org.apache.openjpa.datacache

Class AbstractQueryCache

java.lang.Object

org.apache.openjpa.lib.util.concurrent.AbstractConcurrentEventManager

org.apache.openjpa.datacache.AbstractQueryCache

All Implemented Interfaces:

Serializable, QueryCache, TypesChangedListener, Configurable, Closeable, EventManager

Direct Known Subclasses:

ConcurrentQueryCache

public abstract class AbstractQueryCache
extends AbstractConcurrentEventManager
implements QueryCache, Configurable

Abstract QueryCache implementation that provides various statistics, logging, and timeout functionality common across cache implementations.

Author:

Patrick Linskey, Abe White

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractQueryCache.Default<T> A default implementation of query statistics for the Query result cache.
static class	AbstractQueryCache.EvictPolicy

Field Summary

Fields

Modifier and Type	Field and Description
protected OpenJPAConfiguration	conf The configuration set by the system.
protected ConcurrentHashMap<String,Long>	entityTimestampMap
AbstractQueryCache.EvictPolicy	evictPolicy
protected Log	log The log to use.

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

_listeners

Constructor Summary

Constructors

Constructor and Description
AbstractQueryCache()

Method Summary

Methods

Modifier and Type	Method and Description
void	addTypesChangedListener(TypesChangedListener listen) Add a new types event listener to this cache.
void	afterCommit(RemoteCommitEvent event) This method is part of the RemoteCommitListener interface.
void	clear() Remove all data from this cache.
protected abstract void	clearInternal() Clear the cache.
void	close() Free the resources used by this cache.
protected void	close(boolean clear)
int	count()
void	endConfiguration() Invoked upon completion of bean property configuration for this object.
protected void	fireEvent(Object event, Object listener) Implement this method to fire the given event to the given listener.
QueryResult	get(QueryKey key) Return a list of oids for the given query key.
List<Long>	getAllEntityTimestamp(List<String> keyList) Returns a list of timestamps in the form of Long objects which are the last updated time stamps for the given entities in the keylist.
boolean	getEnableStatistics()
AbstractQueryCache.EvictPolicy	getEvictPolicy() Returns the evictionPolicy for QueryCache
protected abstract QueryResult	getInternal(QueryKey qk) Return the list for the given key.
String	getName()
QueryStatistics<QueryKey>	getStatistics() Gets the simple statistics for query results.
void	initialize(DataCacheManager manager) Initialize any resources associated with the given DataCacheManager.
boolean	isClosed()
protected abstract Collection	keySet() Return a threadsafe view of the keys in this cache.
protected Collection	newListenerCollection() Individual query results will be registered as types changed listeners.
void	onTypesChanged(TypesChangedEvent ev) Notification that instances of persistent types have changed.
boolean	pin(QueryKey key) Pin the value stored under qk into the cache.
protected abstract boolean	pinInternal(QueryKey qk) Pin an object to the cache.
QueryResult	put(QueryKey qk, QueryResult oids) Set the list of OIDs for the given query key.
protected abstract QueryResult	putInternal(QueryKey qk, QueryResult oids) Add the given result to the cache, returning the old result under the given key.
QueryResult	remove(QueryKey key) Remove the value stored under the given query key.
protected void	removeAllInternal(Collection qks) Remove all results under the given keys from the cache.
protected abstract QueryResult	removeInternal(QueryKey qk) Remove the result under the given key from the cache.
boolean	removeTypesChangedListener(TypesChangedListener listen) Remove an types event listener from this cache.
void	setConfiguration(Configuration conf) Invoked prior to setting bean properties.
void	setEnableStatistics(boolean enable)
void	setEvictPolicy(String evictPolicy) Sets the eviction policy for the query cache
void	setName(String n)
void	startConfiguration() Invoked before bean property configuration is begun on this object.
boolean	unpin(QueryKey key) Unpin the value stored under key into the cache.
protected abstract boolean	unpinInternal(QueryKey qk) Unpin an object from the cache.
protected void	updateEntityTimestamp(Map<String,Long> timestampMap) Updates the entity timestamp map with the current time in milliseconds

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.datacache.QueryCache

writeLock, writeUnlock

Field Detail

conf

protected OpenJPAConfiguration conf

The configuration set by the system.

log

protected Log log

The log to use.

entityTimestampMap

protected ConcurrentHashMap<String,Long> entityTimestampMap

evictPolicy

public AbstractQueryCache.EvictPolicy evictPolicy

Constructor Detail

AbstractQueryCache

public AbstractQueryCache()

Method Detail

setEnableStatistics

public void setEnableStatistics(boolean enable)

getEnableStatistics

public boolean getEnableStatistics()

getStatistics

public QueryStatistics<QueryKey> getStatistics()

Description copied from interface: QueryCache

Gets the simple statistics for query results. If the statistics gathering is disabled, an empty statistics is returned.

Specified by:

getStatistics in interface QueryCache

initialize

public void initialize(DataCacheManager manager)

Description copied from interface: QueryCache

Initialize any resources associated with the given DataCacheManager.

Specified by:

initialize in interface QueryCache

onTypesChanged

public void onTypesChanged(TypesChangedEvent ev)

Description copied from interface: TypesChangedListener

Notification that instances of persistent types have changed.

Specified by:

onTypesChanged in interface TypesChangedListener

get

public QueryResult get(QueryKey key)

Description copied from interface: QueryCache

Return a list of oids for the given query key. This is an unmodifiable list.

Specified by:

get in interface QueryCache

Returns:

The query results matching the given key, or null if none

put

public QueryResult put(QueryKey qk,
              QueryResult oids)

Description copied from interface: QueryCache

Set the list of OIDs for the given query key. A reference to the given list will be stored in the query cache, so the list should not be modified after invoking this method.

