Module org.eclipse.persistence.core
Package org.eclipse.persistence.internal.sessions

Class MergeManager

java.lang.Object
org.eclipse.persistence.internal.sessions.MergeManager
public class MergeManager extends Object

Purpose: Used to manage the merge of two objects in a unit of work.

Since:
TOPLink/Java 1.1

  • Field Details

    • session

      protected AbstractSession session
      The unit of work merging for.

    • objectDescriptors

      protected Map<Object,ObjectDescriptor> objectDescriptors
      Used only while refreshing objects on remote session

    • objectsAlreadyMerged

      protected Map<AbstractSession,Map<Object,Object>> objectsAlreadyMerged
      Used to unravel recursion.

    • mergedNewObjects

      protected IdentityHashMap<Object,Object> mergedNewObjects
      Used to keep track of merged new objects.

    • acquiredLocks

      protected ArrayList<CacheKey> acquiredLocks
      Used to store the list of locks that this merge manager has acquired for this merge

    • writeLockQueued

      protected Object writeLockQueued
      If this variable is not null then the mergemanager is waiting on a particular primary key

    • queueNode

      protected LinkedNode queueNode
      Stores the node that holds this mergemanager within the WriteLocksManager queue

    • mergePolicy

      protected int mergePolicy
      Policy that determines merge type (i.e. merge is used for several usages).

    • WORKING_COPY_INTO_ORIGINAL

      protected static final int WORKING_COPY_INTO_ORIGINAL
      See Also:

    • ORIGINAL_INTO_WORKING_COPY

      protected static final int ORIGINAL_INTO_WORKING_COPY
      See Also:

    • CLONE_INTO_WORKING_COPY

      protected static final int CLONE_INTO_WORKING_COPY
      See Also:

    • WORKING_COPY_INTO_REMOTE

      protected static final int WORKING_COPY_INTO_REMOTE
      See Also:

    • REFRESH_REMOTE_OBJECT

      protected static final int REFRESH_REMOTE_OBJECT
      See Also:

    • CHANGES_INTO_DISTRIBUTED_CACHE

      protected static final int CHANGES_INTO_DISTRIBUTED_CACHE
      See Also:

    • CLONE_WITH_REFS_INTO_WORKING_COPY

      protected static final int CLONE_WITH_REFS_INTO_WORKING_COPY
      See Also:

    • cascadePolicy

      protected int cascadePolicy
      Policy that determines how the merge will cascade to its object's parts.

    • NO_CASCADE

      public static final int NO_CASCADE
      See Also:

    • CASCADE_PRIVATE_PARTS

      public static final int CASCADE_PRIVATE_PARTS
      See Also:

    • CASCADE_ALL_PARTS

      public static final int CASCADE_ALL_PARTS
      See Also:

    • CASCADE_BY_MAPPING

      public static final int CASCADE_BY_MAPPING
      See Also:

    • LOCK_ON_MERGE

      public static boolean LOCK_ON_MERGE
      Backdoor to disable merge locks.

    • systemTime

      protected long systemTime
      Stored so that all objects merged by a merge manager can have the same readTime.

    • forceCascade

      protected boolean forceCascade
      Force cascade merge even if a clone is already registered

    • isTransitionedToDeferredLocks

      protected boolean isTransitionedToDeferredLocks
      records that deferred locks have been employed for the merge process

    • lockThread

      protected Thread lockThread
      save the currentThread for later comparison to the activeThread in case they don't match

    • isForRefresh

      protected boolean isForRefresh
      records that this merge process is for a refresh

  • Constructor Details

  • Method Details

    • cascadeAllParts

      public void cascadeAllParts()
      Cascade all parts, this is the default for the merge.

    • cascadePrivateParts

      public void cascadePrivateParts()
      Cascade private parts, this can be used to merge clone when using RMI.

    • dontCascadeParts

      public void dontCascadeParts()
      Merge only direct parts, this can be used to merge clone when using RMI.

