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

Class AfterPane<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.AfterPane<W>

Type Parameters:

W - BoundedWindow subclass used to represent the windows used by this Trigger

All Implemented Interfaces:

TriggerBuilder<W>, Serializable

@Experimental(value=TRIGGER)
public class AfterPane<W extends BoundedWindow>
extends Trigger.OnceTrigger<W>

Triggers that fire based on properties of the elements in the current pane.

See Also:

Serialized Form

Nested Class Summary

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

Trigger.MergingTriggerInfo<W extends BoundedWindow>, Trigger.OnceTrigger<W extends BoundedWindow>, Trigger.OnElementContext, Trigger.OnMergeContext, Trigger.TriggerContext, Trigger.TriggerInfo<W extends BoundedWindow>

Field Summary

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

subTriggers

Method Summary

Modifier and Type	Method and Description
void	clear(Trigger.TriggerContext c) Clear any state associated with this trigger in the given window.
static <W extends BoundedWindow> AfterPane<W>	elementCountAtLeast(int countElems) Creates a trigger that fires when the pane contains at least countElems elements.
boolean	equals(Object obj)
Trigger.OnceTrigger<W>	getContinuationTrigger(List<Trigger<W>> continuationTriggers) Return the Trigger.getContinuationTrigger() of this Trigger.
Instant	getWatermarkThatGuaranteesFiring(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.
int	hashCode()
boolean	isCompatible(Trigger<?> other) Returns whether this performs the same triggering as the given Trigger.
void	onElement(Trigger.OnElementContext c) Called immediately after an element is first incorporated into a window.
void	onMerge(Trigger.OnMergeContext context) Called immediately after windows have been merged.
protected void	onOnlyFiring(Trigger.TriggerContext context) Called exactly once by Trigger.OnceTrigger.onFire(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.TriggerContext) when the trigger is fired.
void	prefetchOnMerge(com.google.cloud.dataflow.sdk.util.state.MergingStateAccessor<?,W> state) Called to allow the trigger to prefetch any state it will likely need to read from during an Trigger.onMerge(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.OnMergeContext) call.
void	prefetchShouldFire(com.google.cloud.dataflow.sdk.util.state.StateAccessor<?> state) Called to allow the trigger to prefetch any state it will likely need to read from during an Trigger.shouldFire(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.TriggerContext) call.
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()

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

getContinuationTrigger, onFire

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

buildTrigger, orFinally, prefetchOnElement, prefetchOnFire, subTriggers

Methods inherited from class java.lang.Object

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

Method Detail

elementCountAtLeast

public static <W extends BoundedWindow> AfterPane<W> elementCountAtLeast(int countElems)

Creates a trigger that fires when the pane contains at least countElems elements.

onElement

public void onElement(Trigger.OnElementContext c)
               throws 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>

Throws:

Exception

prefetchOnMerge

public void prefetchOnMerge(com.google.cloud.dataflow.sdk.util.state.MergingStateAccessor<?,W> state)

Description copied from class: Trigger

Called to allow the trigger to prefetch any state it will likely need to read from during an Trigger.onMerge(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.OnMergeContext) call.

Overrides:

prefetchOnMerge in class Trigger<W extends BoundedWindow>

onMerge

public void onMerge(Trigger.OnMergeContext context)
             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(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.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(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.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<W extends BoundedWindow>

Throws:

Exception

prefetchShouldFire

public void prefetchShouldFire(com.google.cloud.dataflow.sdk.util.state.StateAccessor<?> state)

Description copied from class: Trigger

Called to allow the trigger to prefetch any state it will likely need to read from during an Trigger.shouldFire(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.TriggerContext) call.

Overrides:

prefetchShouldFire in class Trigger<W extends BoundedWindow>

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<W extends BoundedWindow>

Throws:

Exception

clear

public void clear(Trigger.TriggerContext c)
           throws 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.

Overrides:

clear in class Trigger<W extends BoundedWindow>

Throws:

Exception

isCompatible

public boolean isCompatible(Trigger<?> other)

Description copied from class: Trigger

Returns whether this performs the same triggering as the given Trigger.

Overrides:

isCompatible in class Trigger<W extends BoundedWindow>

getWatermarkThatGuaranteesFiring

public Instant getWatermarkThatGuaranteesFiring(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.

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<W extends BoundedWindow>

getContinuationTrigger

public Trigger.OnceTrigger<W> getContinuationTrigger(List<Trigger<W>> 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<W extends BoundedWindow>

toString

public String toString()

Overrides:

toString in class Trigger<W extends BoundedWindow>

equals

public boolean equals(Object obj)

Overrides:

equals in class Trigger<W extends BoundedWindow>

hashCode

public int hashCode()

Overrides:

hashCode in class Trigger<W extends BoundedWindow>

onOnlyFiring

protected void onOnlyFiring(Trigger.TriggerContext context)
                     throws Exception

Description copied from class: Trigger.OnceTrigger

Called exactly once by Trigger.OnceTrigger.onFire(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.TriggerContext) when the trigger is fired. By default, invokes Trigger.OnceTrigger.onFire(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.TriggerContext) on all subtriggers for which Trigger.shouldFire(com.google.cloud.dataflow.sdk.transforms.windowing.Trigger<W>.TriggerContext) is true.

Specified by:

onOnlyFiring in class Trigger.OnceTrigger<W extends BoundedWindow>

Throws:

Exception