java.lang.Object

cloud.opencode.base.cache.WriteBehindCache<K,V>

Type Parameters:

K - the type of keys | 键类型

V - the type of values | 值类型

Security | 安全性:

Thread-safe: Yes - 线程安全: 是
Null-safe: Partial (null values not allowed) - 空值安全: 部分（不允许 null 值）

All Implemented Interfaces:: Cache<K,V>, AutoCloseable

public class WriteBehindCache<K,V> extends Object implements Cache<K,V>, AutoCloseable

Write-Behind Cache - Asynchronous batch persistence cache wrapper 写后缓存 - 异步批量持久化缓存包装器

Implements the Write-Behind (Write-Back) caching pattern where writes are collected and asynchronously persisted in batches, reducing write latency and database load.

实现写后（写回）缓存模式，写入操作被收集并异步批量持久化，降低写入延迟和数据库负载。

Features | 主要功能:

Asynchronous batch writes - 异步批量写入
Write coalescing (multiple writes to same key) - 写合并
Configurable batch size and flush interval - 可配置批量大小和刷新间隔
Retry on write failure - 写入失败重试
Graceful shutdown with flush - 优雅关闭并刷新

Usage Examples | 使用示例:

// Create write-behind cache - 创建写后缓存
Cache<String, User> cache = OpenCache.getOrCreate("users");

WriteBehindCache<String, User> writeBehind = WriteBehindCache.builder(cache)
    .writer(users -> userRepository.saveAll(users))
    .batchSize(100)
    .flushInterval(Duration.ofSeconds(5))
    .maxRetries(3)
    .build();

// Writes are batched and persisted asynchronously
writeBehind.put("user:1", user1);
writeBehind.put("user:2", user2);

// Ensure all pending writes are flushed before shutdown
writeBehind.shutdown();

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

Class

Description

static interface

WriteBehindCache.BatchWriter<K,V>

Batch writer interface for persisting cache changes 批量写入器接口，用于持久化缓存变更

static class

WriteBehindCache.Builder<K,V>

Builder for WriteBehindCache WriteBehindCache 构建器

static final record

WriteBehindCache.WriteBehindStats

Write-behind statistics 写后统计信息

static final record

WriteBehindCache.WriteFailure<K,V>

Write failure information 写入失败信息
Method Summary

Modifier and Type

Method

Description

ConcurrentMap<K,V>

asMap()

Get a concurrent map view of this cache 获取 ConcurrentMap 视图

AsyncCache<K,V>

async()

Get async view of this cache 获取异步视图

static <K,V> WriteBehindCache.Builder<K,V>

builder(Cache<K,V> cache)

Create a builder for WriteBehindCache 创建 WriteBehindCache 构建器

void

cleanUp()

Perform cleanup (expired entries, etc.)

void

close()

boolean

containsKey(K key)

Check if key exists 检查键是否存在

Set<Map.Entry<K,V>>

entries()

Get snapshot of all entries 获取所有条目的快照

long

estimatedSize()

Get estimated entry count (fast) 获取估算条目数（快速）

void

flush()

Force flush all pending writes immediately 立即强制刷新所有待写入

V

get(K key)

Get value by key, returns null if not present 根据键获取值，不存在返回 null

V

get(K key, Function<? super K, ? extends V> loader)

Get value by key, load using loader if not present 根据键获取值，不存在时通过 loader 加载

Map<K,V>

getAll(Iterable<? extends K> keys)

Get all values for given keys, returns only existing entries 批量获取，仅返回存在的条目

Map<K,V>

getAll(Iterable<? extends K> keys, Function<? super Set<? extends K>, ? extends Map<K,V>> loader)

Get all values, load missing keys using loader 批量获取，缺失的键通过 loader 加载

void

invalidate(K key)

Invalidate a single key 使单个键失效

void

invalidateAll()

Invalidate all entries 清空所有缓存

void

invalidateAll(Iterable<? extends K> keys)

Invalidate multiple keys 批量失效

Set<K>

keys()

