org.apache.beam.sdk.transforms.windowing

Class AfterWatermark.FromEndOfWindow

java.lang.Object

org.apache.beam.sdk.transforms.windowing.Trigger

org.apache.beam.sdk.transforms.windowing.Trigger.OnceTrigger

org.apache.beam.sdk.transforms.windowing.AfterWatermark.FromEndOfWindow

All Implemented Interfaces:

Serializable

Enclosing class:

AfterWatermark

public static class AfterWatermark.FromEndOfWindow
extends Trigger.OnceTrigger

A watermark trigger targeted relative to the end of the window.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.beam.sdk.transforms.windowing.Trigger

Trigger.MergingTriggerInfo, Trigger.OnceTrigger, Trigger.OnElementContext, Trigger.OnMergeContext, Trigger.TriggerContext, Trigger.TriggerInfo

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.windowing.Trigger

subTriggers

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
AfterWatermark.FromEndOfWindow	getContinuationTrigger(List<Trigger> continuationTriggers) Return the Trigger.getContinuationTrigger() of this Trigger.
Instant	getWatermarkThatGuaranteesFiring(BoundedWindow 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.
int	hashCode()
void	onElement(Trigger.OnElementContext c) Called every time an element is incorporated into a window.
void	onMerge(Trigger.OnMergeContext c) Called immediately after windows have been merged.
protected void	onOnlyFiring(Trigger.TriggerContext context) Called exactly once by Trigger.OnceTrigger.onFire(org.apache.beam.sdk.transforms.windowing.Trigger.TriggerContext) when the trigger is fired.
boolean	shouldFire(Trigger.TriggerContext context) Returns true if the current state of the trigger indicates that its condition is satisfied and it is ready to fire.
String	toString()
AfterWatermark.AfterWatermarkEarlyAndLate	withEarlyFirings(Trigger.OnceTrigger earlyFirings) Creates a new Trigger like the this, except that it fires repeatedly whenever the given Trigger fires before the watermark has passed the end of the window.
AfterWatermark.AfterWatermarkEarlyAndLate	withLateFirings(Trigger.OnceTrigger lateFirings) Creates a new Trigger like the this, except that it fires repeatedly whenever the given Trigger fires after the watermark has passed the end of the window.

Methods inherited from class org.apache.beam.sdk.transforms.windowing.Trigger.OnceTrigger

getContinuationTrigger, onFire

Methods inherited from class org.apache.beam.sdk.transforms.windowing.Trigger

clear, isCompatible, orFinally, prefetchOnElement, prefetchOnFire, prefetchOnMerge, prefetchShouldFire, subTriggers

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

withEarlyFirings

public AfterWatermark.AfterWatermarkEarlyAndLate withEarlyFirings(Trigger.OnceTrigger earlyFirings)

Creates a new Trigger like the this, except that it fires repeatedly whenever the given Trigger fires before the watermark has passed the end of the window.

withLateFirings

public AfterWatermark.AfterWatermarkEarlyAndLate withLateFirings(Trigger.OnceTrigger lateFirings)

Creates a new Trigger like the this, except that it fires repeatedly whenever the given Trigger fires after the watermark has passed the end of the window.

onElement

public void onElement(Trigger.OnElementContext c)
               throws Exception

Description copied from class: Trigger

Called every time an element is incorporated into a window.

Specified by:

onElement in class Trigger

Throws:

Exception

onMerge

public void onMerge(Trigger.OnMergeContext c)
             throws Exception

Description copied from class: Trigger

Called immediately after windows have been merged.

Leaf triggers should update their state by inspecting their status and any state in the merging windows. Composite triggers should update their state by calling ExecutableTrigger.invokeOnMerge(org.apache.beam.sdk.transforms.windowing.Trigger.OnMergeContext) on their sub-triggers, and applying appropriate logic.

A trigger such as AfterWatermark.pastEndOfWindow() may no longer be finished; it is the responsibility of the trigger itself to record this fact. It is forbidden for a trigger to become finished due to Trigger.onMerge(org.apache.beam.sdk.transforms.windowing.Trigger.OnMergeContext), as it has not yet fired the pending elements that led to it being ready to fire.

The implementation does not need to clear out any state associated with the old windows.

Specified by:

onMerge in class Trigger

Throws:

Exception

getWatermarkThatGuaranteesFiring

public Instant getWatermarkThatGuaranteesFiring(BoundedWindow 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.

This estimate is used to determine that there are no elements in a side-input window, which causes the default value to be used instead.

Specified by:

getWatermarkThatGuaranteesFiring in class Trigger

getContinuationTrigger

public AfterWatermark.FromEndOfWindow getContinuationTrigger(List<Trigger> continuationTriggers)

Description copied from class: Trigger

Return the Trigger.getContinuationTrigger() of this Trigger. For convenience, this is provided the continuation trigger of each of the sub-triggers.

Specified by:

getContinuationTrigger in class Trigger

toString

public String toString()

Overrides:

toString in class Trigger

equals

public boolean equals(Object obj)

Overrides:

equals in class Trigger

hashCode

public int hashCode()

Overrides:

hashCode in class Trigger

shouldFire

public boolean shouldFire(Trigger.TriggerContext context)
                   throws Exception

Description copied from class: Trigger

Returns true if the current state of the trigger indicates that its condition is satisfied and it is ready to fire.

Specified by:

shouldFire in class Trigger

Throws:

Exception

onOnlyFiring

protected void onOnlyFiring(Trigger.TriggerContext context)
                     throws Exception

Description copied from class: Trigger.OnceTrigger

Called exactly once by Trigger.OnceTrigger.onFire(org.apache.beam.sdk.transforms.windowing.Trigger.TriggerContext) when the trigger is fired. By default, invokes Trigger.OnceTrigger.onFire(org.apache.beam.sdk.transforms.windowing.Trigger.TriggerContext) on all subtriggers for which Trigger.shouldFire(org.apache.beam.sdk.transforms.windowing.Trigger.TriggerContext) is true.

Specified by:

onOnlyFiring in class Trigger.OnceTrigger

Throws:

Exception