org.apache.crunch.lib
Class Aggregate.TopKCombineFn<K,V>
java.lang.Object
org.apache.crunch.DoFn<Pair<S,Iterable<T>>,Pair<S,T>>
org.apache.crunch.CombineFn<Integer,Pair<K,V>>
org.apache.crunch.lib.Aggregate.TopKCombineFn<K,V>
- All Implemented Interfaces:
- Serializable
- Enclosing class:
- Aggregate
public static class Aggregate.TopKCombineFn<K,V>
- extends CombineFn<Integer,Pair<K,V>>
- See Also:
- Serialized Form
Methods inherited from class org.apache.crunch.DoFn |
cleanup, configure, disableDeepCopy, getConfiguration, getContext, getCounter, getCounter, getStatus, getTaskAttemptID, increment, increment, increment, increment, initialize, progress, scaleFactor, setConfiguration, setContext, setStatus |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Aggregate.TopKCombineFn
public Aggregate.TopKCombineFn(int limit,
boolean maximize)
process
public void process(Pair<Integer,Iterable<Pair<K,V>>> input,
Emitter<Pair<Integer,Pair<K,V>>> emitter)
- Description copied from class:
DoFn
- Processes the records from a
PCollection
.
Note: Crunch can reuse a single input record object whose content
changes on each DoFn.process(Object, Emitter)
method call. This
functionality is imposed by Hadoop's Reducer implementation: The framework will reuse the key and value
objects that are passed into the reduce, therefore the application should
clone the objects they want to keep a copy of.
- Specified by:
process
in class DoFn<Pair<Integer,Iterable<Pair<K,V>>>,Pair<Integer,Pair<K,V>>>
- Parameters:
input
- The input record.emitter
- The emitter to send the output to
Copyright © 2014 The Apache Software Foundation. All Rights Reserved.