org.apache.beam.sdk.values

Interface POutput

All Known Subinterfaces:

PCollectionView<T>, PValue

All Known Implementing Classes:

PCollection, PCollectionList, PCollectionTuple, PDone, POutputValueBase, PValueBase, TypedPValue

public interface POutput

The interface for things that might be output from a PTransform.

Method Summary

Modifier and Type	Method and Description
Collection<? extends PValue>	expand() Expands this POutput into a list of its component output PValues.
void	finishSpecifyingOutput() As part of applying the producing PTransform, finalizes this output to make it ready for being used as an input and for running.
Pipeline	getPipeline() Returns the owning Pipeline of this POutput.
void	recordAsOutput(AppliedPTransform<?,?,?> transform) Records that this POutput is an output of the given PTransform.

Method Detail

getPipeline

Pipeline getPipeline()

Returns the owning Pipeline of this POutput.

expand

Collection<? extends PValue> expand()

Expands this POutput into a list of its component output PValues.

• A PValue expands to itself.
• A tuple or list of PValues (such as PCollectionTuple or PCollectionList) expands to its component PValue PValues.

Not intended to be invoked directly by user code.

recordAsOutput

void recordAsOutput(AppliedPTransform<?,?,?> transform)

Records that this POutput is an output of the given PTransform.

For a compound POutput, it is advised to call this method on each component POutput.

This is not intended to be invoked by user code, but is automatically invoked as part of applying the producing PTransform.

finishSpecifyingOutput

void finishSpecifyingOutput()

As part of applying the producing PTransform, finalizes this output to make it ready for being used as an input and for running.

This includes ensuring that all PCollections have Coders specified or defaulted.

Automatically invoked whenever this POutput is used as a PInput to another PTransform, or if never used as a PInput, when Pipeline.run() is called, so users do not normally call this explicitly.