org.ehcache.core.spi.store.tiering

Interface CachingTier<K,V>

Type Parameters:

K - the key type

V - the value type

All Superinterfaces:

ConfigurationChangeSupport

All Known Subinterfaces:

HigherCachingTier<K,V>

public interface CachingTier<K,V>
extends ConfigurationChangeSupport

Caching tier is the abstraction for tiers sitting atop the AuthoritativeTier.

As soon as there is more than one tier in a Store, one will be the AuthoritativeTier while others will be regrouped under the CachingTier

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	CachingTier.InvalidationListener<K,V> Caching tier invalidation listener.
static interface	CachingTier.Provider Service interface for providing CachingTier instances.

Method Summary

Modifier and Type	Method and Description
java.util.Map<K,Store.ValueHolder<V>>	bulkGetOrComputeIfAbsent(java.lang.Iterable<? extends K> keys, java.util.function.Function<java.util.Set<? extends K>,java.lang.Iterable<? extends java.util.Map.Entry<? extends K,? extends Store.ValueHolder<V>>>> mappingFunction) Bulk method which takes Set of keys as argument and returns a Map of its mapped value from CachingTier, For all the missing entries from CachingTier using mappingFunction to compute its value
void	clear() Empty out the caching tier.
Store.ValueHolder<V>	getOrComputeIfAbsent(K key, java.util.function.Function<K,Store.ValueHolder<V>> source) Either return the value holder currently in the caching tier, or compute and store it when it isn't present.
Store.ValueHolder<V>	getOrDefault(K key, java.util.function.Function<K,Store.ValueHolder<V>> source) Either return the value holder currently in the caching tier, or return the provided default.
void	invalidate(K key) Removes a mapping, triggering the CachingTier.InvalidationListener if registered.
void	invalidateAll() Empties the CachingTier, triggering the CachingTier.InvalidationListener if registered.
void	invalidateAllWithHash(long hash) Remove all mappings whose key have the specified hash code from the CachingTier, triggering the CachingTier.InvalidationListener if registered.
void	setInvalidationListener(CachingTier.InvalidationListener<K,V> invalidationListener) Set the caching tier's CachingTier.InvalidationListener.

Methods inherited from interface org.ehcache.core.spi.store.ConfigurationChangeSupport

getConfigurationChangeListeners

Method Detail

getOrComputeIfAbsent

Store.ValueHolder<V> getOrComputeIfAbsent(K key,
                                          java.util.function.Function<K,Store.ValueHolder<V>> source)
                                   throws StoreAccessException

Either return the value holder currently in the caching tier, or compute and store it when it isn't present.

Note that in case of expired value holders, null will be returned and the mapping will be invalidated.

Parameters:

key - the key

source - the function that computes the value when absent from this tier

Returns:

the value holder, or null

Throws:

StoreAccessException - if the mapping cannot be retrieved or stored

getOrDefault

Store.ValueHolder<V> getOrDefault(K key,
                                  java.util.function.Function<K,Store.ValueHolder<V>> source)
                           throws StoreAccessException

Either return the value holder currently in the caching tier, or return the provided default.

Note that in case of expired value holders, null will be returned and the mapping will be invalidated.

Parameters:

key - the key

source - the function that computes the default value when absent from this tier

Returns:

the value holder, or null

Throws:

StoreAccessException - if the mapping cannot be retrieved or stored

invalidate

void invalidate(K key)
         throws StoreAccessException

Removes a mapping, triggering the CachingTier.InvalidationListener if registered.

Parameters:

key - the key to remove

Throws:

StoreAccessException - if the mapping cannot be removed

invalidateAll

void invalidateAll()
            throws StoreAccessException

Empties the CachingTier, triggering the CachingTier.InvalidationListener if registered.

Throws:

StoreAccessException - if mappings cannot be removed

invalidateAllWithHash

void invalidateAllWithHash(long hash)
                    throws StoreAccessException

Remove all mappings whose key have the specified hash code from the CachingTier, triggering the CachingTier.InvalidationListener if registered.

Throws:

StoreAccessException - if mappings cannot be removed

clear

void clear()
    throws StoreAccessException

Empty out the caching tier.

Note that this operation is not atomic.

Throws:

StoreAccessException - if mappings cannot be removed

setInvalidationListener

void setInvalidationListener(CachingTier.InvalidationListener<K,V> invalidationListener)

Set the caching tier's CachingTier.InvalidationListener.

Parameters:

invalidationListener - the listener

bulkGetOrComputeIfAbsent

java.util.Map<K,Store.ValueHolder<V>> bulkGetOrComputeIfAbsent(java.lang.Iterable<? extends K> keys,
                                                               java.util.function.Function<java.util.Set<? extends K>,java.lang.Iterable<? extends java.util.Map.Entry<? extends K,? extends Store.ValueHolder<V>>>> mappingFunction)
                                                        throws StoreAccessException

Bulk method which takes Set of keys as argument and returns a Map of its mapped value from CachingTier, For all the missing entries from CachingTier using mappingFunction to compute its value

The function takes an Iterable of missing keys, where each entry's mapping is missing from CachingTier. It is expected that the function should return an Iterable of Map.Entry key/value pairs containing an entry for each key that was passed to it.

Note: This method guarantees atomicity of computations for each individual key in keys. Implementations may choose to provide coarser grained atomicity.

Parameters:

keys - the keys to compute a new value for, if they're not in the store.

mappingFunction - the function that generates new values.

Returns:

a Map of key/value pairs for each key in keys.

Throws:

StoreAccessException - when a failure occurs when accessing the store.