Package com.sodius.oslc.core.cache

Class AbstractCache<K,​V>

  • Type Parameters:
    K - the type of keys maintained by this cache
    V - the type of mapped values
    All Implemented Interfaces:
    Cache<K,​V>
    public abstract class AbstractCache<K,​V>
extends Object
implements Cache<K,​V>
    A skeletal implementation of Cache. This class is to extend when creating builders of cluster compatible caches. Local caches are built with CacheBuilder.local(), one should not try implementing a local cache by any other mean.
    Since:
    3.7.0

    • Constructor Detail

      • AbstractCache

        public AbstractCache()

    • Method Detail

      • get

        public V get​(K key,
             Function<? super K,​? extends V> loader)
        Returns the value associated with the key in this cache, obtaining that value from the loader if necessary. This method provides a simple substitute for the conventional "if cached, return; otherwise create, cache and return" pattern.

        If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this cache. The entire method invocation is performed atomically, so the function is applied at most once per key. Some attempted update operations on this cache by other threads may be blocked while the computation is in progress, so the computation should be short and simple, and must not attempt to update any other mappings of this cache.

        Warning: loader must not attempt to update any other mappings of this cache.

        Warning: loader must not return null; it may either return a non-null value or throw an exception.

        Important Note: contrary to the contract of the overridden method, this implementation does not guarantee the loader is applied at most once per key.

        Specified by:
        get in interface Cache<K,​V>
        Parameters:
        key - the key whose associated value is to be returned
        loader - the function to compute a value
        Returns:
        the current (existing or computed) value associated with the specified key