org.apache.beam.sdk.transforms

Class DoFn.ProcessContext

java.lang.Object

org.apache.beam.sdk.transforms.DoFn.WindowedContext

org.apache.beam.sdk.transforms.DoFn.ProcessContext

Enclosing class:

DoFn<InputT,OutputT>

public abstract class DoFn.ProcessContext
extends DoFn.WindowedContext

Information accessible when running a DoFn.ProcessElement method.

Constructor Summary

Constructors

Constructor and Description
ProcessContext()

Method Summary

Modifier and Type	Method and Description
abstract InputT	element() Returns the input element to be processed.
abstract PaneInfo	pane() Returns information about the pane within this window into which the input element has been assigned.
abstract <T> T	sideInput(PCollectionView<T> view) Returns the value of the side input.
abstract Instant	timestamp() Returns the timestamp of the input element.
abstract void	updateWatermark(Instant watermark) Gives the runner a (best-effort) lower bound about the timestamps of future output associated with the current element.

Methods inherited from class org.apache.beam.sdk.transforms.DoFn.WindowedContext

getPipelineOptions, output, output, outputWithTimestamp, outputWithTimestamp

Methods inherited from class java.lang.Object

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

Constructor Detail

ProcessContext

public ProcessContext()

Method Detail

element

public abstract InputT element()

Returns the input element to be processed.

The element will not be changed -- it is safe to cache, etc. without copying. Implementation of DoFn.ProcessElement method should not mutate the element.

sideInput

public abstract <T> T sideInput(PCollectionView<T> view)

Returns the value of the side input.

Throws:

java.lang.IllegalArgumentException - if this is not a side input

See Also:

ParDo.SingleOutput.withSideInputs(org.apache.beam.sdk.values.PCollectionView<?>...)

timestamp

public abstract Instant timestamp()

Returns the timestamp of the input element.

See Window for more information.

pane

public abstract PaneInfo pane()

Returns information about the pane within this window into which the input element has been assigned.

Generally all data is in a single, uninteresting pane unless custom triggering and/or late data has been explicitly requested. See Window for more information.

updateWatermark

public abstract void updateWatermark(Instant watermark)

Gives the runner a (best-effort) lower bound about the timestamps of future output associated with the current element.

If the DoFn has multiple outputs, the watermark applies to all of them.

Only splittable DoFns are allowed to call this method. It is safe to call this method from a different thread than the one running DoFn.ProcessElement, but all calls must finish before DoFn.ProcessElement returns.