org.olat.commons.coordinate.cluster.lock
Class ClusterLocker

java.lang.Object
  org.olat.commons.coordinate.cluster.lock.ClusterLocker

All Implemented Interfaces:

Locker, GenericEventListener

public class ClusterLocker
extends java.lang.Object
implements Locker, GenericEventListener

Description:
the cluster implementation for the Locker. It uses a database table oc_lock to perform the locking.

Initial Date: 21.09.2007

Author:

Felix Jost, http://www.goodsolutions.ch

Constructor Summary

ClusterLocker()
[used by spring]

Method Summary

LockResult	acquireLock(OLATResourceable ores, Identity requestor, java.lang.String locksubkey)
java.util.List<LockEntry>	adminOnlyGetLockEntries() for admin purposes only.
LockResult	aquirePersistentLock(OLATResourceable ores, Identity ident, java.lang.String locksubkey) acquires a persistent lock.
void	event(Event event) receives all sign on / sign off events so it can release locks of users which have or are logged off
void	init() [used by spring]
boolean	isLocked(OLATResourceable ores, java.lang.String locksubkey)
void	releaseLock(LockResult lockResult) releases the lock.
void	releasePersistentLock(LockResult lockResult) releases a persistent lock.
void	setEventBus(EventBus eventBus) [used by spring]
void	setSyncer(Syncer syncer) [used by spring]

Methods inherited from class java.lang.Object

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

Constructor Detail

ClusterLocker

public ClusterLocker()

[used by spring]

Method Detail

init

public void init()

[used by spring]

acquireLock

public LockResult acquireLock(OLATResourceable ores,
                              Identity requestor,
                              java.lang.String locksubkey)

Specified by:

acquireLock in interface Locker

Parameters:

ores - the OLATResourceable to lock upon, e.g a repositoryentry or such

requestor - the identity who tries to acquire the lock, not null

locksubkey - null or any string to lock finer upon the resource (e.g. "authors", or "write", ...)

Returns:

lock result

event

public void event(Event event)

receives all sign on / sign off events so it can release locks of users which have or are logged off

Specified by:

event in interface GenericEventListener

See Also:

GenericEventListener.event(org.olat.core.gui.control.Event)

isLocked

public boolean isLocked(OLATResourceable ores,
                        java.lang.String locksubkey)

Specified by:

isLocked in interface Locker

Returns:

if the olatresourceable with the subkey is already locked by someone (returns true even if locked by "myself")

releaseLock

public void releaseLock(LockResult lockResult)

Description copied from interface: Locker

releases the lock. can also be called if the lock was not sucessfully acquired

Specified by:

releaseLock in interface Locker

Parameters:

lockResult - the LockResult received when locking

adminOnlyGetLockEntries

public java.util.List<LockEntry> adminOnlyGetLockEntries()

Description copied from interface: Locker

for admin purposes only.

Specified by:

adminOnlyGetLockEntries in interface Locker

Returns:

a list of lockentries.

aquirePersistentLock

public LockResult aquirePersistentLock(OLATResourceable ores,
                                       Identity ident,
                                       java.lang.String locksubkey)

Description copied from interface: Locker

acquires a persistent lock.

Specified by:

aquirePersistentLock in interface Locker

locksubkey - may not be longer than 30 chars

Returns:

the LockResult of this lock trial.

releasePersistentLock

public void releasePersistentLock(LockResult lockResult)

Description copied from interface: Locker

releases a persistent lock.

Specified by:

releasePersistentLock in interface Locker

Parameters:

lockResult - the LockResult which stems from the lock acquired previously

setSyncer

public void setSyncer(Syncer syncer)

[used by spring]

Parameters:

syncer -

setEventBus

public void setEventBus(EventBus eventBus)

[used by spring]