from class: DoFn

Processes the records from a PCollection.

Specified by:

process in class DoFn<Pair<K,V>,Pair<Boolean,Pair<K,V>>>

Parameters:

input - The input record

emitter - The emitter to send the output to

cleanup

public void cleanup(Emitter<Pair<Boolean,Pair<K,V>>> emitter)

Description copied from class: DoFn

Called during the cleanup of the MapReduce job this DoFn is associated with. Subclasses may override this method to do appropriate cleanup.

Overrides:

cleanup in class DoFn<Pair<K,V>,Pair<Boolean,Pair<K,V>>>

Parameters:

emitter - The emitter that was used for output