org.apache.jackrabbit.core.lock
Class LockManagerImpl

java.lang.Object
  org.apache.jackrabbit.core.lock.LockManagerImpl

All Implemented Interfaces:

javax.jcr.observation.EventListener, LockEventListener, LockManager, SynchronousEventListener, Dumpable

public class LockManagerImpl
extends java.lang.Object
implements LockManager, SynchronousEventListener, LockEventListener, Dumpable

Provides the functionality needed for locking and unlocking nodes.

Constructor Summary

LockManagerImpl(SessionImpl session, FileSystem fs)
Create a new instance of this class.

Method Summary

void	beginUpdate() Start an update operation.
void	cancelUpdate() Cancel an update operation.
void	checkLock(NodeImpl node) Check whether the node given is locked by somebody else than the current session.
void	checkLock(Path path, javax.jcr.Session session) Check whether the path given is locked by somebody else than the session described.
void	close() Close this lock manager.
void	dump(java.io.PrintStream ps) Dump contents of path map and elements included to PrintStream given.
void	endUpdate() End an update operation.
void	externalLock(NodeId nodeId, boolean isDeep, java.lang.String userId) Handle an external lock operation.
void	externalUnlock(NodeId nodeId) Handle an external unlock operation.
javax.jcr.lock.Lock	getLock(NodeImpl node) Returns the Lock object that applies to a node.
AbstractLockInfo	getLockInfo(NodeId id) Return the most appropriate lock information for a node.
javax.jcr.lock.Lock[]	getLocks(SessionImpl session) Returns all locks owned by the specified session.
boolean	holdsLock(NodeImpl node) Returns true if the node given holds a lock; otherwise returns false.
boolean	isLocked(NodeImpl node) Returns true if this node is locked either as a result of a lock held by this node or by a deep lock on a node above this node; otherwise returns false
boolean	isLockHolder(javax.jcr.Session session, NodeImpl node) Returns true if the specified session holds a lock on the given node; otherwise returns false.
javax.jcr.lock.Lock	lock(NodeImpl node, boolean isDeep, boolean isSessionScoped) Lock a node.
void	lockTokenAdded(SessionImpl session, java.lang.String lt) Invoked by a session to inform that a lock token has been added.
void	lockTokenRemoved(SessionImpl session, java.lang.String lt) Invoked by a session to inform that a lock token has been removed.
void	onEvent(javax.jcr.observation.EventIterator events)
void	setEventChannel(LockEventChannel eventChannel) Set a lock event channel
void	unlock(NodeImpl node) Removes the lock on a node given by its path.

Methods inherited from class java.lang.Object

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

Constructor Detail

LockManagerImpl

public LockManagerImpl(SessionImpl session,
                       FileSystem fs)
                throws javax.jcr.RepositoryException

Create a new instance of this class.

Parameters:

session - system session

fs - file system for persisting locks

Throws:

javax.jcr.RepositoryException - if an error occurs

Method Detail

close

public void close()

Close this lock manager. Writes back all changes.

getLockInfo

public AbstractLockInfo getLockInfo(NodeId id)
                             throws javax.jcr.RepositoryException

Return the most appropriate lock information for a node. This is either the lock info for the node itself, if it is locked, or a lock info for one of its parents, if that is deep locked.

Returns:

lock info or null if node is not locked

Throws:

javax.jcr.RepositoryException - if an error occurs

lock

public javax.jcr.lock.Lock lock(NodeImpl node,
                                boolean isDeep,
                                boolean isSessionScoped)
                         throws javax.jcr.lock.LockException,
                                javax.jcr.RepositoryException

Lock a node. Checks whether the node is not locked and then returns a lock object for this node.

Specified by:

lock in interface LockManager

Parameters:

node - node

isDeep - whether the lock applies to this node only

isSessionScoped - whether the lock is session scoped

Returns:

lock object

Throws:

javax.jcr.lock.LockException - if this node already is locked, or some descendant node is locked and isDeep is true

javax.jcr.RepositoryException

See Also:

Node.lock(boolean, boolean)

getLock

public javax.jcr.lock.Lock getLock(NodeImpl node)
                            throws javax.jcr.lock.LockException,
                                   javax.jcr.RepositoryException

Returns the Lock object that applies to a node. This may be either a lock on this node itself or a deep lock on a node above this node.

Specified by:

getLock in interface LockManager

Parameters:

node - node

Returns:

lock object

Throws:

javax.jcr.lock.LockException - if this node is not locked

javax.jcr.RepositoryException

See Also:

Node.getLock()

getLocks

public javax.jcr.lock.Lock[] getLocks(SessionImpl session)
                               throws javax.jcr.RepositoryException

Returns all locks owned by the specified session.

Specified by:

getLocks in interface LockManager

Parameters:

session - session

Returns:

an array of lock objects

Throws:

javax.jcr.RepositoryException - if an error occurs

See Also:

SessionImpl.getLocks()

unlock

public void unlock(NodeImpl node)
            throws javax.jcr.lock.LockException,
                   javax.jcr.RepositoryException

Removes the lock on a node given by its path.

