kodo.datacache
Class LRUQueryCache

java.lang.Object
  org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager
      org.apache.openjpa.datacache.AbstractQueryCache
          kodo.datacache.LRUQueryCache

All Implemented Interfaces:

Serializable, QueryCache, TypesChangedListener, RemoteCommitListener, Configurable, Closeable, EventManager

public class LRUQueryCache
extends AbstractQueryCache
implements RemoteCommitListener

An lru-based query cache.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.openjpa.datacache.AbstractQueryCache

conf, log

Fields inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

_listeners

Constructor Summary

LRUQueryCache()

Method Summary

protected void	clearInternal()
CacheMap	getCacheMap() Returns the underlying CacheMap that this LRUQueryCache is using.
int	getCacheSize() Returns the maximum number of unpinned objects to keep hard references to.
protected QueryResult	getInternal(QueryKey qk)
int	getSoftReferenceSize() Returns the maximum number of unpinned objects to keep soft references to.
void	initialize(DataCacheManager mgr)
protected Collection	keySet()
protected boolean	pinInternal(QueryKey qk)
protected QueryResult	putInternal(QueryKey qk, QueryResult result)
protected QueryResult	removeInternal(QueryKey qk)
void	setCacheSize(int size) Sets the maximum number of unpinned objects to keep hard references to.
void	setSoftReferenceSize(int size) Sets the maximum number of unpinned objects to keep soft references to.
protected boolean	unpinInternal(QueryKey qk)
void	writeLock()
void	writeUnlock()

Methods inherited from class org.apache.openjpa.datacache.AbstractQueryCache

addTypesChangedListener, afterCommit, clear, close, close, endConfiguration, fireEvent, get, isClosed, newListenerCollection, onTypesChanged, pin, put, remove, removeAllInternal, removeTypesChangedListener, setConfiguration, startConfiguration, unpin

Methods inherited from class org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

addListener, fireEvent, getListeners, hasListener, hasListeners, isFailFast, removeListener, setFailFast

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.openjpa.event.RemoteCommitListener

afterCommit, close

Constructor Detail

LRUQueryCache

public LRUQueryCache()

Method Detail

getCacheMap

public CacheMap getCacheMap()

Returns the underlying CacheMap that this LRUQueryCache is using. This is not an unmodifiable view on the map, so care should be taken with this reference. Implementations should probably not mess with the contents of the cache, but should only use this reference to obtain cache metrics. Additionally, this map may contain expired data. Removal of timed-out data is done in a lazy fashion, so the actual size of the map may be greater than the number of non-expired query results in cache.

getCacheSize

public int getCacheSize()

Returns the maximum number of unpinned objects to keep hard references to.

setCacheSize

public void setCacheSize(int size)

Sets the maximum number of unpinned objects to keep hard references to. If the map contains more unpinned objects than size, then this method will result in the cache flushing old values.

getSoftReferenceSize

public int getSoftReferenceSize()

Returns the maximum number of unpinned objects to keep soft references to. Defaults to -1.

setSoftReferenceSize

public void setSoftReferenceSize(int size)

Sets the maximum number of unpinned objects to keep soft references to. If the map contains more soft references than size, then this method will result in the cache flushing values.

initialize

public void initialize(DataCacheManager mgr)

Specified by:

initialize in interface QueryCache

Overrides:

initialize in class AbstractQueryCache

writeLock

public void writeLock()

Specified by:

writeLock in interface QueryCache

writeUnlock

public void writeUnlock()

Specified by:

writeUnlock in interface QueryCache

getInternal

protected QueryResult getInternal(QueryKey qk)

Specified by:

getInternal in class AbstractQueryCache

putInternal

protected QueryResult putInternal(QueryKey qk,
                                  QueryResult result)

Specified by:

putInternal in class AbstractQueryCache

removeInternal

protected QueryResult removeInternal(QueryKey qk)

Specified by:

removeInternal in class AbstractQueryCache

clearInternal

protected void clearInternal()

Specified by:

clearInternal in class AbstractQueryCache

pinInternal

protected boolean pinInternal(QueryKey qk)

Specified by:

pinInternal in class AbstractQueryCache

unpinInternal

protected boolean unpinInternal(QueryKey qk)

Specified by:

unpinInternal in class AbstractQueryCache

keySet

protected Collection keySet()

Specified by:

keySet in class AbstractQueryCache