Package org.apache.heron.api.windowing

Interface TriggerPolicy<T extends Serializable,S>

Type Parameters:

T - the type of the event that is tracked

S - the type of state that is used

All Known Implementing Classes:

AbstractBaseTriggerPolicy, CountTriggerPolicy, TimeTriggerPolicy, WatermarkCountTriggerPolicy, WatermarkTimeTriggerPolicy

public interface TriggerPolicy<T extends Serializable,S>

Triggers the window calculations based on the policy.

Method Summary

Modifier and Type	Method	Description
S	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(S state)	Restore the trigger policy from the state that was earlier checkpointed by the framework.
void	setEvictionPolicy(EvictionPolicy<T,?> evictionPolicy)	Set the eviction policy to whatever eviction policy to use this with
void	setTopologyConfig(Map<String,Object> config)	Sets the Config used for this topology
void	setTriggerHandler(TriggerHandler triggerHandler)	Set the trigger handler for this trigger policy to trigger
void	setWindowManager(WindowManager<T> windowManager)	Sets the window manager that uses this trigger policy
void	shutdown()	Any clean up could be handled here.
void	start()	Starts the trigger policy.
void	track(Event<T> event)	Tracks the event and could use this to invoke the trigger.

Method Detail

track

void track(Event<T> event)

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

Parameters:

event - the input event

reset

void reset()

resets the trigger policy.

start

void start()

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

shutdown

void shutdown()

Any clean up could be handled here.

getState

S getState()

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

Returns:

the state

restoreState

void restoreState(S state)

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

Parameters:

state - the state

setEvictionPolicy

void setEvictionPolicy(EvictionPolicy<T,?> evictionPolicy)

Set the eviction policy to whatever eviction policy to use this with

Parameters:

evictionPolicy - the eviction policy

setTriggerHandler

void setTriggerHandler(TriggerHandler triggerHandler)

Set the trigger handler for this trigger policy to trigger

Parameters:

triggerHandler - the trigger handler

setWindowManager

void setWindowManager(WindowManager<T> windowManager)

Sets the window manager that uses this trigger policy

Parameters:

windowManager - the window manager

setTopologyConfig

void setTopologyConfig(Map<String,Object> config)

Sets the Config used for this topology

Parameters:

config - the configuration policy