com.opensymphony.oscache.base.algorithm
Class FIFOCache

java.lang.Object
  java.util.AbstractMap
      com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache
          com.opensymphony.oscache.base.algorithm.FIFOCache

All Implemented Interfaces:

Serializable, Cloneable, Map

public class FIFOCache
extends AbstractConcurrentReadCache

FIFO (First In First Out) based queue algorithm for the cache. No synchronization is required in this class since the AbstractConcurrentReadCache already takes care of any synchronization requirements.

Version:

$Revision: 427 $

Author:

Mike Cannon-Brookes, Alain Bergevin, Chris Miller

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache

AbstractConcurrentReadCache.Entry, AbstractConcurrentReadCache.HashIterator, AbstractConcurrentReadCache.KeyIterator, AbstractConcurrentReadCache.ValueIterator

Field Summary

private Collection	list A queue containing all cache keys
private static long	serialVersionUID

Fields inherited from class com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache

barrierLock, count, DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_MAX_ENTRIES, entrySet, groups, keySet, lastWrite, loadFactor, maxEntries, memoryCaching, NULL, persistenceListener, table, threshold, UNLIMITED, unlimitedDiskCache, values

Constructor Summary

FIFOCache()
Constructs a FIFO Cache.

FIFOCache(int capacity)
Constructs a FIFO Cache of the specified capacity.

Method Summary

protected void	itemPut(Object key) An object was put in the cache.
protected void	itemRemoved(Object key) Remove specified key since that object has been removed from the cache.
protected void	itemRetrieved(Object key) An object was retrieved from the cache.
protected Object	removeItem() An item needs to be removed from the cache.

Methods inherited from class com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache

capacity, clear, clone, contains, containsKey, containsValue, elements, entrySet, findAndRemoveEntry, get, getGroup, getGroupForReading, getGroupsForReading, getMaxEntries, getPersistenceListener, getTableForReading, isEmpty, isMemoryCaching, isOverflowPersistence, isUnlimitedDiskCache, keys, keySet, loadFactor, persistClear, persistRemove, persistRemoveGroup, persistRetrieve, persistRetrieveGroup, persistStore, persistStoreGroup, put, putAll, recordModification, rehash, remove, removeForce, setMaxEntries, setMemoryCaching, setOverflowPersistence, setPersistenceListener, setUnlimitedDiskCache, size, sput, sremove, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

list

private Collection list

A queue containing all cache keys

Constructor Detail

FIFOCache

public FIFOCache()

Constructs a FIFO Cache.

FIFOCache

public FIFOCache(int capacity)

Constructs a FIFO Cache of the specified capacity.

Parameters:

capacity - The maximum cache capacity.

Method Detail

itemRetrieved

protected void itemRetrieved(Object key)

An object was retrieved from the cache. This implementation does noting since this event has no impact on the FIFO algorithm.

Specified by:

itemRetrieved in class AbstractConcurrentReadCache

Parameters:

key - The cache key of the item that was retrieved.

itemPut

protected void itemPut(Object key)

An object was put in the cache. This implementation just adds the key to the end of the list if it doesn't exist in the list already.

Specified by:

itemPut in class AbstractConcurrentReadCache

Parameters:

key - The cache key of the item that was put.

removeItem

protected Object removeItem()

An item needs to be removed from the cache. The FIFO implementation removes the first element in the list (ie, the item that has been in the cache for the longest time).

Specified by:

removeItem in class AbstractConcurrentReadCache

Returns:

The key of whichever item was removed.

itemRemoved

protected void itemRemoved(Object key)

Remove specified key since that object has been removed from the cache.

Specified by:

itemRemoved in class AbstractConcurrentReadCache

Parameters:

key - The cache key of the item that was removed.