org.jadice.util.mm.ckc.expiry

Interface ExpiryStrategy

All Known Implementing Classes:

CompositeExpiryStrategy, LRUExpiryStrategy, MaximumAgeExpiryStrategy

public interface ExpiryStrategy

This is the basic functionality an ExpiryStrategy needs to implement.

An expiry strategy is a strategy to evict cache entries due to the need to free up space. It will get an Iterator to the cache entries and the information if the iterator will iterate the elements in an LRU order or not. There might be different strategies for the cache.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ExpiryStrategy.ExpiryPressure Defines the importance of expiry.

Method Summary

Modifier and Type	Method and Description
void	performExpiry(CacheIteratorFactory iteratorFactory, TrackableCache cache, boolean hasLRUOrdering, ExpiryStrategy.ExpiryPressure expiryPressure) Initiates an expiry call to the cache and returns how many objects have been expired.

Method Detail

performExpiry

void performExpiry(CacheIteratorFactory iteratorFactory,
                   TrackableCache cache,
                   boolean hasLRUOrdering,
                   ExpiryStrategy.ExpiryPressure expiryPressure)

Initiates an expiry call to the cache and returns how many objects have been expired. Each expiry call has an ExpiryStrategy.ExpiryPressure indicating how urgent it is.

The expiry of cache entries shall be triggered by calling Iterator.remove() on the Iterator provided by CacheIteratorFactory.create(). Iterators created using that method, will allow cache modifications during iteration.

Attention: This is not thread safe! Locking has to happen in the cache's implementation!

Parameters:

iteratorFactory - A CacheIteratorFactory that creates an Iterator to the caches entries. The Iterator created using the CacheIteratorFactory shall be used to removed entries from the cache.

cache - the TrackableCache the ExpiryStrategy is assigned to

hasLRUOrdering - If this is true, the collection has an LRU ordering, implying that it will iterate from the oldest to the newest entry.

expiryPressure - Indicates if the expiry call is urgent or not.