org.apache.storm.windowing

Interface TriggerPolicy<T,S>

Type Parameters:

T - the type of the event that is tracked

All Known Implementing Classes:

CountTriggerPolicy, TimeTriggerPolicy, WatermarkCountTriggerPolicy, WatermarkTimeTriggerPolicy

public interface TriggerPolicy<T,S>

Triggers the window calculations based on the policy.

Method Summary

Modifier and Type	Method and 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	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