org.alfresco.repo.domain.locks

Class AbstractLockDAOImpl

java.lang.Object

org.alfresco.repo.domain.locks.AbstractLockDAOImpl

All Implemented Interfaces:

LockDAO

Direct Known Subclasses:

LockDAOImpl

public abstract class AbstractLockDAOImpl
extends Object
implements LockDAO

Abstract implementation of the Locks DAO.

Since:

3.2

Author:

Derek Hulley

Constructor Summary

Constructors

Constructor and Description
AbstractLockDAOImpl()

Method Summary

Modifier and Type	Method and Description
protected abstract LockEntity	createLock(Long sharedResourceId, Long exclusiveResourceId, String lockToken, long timeToLive) Create a new lock.
protected abstract LockResourceEntity	createLockResource(Long qnameNamespaceId, String qnameLocalName) Create a unique lock resource
protected abstract LockEntity	getLock(Long id)
protected abstract LockEntity	getLock(Long sharedResourceId, Long exclusiveResourceId)
void	getLock(org.alfresco.service.namespace.QName lockQName, String lockToken, long timeToLive) Acquire a given exclusive lock, assigning it (and any implicitly shared locks) a timeout.
protected abstract LockResourceEntity	getLockResource(Long qnameNamespaceId, String qnameLocalName) Override to get the unique, lock resource entity if one exists.
protected abstract List<LockEntity>	getLocksBySharedResourceIds(List<Long> sharedLockResourceIds) Get any existing lock data for the shared resources.
protected QNameDAO	getQNameDAO()
void	refreshLock(org.alfresco.service.namespace.QName lockQName, String lockToken, long timeToLive) Refresh a held lock.
boolean	releaseLock(org.alfresco.service.namespace.QName lockQName, String lockToken, boolean optimistic) Release a lock.
void	setQnameDAO(QNameDAO qnameDAO)
protected List<org.alfresco.service.namespace.QName>	splitLockQName(org.alfresco.service.namespace.QName lockQName) Split a lock's qualified name into the component parts using the '.' (period) as a separator on the localname.
protected abstract LockEntity	updateLock(LockEntity lockEntity, String lockToken, long timeToLive) Update an existing lock
protected abstract int	updateLocks(Long exclusiveLockResourceId, String oldLockToken, String newLockToken, long timeToLive)

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractLockDAOImpl

public AbstractLockDAOImpl()

Method Detail

getQNameDAO

protected QNameDAO getQNameDAO()

Returns:

Returns the DAO for namespace ID resolution

setQnameDAO

public void setQnameDAO(QNameDAO qnameDAO)

Parameters:

qnameDAO - DAO for namespace ID resolution

getLock

public void getLock(org.alfresco.service.namespace.QName lockQName,
                    String lockToken,
                    long timeToLive)

Description copied from interface: LockDAO

Acquire a given exclusive lock, assigning it (and any implicitly shared locks) a timeout. All shared locks are implicitly taken as well.

A lock can be re-taken if it has expired and if the lock token has not changed

Specified by:

getLock in interface LockDAO

Parameters:

lockQName - the unique name of the lock to acquire

lockToken - the potential lock token (max 36 chars)

timeToLive - the time (in milliseconds) that the lock must remain

refreshLock

public void refreshLock(org.alfresco.service.namespace.QName lockQName,
                        String lockToken,
                        long timeToLive)

Description copied from interface: LockDAO

Refresh a held lock. This is successful if the lock in question still exists and if the lock token has not changed. Lock expiry does not prevent the lock from being refreshed.

Specified by:

refreshLock in interface LockDAO

Parameters:

lockQName - the unique name of the lock to update

lockToken - the lock token for the lock held

timeToLive - the new time to live (in milliseconds)

releaseLock

public boolean releaseLock(org.alfresco.service.namespace.QName lockQName,
                           String lockToken,
                           boolean optimistic)

Description copied from interface: LockDAO

Release a lock. The lock token must still apply and all the shared and exclusive locks need to still be present, unless the method is optimistic, in which case the unlock is considered to be a success.
Lock expiration does not prevent this operation from succeeding.

