LoadingCache

Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to the map directly affect the cache.

Returns the value associated with key in this cache, first loading that value if necessary. No observable state associated with this cache is modified until loading completes.

If another call to #get or #getIfPresent is currently loading the value for key, simply waits for that thread to finish and returns its loaded value. Note that multiple threads can concurrently load values for distinct keys.

Caches loaded by a CacheLoader will call CacheLoader#load to load new values into the cache. If another value was associated with key while the new value was loading then a removal notification will be sent for the new value.

The CacheLoader should not throw exceptions. If the calculation from a CacheLoader can fail the use of CacheLoader[K,Option[V]] or CacheLoader[K,Try[V]] is preferred. If the cache loader associated with this cache is known not to throw checked exceptions, then prefer #getUnchecked over this method.

Returns an Option which is Some(value) with the value associated with key in this cache, or None if there is no cached value for key.

Returns the value associated with key in this cache, obtaining that value from loader if necessary. No observable state associated with this cache is modified until loading completes. This method provides a simple substitute for the conventional if cached, return; otherwise create, cache and return pattern.

Warning: as with CacheLoader#load, loader must not return null; it may either return a non-null value or throw an exception. The recommend way would be to use a Cache[K, Option[V]] with loader return None instead of throwing an exception.

This method is equivalent to Cache.get(K, Callable<? extends V>) from the Guava-Libraries.

Discards any cached value for key key.

Discards all entries in the cache.

Adds a new key/value pair to this cache. If the cache previously contained a value associated with the key, the old value is replaced by the value.

Prefer getOrElseUpdate(key, loader) when using the conventional if cached, return; otherwise create, cache and return pattern.

Loads a new value for key key, possibly asynchronously. While the new value is loading the previous value (if any) will continue to be returned by get(key) unless it is evicted. If the new value is loaded successfully it will replace the previous value in the cache; if an exception is thrown while refreshing the previous value will remain, and the exception will be logged (using `java.util.logging.Logger`) and swallowed.

Caches loaded by a CacheLoader will call CacheLoader#reload if the cache currently contains a value for key, and CacheLoader#load otherwise. Loading is asynchronous only if CacheLoader#reload was overridden with an asynchronous implementation.

Returns without doing anything if another thread is currently loading the value for key. If the cache loader associated with this cache performs refresh asynchronously then this method may return before refresh completes.

Returns the approximate number of entries in this cache.

Returns a current snapshot of this cache's cumulative statistics. All stats are initialized to zero, and are monotonically increasing over the lifetime of the cache.

Returns 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. The method simply forwards to getAll(keys).

Returns the value associated with key in this cache, first loading that value if necessary. No observable state associated with this cache is modified until loading completes. The method simply forwards to get(key).

Performs any pending maintenance operations needed by the cache. Exactly which activities are performed -- if any -- is implementation-dependent.

Returns 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.

Caches loaded by a CacheLoader will issue a single request to CacheLoader#loadAll for all keys which are not already present in the cache. All entries returned by CacheLoader#loadAll will be stored in the cache, over-writing any previously cached values. This method will throw an exception if CacheLoader#loadAll returns null, returns a map containing null keys or values, or fails to return an entry for each requested key.

Note that duplicate elements in keys, as determined by ==, will be ignored.

Returns a map of the values associated with keys in this cache. The returned map will only contain entries which are already present in the cache.

Returns the value associated with key in this cache, first loading that value if necessary. No observable state associated with this cache is modified until loading completes. Unlike #get, this method does not handle checked exceptions, and thus should only be used in situations where checked exceptions are not thrown by the cache loader.

If another call to #get or #getUnchecked is currently loading the value for key, simply waits for that thread to finish and returns its loaded value. Note that multiple threads can concurrently load values for distinct keys.

Caches loaded by a CacheLoader will call CacheLoader#load to load new values into the cache. Newly loaded values are added to the cache using Cache.asMap().putIfAbsent after loading has completed; if another value was associated with key while the new value was loading then a removal notification will be sent for the new value.

Warning: this method silently converts checked exceptions to unchecked exceptions, and should not be used with cache loaders which throw checked exceptions. In such cases use #get instead.

Discards any cached values for keys keys.

Puts all key/value pairs from the specified Traversable to the cache. The effect of this call is equivalent to that of calling put(key, value) for each (key, value) in the Traversable. The behavior of this operation is undefined if the specified map is modified while the operation is in progress.