cn.hutool.cache.impl

Class LFUCache<K,V>

java.lang.Object

cn.hutool.cache.impl.AbstractCache<K,V>

cn.hutool.cache.impl.StampedCache<K,V>

cn.hutool.cache.impl.LFUCache<K,V>

Type Parameters:

K - 键类型

V - 值类型

All Implemented Interfaces:

Cache<K,V>, Serializable, Iterable<V>

public class LFUCache<K,V>
extends StampedCache<K,V>

LFU(least frequently used) 最少使用率缓存
根据使用次数来判定对象是否被持续缓存
使用率是通过访问次数计算的。
当缓存满时清理过期对象。
清理后依旧满的情况下清除最少访问（访问计数最小）的对象并将其他对象的访问数减去这个最小访问数，以便新对象进入后可以公平计数。

Author:

Looly,jodd

See Also:

Serialized Form

Field Summary

Fields inherited from class cn.hutool.cache.impl.StampedCache

lock

Fields inherited from class cn.hutool.cache.impl.AbstractCache

cacheMap, capacity, existCustomTimeout, hitCount, keyLockMap, listener, missCount, timeout

Constructor Summary

Constructors

Constructor and Description
LFUCache(int capacity) 构造
LFUCache(int capacity, long timeout) 构造

Method Summary

Modifier and Type	Method and Description
protected int	pruneCache() 清理过期对象。

Methods inherited from class cn.hutool.cache.impl.StampedCache

cacheObjIterator, clear, containsKey, get, prune, put, remove

Methods inherited from class cn.hutool.cache.impl.AbstractCache

cacheObjIter, capacity, get, get, getHitCount, getMissCount, getWithoutLock, isEmpty, isFull, isPruneExpiredActive, iterator, keySet, onRemove, put, putWithoutLock, removeWithoutLock, setListener, size, timeout, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface cn.hutool.cache.Cache

get, get

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

LFUCache

public LFUCache(int capacity)

构造

Parameters:

capacity - 容量

LFUCache

public LFUCache(int capacity,
                long timeout)

构造

Parameters:

capacity - 容量

timeout - 过期时长

Method Detail

pruneCache

protected int pruneCache()

清理过期对象。
清理后依旧满的情况下清除最少访问（访问计数最小）的对象并将其他对象的访问数减去这个最小访问数，以便新对象进入后可以公平计数。

Specified by:

pruneCache in class AbstractCache<K,V>

Returns:

清理个数