net.openhft.chronicle.map

Class MapEventListener<K,V,M extends ChronicleMap<K,V>>

java.lang.Object

net.openhft.chronicle.map.MapEventListener<K,V,M>

Type Parameters:

K - key type of the maps, trackable by this event listener

V - value type of the maps, trackable by this event listener

M - ChronicleMap subtype, trackable by this event listener

All Implemented Interfaces:

Serializable

public abstract class MapEventListener<K,V,M extends ChronicleMap<K,V>>
extends Object
implements Serializable

Contains methods which are called when ChronicleMap key events occur. Typical use cases:

• Map data backup / replication.
• Logging, monitoring, debugging.

This is an adapter class - all methods have default implementations as no-ops. Extend this class and override only methods corresponding the events you are interested in.

To configure MapEventListener for ChronicleMap, use AbstractChronicleMapBuilder.eventListener(MapEventListener) method.

MapEventListeners uninstantiable class contains several logging implementations and the default no-op implementation.

All these calls are synchronous while a ChronicleMap lock is held so make them as quick as possible.

The entry passed to the methods is Bytes instance positioned at meta data area. See ChronicleHashBuilder.metaDataBytes(int) for more information.

See Also:

AbstractChronicleMapBuilder.eventListener(MapEventListener), MapEventListeners, Serialized Form

Constructor Summary

Constructors

Constructor and Description
MapEventListener()

Method Summary

Methods

Modifier and Type	Method and Description
void	onGetFound(M map, Bytes entry, int metaDataBytes, K key, V value) This method is called if the key is found in the map during get, getUsing or acquireUsing method call.
void	onPut(M map, Bytes entry, int metaDataBytes, boolean added, K key, V value, V replacedValue) This method is called whenever a new value is put for the key in the map during calls of such methods as put, putIfAbsent, replace, etc.
void	onRemove(M map, Bytes entry, int metaDataBytes, K key, V value) This is called when an entry is removed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MapEventListener

public MapEventListener()

Method Detail

onGetFound

public void onGetFound(M map,
              Bytes entry,
              int metaDataBytes,
              K key,
              V value)

This method is called if the key is found in the map during get, getUsing or acquireUsing method call.

Parameters:

map - the accessed map

entry - bytes of the entry

metaDataBytes - length of meta data for this map

key - the key looked up

value - the value found for the key

onPut

public void onPut(M map,
         Bytes entry,
         int metaDataBytes,
         boolean added,
         K key,
         V value,
         @Nullable
         V replacedValue)

This method is called whenever a new value is put for the key in the map during calls of such methods as put, putIfAbsent, replace, etc. When a new value is default for the map or obtained during acquireUsing call is put for the key, this method is called as well.

This method is called when put is already happened.

Parameters:

map - the accessed map

entry - bytes of the entry (with the value already written to)

metaDataBytes - length of meta data for this map

added - true is the key was absent in the map before current ChronicleMap method call, led to putting a value and inherently calling this listener method

key - the key the given value is put for

value - the value which is now associated with the given key

replacedValue - the value which was replaced by value, is NULL if added is true

onRemove

public void onRemove(M map,
            Bytes entry,
            int metaDataBytes,
            K key,
            V value)

This is called when an entry is removed. Misses, i. e. when map.remove(key) is called, but key is already absent in the map, are not notified.

Parameters:

map - accessed

entry - bytes of the entry just removed, but any data is not yet erased

metaDataBytes - length of meta data for this map

key - the key removed from the map

value - the value which was associated with the given key