io.lettuce.core.support.caching

Class ClientSideCaching<K,V>

java.lang.Object

io.lettuce.core.support.caching.ClientSideCaching<K,V>

Type Parameters:

K - Key type.

V - Value type.

All Implemented Interfaces:

CacheFrontend<K,V>, Closeable, AutoCloseable

public class ClientSideCaching<K,V>
extends Object
implements CacheFrontend<K,V>

Utility to provide server-side assistance for client-side caches. This is a CacheFrontend that represents a two-level cache backed by a client-side and a Redis cache. For example:

 Map clientCache = new ConcurrentHashMap<>();

 StatefulRedisConnection<String, String> connection = redisClient.connect();

 CacheFrontend<String, String> frontend = ClientSideCaching.enable(CacheAccessor.forMap(clientCache), connection,
         TrackingArgs.Builder.enabled());

 String value = frontend.get(key);
 

Since:

6.0

Author:

Mark Paluch

Nested Class Summary

Nested classes/interfaces inherited from interface io.lettuce.core.support.caching.CacheFrontend

CacheFrontend.ValueRetrievalException

Method Summary

Modifier and Type	Method and Description
void	addInvalidationListener(Consumer<K> invalidationListener)
void	close() Closes this cache frontend and releases any system resources associated with it.
static <K,V> CacheFrontend<K,V>	create(CacheAccessor<K,V> cacheAccessor, StatefulRedisConnection<K,V> connection) Create a server-assisted Client side caching for the given CacheAccessor and StatefulRedisConnection.
static <K,V> CacheFrontend<K,V>	enable(CacheAccessor<K,V> cacheAccessor, StatefulRedisConnection<K,V> connection, TrackingArgs tracking) Enable server-assisted Client side caching for the given CacheAccessor and StatefulRedisConnection.
V	get(K key) Return the value to which this cache maps the specified key.
V	get(K key, Callable<V> valueLoader) Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary.

Methods inherited from class java.lang.Object

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

Method Detail

enable

public static <K,V> CacheFrontend<K,V> enable(CacheAccessor<K,V> cacheAccessor,
                                              StatefulRedisConnection<K,V> connection,
                                              TrackingArgs tracking)

Enable server-assisted Client side caching for the given CacheAccessor and StatefulRedisConnection.

Note that the CacheFrontend is associated with a Redis connection. Make sure to close the frontend object to release the Redis connection after use.

Type Parameters:

K - Key type.

V - Value type.

Parameters:

cacheAccessor - the accessor used to interact with the client-side cache.

connection - the Redis connection to use. The connection will be associated with CacheFrontend and must be closed through CacheFrontend.close().

tracking - the tracking parameters.

Returns:

the CacheFrontend for value retrieval.

create

public static <K,V> CacheFrontend<K,V> create(CacheAccessor<K,V> cacheAccessor,
                                              StatefulRedisConnection<K,V> connection)

Create a server-assisted Client side caching for the given CacheAccessor and StatefulRedisConnection. This method expects that client key tracking is already configured.

Note that the CacheFrontend is associated with a Redis connection. Make sure to close the frontend object to release the Redis connection after use.

Type Parameters:

K - Key type.

V - Value type.

Parameters:

cacheAccessor - the accessor used to interact with the client-side cache.

connection - the Redis connection to use. The connection will be associated with CacheFrontend and must be closed through CacheFrontend.close().

Returns:

the CacheFrontend for value retrieval.

close

public void close()

Description copied from interface: CacheFrontend

Closes this cache frontend and releases any system resources associated with it. If the frontend is already closed then invoking this method has no effect.

Specified by:

close in interface CacheFrontend<K,V>

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

addInvalidationListener

public void addInvalidationListener(Consumer<K> invalidationListener)

get

public V get(K key)

Description copied from interface: CacheFrontend

Return the value to which this cache maps the specified key.

Note: This method does not allow for differentiating between a cached null value and no cache entry found at all.

Specified by:

get in interface CacheFrontend<K,V>

Parameters:

key - the key whose associated value is to be returned.

Returns:

the value to which this cache maps the specified key (which may be null itself), or also null if the cache contains no mapping for this key.

See Also:

CacheAccessor.get(Object), RedisCache.get(Object)

get

public V get(K key,
             Callable<V> valueLoader)

Description copied from interface: CacheFrontend

Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary. This method provides a simple substitute for the conventional "if cached, return; otherwise create, cache and return" pattern. If the valueLoader throws an exception, it is wrapped in a CacheFrontend.ValueRetrievalException

Specified by:

get in interface CacheFrontend<K,V>

Parameters:

key - the key whose associated value is to be returned

valueLoader - the value loader that is used to obtain the value if the client-side cache and Redis cache are not associated with a value.

Returns:

the value to which this cache maps the specified key.