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

public class LockManagerImpl
extends Object
implements LockManager, SynchronousEventListener, LockEventListener

Provides the functionality needed for locking and unlocking nodes.

Constructor Summary

Constructors

Constructor and Description
LockManagerImpl(SessionImpl session, FileSystem fs, ScheduledExecutorService executor) Create a new instance of this class.

Method Summary

Methods

Modifier and Type	Method and Description
void	addLockToken(SessionImpl session, String lt) Invoked by a session to inform that a lock token has been added.
void	beginUpdate() Start an update operation.
void	cancelUpdate() Cancel an update operation.
protected void	checkLock(LockInfo info, javax.jcr.Session session) Check whether a lock info allows access to a session.
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.
protected void	checkUnlock(LockInfo info, javax.jcr.Session session) Check whether a session is allowed to unlock a node.
void	checkUnlock(javax.jcr.Session session, NodeImpl node) Check whether a session is allowed to unlock a node.
void	close() Close this lock manager.
void	copyOpenScopedLocksFrom(LockManagerImpl source) Helper method that copies all the active open-scoped locks from the given source to this lock manager.
void	endUpdate() End an update operation.
void	externalLock(NodeId nodeId, boolean isDeep, String lockOwner) 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.
LockInfo	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
javax.jcr.lock.Lock	lock(NodeImpl node, boolean isDeep, boolean isSessionScoped) Lock a node.
javax.jcr.lock.Lock	lock(NodeImpl node, boolean isDeep, boolean isSessionScoped, long timoutHint, String ownerInfo) Lock a node.
void	onEvent(javax.jcr.observation.EventIterator events)
protected void	removeLockProperties(NodeImpl node)
void	removeLockToken(SessionImpl session, String lt) Invoked by a session to inform that a lock token has been removed.
void	setEventChannel(LockEventChannel eventChannel) Set a lock event channel
String	toString() Dump contents of path map and elements included to a string.
void	unlock(NodeImpl node) Removes the lock on a node given by its path.
protected void	writeLockProperties(NodeImpl node, String lockOwner, boolean isDeep) Add the lock related properties to the target node.

Methods inherited from class java.lang.Object

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

Constructor Detail

LockManagerImpl

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

Create a new instance of this class.

Parameters:

session - system session

fs - file system for persisting locks

executor - scheduled executor service for handling lock timeouts

Throws:

javax.jcr.RepositoryException - if an error occurs

Method Detail

close

public void close()

Close this lock manager. Writes back all changes.

copyOpenScopedLocksFrom

public void copyOpenScopedLocksFrom(LockManagerImpl source)

Helper method that copies all the active open-scoped locks from the given source to this lock manager. This method is used when backing up repositories, and only works correctly when the source lock manager belongs to the original copy of the workspace being backed up.

Parameters:

source - source lock manager

See Also:

RepositoryCopier

getLockInfo

public LockInfo 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)

lock

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

Description copied from interface: LockManager

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 to create the lock for.

isDeep - whether the lock applies to this node only

isSessionScoped - whether the lock is session scoped

timoutHint - Desired lock timeout in seconds.

ownerInfo - Optional string acting as information about the owner.

Returns:

the lock.

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:

LockManager.lock(String, boolean, boolean, long, String)

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 - If an exception occurs.

See Also:

Node.holdsLock()

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 - If an exception occurs.

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

checkLock

protected void checkLock(LockInfo info,
             javax.jcr.Session session)
                  throws javax.jcr.lock.LockException,
                         javax.jcr.RepositoryException

Check whether a lock info allows access to a session. May be overridden by subclasses to allow access to nodes for sessions other than the lock holder itself.

Default implementation allows access to the lock holder only.

Parameters:

info - info 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

checkUnlock

public void checkUnlock(javax.jcr.Session session,
               NodeImpl node)
                 throws javax.jcr.lock.LockException,
                        javax.jcr.RepositoryException

Check whether a session is allowed to unlock a node.

Specified by:

checkUnlock in interface LockManager

Throws:

javax.jcr.lock.LockException - if unlocking is denied

javax.jcr.RepositoryException - if some other error occurs

checkUnlock

protected void checkUnlock(LockInfo info,
               javax.jcr.Session session)
                    throws javax.jcr.lock.LockException,
                           javax.jcr.RepositoryException

Check whether a session is allowed to unlock a node. May be overridden by subclasses to allow this to sessions other than the lock holder itself.

Default implementation allows unlocking to the lock holder only.

Parameters:

info - info to check

session - session

Throws:

javax.jcr.lock.LockException - if unlocking is denied

javax.jcr.RepositoryException - if some other error occurs

addLockToken

public void addLockToken(SessionImpl session,
                String lt)
                  throws javax.jcr.lock.LockException,
                         javax.jcr.RepositoryException

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

Specified by:

addLockToken in interface LockManager

Parameters:

session - session that has a added lock token

lt - added lock token

Throws:

javax.jcr.lock.LockException

javax.jcr.RepositoryException

removeLockToken

public void removeLockToken(SessionImpl session,
                   String lt)
                     throws javax.jcr.lock.LockException,
                            javax.jcr.RepositoryException

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

Specified by:

removeLockToken in interface LockManager

Parameters:

session - session that has a removed lock token

lt - removed lock token

Throws:

javax.jcr.lock.LockException

javax.jcr.RepositoryException

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.

writeLockProperties

protected void writeLockProperties(NodeImpl node,
                       String lockOwner,
                       boolean isDeep)
                            throws javax.jcr.RepositoryException

Add the lock related properties to the target node.

Parameters:

node -

lockOwner -

isDeep -

Throws:

javax.jcr.RepositoryException

removeLockProperties

protected void removeLockProperties(NodeImpl node)
                             throws javax.jcr.RepositoryException

Parameters:

node -

Throws:

javax.jcr.RepositoryException

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,
                String lockOwner)
                  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

lockOwner - lock owner

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

toString

public String toString()

Dump contents of path map and elements included to a string.

Overrides:

toString in class Object