Note: Failure to release a lock due to a exception condition is dealt with by passing the exception out.

Specified by:

releaseLock in interface LockDAO

Parameters:

lockQName - the unique name of the lock to release

lockToken - the current lock token

optimistic - true if the release attempt is enough even if the number of released locks was incorrect.

Returns:

Returns true if all the required locks were (still) held under the lock token and were valid at the time of release, otherwise false

getLockResource

protected abstract LockResourceEntity getLockResource(Long qnameNamespaceId,
                                                      String qnameLocalName)

Override to get the unique, lock resource entity if one exists.

Parameters:

qnameNamespaceId - the namespace entity ID

qnameLocalName - the lock localname

Returns:

Returns the lock resource entity, or null if it doesn't exist

createLockResource

protected abstract LockResourceEntity createLockResource(Long qnameNamespaceId,
                                                         String qnameLocalName)

Create a unique lock resource

Parameters:

qnameNamespaceId - the namespace entity ID

qnameLocalName - the lock localname

Returns:

Returns the newly created lock resource entity

getLock

protected abstract LockEntity getLock(Long id)

Parameters:

id - the lock instance ID

Returns:

Returns the lock, if it exists, otherwise null

getLock

protected abstract LockEntity getLock(Long sharedResourceId,
                                      Long exclusiveResourceId)

Parameters:

sharedResourceId - the shared lock resource ID

exclusiveResourceId - the exclusive lock resource ID

Returns:

Returns the lock, if it exists, otherwise null

getLocksBySharedResourceIds

protected abstract List<LockEntity> getLocksBySharedResourceIds(List<Long> sharedLockResourceIds)

Get any existing lock data for the shared resources. The locks returned are not filtered and may be expired.

Parameters:

sharedLockResourceIds - a list of shared resource IDs for which to retrieve the current locks

Returns:

Returns a list of locks (expired or not) for the given lock resources

createLock

protected abstract LockEntity createLock(Long sharedResourceId,
                                         Long exclusiveResourceId,
                                         String lockToken,
                                         long timeToLive)

Create a new lock.

Parameters:

sharedResourceId - the specific resource to lock

exclusiveResourceId - the exclusive lock that is being sought

lockToken - the lock token to assign

timeToLive - the time, in milliseconds, for the lock to remain valid

Returns:

Returns the new lock

Throws:

org.springframework.dao.ConcurrencyFailureException - if the lock was already taken at the time of creation

updateLock

protected abstract LockEntity updateLock(LockEntity lockEntity,
                                         String lockToken,
                                         long timeToLive)

Update an existing lock

Parameters:

lockEntity - the specific lock to update

lockToken - the new lock token

timeToLive - the new lock time, in milliseconds, for the lock to remain valid

Returns:

Returns the updated lock

Throws:

org.springframework.dao.ConcurrencyFailureException - if the entity was not updated

updateLocks

protected abstract int updateLocks(Long exclusiveLockResourceId,
                                   String oldLockToken,
                                   String newLockToken,
                                   long timeToLive)

Parameters:

exclusiveLockResourceId - the exclusive resource ID being locks

oldLockToken - the lock token to change from

newLockToken - the new lock token

timeToLive - the new time to live (in milliseconds)

Returns:

the number of rows updated

splitLockQName

protected List<org.alfresco.service.namespace.QName> splitLockQName(org.alfresco.service.namespace.QName lockQName)

Split a lock's qualified name into the component parts using the '.' (period) as a separator on the localname. The namespace is preserved. The provided qualified name will always be the last component in the returned list.

Parameters:

lockQName - the lock name to split into it's higher-level paths

Returns:

Returns the namespace ID along with the ordered localnames