Get snapshot of all keys 获取所有键的快照

CacheMetrics

metrics()

Get detailed cache metrics with latency percentiles 获取带延迟百分位数的详细缓存指标

String

name()

Get cache name 获取缓存名称

long

pendingWriteCount()

Get count of pending writes 获取待写入数量

void

put(K key, V value)

Put a key-value pair into cache 放入键值对

void

putAll(Map<? extends K, ? extends V> map)

Put all key-value pairs into cache 批量放入

void

putAllWithTtl(Map<? extends K, ? extends V> map, Duration ttl)

Put all entries with custom TTL 批量放入并指定自定义 TTL

boolean

putIfAbsent(K key, V value)

Put if the key is absent, returns true if successful 不存在时放入，成功返回 true

boolean

putIfAbsentWithTtl(K key, V value, Duration ttl)

Put if absent with custom TTL 不存在时放入并指定自定义 TTL

void

putWithTtl(K key, V value, Duration ttl)

Put a key-value pair with custom TTL (overrides default expiration) 放入键值对并指定自定义 TTL（覆盖默认过期时间）

void

shutdown()

Shutdown the write-behind cache, flushing pending writes 关闭写后缓存，刷新待写入

void

shutdown(Duration timeout)

Shutdown with timeout 带超时关闭

long

size()

Get exact entry count (may be slow) 获取精确条目数（可能较慢）

CacheStats

stats()

Get cache statistics 获取缓存统计信息

Collection<V>

values()

Get snapshot of all values 获取所有值的快照

WriteBehindCache.WriteBehindStats

writeBehindStats()

Get write-behind statistics 获取写后统计信息

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface Cache
clear, compute, computeIfAbsent, computeIfMatch, computeIfPresent, containsValue, entryIterator, entryParallelStream, entryStream, forEach, forEachKey, forEachValue, getAndRemove, getByPattern, getIfPresent, getOptional, getOrDefault, getOrNull, invalidateByPattern, invalidateByValue, invalidateIf, isEmpty, keyIterator, keyParallelStream, keyStream, merge, putAllIfAbsent, putIfPresent, removeIfEquals, removeIfPresent, replace, replace, replaceAll, replaceIf, resetStats, updateAll, updateTtl, updateTtl, updateTtlAll, valueParallelStream, valueStream

Method Details
- builder
  
  public static <K,V> WriteBehindCache.Builder<K,V> builder(Cache<K,V> cache)
  
  Create a builder for WriteBehindCache 创建 WriteBehindCache 构建器
  
  Type Parameters:
  
  K - key type | 键类型
  
  V - value type | 值类型
  
  Parameters:
  
  cache - the underlying cache | 底层缓存
  
  Returns:
  
  builder | 构建器
- put
  
  public void put(K key, V value)
  
  Description copied from interface: Cache
  
  Put a key-value pair into cache 放入键值对
  
  Specified by:
  
  put in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  value - the value | 值
- putAll
  
  public void putAll(Map<? extends K, ? extends V> map)
  
  Description copied from interface: Cache
  
  Put all key-value pairs into cache 批量放入
  
  Specified by:
  
  putAll in interface Cache<K,V>
  
  Parameters:
  
  map - the key-value pairs | 键值对 Map
- putIfAbsent
  
  public boolean putIfAbsent(K key, V value)
  
  Description copied from interface: Cache
  
  Put if the key is absent, returns true if successful 不存在时放入，成功返回 true
  
  Specified by:
  
  putIfAbsent in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  value - the value | 值
  
  Returns:
  
  true if put successfully | 成功放入返回 true
- putWithTtl
  
  public void putWithTtl(K key, V value, Duration ttl)
  
  Description copied from interface: Cache
  
  Put a key-value pair with custom TTL (overrides default expiration) 放入键值对并指定自定义 TTL（覆盖默认过期时间）
  
  Specified by:
  
  putWithTtl in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  value - the value | 值
  
  ttl - the time-to-live for this entry | 此条目的存活时间
- putAllWithTtl
  
  public void putAllWithTtl(Map<? extends K, ? extends V> map, Duration ttl)
  
