org.apache.storm.windowing

Class CountTriggerPolicy<T>

java.lang.Object

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

Type Parameters:

T - the type of event tracked by this policy.

All Implemented Interfaces:

TriggerPolicy<T,Integer>

public class CountTriggerPolicy<T>
extends Object
implements TriggerPolicy<T,Integer>

A trigger that tracks event counts and calls back TriggerHandler.onTrigger() when the count threshold is hit.

Constructor Summary

Constructors

Constructor and Description
CountTriggerPolicy(int count, TriggerHandler handler, EvictionPolicy<T,?> evictionPolicy)

Method Summary

Modifier and Type	Method and Description
Integer	getState() Return runtime state to be checkpointed by the framework for restoring the trigger policy in case of failures.
void	reset() resets the trigger policy.
void	restoreState(Integer state) Restore the trigger policy from the state that was earlier checkpointed by the framework.
void	shutdown() Any clean up could be handled here.
void	start() Starts the trigger policy.
String	toString()
void	track(Event<T> event) Tracks the event and could use this to invoke the trigger.

Methods inherited from class java.lang.Object

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

Constructor Detail

CountTriggerPolicy

public CountTriggerPolicy(int count,
                          TriggerHandler handler,
                          EvictionPolicy<T,?> evictionPolicy)

Method Detail

track

public void track(Event<T> event)

Description copied from interface: TriggerPolicy

Tracks the event and could use this to invoke the trigger.

Specified by:

track in interface TriggerPolicy<T,Integer>

Parameters:

event - the input event

reset

public void reset()

Description copied from interface: TriggerPolicy

resets the trigger policy.

Specified by:

reset in interface TriggerPolicy<T,Integer>

start

public void start()

Description copied from interface: TriggerPolicy

Starts the trigger policy. This can be used during recovery to start the triggers after recovery is complete.

Specified by:

start in interface TriggerPolicy<T,Integer>

shutdown

public void shutdown()

Description copied from interface: TriggerPolicy

Any clean up could be handled here.

Specified by:

shutdown in interface TriggerPolicy<T,Integer>

getState

public Integer getState()

Description copied from interface: TriggerPolicy

Return runtime state to be checkpointed by the framework for restoring the trigger policy in case of failures.

Specified by:

getState in interface TriggerPolicy<T,Integer>

Returns:

the state

restoreState

public void restoreState(Integer state)

Description copied from interface: TriggerPolicy

Restore the trigger policy from the state that was earlier checkpointed by the framework.

Specified by:

restoreState in interface TriggerPolicy<T,Integer>

Parameters:

state - the state

toString

public String toString()

Overrides:

toString in class Object