Package org.apache.flink.runtime.asyncprocessing.operators.windowing.triggers

Class AsyncCountTrigger<W extends Window>

java.lang.Object

org.apache.flink.runtime.asyncprocessing.operators.windowing.triggers.AsyncTrigger<Object,W>

org.apache.flink.runtime.asyncprocessing.operators.windowing.triggers.AsyncCountTrigger<W>

Type Parameters:

W - The type of Windows on which this trigger can operate.

All Implemented Interfaces:

Serializable

@Experimental
public class AsyncCountTrigger<W extends Window>
extends AsyncTrigger<Object,W>

A AsyncTrigger that fires once the count of elements in a pane reaches the given count. This is for async window operator.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.runtime.asyncprocessing.operators.windowing.triggers.AsyncTrigger

AsyncTrigger.OnMergeContext, AsyncTrigger.TriggerContext

Method Summary

Modifier and Type	Method	Description
boolean	canMerge()	Returns true if this trigger supports merging of trigger state and can therefore be used with a MergingWindowAssigner.
org.apache.flink.api.common.state.v2.StateFuture<Void>	clear(W window, AsyncTrigger.TriggerContext ctx)	Clears any state that the trigger might still hold for the given window.
static <W extends Window> AsyncCountTrigger<W>	of(long maxCount)	Creates a trigger that fires once the number of elements in a pane reaches the given count.
org.apache.flink.api.common.state.v2.StateFuture<TriggerResult>	onElement(Object element, long timestamp, W window, AsyncTrigger.TriggerContext ctx)	Called for every element that gets added to a pane.
org.apache.flink.api.common.state.v2.StateFuture<TriggerResult>	onEventTime(long time, W window, AsyncTrigger.TriggerContext ctx)	Called when an event-time timer that was set using the trigger context fires.
void	onMerge(W window, AsyncTrigger.OnMergeContext ctx)	Called when several windows have been merged into one window by the WindowAssigner.
org.apache.flink.api.common.state.v2.StateFuture<TriggerResult>	onProcessingTime(long time, W window, AsyncTrigger.TriggerContext ctx)	Called when a processing-time timer that was set using the trigger context fires.
String	toString()

Methods inherited from class org.apache.flink.runtime.asyncprocessing.operators.windowing.triggers.AsyncTrigger

isEndOfStreamTrigger

Methods inherited from class java.lang.Object

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

Method Details

onElement

public org.apache.flink.api.common.state.v2.StateFuture<TriggerResult> onElement(Object element,
 long timestamp,
 W window,
 AsyncTrigger.TriggerContext ctx)
                                                                          throws Exception

Description copied from class: AsyncTrigger

Called for every element that gets added to a pane. The result of this will determine whether the pane is evaluated to emit results.

Specified by:

onElement in class AsyncTrigger<Object,W extends Window>

Parameters:

element - The element that arrived.

timestamp - The timestamp of the element that arrived.

window - The window to which the element is being added.

ctx - A context object that can be used to register timer callbacks.

Throws:

Exception

onEventTime

public org.apache.flink.api.common.state.v2.StateFuture<TriggerResult> onEventTime(long time,
 W window,
 AsyncTrigger.TriggerContext ctx)

Description copied from class: AsyncTrigger

Called when an event-time timer that was set using the trigger context fires.

Specified by:

onEventTime in class AsyncTrigger<Object,W extends Window>

Parameters:

time - The timestamp at which the timer fired.

window - The window for which the timer fired.

ctx - A context object that can be used to register timer callbacks.

onProcessingTime

public org.apache.flink.api.common.state.v2.StateFuture<TriggerResult> onProcessingTime(long time,
 W window,
 AsyncTrigger.TriggerContext ctx)
                                                                                 throws Exception

Description copied from class: AsyncTrigger

Called when a processing-time timer that was set using the trigger context fires.

Specified by:

onProcessingTime in class AsyncTrigger<Object,W extends Window>

Parameters:

time - The timestamp at which the timer fired.

window - The window for which the timer fired.

ctx - A context object that can be used to register timer callbacks.

Throws:

Exception

clear

public org.apache.flink.api.common.state.v2.StateFuture<Void> clear(W window,
 AsyncTrigger.TriggerContext ctx)
                                                             throws Exception

Description copied from class: AsyncTrigger

Clears any state that the trigger might still hold for the given window. This is called when a window is purged. Timers set using AsyncTrigger.TriggerContext.registerEventTimeTimer(long) and AsyncTrigger.TriggerContext.registerProcessingTimeTimer(long) should be deleted here as well as state acquired using AsyncTrigger.TriggerContext.getPartitionedState(StateDescriptor).

Specified by:

clear in class AsyncTrigger<Object,W extends Window>

Throws:

Exception

canMerge

public boolean canMerge()

Description copied from class: AsyncTrigger

Returns true if this trigger supports merging of trigger state and can therefore be used with a MergingWindowAssigner.

If this returns true you must properly implement AsyncTrigger.onMerge(Window, OnMergeContext)

Overrides:

canMerge in class AsyncTrigger<Object,W extends Window>

onMerge

public void onMerge(W window,
 AsyncTrigger.OnMergeContext ctx)
             throws Exception

Description copied from class: AsyncTrigger

Called when several windows have been merged into one window by the WindowAssigner.

Overrides:

onMerge in class AsyncTrigger<Object,W extends Window>

Parameters:

window - The new window that results from the merge.

ctx - A context object that can be used to register timer callbacks and access state.

Throws:

Exception

toString

public String toString()

Overrides:

toString in class Object

of

public static <W extends Window>
AsyncCountTrigger<W> of(long maxCount)

Creates a trigger that fires once the number of elements in a pane reaches the given count.

Type Parameters:

W - The type of Windows on which this trigger can operate.

Parameters:

maxCount - The count of elements at which to fire.