com.google.cloud.dataflow.sdk.values

Interface POutput

All Known Subinterfaces:

PCollectionView<T,WT>, PValue

All Known Implementing Classes:

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

public interface POutput

The abstract interface of things that might be output from a PTransform.

Method Summary

Methods

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

Method Detail

expand

java.util.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 (e.g., PCollectionTuple, and PCollectionList) expands to its component PValues.

Not intended to be invoked directly by user code.

recordAsOutput

void recordAsOutput(Pipeline pipeline,
                  PTransform<?,?> transform)

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

Should expand this POutput and invoke PValue#recordAsOutput(Pipeline, com.google.cloud.dataflow.sdk.transforms.PTransform, String) on each component output PValue.

Automatically invoked as part of applying a PTransform. Not to be invoked directly by user code.

finishSpecifyingOutput

void finishSpecifyingOutput()

As part of finishing the producing PTransform, finalizes this PTransform 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.