org.apache.crunch.fn

Class CompositeMapFn<R,S,T>

java.lang.Object

org.apache.crunch.DoFn<S,T>

org.apache.crunch.MapFn<R,T>

org.apache.crunch.fn.CompositeMapFn<R,S,T>

All Implemented Interfaces:

Serializable

public class CompositeMapFn<R,S,T>
extends MapFn<R,T>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CompositeMapFn(MapFn<R,S> first, MapFn<S,T> second)

Method Summary

Methods

Modifier and Type	Method and Description
void	cleanup(Emitter<T> emitter) Called during the cleanup of the MapReduce job this DoFn is associated with.
void	configure(org.apache.hadoop.conf.Configuration conf) Configure this DoFn.
MapFn<R,S>	getFirst()
MapFn<S,T>	getSecond()
void	initialize() Initialize this DoFn.
T	map(R input) Maps the given input into an instance of the output type.
void	setContext(org.apache.hadoop.mapreduce.TaskInputOutputContext<?,?,?,?> context) Called during setup to pass the TaskInputOutputContext to this DoFn instance.

Methods inherited from class org.apache.crunch.MapFn

process, scaleFactor

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeMapFn

public CompositeMapFn(MapFn<R,S> first,
              MapFn<S,T> second)

Method Detail

setContext

public void setContext(org.apache.hadoop.mapreduce.TaskInputOutputContext<?,?,?,?> context)

Description copied from class: DoFn

Called during setup to pass the TaskInputOutputContext to this DoFn instance.

Overrides:

setContext in class DoFn<R,T>

initialize

public void initialize()

Description copied from class: DoFn

Initialize this DoFn. This initialization will happen before the actual DoFn.process(Object, Emitter) is triggered. Subclasses may override this method to do appropriate initialization.

Called during the setup of the job instance this DoFn is associated with.

Overrides:

initialize in class DoFn<R,T>

getFirst

public MapFn<R,S> getFirst()

getSecond

public MapFn<S,T> getSecond()

map

public T map(R input)

Description copied from class: MapFn

Maps the given input into an instance of the output type.

Specified by:

map in class MapFn<R,T>

cleanup

public void cleanup(Emitter<T> 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<R,T>

Parameters:

emitter - The emitter that was used for output

configure

public void configure(org.apache.hadoop.conf.Configuration conf)

Description copied from class: DoFn

Configure this DoFn. Subclasses may override this method to modify the configuration of the Job that this DoFn instance belongs to.

Called during the job planning phase by the crunch-client.

Overrides:

configure in class DoFn<R,T>

Parameters:

conf - The Configuration instance for the Job.