org.apache.jcs.auxiliary.disk.indexed
Class IndexedDiskCache

java.lang.Object
  org.apache.jcs.auxiliary.disk.AbstractDiskCache
      org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCache

All Implemented Interfaces:

AuxiliaryCache, ICache, ICacheType, java.io.Serializable

public class IndexedDiskCache

extends AbstractDiskCache

Disk cache that uses a RandomAccessFile with keys stored in memory. The maximum number of keys stored in memory is configurable. The disk cache tries to recycle spots on disk to limit file expansion.

Version:

$Id: IndexedDiskCache.java,v 1.22 2005/06/04 02:01:55 asmuts Exp $

See Also:

Serialized Form

Nested Class Summary

class

IndexedDiskCache.LRUMap class for recylcing and lru

Field Summary

protected EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock

storageLock use this lock to synchronize reads and writes to the underlying storage mechansism.

Fields inherited from class org.apache.jcs.auxiliary.disk.AbstractDiskCache

alive, cacheEventQueue, cacheName, purgatory, purgHits

Fields inherited from interface org.apache.jcs.engine.behavior.ICacheType

CACHE_HUB, DISK_CACHE, LATERAL_CACHE, REMOTE_CACHE

Constructor Summary

IndexedDiskCache(IndexedDiskCacheAttributes cattr)
Constructor for the DiskCache object

Method Summary

void	doDispose() Dispose of the disk cache in a background thread.
protected ICacheElement	doGet(java.io.Serializable key) Get a value from the persistent store.
void	doOptimizeRealTime() Dispose of the disk cache in a background thread.
boolean	doRemove(java.io.Serializable key) Returns true if the removal was succesful; or false if there is nothing to remove.
void	doRemoveAll() Remove all the items fromt he disk cache by reseting everything.
void	doUpdate(ICacheElement ce) Update the disk cache.
void	dump() For debugging.
java.util.Set	getGroupKeys(java.lang.String groupName) Gets the set of keys of objects currently in the group
int	getSize() Returns the current cache size.
IStats	getStatistics() Returns the historical and statistical data for a region's auxiliary cache.
java.lang.String	getStats() Gets basic stats for the disk cache.

Methods inherited from class org.apache.jcs.auxiliary.disk.AbstractDiskCache

dispose, get, getCacheName, getCacheType, getStatus, remove, removeAll, update

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

storageLock

protected EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock storageLock

use this lock to synchronize reads and writes to the underlying storage mechansism.

Constructor Detail

IndexedDiskCache

public IndexedDiskCache(IndexedDiskCacheAttributes cattr)

Constructor for the DiskCache object

Parameters:

cattr -

Method Detail

doUpdate

public void doUpdate(ICacheElement ce)

Update the disk cache. Called from the Queue. Makes sure the Item has not been retireved from purgatory while in queue for disk. Remove items from purgatory when they go to disk.

Specified by:

doUpdate in class AbstractDiskCache

Parameters:

ce -

doGet

protected ICacheElement doGet(java.io.Serializable key)

Description copied from class: AbstractDiskCache

Get a value from the persistent store.

Specified by:

doGet in class AbstractDiskCache

Parameters:

key -

Returns:

ICacheElement or null

See Also:

AbstractDiskCache.doGet(java.io.Serializable)

getGroupKeys

public java.util.Set getGroupKeys(java.lang.String groupName)

Description copied from interface: AuxiliaryCache

Gets the set of keys of objects currently in the group

Specified by:

getGroupKeys in interface AuxiliaryCache

Specified by:

getGroupKeys in class AbstractDiskCache

doRemove

public boolean doRemove(java.io.Serializable key)

Returns true if the removal was succesful; or false if there is nothing to remove. Current implementation always result in a disk orphan.

Specified by:

doRemove in class AbstractDiskCache

Parameters:

key -

Returns:

doRemoveAll

public void doRemoveAll()

Remove all the items fromt he disk cache by reseting everything.

Specified by:

doRemoveAll in class AbstractDiskCache

doDispose

public void doDispose()

Dispose of the disk cache in a background thread. Joins against this thread to put a cap on the disposal time.

Specified by:

doDispose in class AbstractDiskCache

doOptimizeRealTime

public void doOptimizeRealTime()

Dispose of the disk cache in a background thread. Joins against this thread to put a cap on the disposal time.

getSize

public int getSize()

Returns the current cache size.

Specified by:

getSize in interface AuxiliaryCache

Specified by:

getSize in class AbstractDiskCache

Returns:

The size value

See Also:

ICache.getSize()

dump

public void dump()

For debugging.

getStats

public java.lang.String getStats()

Gets basic stats for the disk cache.

Specified by:

getStats in interface ICache

Overrides:

getStats in class AbstractDiskCache

Returns:

String

getStatistics

public IStats getStatistics()

Description copied from interface: AuxiliaryCache

Returns the historical and statistical data for a region's auxiliary cache.

Specified by:

getStatistics in interface AuxiliaryCache

Overrides:

getStatistics in class AbstractDiskCache