com.google.cloud.dataflow.sdk.transforms

Class DoFn.ProcessContext

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.DoFn.Context

com.google.cloud.dataflow.sdk.transforms.DoFn.ProcessContext

Enclosing class:

DoFn<I,O>

public abstract class DoFn.ProcessContext
extends DoFn.Context

Information accessible when running DoFn.processElement(com.google.cloud.dataflow.sdk.transforms.DoFn<I, O>.ProcessContext).

Constructor Summary

Constructors

Constructor and Description
DoFn.ProcessContext()

Method Summary

Methods

Modifier and Type	Method and Description
abstract I	element() Returns the input element to be processed.
abstract DoFn.KeyedState	keyedState() Returns this DoFn's state associated with the input element's key.
abstract <T> T	sideInput(PCollectionView<T> view) Returns the value of the side input for the window corresponding to the window of the main input element.
abstract Instant	timestamp() Returns the timestamp of the input element.
abstract BoundedWindow	window() Returns the window into which the input element has been assigned.

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.DoFn.Context

createAggregator, createAggregator, getPipelineOptions, output, outputWithTimestamp, sideOutput, sideOutputWithTimestamp

Methods inherited from class java.lang.Object

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

Constructor Detail

DoFn.ProcessContext

public DoFn.ProcessContext()

Method Detail

element

public abstract I element()

Returns the input element to be processed.

sideInput

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

Returns the value of the side input for the window corresponding to the window of the main input element.

See WindowFn.getSideInputWindow(com.google.cloud.dataflow.sdk.transforms.windowing.BoundedWindow) for how this corresponding window is determined.

Throws:

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

See Also:

ParDo.withSideInputs(com.google.cloud.dataflow.sdk.values.PCollectionView<?>...)

keyedState

public abstract DoFn.KeyedState keyedState()

Returns this DoFn's state associated with the input element's key. This state can be used by the DoFn to store whatever information it likes with that key. Unlike DoFn instance variables, this state is persistent and can be arbitrarily large; it is more expensive than instance variable state, however. It is particularly intended for streaming computations.

Requires that this DoFn implements DoFn.RequiresKeyedState.

Each ParDo invocation with this DoFn as an argument will maintain its own KeyedState maps, one per key.

Throws:

java.lang.UnsupportedOperationException - if this DoFn does not implement DoFn.RequiresKeyedState.

timestamp

public abstract Instant timestamp()

Returns the timestamp of the input element.

See Window for more information.

window

public abstract BoundedWindow window()

Returns the window into which the input element has been assigned.

See Window for more information.

Throws:

java.lang.UnsupportedOperationException - if this DoFn does not implement DoFn.RequiresWindowAccess.