org.apache.storm.windowing

Class WatermarkCountEvictionPolicy<T>

java.lang.Object

org.apache.storm.windowing.CountEvictionPolicy<T>

org.apache.storm.windowing.WatermarkCountEvictionPolicy<T>

All Implemented Interfaces:

EvictionPolicy<T>

public class WatermarkCountEvictionPolicy<T>
extends CountEvictionPolicy<T>

An eviction policy that tracks count based on watermark ts and evicts events up to the watermark based on a threshold count.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.storm.windowing.EvictionPolicy

EvictionPolicy.Action

Field Summary

Fields inherited from class org.apache.storm.windowing.CountEvictionPolicy

currentCount, threshold

Constructor Summary

Constructors

Constructor and Description
WatermarkCountEvictionPolicy(int count)

Method Summary

Modifier and Type	Method and Description
EvictionPolicy.Action	evict(org.apache.storm.windowing.Event<T> event) Decides if an event should be expired from the window, processed in the current window or kept for later processing.
void	setContext(EvictionContext context) Sets a context in the eviction policy that can be used while evicting the events.
String	toString()
void	track(org.apache.storm.windowing.Event<T> event) Tracks the event to later decide whether EvictionPolicy.evict(Event) should evict it or not.

Methods inherited from class java.lang.Object

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

Constructor Detail

WatermarkCountEvictionPolicy

public WatermarkCountEvictionPolicy(int count)

Method Detail

evict

public EvictionPolicy.Action evict(org.apache.storm.windowing.Event<T> event)

Description copied from interface: EvictionPolicy

Decides if an event should be expired from the window, processed in the current window or kept for later processing.

Specified by:

evict in interface EvictionPolicy<T>

Overrides:

evict in class CountEvictionPolicy<T>

Parameters:

event - the input event

Returns:

the EvictionPolicy.Action to be taken based on the input event

track

public void track(org.apache.storm.windowing.Event<T> event)

Description copied from interface: EvictionPolicy

Tracks the event to later decide whether EvictionPolicy.evict(Event) should evict it or not.

Specified by:

track in interface EvictionPolicy<T>

Overrides:

track in class CountEvictionPolicy<T>

Parameters:

event - the input event to be tracked

setContext

public void setContext(EvictionContext context)

Description copied from interface: EvictionPolicy

Sets a context in the eviction policy that can be used while evicting the events. E.g. For TimeEvictionPolicy, this could be used to set the reference timestamp.

Specified by:

setContext in interface EvictionPolicy<T>

Overrides:

setContext in class CountEvictionPolicy<T>

toString

public String toString()

Overrides:

toString in class CountEvictionPolicy<T>