com.google.cloud.dataflow.sdk.transforms.windowing

Class AfterProcessingTime<W extends BoundedWindow>

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>

com.google.cloud.dataflow.sdk.transforms.windowing.Trigger.OnceTrigger<W>

com.google.cloud.dataflow.sdk.transforms.windowing.TimeTrigger<W,AfterProcessingTime<W>>

com.google.cloud.dataflow.sdk.transforms.windowing.AfterProcessingTime<W>

Type Parameters:

W - BoundedWindow subclass used to represent the windows used

All Implemented Interfaces:

java.io.Serializable

@Experimental(value=TRIGGER)
public class AfterProcessingTime<W extends BoundedWindow>
extends TimeTrigger<W,AfterProcessingTime<W>>

AfterProcessingTime triggers fire based on the current processing time. They operate in the real-time domain.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.google.cloud.dataflow.sdk.transforms.windowing.Trigger

Trigger.OnceTrigger<W extends BoundedWindow>, Trigger.OnElementEvent<W>, Trigger.OnMergeEvent<W>, Trigger.OnTimerEvent<W extends BoundedWindow>, Trigger.TimeDomain, Trigger.TriggerContext<W extends BoundedWindow>, Trigger.TriggerId<W extends BoundedWindow>, Trigger.TriggerResult, Trigger.WindowStatus

Field Summary

Fields inherited from class com.google.cloud.dataflow.sdk.transforms.windowing.TimeTrigger

IDENTITY

Method Summary

Methods

Modifier and Type	Method and Description
void	clear(Trigger.TriggerContext<W> c, W window) Clear any state associated with this trigger in the given window.
Instant	getWatermarkCutoff(W window) Returns a bound in watermark time by which this trigger would have fired at least once for a given window had there been input data.
protected AfterProcessingTime<W>	newWith(com.google.common.collect.ImmutableList<SerializableFunction<Instant,Instant>> transforms) Method to create an updated version of this TimeTrigger modified to use the specified transform.
Trigger.TriggerResult	onElement(Trigger.TriggerContext<W> c, Trigger.OnElementEvent<W> e) Called immediately after an element is first incorporated into a window.
Trigger.TriggerResult	onMerge(Trigger.TriggerContext<W> c, Trigger.OnMergeEvent<W> e) Called immediately after windows have been merged.
Trigger.TriggerResult	onTimer(Trigger.TriggerContext<W> c, Trigger.OnTimerEvent<W> e) Called when a timer has fired for the trigger or one of it’s sub-triggers.
static <W extends BoundedWindow> AfterProcessingTime<W>	pastFirstElementInPane() Creates a trigger that fires when the current processing time passes the processing time at which this trigger saw the first element in a pane.
boolean	willNeverFinish() Return true if the trigger is guaranteed to never finish.

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.windowing.TimeTrigger

alignedTo, alignedTo, computeTargetTimestamp, isCompatible, mappedTo, plusDelayOf

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.windowing.Trigger

orFinally

Methods inherited from class java.lang.Object

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

Method Detail

pastFirstElementInPane

public static <W extends BoundedWindow> AfterProcessingTime<W> pastFirstElementInPane()

Creates a trigger that fires when the current processing time passes the processing time at which this trigger saw the first element in a pane.

newWith

protected AfterProcessingTime<W> newWith(com.google.common.collect.ImmutableList<SerializableFunction<Instant,Instant>> transforms)

Description copied from class: TimeTrigger

Method to create an updated version of this TimeTrigger modified to use the specified transform.

Specified by:

newWith in class TimeTrigger<W extends BoundedWindow,AfterProcessingTime<W extends BoundedWindow>>

Parameters:

transforms - The new transform to apply to target times.

Returns:

a new TimeTrigger.

onElement

public Trigger.TriggerResult onElement(Trigger.TriggerContext<W> c,
                              Trigger.OnElementEvent<W> e)
                                throws java.lang.Exception

Description copied from class: Trigger

Called immediately after an element is first incorporated into a window.

Specified by:

onElement in class Trigger<W extends BoundedWindow>

Parameters:

c - the context to interact with

e - an event describing the cause of this callback being executed

Throws:

java.lang.Exception

onMerge

public Trigger.TriggerResult onMerge(Trigger.TriggerContext<W> c,
                            Trigger.OnMergeEvent<W> e)
                              throws java.lang.Exception

Description copied from class: Trigger

Called immediately after windows have been merged.

This will only be called if the trigger hasn't finished in any of the oldWindows. If it had finished, we assume that it is also finished in the resulting window.

The implementation does not need to clear out any state associated with the old windows. That will automatically be done by the trigger execution layer.

Specified by:

onMerge in class Trigger<W extends BoundedWindow>

Parameters:

c - the context to interact with

e - an event describnig the cause of this callback being executed

Throws:

java.lang.Exception

onTimer

public Trigger.TriggerResult onTimer(Trigger.TriggerContext<W> c,
                            Trigger.OnTimerEvent<W> e)
                              throws java.lang.Exception

Description copied from class: Trigger

Called when a timer has fired for the trigger or one of it’s sub-triggers.

Specified by:

onTimer in class Trigger<W extends BoundedWindow>

Parameters:

c - the context to interact with

e - identifier for the trigger that the timer is for.

Throws:

java.lang.Exception

clear

public void clear(Trigger.TriggerContext<W> c,
         W window)
           throws java.lang.Exception

Description copied from class: Trigger

Clear any state associated with this trigger in the given window.

This is called after a trigger has indicated it will never fire again. The trigger system keeps enough information to know that the trigger is finished, so this trigger should clear all of its state.

Specified by:

clear in class Trigger<W extends BoundedWindow>

Parameters:

c - the context to interact with

window - the window that is being cleared

Throws:

java.lang.Exception

willNeverFinish

public boolean willNeverFinish()

Description copied from class: Trigger

Return true if the trigger is guaranteed to never finish.

Overrides:

willNeverFinish in class Trigger<W extends BoundedWindow>

getWatermarkCutoff

public Instant getWatermarkCutoff(W window)

Description copied from class: Trigger

Returns a bound in watermark time by which this trigger would have fired at least once for a given window had there been input data. This is a static property of a trigger that does not depend on its state.

For triggers that do not fire based on the watermark advancing, returns BoundedWindow.TIMESTAMP_MAX_VALUE.

Specified by:

getWatermarkCutoff in class Trigger<W extends BoundedWindow>