  Description copied from interface: Cache
  
  Put all entries with custom TTL 批量放入并指定自定义 TTL
  
  Specified by:
  
  putAllWithTtl in interface Cache<K,V>
  
  Parameters:
  
  map - the key-value pairs | 键值对 Map
  
  ttl - the time-to-live for all entries | 所有条目的存活时间
- putIfAbsentWithTtl
  
  public boolean putIfAbsentWithTtl(K key, V value, Duration ttl)
  
  Description copied from interface: Cache
  
  Put if absent with custom TTL 不存在时放入并指定自定义 TTL
  
  Specified by:
  
  putIfAbsentWithTtl in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  value - the value | 值
  
  ttl - the time-to-live | 存活时间
  
  Returns:
  
  true if put successfully | 成功放入返回 true
- invalidate
  
  public void invalidate(K key)
  
  Description copied from interface: Cache
  
  Invalidate a single key 使单个键失效
  
  Specified by:
  
  invalidate in interface Cache<K,V>
  
  Parameters:
  
  key - the key to invalidate | 要失效的键
- invalidateAll
  
  public void invalidateAll(Iterable<? extends K> keys)
  
  Description copied from interface: Cache
  
  Invalidate multiple keys 批量失效
  
  Specified by:
  
  invalidateAll in interface Cache<K,V>
  
  Parameters:
  
  keys - the keys to invalidate | 要失效的键集合
- invalidateAll
  
  public void invalidateAll()
  
  Description copied from interface: Cache
  
  Invalidate all entries 清空所有缓存
  
  Specified by:
  
  invalidateAll in interface Cache<K,V>
- get
  
  public V get(K key)
  
  Description copied from interface: Cache
  
  Get value by key, returns null if not present 根据键获取值，不存在返回 null
  
  Specified by:
  
  get in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  Returns:
  
  the value or null | 值或 null
- get
  
  public V get(K key, Function<? super K, ? extends V> loader)
  
  Description copied from interface: Cache
  
  Get value by key, load using loader if not present 根据键获取值，不存在时通过 loader 加载
  
  Specified by:
  
  get in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  loader - the loader function | 加载函数
  
  Returns:
  
  the value | 值
- getAll
  
  public Map<K,V> getAll(Iterable<? extends K> keys)
  
  Description copied from interface: Cache
  
  Get all values for given keys, returns only existing entries 批量获取，仅返回存在的条目
  
  Specified by:
  
  getAll in interface Cache<K,V>
  
  Parameters:
  
  keys - the keys | 键集合
  
  Returns:
  
  map of existing entries | 存在的条目 Map
- getAll
  
  public Map<K,V> getAll(Iterable<? extends K> keys, Function<? super Set<? extends K>, ? extends Map<K,V>> loader)
  
  Description copied from interface: Cache
  
  Get all values, load missing keys using loader 批量获取，缺失的键通过 loader 加载
  
  Specified by:
  
  getAll in interface Cache<K,V>
  
  Parameters:
  
  keys - the keys | 键集合
  
  loader - the batch loader function | 批量加载函数
  
  Returns:
  
  map of all entries | 所有条目 Map
- containsKey
  
  public boolean containsKey(K key)
  
  Description copied from interface: Cache
  
  Check if key exists 检查键是否存在
  
  Specified by:
  
  containsKey in interface Cache<K,V>
  
  Parameters:
  
  key - the key | 键
  
  Returns:
  
  true if exists | 存在返回 true
- size
  
  public long size()
  
  Description copied from interface: Cache
  
  Get exact entry count (may be slow) 获取精确条目数（可能较慢）
  
  Specified by:
  
  size in interface Cache<K,V>
  
  Returns:
  
  entry count | 条目数
- estimatedSize
  
  public long estimatedSize()
  
  Description copied from interface: Cache
  
  Get estimated entry count (fast) 获取估算条目数（快速）
  
  Specified by:
  
  estimatedSize in interface Cache<K,V>
  
  Returns:
  
  estimated count | 估算数量
- keys
  
  public Set<K> keys()
  
