Arrow Resilience Kit/com.sorinirmies.arrow.resiliencekit/Cache

Cache

Thread-safe cache with TTL, eviction strategies, and statistics.

Provides a configurable in-memory cache with support for multiple eviction strategies (LRU, LFU, FIFO), time-to-live expiration, and hit/miss statistics.

Basic usage:

val cache = Cache.create<String, User>()
cache.put("user-1", User("Alice"))
val user = cache.get("user-1") // User("Alice")

With TTL and LRU eviction:

val cache = Cache.create<String, User>(config = CacheConfig(
    maxSize = 1000,
    ttl = 5.minutes,
    evictionStrategy = EvictionStrategy.LRU
))

Compute-if-absent:

val user = cache.getOrPut("user-1") {
    userRepository.findById("user-1")
}

Auto-loading cache:

val cache = LoadingCache.create<String, User>(
    config = CacheConfig(maxSize = 100)
) { key ->
    userRepository.findById(key)
}
val user = cache.get("user-1") // auto-loads on miss

DSL builder:

val cache = cache<String, User> {
    maxSize = 500
    ttl = 10.minutes
    evictionStrategy = EvictionStrategy.LFU
}

Parameters

config

Configuration for cache behavior

Type Parameters

Key type

Value type

Types

Companion

object Companion

Factory for Cache.

Functions

addListener

fun addListener(listener: CacheListener<K, V>)

Adds a listener for cache events.

cleanUp

suspend fun cleanUp(): Int

Removes all expired entries from the cache.

clear

suspend fun clear()

Removes all entries from the cache.

containsKey

suspend fun containsKey(key: K): Boolean

Checks if the cache contains a non-expired entry for the given key.

get

suspend fun get(key: K): V?

Gets a value from the cache by key.

getOrPut

suspend fun getOrPut(key: K, loader: suspend () -> V): V

Gets a cached value or computes and caches it if absent.

invalidate

suspend fun invalidate(key: K)

Invalidates a cache entry by key.

invalidateAll

suspend fun invalidateAll(keys: Iterable<K>)

Invalidates multiple cache entries.

keys

suspend fun keys(): Set<K>

Returns all non-expired keys in the cache.

put

suspend fun put(key: K, value: V)

Puts a value into the cache, evicting an entry if at capacity.

remove

suspend fun remove(key: K): V?

Removes an entry from the cache.

removeListener

fun removeListener(listener: CacheListener<K, V>)

Removes a previously added cache listener.

resetStatistics

suspend fun resetStatistics()

Resets all statistics counters to zero.

size

suspend fun size(): Int

Returns the total number of entries in the cache (including expired).

statistics

suspend fun statistics(): CacheStatistics

Returns a snapshot of the current cache statistics.

validKeys

suspend fun validKeys(): Set<K>

Returns all non-expired keys in the cache. Alias for keys.

validSize

suspend fun validSize(): Int

Returns the number of non-expired entries in the cache.