Type Parameters:: K - the type of keys | 键类型; V - the type of values | 值类型

public interface EvictionPolicy<K,V>

Eviction Policy SPI - Cache entry eviction strategy interface 淘汰策略 SPI - 缓存条目淘汰策略接口

Provides interface for selecting which entries to evict when cache is full.

提供当缓存已满时选择要淘汰哪些条目的接口。

Features | 主要功能:

LRU - Least Recently Used - 最近最少使用
LFU - Least Frequently Used - 最不经常使用
FIFO - First In First Out - 先进先出
W-TinyLFU - Window TinyLFU - 窗口 TinyLFU

Usage Examples | 使用示例:

// Use LRU policy - 使用 LRU 策略
EvictionPolicy<String, User> policy = EvictionPolicy.lru();

// Use W-TinyLFU for better hit rate - 使用 W-TinyLFU 获得更好的命中率
EvictionPolicy<String, User> policy = EvictionPolicy.wTinyLfu();

Security | 安全性:

Thread-safe: Implementation dependent - 线程安全: 取决于实现
Null-safe: Yes - 空值安全: 是

Since:

JDK 25, opencode-base-cache V1.0.0

Author:

Leon Soo www.LeonSoo.com

See Also:

Nested Class Summary

Nested Classes

Modifier and Type

Interface

Description

static final record

EvictionPolicy.WeightedPolicy<K,V>

Weighted policy wrapper 加权策略包装器
Method Summary

Modifier and Type

Method

Description

default EvictionPolicy<K,V>

and(EvictionPolicy<K,V> other)

Combine with another policy using AND logic (evict only if both suggest same victim) 使用 AND 逻辑与另一个策略组合（仅当两个策略建议相同候选时淘汰）

static <K,V> EvictionPolicy<K,V>

fifo()

Create FIFO (First In First Out) policy 创建 FIFO（先进先出）策略

static <K,V> EvictionPolicy<K,V>

lfu()

Create LFU (Least Frequently Used) policy 创建 LFU（最不经常使用）策略

static <K,V> EvictionPolicy<K,V>

lru()

Create LRU (Least Recently Used) policy 创建 LRU（最近最少使用）策略

void

onRemoval(K key)

Called when entry is removed 当条目被移除时调用

default EvictionPolicy<K,V>

or(EvictionPolicy<K,V> other)

Combine with another policy using OR logic (evict if either suggests eviction) 使用 OR 逻辑与另一个策略组合（任一策略建议淘汰则淘汰）

void

recordAccess(CacheEntry<K,V> entry)

Record access to an entry 记录条目访问

void

recordWrite(CacheEntry<K,V> entry)

Record write to an entry 记录条目写入

default void

reset()

Reset policy state 重置策略状态

Optional<K>

selectVictim(Map<K, CacheEntry<K,V>> entries)

Select victim entry to evict 选择要淘汰的条目

static <K,V> EvictionPolicy<K,V>

weighted(EvictionPolicy.WeightedPolicy<K,V>... policies)

Create a weighted composite of multiple policies 创建多个策略的加权组合

static <K,V> EvictionPolicy<K,V>

wTinyLfu()

Create W-TinyLFU (Window TinyLFU) policy with default expected size (10,000) 创建默认期望大小（10,000）的 W-TinyLFU（窗口 TinyLFU）策略

static <K,V> EvictionPolicy<K,V>

wTinyLfu(int expectedSize)

Create W-TinyLFU (Window TinyLFU) policy sized for the expected cache capacity.

