org.cache2k

Interface RefreshController<T>

All Known Implementing Classes:

AutoEntryRefreshController, EntryRefreshController

public interface RefreshController<T>

Calculates the time when the object needs to be updated next.

Author:

Jens Wilke; created: 2010-06-24

Method Summary

Modifier and Type	Method and Description
long	calculateNextRefreshTime(T _oldObject, T _newObject, long _timeOfLastRefresh, long _fetchTime) Returns the time of next refresh (expiry time) in milliseconds since epoch.

Method Detail

calculateNextRefreshTime

long calculateNextRefreshTime(T _oldObject,
                              T _newObject,
                              long _timeOfLastRefresh,
                              long _fetchTime)

Returns the time of next refresh (expiry time) in milliseconds since epoch. If 0 is returned, this means entry expires immediately, or is always fetched from the source. If Long.MAX_VALUE is returned it means there is no specific expiry time known or needed. In case a reasonable default can be assumed for the expiry, the cache will use the configured expiry time.

The cache may call the method a second (or more) times, if the expiry time needs a recalculation. The reason for this is to react on possible configuration changes properly. This may happen when an entry is read back from storage.

Parameters:

_oldObject - the value currently in the cache. null if it is not in the cache, is a null value (null is supported for values) or the previous fetch operation yielded in an exception.

_timeOfLastRefresh - time of the last cache refresh, by put or from the cache source.

_newObject - the value which will be put in the cache.

_fetchTime - this is the current time in millis. If a cache source was used to fetch the value, this is the time before the fetch was started.

Returns:

time of next refresh in millis. 0 if it should not be cached at all.