Package org.apache.flink.streaming.api.windowing.evictors

Class DeltaEvictor<T,W extends Window>

java.lang.Object

org.apache.flink.streaming.api.windowing.evictors.DeltaEvictor<T,W>

Type Parameters:

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

All Implemented Interfaces:

Serializable, Evictor<T,W>

@PublicEvolving
public class DeltaEvictor<T,W extends Window>
extends Object
implements Evictor<T,W>

An Evictor that keeps elements based on a DeltaFunction and a threshold.

Eviction starts from the first element of the buffer and removes all elements from the buffer which have a higher delta then the threshold.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.streaming.api.windowing.evictors.Evictor

Evictor.EvictorContext

Method Summary

Modifier and Type	Method	Description
void	evictAfter(Iterable<TimestampedValue<T>> elements, int size, W window, Evictor.EvictorContext ctx)	Optionally evicts elements.
void	evictBefore(Iterable<TimestampedValue<T>> elements, int size, W window, Evictor.EvictorContext ctx)	Optionally evicts elements.
static <T,W extends Window> DeltaEvictor<T,W>	of(double threshold, DeltaFunction<T> deltaFunction)	Creates a DeltaEvictor from the given threshold and DeltaFunction.
static <T,W extends Window> DeltaEvictor<T,W>	of(double threshold, DeltaFunction<T> deltaFunction, boolean doEvictAfter)	Creates a DeltaEvictor from the given threshold, DeltaFunction.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

evictBefore

public void evictBefore(Iterable<TimestampedValue<T>> elements,
                        int size,
                        W window,
                        Evictor.EvictorContext ctx)

Description copied from interface: Evictor

Optionally evicts elements. Called before windowing function.

Specified by:

evictBefore in interface Evictor<T,W extends Window>

Parameters:

elements - The elements currently in the pane.

size - The current number of elements in the pane.

window - The Window

ctx - The context for the Evictor

evictAfter

public void evictAfter(Iterable<TimestampedValue<T>> elements,
                       int size,
                       W window,
                       Evictor.EvictorContext ctx)

Description copied from interface: Evictor

Optionally evicts elements. Called after windowing function.

Specified by:

evictAfter in interface Evictor<T,W extends Window>

Parameters:

elements - The elements currently in the pane.

size - The current number of elements in the pane.

window - The Window

ctx - The context for the Evictor

toString

public String toString()

Overrides:

toString in class Object

of

public static <T,W extends Window> DeltaEvictor<T,W> of(double threshold,
                                                                    DeltaFunction<T> deltaFunction)

Creates a DeltaEvictor from the given threshold and DeltaFunction. Eviction is done before the window function.

Parameters:

threshold - The threshold

deltaFunction - The DeltaFunction

of

public static <T,W extends Window> DeltaEvictor<T,W> of(double threshold,
                                                                    DeltaFunction<T> deltaFunction,
                                                                    boolean doEvictAfter)

Creates a DeltaEvictor from the given threshold, DeltaFunction. Eviction is done before/after the window function based on the value of doEvictAfter.

Parameters:

threshold - The threshold

deltaFunction - The DeltaFunction

doEvictAfter - Whether eviction should be done after window function