  Description copied from interface: Cache
  
  Get snapshot of all keys 获取所有键的快照
  
  Specified by:
  
  keys in interface Cache<K,V>
  
  Returns:
  
  set of keys | 键集合
- values
  
  public Collection<V> values()
  
  Description copied from interface: Cache
  
  Get snapshot of all values 获取所有值的快照
  
  Specified by:
  
  values in interface Cache<K,V>
  
  Returns:
  
  collection of values | 值集合
- entries
  
  public Set<Map.Entry<K,V>> entries()
  
  Description copied from interface: Cache
  
  Get snapshot of all entries 获取所有条目的快照
  
  Specified by:
  
  entries in interface Cache<K,V>
  
  Returns:
  
  set of entries | 条目集合
- asMap
  
  public ConcurrentMap<K,V> asMap()
  
  Description copied from interface: Cache
  
  Get a concurrent map view of this cache 获取 ConcurrentMap 视图
  
  Specified by:
  
  asMap in interface Cache<K,V>
  
  Returns:
  
  concurrent map view | ConcurrentMap 视图
- stats
  
  public CacheStats stats()
  
  Description copied from interface: Cache
  
  Get cache statistics 获取缓存统计信息
  
  Specified by:
  
  stats in interface Cache<K,V>
  
  Returns:
  
  cache statistics | 缓存统计
- metrics
  
  public CacheMetrics metrics()
  
  Description copied from interface: Cache
  
  Get detailed cache metrics with latency percentiles 获取带延迟百分位数的详细缓存指标
  
  Specified by:
  
  metrics in interface Cache<K,V>
  
  Returns:
  
  cache metrics or null if not enabled | 缓存指标，未启用则返回 null
- cleanUp
  
  public void cleanUp()
  
  Description copied from interface: Cache
  
  Perform cleanup (expired entries, etc.) 执行清理（过期条目等）
  
  Specified by:
  
  cleanUp in interface Cache<K,V>
- async
  
  public AsyncCache<K,V> async()
  
  Description copied from interface: Cache
  
  Get async view of this cache 获取异步视图
  
  Specified by:
  
  async in interface Cache<K,V>
  
  Returns:
  
  async cache view | 异步缓存视图
- name
  
  public String name()
  
  Description copied from interface: Cache
  
  Get cache name 获取缓存名称
  
  Specified by:
  
  name in interface Cache<K,V>
  
  Returns:
  
  cache name | 缓存名称
- pendingWriteCount
  
  public long pendingWriteCount()
  
  Get count of pending writes 获取待写入数量
  
  Returns:
  
  pending write count | 待写入数量
- flush
  
  public void flush()
  
  Force flush all pending writes immediately 立即强制刷新所有待写入
- writeBehindStats
  
  public WriteBehindCache.WriteBehindStats writeBehindStats()
  
  Get write-behind statistics 获取写后统计信息
  
  Returns:
  
  write-behind stats | 写后统计
- shutdown
  
  public void shutdown()
  
  Shutdown the write-behind cache, flushing pending writes 关闭写后缓存，刷新待写入
- shutdown
  
  public void shutdown(Duration timeout)
  
  Shutdown with timeout 带超时关闭
  
  Parameters:
  
  timeout - maximum wait time | 最大等待时间
- close
  
  public void close()
  
  Specified by:
  
  close in interface AutoCloseable

Class WriteBehindCache<K,V>

Nested Class Summary

Method Summary

Methods inherited from class Object

Methods inherited from interface Cache

Method Details

builder

put

putAll

putIfAbsent

putWithTtl

putAllWithTtl

putIfAbsentWithTtl

invalidate

invalidateAll

invalidateAll

get

get

getAll

getAll

containsKey

size

estimatedSize

keys

values

entries

asMap

stats

metrics

cleanUp

async

name

pendingWriteCount

flush

writeBehindStats

shutdown

shutdown

close