org.apache.crunch.fn

Class MapValuesFn<K,V1,V2>

java.lang.Object

org.apache.crunch.DoFn<Pair<K,V1>,Pair<K,V2>>

org.apache.crunch.fn.MapValuesFn<K,V1,V2>

All Implemented Interfaces:

Serializable

public abstract class MapValuesFn<K,V1,V2>
extends DoFn<Pair<K,V1>,Pair<K,V2>>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
MapValuesFn()

Method Summary

Methods

Modifier and Type	Method and Description
abstract V2	map(V1 v)
void	process(Pair<K,V1> input, Emitter<Pair<K,V2>> emitter) Processes the records from a PCollection.

Methods inherited from class org.apache.crunch.DoFn

cleanup, configure, initialize, scaleFactor, setContext

Methods inherited from class java.lang.Object

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

Constructor Detail

MapValuesFn

public MapValuesFn()

Method Detail

process

public void process(Pair<K,V1> input,
           Emitter<Pair<K,V2>> 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<K,V1>,Pair<K,V2>>

Parameters:

input - The input record.

emitter - The emitter to send the output to

map

public abstract V2 map(V1 v)