    • getAcquiredLocks

      public ArrayList<CacheKey> getAcquiredLocks()

    • getCascadePolicy

      public int getCascadePolicy()

    • getMergePolicy

      protected int getMergePolicy()

    • getObjectDescriptors

      public Map<Object,ObjectDescriptor> getObjectDescriptors()

    • getObjectsAlreadyMerged

      public Map<AbstractSession,Map<Object,Object>> getObjectsAlreadyMerged()

    • getObjectToMerge

      public Object getObjectToMerge(Object sourceValue, ClassDescriptor descriptor, AbstractSession targetSession)

    • getQueueNode

      public LinkedNode getQueueNode()
      INTENRAL: Used to get the node that this merge manager is stored in, within the WriteLocksManager write lockers queue

    • getSession

      public AbstractSession getSession()

    • getSystemTime

      public long getSystemTime()
      Get the stored value of the current time. This method lazily initializes so that read times for the same merge manager can all be set to the same read time

    • getTargetVersionOfSourceObject

      public Object getTargetVersionOfSourceObject(Object source, ClassDescriptor descriptor, AbstractSession targetSession)
      Return the corresponding value that should be assigned to the target object for the source object. This value must be local to the targets object space.

    • registerExistingObjectOfReadOnlyClassInNestedTransaction

      public Object registerExistingObjectOfReadOnlyClassInNestedTransaction(Object source, ClassDescriptor descriptor, AbstractSession targetSession)
      INTERNAL: Used to register an existing object used in nested unit of work with read-only class in root unit of work.

    • getWriteLockQueued

      public Object getWriteLockQueued()
      INTENRAL: Used to get the object that the merge manager is waiting on, in order to acquire locks

    • isForRefresh

      public boolean isForRefresh()
      Returns:
      the isForMerge

    • setForRefresh

      public void setForRefresh(boolean isforRefresh)
      Parameters:
      isforRefresh - the isForMerge to set

    • isTransitionedToDeferredLocks

      public boolean isTransitionedToDeferredLocks()
      INTERNAL: Will return if the merge process has transitioned the active merge locks to deferred locks for readlock deadlock avoidance.

    • mergeChanges

      public Object mergeChanges(Object object, ObjectChangeSet objectChangeSet, AbstractSession targetSession) throws ValidationException
      Recursively merge changes in the object dependent on the merge policy. The map is used to resolve recursion.
      Throws:
      ValidationException

    • recordMerge

      public void recordMerge(Object key, Object value, AbstractSession targetSession)

    • isAlreadyMerged

      public boolean isAlreadyMerged(Object object, AbstractSession targetSession)

    • getMergedObject

      public Object getMergedObject(Object key, AbstractSession targetSession)

    • mergeChangesForRefreshingRemoteObject

      protected Object mergeChangesForRefreshingRemoteObject(Object serverSideDomainObject)
      Recursively merge the RMI clone from the server into the client unit of work working copy. This will only be called if the working copy exists.

    • mergeChangesFromChangeSet

      public void mergeChangesFromChangeSet(UnitOfWorkChangeSet uowChangeSet)
      INTERNAL: Merge the changes to all objects to session's cache.

    • mergeChangesIntoDistributedCache

      protected Object mergeChangesIntoDistributedCache(Object original, ObjectChangeSet changeSet)
      Merge the changes specified within the changeSet into the cache. The object passed in is the original object from the cache.

    • mergeChangesOfCloneIntoWorkingCopy

      protected Object mergeChangesOfCloneIntoWorkingCopy(Object rmiClone)
      Recursively merge to rmi clone into the unit of work working copy. The map is used to resolve recursion.

    • mergeChangesOfOriginalIntoWorkingCopy

      protected Object mergeChangesOfOriginalIntoWorkingCopy(Object clone)
      Recursively merge to original from its parent into the clone. The map is used to resolve recursion.

    • mergeChangesOfWorkingCopyIntoOriginal

      protected Object mergeChangesOfWorkingCopyIntoOriginal(Object clone, ObjectChangeSet objectChangeSet)
      Recursively merge to clone into the original in its parent. The map is used to resolve recursion.

    • mergeChangesOfWorkingCopyIntoOriginal

      protected CacheKey mergeChangesOfWorkingCopyIntoOriginal(Object clone, ObjectChangeSet objectChangeSet, ClassDescriptor descriptor, AbstractSession targetSession, UnitOfWorkImpl unitOfWork)
      Recursively merge to clone into the original in its parent. The map is used to resolve recursion. This is used to merge objects from the unit of work into the shared (or isolated) cache.