In order to prevent deadlocks from within the synchronous dispatching of events, content modifications should not be made from within code sections that hold monitors. (see #JCR-194)

Specified by:

unlock in interface LockManager

Parameters:

node - node

Throws:

javax.jcr.lock.LockException - if this node is not locked or the session does not have the correct lock token

javax.jcr.RepositoryException

See Also:

Node.unlock()

holdsLock

public boolean holdsLock(NodeImpl node)
                  throws javax.jcr.RepositoryException

Returns true if the node given holds a lock; otherwise returns false.

Specified by:

holdsLock in interface LockManager

Parameters:

node - node

Returns:

true if the node given holds a lock; otherwise returns false

Throws:

javax.jcr.RepositoryException

See Also:

Node.holdsLock()

isLockHolder

public boolean isLockHolder(javax.jcr.Session session,
                            NodeImpl node)
                     throws javax.jcr.RepositoryException

Returns true if the specified session holds a lock on the given node; otherwise returns false.

Note that isLockHolder(session, node)==true implies holdsLock(node)==true.

Specified by:

isLockHolder in interface LockManager

Parameters:

session - session

node - node

Returns:

if the specified session holds a lock on the given node; otherwise returns false

Throws:

javax.jcr.RepositoryException

isLocked

public boolean isLocked(NodeImpl node)
                 throws javax.jcr.RepositoryException

Returns true if this node is locked either as a result of a lock held by this node or by a deep lock on a node above this node; otherwise returns false

Specified by:

isLocked in interface LockManager

Parameters:

node - node

Returns:

true if this node is locked either as a result of a lock held by this node or by a deep lock on a node above this node; otherwise returns false

Throws:

javax.jcr.RepositoryException

See Also:

Node.isLocked()

checkLock

public void checkLock(NodeImpl node)
               throws javax.jcr.lock.LockException,
                      javax.jcr.RepositoryException

Check whether the node given is locked by somebody else than the current session. Access is allowed if the node is not locked or if the session itself holds the lock to this node, i.e. the session contains the lock token for the lock.

Specified by:

checkLock in interface LockManager

Parameters:

node - node to check

Throws:

javax.jcr.lock.LockException - if write access to the specified node is not allowed

javax.jcr.RepositoryException - if some other error occurs

checkLock

public void checkLock(Path path,
                      javax.jcr.Session session)
               throws javax.jcr.lock.LockException,
                      javax.jcr.RepositoryException

Check whether the path given is locked by somebody else than the session described. Access is allowed if the node is not locked or if the session itself holds the lock to this node, i.e. the session contains the lock token for the lock.

Specified by:

checkLock in interface LockManager

Parameters:

path - path to check

session - session

Throws:

javax.jcr.lock.LockException - if write access to the specified path is not allowed

javax.jcr.RepositoryException - if some other error occurs

lockTokenAdded

public void lockTokenAdded(SessionImpl session,
                           java.lang.String lt)

Invoked by a session to inform that a lock token has been added.

Specified by:

lockTokenAdded in interface LockManager

Parameters:

session - session that has a added lock token

lt - added lock token

lockTokenRemoved

public void lockTokenRemoved(SessionImpl session,
                             java.lang.String lt)

Invoked by a session to inform that a lock token has been removed.

Specified by:

lockTokenRemoved in interface LockManager

Parameters:

session - session that has a removed lock token

lt - removed lock token

beginUpdate

public void beginUpdate()

Start an update operation. This will acquire the lock on the lock map and disable saving the lock map file.

endUpdate

public void endUpdate()

End an update operation. This will save the lock map file and release the lock on the lock map.

cancelUpdate

public void cancelUpdate()

Cancel an update operation. This will release the lock on the lock map.

onEvent

public void onEvent(javax.jcr.observation.EventIterator events)

Specified by:

onEvent in interface javax.jcr.observation.EventListener

setEventChannel

public void setEventChannel(LockEventChannel eventChannel)

Set a lock event channel

Parameters:

eventChannel - lock event channel

externalLock

public void externalLock(NodeId nodeId,
                         boolean isDeep,
                         java.lang.String userId)
                  throws javax.jcr.RepositoryException

Handle an external lock operation.

Specified by:

externalLock in interface LockEventListener

Parameters:

nodeId - node id

isDeep - true if the lock is deep; false otherwise

userId - user id

Throws:

javax.jcr.RepositoryException - if the lock cannot be processed

externalUnlock

public void externalUnlock(NodeId nodeId)
                    throws javax.jcr.RepositoryException

Handle an external unlock operation.

Specified by:

externalUnlock in interface LockEventListener

Parameters:

nodeId - node id

Throws:

javax.jcr.RepositoryException - if the unlock cannot be processed

dump

public void dump(java.io.PrintStream ps)

Dump contents of path map and elements included to PrintStream given.

Specified by:

dump in interface Dumpable

Parameters:

ps - print stream to dump to