com.tinkerpop.pipes.sideeffect

Class GroupByPipe<S,K,V>

java.lang.Object

com.tinkerpop.pipes.AbstractPipe<S,S>

com.tinkerpop.pipes.sideeffect.GroupByPipe<S,K,V>

All Implemented Interfaces:

Pipe<S,S>, SideEffectPipe<S,Map<K,List<V>>>, SideEffectPipe.GreedySideEffectPipe<S,Map<K,List<V>>>, Iterable<S>, Iterator<S>

Direct Known Subclasses:

GroupByReducePipe

public class GroupByPipe<S,K,V>
extends AbstractPipe<S,S>
implements SideEffectPipe.GreedySideEffectPipe<S,Map<K,List<V>>>

Author:

Marko A. Rodriguez (http://markorodriguez.com)

Nested Class Summary

Nested classes/interfaces inherited from interface com.tinkerpop.pipes.sideeffect.SideEffectPipe

SideEffectPipe.GreedySideEffectPipe<S,T>, SideEffectPipe.LazySideEffectPipe<S,T>

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<K,Collection<V>>	byMap
protected PipeFunction<S,K>	keyFunction
protected PipeFunction<S,V>	valueFunction

Fields inherited from class com.tinkerpop.pipes.AbstractPipe

currentEnd, pathEnabled, starts

Fields inherited from interface com.tinkerpop.pipes.Pipe

NO_PATH_MESSAGE

Constructor Summary

Constructors

Constructor and Description
GroupByPipe(Map<K,Collection<V>> byMap, PipeFunction<S,K> keyFunction, PipeFunction<S,V> valueFunction)
GroupByPipe(PipeFunction<S,K> keyFunction, PipeFunction<S,V> valueFunction)

Method Summary

Methods

Modifier and Type	Method and Description
void	addValue(V value, Collection values)
protected K	getKey(S start)
Map	getSideEffect()
protected V	getValue(S start)
protected S	processNextStart()
void	reset() A pipe may maintain state.

Methods inherited from class com.tinkerpop.pipes.AbstractPipe

enablePath, getCurrentPath, getPathToHere, hasNext, iterator, next, remove, setStarts, setStarts, setStarts, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.tinkerpop.pipes.Pipe

enablePath, getCurrentPath, setStarts, setStarts

Methods inherited from interface java.util.Iterator

hasNext, next, remove

Methods inherited from interface java.lang.Iterable

iterator

Field Detail

byMap

protected Map<K,Collection<V>> byMap

keyFunction

protected final PipeFunction<S,K> keyFunction

valueFunction

protected final PipeFunction<S,V> valueFunction

Constructor Detail

GroupByPipe

public GroupByPipe(Map<K,Collection<V>> byMap,
           PipeFunction<S,K> keyFunction,
           PipeFunction<S,V> valueFunction)

GroupByPipe

public GroupByPipe(PipeFunction<S,K> keyFunction,
           PipeFunction<S,V> valueFunction)

Method Detail

processNextStart

protected S processNextStart()

Specified by:

processNextStart in class AbstractPipe<S,S>

getSideEffect

public Map getSideEffect()

Specified by:

getSideEffect in interface SideEffectPipe<S,Map<K,List<V>>>

addValue

public void addValue(V value,
            Collection values)

getKey

protected K getKey(S start)

getValue

protected V getValue(S start)

reset

public void reset()

Description copied from interface: Pipe

A pipe may maintain state. Reset is used to remove state. The general use case for reset() is to reuse a pipe in another computation without having to create a new Pipe object. An implementation of this method should be recursive whereby the starts (if a Pipe) should have this method called on it.

Specified by:

reset in interface Pipe<S,S>

Overrides:

reset in class AbstractPipe<S,S>