Module lettuce.core
Package 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

  • Method Details

    • 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 AutoCloseable
      Specified by:
      close in interface CacheFrontend<K,​V>
      Specified by:
      close in interface Closeable

    • 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.