Class AsyncClaimingCacheImpl<K,V>

java.lang.Object

org.aksw.commons.cache.async.AsyncClaimingCacheImpl<K,V>

Type Parameters:

K -

V -

All Implemented Interfaces:

AsyncClaimingCache<K,V>

public class AsyncClaimingCacheImpl<K,V>
extends Object
implements AsyncClaimingCache<K,V>

Implementation of async claiming cache. Claimed entries will never be evicted. Conversely, unclaimed items remain are added to a cache such that timely re-claiming will be fast. Use cases: - Resource sharing: Ensure that the same resource is handed to all clients requesting one by key. - Resource pooling: Claimed resources will never be closed, but unclaimed resources (e.g. something backed by an input stream) may remain on standby for a while. Another way to view this class is as a mix of a map with weak values and a cache.

Author:

raven

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AsyncClaimingCacheImpl.Builder<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
protected BiConsumer<K, RefFuture<V>>	claimListener
protected LinkedList<Predicate<? super K>>	evictionGuards
protected com.github.benmanes.caffeine.cache.RemovalListener<K,V>	evictionListener
protected ReentrantReadWriteLock	invalidationLock
protected Map<K, org.aksw.commons.cache.async.AsyncClaimingCacheImpl.Latch>	keyToSynchronizer
protected Map<K, RefFuture<V>>	level1
protected com.github.benmanes.caffeine.cache.AsyncLoadingCache<K,V>	level2
protected Map<K,V>	level3
protected BiConsumer<K, RefFuture<V>>	unclaimListener

Constructor Summary

Constructors

Constructor	Description
AsyncClaimingCacheImpl(Map<K, RefFuture<V>> level1, com.github.benmanes.caffeine.cache.AsyncLoadingCache<K,V> level2, Map<K,V> level3, LinkedList<Predicate<? super K>> evictionGuards, BiConsumer<K, RefFuture<V>> claimListener, BiConsumer<K, RefFuture<V>> unclaimListener, com.github.benmanes.caffeine.cache.RemovalListener<K,V> evictionListener)

Method Summary

Modifier and Type	Method	Description
Disposable	addEvictionGuard(Predicate<? super K> predicate)	Registers a predicate that 'caches' entries about to be evicted When closing the registration then keys that have not moved back into the ache by reference will be immediately evicted.
RefFuture<V>	claim(K key)	Claim a reference to the key's entry.
RefFuture<V>	claimIfPresent(K key)	Claim a key only if it is already present.
void	invalidateAll()
static <K,V> AsyncClaimingCacheImpl.Builder<K,V>	newBuilder(com.github.benmanes.caffeine.cache.Caffeine<Object,Object> caffeine)
protected void	runLevel3Eviction()

Methods inherited from class Object

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

Field Details

level1

protected Map<K, RefFuture<V>> level1

level2

protected com.github.benmanes.caffeine.cache.AsyncLoadingCache<K,V> level2

level3

protected Map<K,V> level3

claimListener

protected BiConsumer<K, RefFuture<V>> claimListener

unclaimListener

protected BiConsumer<K, RefFuture<V>> unclaimListener

invalidationLock

protected ReentrantReadWriteLock invalidationLock

evictionGuards

protected LinkedList<Predicate<? super K>> evictionGuards

evictionListener

protected com.github.benmanes.caffeine.cache.RemovalListener<K,V> evictionListener

keyToSynchronizer

protected Map<K, org.aksw.commons.cache.async.AsyncClaimingCacheImpl.Latch> keyToSynchronizer

Constructor Details

AsyncClaimingCacheImpl

public AsyncClaimingCacheImpl(Map<K, RefFuture<V>> level1,
 com.github.benmanes.caffeine.cache.AsyncLoadingCache<K,V> level2,
 Map<K,V> level3,
 LinkedList<Predicate<? super K>> evictionGuards,
 BiConsumer<K, RefFuture<V>> claimListener,
 BiConsumer<K, RefFuture<V>> unclaimListener,
 com.github.benmanes.caffeine.cache.RemovalListener<K,V> evictionListener)

Method Details

addEvictionGuard

public Disposable addEvictionGuard(Predicate<? super K> predicate)

Registers a predicate that 'caches' entries about to be evicted When closing the registration then keys that have not moved back into the ache by reference will be immediately evicted.

Specified by:

addEvictionGuard in interface AsyncClaimingCache<K,V>

runLevel3Eviction

protected void runLevel3Eviction()

claim

public RefFuture<V> claim(K key)

Description copied from interface: AsyncClaimingCache

Claim a reference to the key's entry.

Specified by:

claim in interface AsyncClaimingCache<K,V>

Parameters:

key -

Returns:

newBuilder

public static <K,V>
AsyncClaimingCacheImpl.Builder<K,V> newBuilder(com.github.benmanes.caffeine.cache.Caffeine<Object,Object> caffeine)

claimIfPresent

public RefFuture<V> claimIfPresent(K key)

Claim a key only if it is already present. This implementation is a best effort approach: There is a very slim chance that just between testing a key for presence and claiming its entry an eviction occurs - causing claiming of a non-present key and thus triggering a load action.

Specified by:

claimIfPresent in interface AsyncClaimingCache<K,V>

invalidateAll

public void invalidateAll()

Specified by:

invalidateAll in interface AsyncClaimingCache<K,V>