org.apache.beam.sdk.transforms

Class Impulse

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PBegin,PCollection<byte[]>>

org.apache.beam.sdk.transforms.Impulse

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

@Internal
public class Impulse
extends PTransform<PBegin,PCollection<byte[]>>

For internal use only; no backwards-compatibility guarantees.

A PTransform which produces a single empty byte array at the minimum timestamp in the GlobalWindow.

Users should instead use Create or another Read transform to begin consuming elements.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

annotations, displayData, name, resourceHints

Method Summary

Modifier and Type	Method and Description
static Impulse	create() Create a new Impulse PTransform.
PCollection<byte[]>	expand(PBegin input) Override this method to specify how this PTransform should be expanded on the given InputT.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

addAnnotation, compose, compose, getAdditionalInputs, getAnnotations, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, getResourceHints, populateDisplayData, setDisplayData, setResourceHints, toString, validate, validate

Methods inherited from class java.lang.Object

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

Method Detail

create

public static Impulse create()

Create a new Impulse PTransform.

expand

public PCollection<byte[]> expand(PBegin input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PBegin,PCollection<byte[]>>