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org.apache.crunch.impl.dist.collect
Class EmptyPCollection<T>

java.lang.Object
  org.apache.crunch.impl.dist.collect.PCollectionImpl<T>
      org.apache.crunch.impl.dist.collect.EmptyPCollection<T>

All Implemented Interfaces:

PCollection<T>

Direct Known Subclasses:

EmptyPCollection

public class EmptyPCollection<T>
extends PCollectionImpl<T>

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.crunch.impl.dist.collect.PCollectionImpl

PCollectionImpl.Visitor

Constructor Summary

EmptyPCollection(DistributedPipeline pipeline, PType<T> ptype)

Method Summary

long	getLastModifiedAt() The time of the most recent modification to one of the input sources to the collection.
List<PCollectionImpl<?>>	getParents()
PType<T>	getPType() Returns the PType of this PCollection.

Methods inherited from class org.apache.crunch.impl.dist.collect.PCollectionImpl

accept, aggregate, asCollection, asReadable, by, by, cache, cache, count, filter, filter, first, getDepth, getMaterializedAt, getName, getOnlyParent, getParallelDoOptions, getPipeline, getSize, getTargetDependencies, getTypeFamily, isBreakpoint, length, materialize, materializeAt, max, min, parallelDo, parallelDo, parallelDo, parallelDo, parallelDo, parallelDo, sequentialDo, setBreakpoint, toString, union, union, write, write

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyPCollection

public EmptyPCollection(DistributedPipeline pipeline,
                        PType<T> ptype)

Method Detail

getParents

public List<PCollectionImpl<?>> getParents()

Specified by:

getParents in class PCollectionImpl<T>

getLastModifiedAt

public long getLastModifiedAt()

Description copied from class: PCollectionImpl

The time of the most recent modification to one of the input sources to the collection. If the time can not be determined then -1 should be returned.

Specified by:

getLastModifiedAt in class PCollectionImpl<T>

Returns:

time of the most recent modification to one of the input sources to the collection.

getPType

public PType<T> getPType()

Description copied from interface: PCollection

Returns the PType of this PCollection.