Package gw.util.concurrent

Enum Cache.ConcurrentLinkedHashMap.EvictionPolicy

java.lang.Object

java.lang.Enum<Cache.ConcurrentLinkedHashMap.EvictionPolicy>

gw.util.concurrent.Cache.ConcurrentLinkedHashMap.EvictionPolicy

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<Cache.ConcurrentLinkedHashMap.EvictionPolicy>

Enclosing class:

Cache.ConcurrentLinkedHashMap<K,V>

public static enum Cache.ConcurrentLinkedHashMap.EvictionPolicy
extends java.lang.Enum<Cache.ConcurrentLinkedHashMap.EvictionPolicy>

The replacement policy to apply to determine which entry to discard to when the capacity has been reached.

Enum Constant Summary

Enum Constants

Enum Constant	Description
FIFO	Evicts entries based on insertion order.
LRU	Evicts entries based on how recently they are used, with the least recent evicted first.
SECOND_CHANCE	Evicts entries based on insertion order, but gives an entry a "second chance" if it has been requested recently.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	EvictionPolicy()

Method Summary

Modifier and Type	Method	Description
(package private) abstract <K,V> boolean	onEvict(Cache.ConcurrentLinkedHashMap<K,V> map, Cache.ConcurrentLinkedHashMap.Node<K,V> node)	Determines whether to evict the node at the head of the list.
(package private) abstract <K,V> void	onGet(Cache.ConcurrentLinkedHashMap<K,V> map, Cache.ConcurrentLinkedHashMap.Node<K,V> node)	Performs any operations required by the policy after a node was successfully retrieved.
(package private) <K,V> void	onRemove(Cache.ConcurrentLinkedHashMap<K,V> map, Cache.ConcurrentLinkedHashMap.Node<K,V> node)	Expires a node so that, for all intents and purposes, it is a dead on the list.
static Cache.ConcurrentLinkedHashMap.EvictionPolicy	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static Cache.ConcurrentLinkedHashMap.EvictionPolicy[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

FIFO

public static final Cache.ConcurrentLinkedHashMap.EvictionPolicy FIFO

Evicts entries based on insertion order.

SECOND_CHANCE

public static final Cache.ConcurrentLinkedHashMap.EvictionPolicy SECOND_CHANCE

Evicts entries based on insertion order, but gives an entry a "second chance" if it has been requested recently.

LRU

public static final Cache.ConcurrentLinkedHashMap.EvictionPolicy LRU

Evicts entries based on how recently they are used, with the least recent evicted first.

Constructor Detail

EvictionPolicy

private EvictionPolicy()

Method Detail

values

public static Cache.ConcurrentLinkedHashMap.EvictionPolicy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Cache.ConcurrentLinkedHashMap.EvictionPolicy c : Cache.ConcurrentLinkedHashMap.EvictionPolicy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Cache.ConcurrentLinkedHashMap.EvictionPolicy valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

onGet

abstract <K,V> void onGet(Cache.ConcurrentLinkedHashMap<K,V> map,
                                Cache.ConcurrentLinkedHashMap.Node<K,V> node)

Performs any operations required by the policy after a node was successfully retrieved.

Parameters:

map - the map to for this listener

node - the specific node

onRemove

<K,V> void onRemove(Cache.ConcurrentLinkedHashMap<K,V> map,
                          Cache.ConcurrentLinkedHashMap.Node<K,V> node)

Expires a node so that, for all intents and purposes, it is a dead on the list. The caller of this method should have already removed the node from the mapping so that no key can look it up. When the node reaches the head of the list it will be evicted.

Parameters:

map - the map to for this listener

node - the specific node

onEvict

abstract <K,V> boolean onEvict(Cache.ConcurrentLinkedHashMap<K,V> map,
                                     Cache.ConcurrentLinkedHashMap.Node<K,V> node)

Determines whether to evict the node at the head of the list. If false, the node is offered to the tail.

Parameters:

map - the map to for this listener

node - the specific node

Returns:

whether this node is to be evicted