public class CountEvictionPolicy<T> extends Object implements EvictionPolicy<T,Long>
An eviction policy that tracks event counts and can evict based on a threshold count.
EvictionPolicy.Action| Modifier and Type | Field and Description |
|---|---|
protected AtomicLong |
currentCount |
protected int |
threshold |
| Constructor and Description |
|---|
CountEvictionPolicy(int count) |
| Modifier and Type | Method and Description |
|---|---|
EvictionPolicy.Action |
evict(Event<T> event)
Decides if an event should be expired from the window, processed in the current window or kept for later processing.
|
EvictionContext |
getContext()
Returns the current context that is part of this eviction policy.
|
Long |
getState()
Return runtime state to be checkpointed by the framework for restoring the eviction policy in case of failures.
|
void |
reset()
Resets the eviction policy.
|
void |
restoreState(Long state)
Restore the eviction policy from the state that was earlier checkpointed by the framework.
|
void |
setContext(EvictionContext context)
Sets a context in the eviction policy that can be used while evicting the events.
|
String |
toString() |
void |
track(Event<T> event)
Tracks the event to later decide whether
EvictionPolicy.evict(Event) should evict it or not. |
protected final int threshold
protected final AtomicLong currentCount
public EvictionPolicy.Action evict(Event<T> event)
EvictionPolicyDecides if an event should be expired from the window, processed in the current window or kept for later processing.
evict in interface EvictionPolicy<T,Long>event - the input eventEvictionPolicy.Action to be taken based on the input eventpublic void track(Event<T> event)
EvictionPolicyTracks the event to later decide whether EvictionPolicy.evict(Event) should evict it or not.
track in interface EvictionPolicy<T,Long>event - the input event to be trackedpublic EvictionContext getContext()
EvictionPolicyReturns the current context that is part of this eviction policy.
getContext in interface EvictionPolicy<T,Long>public void setContext(EvictionContext context)
EvictionPolicySets a context in the eviction policy that can be used while evicting the events. E.g. For TimeEvictionPolicy, this could be used to set the reference timestamp.
setContext in interface EvictionPolicy<T,Long>context - the eviction contextpublic void reset()
EvictionPolicyResets the eviction policy.
reset in interface EvictionPolicy<T,Long>public Long getState()
EvictionPolicyReturn runtime state to be checkpointed by the framework for restoring the eviction policy in case of failures.
getState in interface EvictionPolicy<T,Long>public void restoreState(Long state)
EvictionPolicyRestore the eviction policy from the state that was earlier checkpointed by the framework.
restoreState in interface EvictionPolicy<T,Long>state - the stateCopyright © 2022 The Apache Software Foundation. All rights reserved.