Specified by:

put in interface QueryCache

Returns:

The previously cached value, or null if the key was not previously cached. See Map.put(K, V) for more information.

remove

public QueryResult remove(QueryKey key)

Description copied from interface: QueryCache

Remove the value stored under the given query key. This method is typically not invoked directly from outside the QueryCache class. Instead, the cache should be updated by implementing RemoteCommitListener, which will result in all queries that may be invalid being dropped.

Specified by:

remove in interface QueryCache

Returns:

The previously cached value, or null if the key was not previously cached. See Map.remove(java.lang.Object) for more information.

pin

public boolean pin(QueryKey key)

Description copied from interface: QueryCache

Pin the value stored under qk into the cache. This method guarantees that qk's value will not be expired if the cache exceeds its capacity. It causes this data to be ignored when determining whether or not the cache is full, effectively increasing the total amount of data stored in the cache. This method does not affect the behavior of QueryCache.remove(org.apache.openjpa.datacache.QueryKey) or TypesChangedListener.onTypesChanged(org.apache.openjpa.datacache.TypesChangedEvent).

Specified by:

pin in interface QueryCache

Returns:

true if key's value was pinned into the cache; false if the key is not in the cache.

unpin

public boolean unpin(QueryKey key)

Description copied from interface: QueryCache

Unpin the value stored under key into the cache. This method reverses a previous invocation of QueryCache.pin(org.apache.openjpa.datacache.QueryKey). This method does not remove anything from the cache; it merely makes key's value a candidate for flushing from the cache.

Specified by:

unpin in interface QueryCache

Returns:

true if key's value was unpinned from the cache; false if the key is not in the cache.

clear

public void clear()

Description copied from interface: QueryCache

Remove all data from this cache.

Specified by:

clear in interface QueryCache

close

public void close()

Description copied from interface: QueryCache

Free the resources used by this cache.

Specified by:

close in interface QueryCache

Specified by:

close in interface Closeable

close

protected void close(boolean clear)

isClosed

public boolean isClosed()

addTypesChangedListener

public void addTypesChangedListener(TypesChangedListener listen)

Description copied from interface: QueryCache

Add a new types event listener to this cache.

Specified by:

addTypesChangedListener in interface QueryCache

removeTypesChangedListener

public boolean removeTypesChangedListener(TypesChangedListener listen)

Description copied from interface: QueryCache

Remove an types event listener from this cache.

Specified by:

removeTypesChangedListener in interface QueryCache

afterCommit

public void afterCommit(RemoteCommitEvent event)

This method is part of the RemoteCommitListener interface. If your cache subclass relies on OpenJPA for clustering support, make it implement RemoteCommitListener. This method will take care of invalidating entries from remote commits, by delegating to onTypesChanged(org.apache.openjpa.datacache.TypesChangedEvent).

keySet

protected abstract Collection keySet()

Return a threadsafe view of the keys in this cache. This collection must be iterable without risk of concurrent modification exceptions. It does not have to implement contains() efficiently or use set semantics.

getInternal

protected abstract QueryResult getInternal(QueryKey qk)

Return the list for the given key.

putInternal

protected abstract QueryResult putInternal(QueryKey qk,
                      QueryResult oids)

Add the given result to the cache, returning the old result under the given key.

removeInternal

protected abstract QueryResult removeInternal(QueryKey qk)

Remove the result under the given key from the cache.

removeAllInternal

protected void removeAllInternal(Collection qks)

Remove all results under the given keys from the cache.

clearInternal

protected abstract void clearInternal()

Clear the cache.

pinInternal

protected abstract boolean pinInternal(QueryKey qk)

Pin an object to the cache.

unpinInternal

protected abstract boolean unpinInternal(QueryKey qk)

Unpin an object from the cache.

setConfiguration

public void setConfiguration(Configuration conf)

Description copied from interface: Configurable

Invoked prior to setting bean properties.

Specified by:

setConfiguration in interface Configurable

startConfiguration

public void startConfiguration()

Description copied from interface: Configurable

Invoked before bean property configuration is begun on this object.

Specified by:

startConfiguration in interface Configurable

endConfiguration

public void endConfiguration()

Description copied from interface: Configurable

Invoked upon completion of bean property configuration for this object.

Specified by:

endConfiguration in interface Configurable

fireEvent

protected void fireEvent(Object event,
             Object listener)

Description copied from class: AbstractConcurrentEventManager

Implement this method to fire the given event to the given listener.

Specified by:

fireEvent in class AbstractConcurrentEventManager

newListenerCollection

protected Collection newListenerCollection()

Individual query results will be registered as types changed listeners. We want such query results to be gc'd once the only reference is held by the list of expiration listeners.

Overrides:

newListenerCollection in class AbstractConcurrentEventManager

setEvictPolicy

public void setEvictPolicy(String evictPolicy)

Sets the eviction policy for the query cache

Parameters:

evictPolicy - -- String value that specifies the eviction policy

getEvictPolicy

public AbstractQueryCache.EvictPolicy getEvictPolicy()

Returns the evictionPolicy for QueryCache

Returns:

-- returns a String value of evictPolicy attribute

updateEntityTimestamp

protected void updateEntityTimestamp(Map<String,Long> timestampMap)

Updates the entity timestamp map with the current time in milliseconds

Parameters:

timestampMap - -- a map that contains entityname and its last updated timestamp

getAllEntityTimestamp

public List<Long> getAllEntityTimestamp(List<String> keyList)

Returns a list of timestamps in the form of Long objects which are the last updated time stamps for the given entities in the keylist.

Parameters:

keyList - -- List of entity names

Returns:

-- Returns a list that has the timestamp for the given entities

setName

public void setName(String n)

getName

public String getName()

count

public int count()