Method Details
- recordAccess
  
  void recordAccess(CacheEntry<K,V> entry)
  
  Record access to an entry 记录条目访问
  
  Parameters:
  
  entry - the accessed entry | 被访问的条目
- recordWrite
  
  void recordWrite(CacheEntry<K,V> entry)
  
  Record write to an entry 记录条目写入
  
  Parameters:
  
  entry - the written entry | 被写入的条目
- selectVictim
  
  Optional<K> selectVictim(Map<K, CacheEntry<K,V>> entries)
  
  Select victim entry to evict 选择要淘汰的条目
  
  Parameters:
  
  entries - current cache entries | 当前缓存条目
  
  Returns:
  
  key of entry to evict | 要淘汰的条目的键
- onRemoval
  
  void onRemoval(K key)
  
  Called when entry is removed 当条目被移除时调用
  
  Parameters:
  
  key - the removed key | 被移除的键
- reset
  
  default void reset()
  
  Reset policy state 重置策略状态
- lru
  
  static <K,V> EvictionPolicy<K,V> lru()
  
  Create LRU (Least Recently Used) policy 创建 LRU（最近最少使用）策略
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Returns:
  
  LRU policy | LRU 策略
- lfu
  
  static <K,V> EvictionPolicy<K,V> lfu()
  
  Create LFU (Least Frequently Used) policy 创建 LFU（最不经常使用）策略
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Returns:
  
  LFU policy | LFU 策略
- fifo
  
  static <K,V> EvictionPolicy<K,V> fifo()
  
  Create FIFO (First In First Out) policy 创建 FIFO（先进先出）策略
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Returns:
  
  FIFO policy | FIFO 策略
- wTinyLfu
  
  static <K,V> EvictionPolicy<K,V> wTinyLfu()
  
  Create W-TinyLFU (Window TinyLFU) policy with default expected size (10,000) 创建默认期望大小（10,000）的 W-TinyLFU（窗口 TinyLFU）策略
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Returns:
  
  W-TinyLFU policy | W-TinyLFU 策略
- wTinyLfu
  
  static <K,V> EvictionPolicy<K,V> wTinyLfu(int expectedSize)
  
  Create W-TinyLFU (Window TinyLFU) policy sized for the expected cache capacity. 创建根据期望缓存容量调整大小的 W-TinyLFU（窗口 TinyLFU）策略。
  The internal Count-Min Sketch is sized proportionally to expectedSize to maintain a low collision rate. Use this overload when the cache maximum size is known in advance.
  
  内部 Count-Min Sketch 的大小与 expectedSize 成比例，以保持较低的碰撞率。当缓存最大大小事先已知时，使用此重载。
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Parameters:
  
  expectedSize - the expected maximum number of cache entries | 期望的缓存最大条目数
  
  Returns:
  
  W-TinyLFU policy | W-TinyLFU 策略
- or
  
  default EvictionPolicy<K,V> or(EvictionPolicy<K,V> other)
  
  Combine with another policy using OR logic (evict if either suggests eviction) 使用 OR 逻辑与另一个策略组合（任一策略建议淘汰则淘汰）
  The combined policy selects a victim if either policy returns one. Priority is given to this policy's selection.
  
  组合策略在任一策略返回候选时选择该候选。优先选择当前策略的选择。
  
  Parameters:
  
  other - the other policy | 另一个策略
  
  Returns:
  
  combined policy | 组合后的策略
- and
  
  default EvictionPolicy<K,V> and(EvictionPolicy<K,V> other)
  
  Combine with another policy using AND logic (evict only if both suggest same victim) 使用 AND 逻辑与另一个策略组合（仅当两个策略建议相同候选时淘汰）
  The combined policy only evicts if both policies agree on the same victim.
  
  组合策略仅在两个策略同意相同候选时淘汰。
  
  Parameters:
  
  other - the other policy | 另一个策略
  
  Returns:
  
  combined policy | 组合后的策略
- weighted
  
  @SafeVarargs static <K,V> EvictionPolicy<K,V> weighted(EvictionPolicy.WeightedPolicy<K,V>... policies)
  
  Create a weighted composite of multiple policies 创建多个策略的加权组合
  Scores each candidate by weighted vote from each policy.
  
  通过每个策略的加权投票对每个候选评分。
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Parameters:
  
  policies - policies with weights | 带权重的策略
  
  Returns:
  
  weighted composite policy | 加权组合策略

Interface EvictionPolicy<K,V>

Nested Class Summary

Method Summary

Method Details

recordAccess

recordWrite

selectVictim

onRemoval

reset

lru

lfu

fifo

wTinyLfu

wTinyLfu

or

and

weighted