WatermarkCountTriggerPolicy (Heron Api Documentation)

java.lang.Object
- org.apache.heron.api.windowing.triggers.AbstractBaseTriggerPolicy<T,Long>
- - org.apache.heron.api.windowing.triggers.WatermarkCountTriggerPolicy<T>

Type Parameters:

T - the type of event tracked by this policy.

All Implemented Interfaces:

TriggerPolicy<T,Long>
```
public class WatermarkCountTriggerPolicy<T extends Serializable>
extends AbstractBaseTriggerPolicy<T,Long>
```
A trigger policy that tracks event counts and sets the context for eviction policy to evict based on latest watermark time.

Field Summary
- Fields inherited from class org.apache.heron.api.windowing.triggers.AbstractBaseTriggerPolicy
  evictionPolicy, handler, started, topoConf, windowManager

Constructor Summary

Constructors
Constructor Description

WatermarkCountTriggerPolicy(int count)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Long`	`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(Long state)`	Restore the trigger policy from the state that was earlier checkpointed by the framework.
`void`	`shutdown()`	Any clean up could be handled here.
`String`	`toString()`
`void`	`track(Event<T> event)`	Tracks the event and could use this to invoke the trigger.

Methods inherited from class org.apache.heron.api.windowing.triggers.AbstractBaseTriggerPolicy
setEvictionPolicy, setTopologyConfig, setTriggerHandler, setWindowManager, start

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - WatermarkCountTriggerPolicy
```
public WatermarkCountTriggerPolicy(int count)
```
- 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.
    
    Parameters:
    
    event - the input event
  - reset
```
public void reset()
```
    Description copied from interface: TriggerPolicy
    
    resets the trigger policy.
  - shutdown
```
public void shutdown()
```
    Description copied from interface: TriggerPolicy
    
    Any clean up could be handled here.
  - getState
```
public Long getState()
```
    Description copied from interface: TriggerPolicy
    
    Return runtime state to be checkpointed by the framework for restoring the trigger policy in case of failures.
    
    Returns:
    
    the state
  - restoreState
```
public void restoreState(Long state)
```
    Description copied from interface: TriggerPolicy
    
    Restore the trigger policy from the state that was earlier checkpointed by the framework.
    
    Parameters:
    
    state - the state
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object