Package org.apache.cayenne.access

Class DataRowStore

java.lang.Object

org.apache.cayenne.access.DataRowStore

All Implemented Interfaces:

Serializable

public class DataRowStore
extends Object
implements Serializable

A fixed size cache of DataRows keyed by ObjectId.

Since:

1.1

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected EventManager	eventManager
protected EventSubject	eventSubject
protected String	name
protected EventBridge	remoteNotificationsHandler
static final int	SNAPSHOT_CACHE_SIZE_DEFAULT	Deprecated, for removal: This API element is subject to removal in a future version. use DefaultDataRowStoreFactory.SNAPSHOT_CACHE_SIZE_DEFAULT
static final long	SNAPSHOT_EXPIRATION_DEFAULT	Deprecated, for removal: This API element is subject to removal in a future version. unused
protected final ConcurrentMap<ObjectId,DataRow>	snapshots

Constructor Summary

Constructors

Constructor	Description
DataRowStore(String name, int maxSize, EventManager eventManager)

Method Summary

Modifier and Type	Method	Description
void	clear()	Expires and removes all stored snapshots without sending any notification events.
void	forgetSnapshot(ObjectId id)	Evicts a snapshot from cache without generating any SnapshotEvents.
DataRow	getCachedSnapshot(ObjectId oid)	Returns cached snapshot or null if no snapshot is currently cached for the given ObjectId.
protected EventBridge	getEventBridge()
EventManager	getEventManager()	Returns an EventManager associated with this DataRowStore.
String	getName()	Returns the name of this DataRowStore.
EventSubject	getSnapshotEventSubject()	Returns EventSubject used by this SnapshotCache to notify of snapshot changes.
int	maximumSize()	Returns maximum allowed cache size.
void	processRemoteEvent(SnapshotEvent event)	Handles remote events received via EventBridge.
void	processSnapshotChanges(Object postedBy, Map<ObjectId,DataRow> updatedSnapshots, Collection<ObjectId> deletedSnapshotIds, Collection<ObjectId> invalidatedSnapshotIds, Collection<ObjectId> indirectlyModifiedIds)	Processes changes made to snapshots.
protected void	setEventBridge(EventBridge eventBridge)
void	setEventManager(EventManager eventManager)	Sets an EventManager associated with this DataRowStore.
void	setName(String name)	Sets the name of this DataRowStore.
void	shutdown()	Shuts down any remote notification connections, and clears internal cache.
int	size()	Returns current cache size.

Methods inherited from class java.lang.Object

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

Field Details

SNAPSHOT_EXPIRATION_DEFAULT

@Deprecated(since="5.0",
            forRemoval=true)
public static final long SNAPSHOT_EXPIRATION_DEFAULT

Deprecated, for removal: This API element is subject to removal in a future version.

unused

See Also:

• Constant Field Values

SNAPSHOT_CACHE_SIZE_DEFAULT

@Deprecated(since="5.0",
            forRemoval=true)
public static final int SNAPSHOT_CACHE_SIZE_DEFAULT

Deprecated, for removal: This API element is subject to removal in a future version.

use DefaultDataRowStoreFactory.SNAPSHOT_CACHE_SIZE_DEFAULT

See Also:

• Constant Field Values

name

protected String name

snapshots

protected final ConcurrentMap<ObjectId,DataRow> snapshots

eventManager

protected transient EventManager eventManager

remoteNotificationsHandler

protected transient EventBridge remoteNotificationsHandler

eventSubject

protected transient EventSubject eventSubject

Constructor Details

DataRowStore

public DataRowStore(String name,
 int maxSize,
 EventManager eventManager)

Parameters:

name - DataRowStore name. Used to identify this DataRowStore in events, etc. Can't be null.

maxSize - max number of cached snapshots. The cache is LRU, evicting the oldest snapshots past this size.

eventManager - EventManager that should be used for posting and receiving events.

Since:

5.0

Method Details

setEventBridge

protected void setEventBridge(EventBridge eventBridge)

getEventBridge

protected EventBridge getEventBridge()

size

public int size()

Returns current cache size.

maximumSize

public int maximumSize()

Returns maximum allowed cache size.

shutdown

public void shutdown()

Shuts down any remote notification connections, and clears internal cache.

getName

public String getName()

Returns the name of this DataRowStore. Name allows to create EventSubjects for event notifications addressed to or sent from this DataRowStore.

setName

public void setName(String name)

Sets the name of this DataRowStore. Name allows to create EventSubjects for event notifications addressed to or sent from this DataRowStore.

getEventManager

public EventManager getEventManager()

Returns an EventManager associated with this DataRowStore.

Since:

1.2

setEventManager

public void setEventManager(EventManager eventManager)

Sets an EventManager associated with this DataRowStore.

Since:

1.2

getCachedSnapshot

public DataRow getCachedSnapshot(ObjectId oid)

Returns cached snapshot or null if no snapshot is currently cached for the given ObjectId.

getSnapshotEventSubject

public EventSubject getSnapshotEventSubject()

Returns EventSubject used by this SnapshotCache to notify of snapshot changes.

clear

public void clear()

Expires and removes all stored snapshots without sending any notification events.

forgetSnapshot

public void forgetSnapshot(ObjectId id)

Evicts a snapshot from cache without generating any SnapshotEvents.

processRemoteEvent

public void processRemoteEvent(SnapshotEvent event)

Handles remote events received via EventBridge. Performs needed snapshot updates, and then resends the event to local listeners.

processSnapshotChanges

public void processSnapshotChanges(Object postedBy,
 Map<ObjectId,DataRow> updatedSnapshots,
 Collection<ObjectId> deletedSnapshotIds,
 Collection<ObjectId> invalidatedSnapshotIds,
 Collection<ObjectId> indirectlyModifiedIds)

Processes changes made to snapshots. Modifies internal cache state, and then sends the event to all listeners. Source of these changes is usually an ObjectStore.