StatefulWindowManager (Storm 2.7.1 API)

java.lang.Object
- org.apache.storm.windowing.WindowManager<T>
- - org.apache.storm.windowing.StatefulWindowManager<T>

All Implemented Interfaces:

TriggerHandler
```
public class StatefulWindowManager<T>
extends WindowManager<T>
```
Window manager that handles windows with state persistence.

Field Summary
- Fields inherited from class org.apache.storm.windowing.WindowManager
  evictionPolicy, EXPIRE_EVENTS_THRESHOLD, queue, triggerPolicy, windowLifecycleListener

Constructor Summary

Constructors
Constructor	Description
`StatefulWindowManager(WindowLifecycleListener<T> lifecycleListener)`
`StatefulWindowManager(WindowLifecycleListener<T> lifecycleListener, Collection<Event<T>> queue)`	Constructs a `StatefulWindowManager`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`compactWindow()`	expires events that fall out of the window every EXPIRE_EVENTS_THRESHOLD so that the window does not grow too big.
`boolean`	`onTrigger()`	The callback invoked by the trigger policy.

Methods inherited from class org.apache.storm.windowing.WindowManager
add, add, add, getEarliestEventTs, getEventCount, getSlidingCountTimestamps, getState, restoreState, setEvictionPolicy, setTriggerPolicy, shutdown, toString

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

- Constructor Detail
  - StatefulWindowManager
```
public StatefulWindowManager(WindowLifecycleListener<T> lifecycleListener)
```
  - StatefulWindowManager
```
public StatefulWindowManager(WindowLifecycleListener<T> lifecycleListener,
                             Collection<Event<T>> queue)
```
    Constructs a StatefulWindowManager.
    
    Parameters:
    
    lifecycleListener - the WindowLifecycleListener
    
    queue - a collection where the events in the window can be enqueued.
    Note: This collection has to be thread safe.
- Method Detail
  - compactWindow
```
protected void compactWindow()
```
    Description copied from class: WindowManager
    
    expires events that fall out of the window every EXPIRE_EVENTS_THRESHOLD so that the window does not grow too big.
    
    Overrides:
    
    compactWindow in class WindowManager<T>
  - onTrigger
```
public boolean onTrigger()
```
    Description copied from class: WindowManager
    
    The callback invoked by the trigger policy.
    
    Specified by:
    
    onTrigger in interface TriggerHandler
    
    Overrides:
    
    onTrigger in class WindowManager<T>
    
    Returns:
    
    true if the window was evaluated with at least one event in the window, false otherwise