Class LocalAsyncLoadingCache<K,V>

java.lang.Object
com.github.benmanes.caffeine.cache.LocalAsyncLoadingCache<K,V>
All Implemented Interfaces:
AsyncCache<K,V>, AsyncLoadingCache<K,V>, LocalAsyncCache<K,V>
Direct Known Subclasses:
BoundedLocalCache.BoundedLocalAsyncLoadingCache, UnboundedLocalCache.UnboundedLocalAsyncLoadingCache

abstract class LocalAsyncLoadingCache<K,V> extends Object implements LocalAsyncCache<K,V>, AsyncLoadingCache<K,V>
This class provides a skeletal implementation of the AsyncLoadingCache interface to minimize the effort required to implement a LocalCache.
  • Field Details

  • Constructor Details

  • Method Details

    • canBulkLoad

      private static boolean canBulkLoad(AsyncCacheLoader<?,?> loader)
      Returns whether the supplied cache loader has bulk load functionality.
    • get

      public CompletableFuture<V> get(K key)
      Description copied from interface: AsyncLoadingCache
      Returns the future associated with key in this cache, obtaining that value from AsyncCacheLoader.asyncLoad(K, java.util.concurrent.Executor) if necessary. If the asynchronous computation fails, the entry will be automatically removed from this cache.

      If the specified key is not already associated with a value, attempts to compute its value asynchronously and enters it into this cache unless null. The entire method invocation is performed atomically, so the function is applied at most once per key.

      Specified by:
      get in interface AsyncLoadingCache<K,V>
      Parameters:
      key - key with which the specified value is to be associated
      Returns:
      the current (existing or computed) future value associated with the specified key
    • getAll

      public CompletableFuture<Map<K,V>> getAll(Iterable<? extends K> keys)
      Description copied from interface: AsyncLoadingCache
      Returns the future of a map of the values associated with keys, creating or retrieving those values if necessary. The returned map contains entries that were already cached, combined with newly loaded entries; it will never contain null keys or values. If the any of the asynchronous computations fail, those entries will be automatically removed from this cache.

      Caches loaded by a AsyncCacheLoader supporting bulk loading will issue a single request to AsyncCacheLoader.asyncLoadAll(java.lang.Iterable<? extends K>, java.util.concurrent.Executor) for all keys which are not already present in the cache. If another call to AsyncLoadingCache.get(K) tries to load the value for a key in keys, that thread retrieves a future that is completed by this bulk computation. Caches that do not use a AsyncCacheLoader with an optimized bulk load implementation will sequentially load each key by making individual AsyncCacheLoader.asyncLoad(K, java.util.concurrent.Executor) calls. Note that multiple threads can concurrently load values for distinct keys.

      Note that duplicate elements in keys, as determined by Object.equals(java.lang.Object), will be ignored.

      Specified by:
      getAll in interface AsyncLoadingCache<K,V>
      Parameters:
      keys - the keys whose associated values are to be returned
      Returns:
      the future containing an unmodifiable mapping of keys to values for the specified keys in this cache
    • synchronous

      public LoadingCache<K,V> synchronous()
      Description copied from interface: AsyncCache
      Returns a view of the entries stored in this cache as a synchronous Cache. A mapping is not present if the value is currently being loaded. Modifications made to the synchronous cache directly affect the asynchronous cache. If a modification is made to a mapping that is currently loading, the operation blocks until the computation completes.
      Specified by:
      synchronous in interface AsyncCache<K,V>
      Specified by:
      synchronous in interface AsyncLoadingCache<K,V>
      Returns:
      a thread-safe synchronous view of this cache