org.apache.beam.sdk.values

Class PValueBase

java.lang.Object

org.apache.beam.sdk.values.POutputValueBase

org.apache.beam.sdk.values.PValueBase

All Implemented Interfaces:

PInput, POutput, PValue

Direct Known Subclasses:

TypedPValue

public abstract class PValueBase
extends POutputValueBase
implements PValue

A PValueBase is an abstract base class that provides sensible default implementations for methods of PValue. In particular, this includes functionality for getting/setting:

• The Pipeline that the PValue is part of.
• Whether the PValue has bee finalized (as an input or an output), after which its properties can no longer be changed.

For internal use.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PValueBase() No-arg constructor for Java serialization only.
protected	PValueBase(Pipeline pipeline)

Method Summary

Modifier and Type	Method and Description
Collection<? extends PValue>	expand() Expands this POutput into a list of its component output PValues.
void	finishSpecifying() After building, finalizes this PInput to make it ready for being used as an input to a PTransform.
protected String	getKindString() Returns a String capturing the kind of this PValueBase.
String	getName() Returns the name of this PValueBase.
boolean	isFinishedSpecifyingInternal() Returns whether this PValueBase has been finalized, and its core properties, e.g., name, can no longer be changed.
void	recordAsOutput(AppliedPTransform<?,?,?> transform) Records that this POutputValueBase is an output with the given name of the given AppliedPTransform.
protected void	recordAsOutput(AppliedPTransform<?,?,?> transform, String outName) Records that this POutputValueBase is an output with the given name of the given AppliedPTransform in the given Pipeline.
PValueBase	setName(String name) Sets the name of this PValueBase.
String	toString()

Methods inherited from class org.apache.beam.sdk.values.POutputValueBase

finishSpecifyingOutput, getPipeline, getProducingTransformInternal

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.beam.sdk.values.PValue

getProducingTransformInternal

Methods inherited from interface org.apache.beam.sdk.values.POutput

finishSpecifyingOutput, getPipeline

Methods inherited from interface org.apache.beam.sdk.values.PInput

getPipeline

Constructor Detail

PValueBase

protected PValueBase(Pipeline pipeline)

PValueBase

protected PValueBase()

No-arg constructor for Java serialization only. The resulting PValueBase is unlikely to be valid.

Method Detail

getName

public String getName()

Returns the name of this PValueBase.

By default, the name of a PValueBase is based on the name of the PTransform that produces it. It can be specified explicitly by calling setName(java.lang.String).

Specified by:

getName in interface PValue

Throws:

IllegalStateException - if the name hasn't been set yet

setName

public PValueBase setName(String name)

Sets the name of this PValueBase. Returns this.

Throws:

IllegalStateException - if this PValueBase has already been finalized and may no longer be set.

recordAsOutput

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

Description copied from class: POutputValueBase

Records that this POutputValueBase is an output with the given name of the given AppliedPTransform.

To be invoked only by POutput.recordAsOutput(org.apache.beam.sdk.transforms.AppliedPTransform<?, ?, ?>) implementations. Not to be invoked directly by user code.

Specified by:

recordAsOutput in interface POutput

Overrides:

recordAsOutput in class POutputValueBase

recordAsOutput

protected void recordAsOutput(AppliedPTransform<?,?,?> transform,
                              String outName)

Records that this POutputValueBase is an output with the given name of the given AppliedPTransform in the given Pipeline.

To be invoked only by POutput.recordAsOutput(org.apache.beam.sdk.transforms.AppliedPTransform<?, ?, ?>) implementations. Not to be invoked directly by user code.

isFinishedSpecifyingInternal

public boolean isFinishedSpecifyingInternal()

Returns whether this PValueBase has been finalized, and its core properties, e.g., name, can no longer be changed.

For internal use only.

expand

public Collection<? extends PValue> expand()

Description copied from interface: POutput

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.

Specified by:

expand in interface PInput

Specified by:

expand in interface POutput

finishSpecifying

public void finishSpecifying()

Description copied from interface: PInput

After building, finalizes this PInput to make it ready for being used as an input to a PTransform.

Automatically invoked whenever apply() is invoked on this PInput, so users do not normally call this explicitly.

Specified by:

finishSpecifying in interface PInput

toString

public String toString()

Overrides:

toString in class Object

getKindString

protected String getKindString()

Returns a String capturing the kind of this PValueBase.

By default, uses the base name of the current class as its kind string.