    • mergeChangesOfWorkingCopyIntoRemote

      public Object mergeChangesOfWorkingCopyIntoRemote(Object clone) throws ValidationException
      Recursively merge changes in the object dependent on the merge policy. This merges changes from a remote unit of work back from the server into the original remote unit of work. This is meant to merge server-side changes such as sequence numbers, version numbers or events triggered changes.
      Throws:
      ValidationException

    • mergeCloneIntoWorkingCopy

      public void mergeCloneIntoWorkingCopy()
      This can be used by the user for merging clones from RMI into the unit of work.

    • mergeCloneWithReferencesIntoWorkingCopy

      public void mergeCloneWithReferencesIntoWorkingCopy()
      This is used during the merge of dependent objects referencing independent objects, where you want the independent objects merged as well.

    • mergeIntoDistributedCache

      public void mergeIntoDistributedCache()
      This is used during cache synchronization to merge the changes into the distributed cache.

    • mergeNewObjectIntoCache

      public Object mergeNewObjectIntoCache(ObjectChangeSet changeSet)
      Merge a change set for a new object into the cache. This method will create a shell for the new object and then merge the changes from the change set into the object. The newly merged object will then be added to the cache.

    • mergeOriginalIntoWorkingCopy

      public void mergeOriginalIntoWorkingCopy()
      This is used to revert changes to objects, or during refreshes.

    • mergeWorkingCopyIntoOriginal

      public void mergeWorkingCopyIntoOriginal()
      This is used during the unit of work commit to merge changes into the parent.

    • mergeWorkingCopyIntoRemote

      public void mergeWorkingCopyIntoRemote()
      This is used during the unit of work commit to merge changes into the parent.

    • refreshRemoteObject

      public void refreshRemoteObject()
      INTERNAL: This is used to refresh remote session object

    • registerObjectForMergeCloneIntoWorkingCopy

      protected Object registerObjectForMergeCloneIntoWorkingCopy(Object clone, boolean shouldForceCascade)
      INTERNAL: When merging from a clone when the cache cannot be guaranteed the object must be first read if it is existing and not in the cache. Otherwise no changes will be detected as the original state is missing.

    • checkNewObjectLockVersion

      public void checkNewObjectLockVersion(Object clone, Object primaryKey, ClassDescriptor descriptor, UnitOfWorkImpl unitOfWork)
      Check if the new object's version has been set, if so, then it was an existing object that was deleted. Raise an error instead of reincarnating the object.

    • registerRemovedNewObjectIfRequired

      public void registerRemovedNewObjectIfRequired(Object removedObject)
      Determine if the object is a registered new object, and that this is a nested unit of work merge into the parent. In this case private mappings will register the object as being removed.

    • setCascadePolicy

      public void setCascadePolicy(int cascadePolicy)

    • setMergePolicy

      protected void setMergePolicy(int mergePolicy)

    • setForceCascade

      public void setForceCascade(boolean forceCascade)

    • setObjectDescriptors

      public void setObjectDescriptors(Map<Object,ObjectDescriptor> objectDescriptors)

    • setObjectsAlreadyMerged

      protected void setObjectsAlreadyMerged(Map<AbstractSession,Map<Object,Object>> objectsAlreadyMerged)

    • setQueueNode

      public void setQueueNode(LinkedNode node)
      INTENRAL: Used to set the node that this merge manager is stored in, within the WriteLocksManager write lockers queue

    • setSession

      protected void setSession(AbstractSession session)

    • setWriteLockQueued

      public void setWriteLockQueued(Object primaryKey)
      INTENRAL: Used to set the object that the merge manager is waiting on, in order to acquire locks If this value is null then the merge manager is not waiting on any locks.

    • shouldCascadeByMapping

      public boolean shouldCascadeByMapping()
      Flag used to determine that the mappings should be checked for cascade requirements.

    • shouldCascadeAllParts

      public boolean shouldCascadeAllParts()
      Flag used to determine if all parts should be cascaded

    • shouldCascadeParts

      public boolean shouldCascadeParts()
      Flag used to determine if any parts should be cascaded

    • shouldCascadePrivateParts

      public boolean shouldCascadePrivateParts()
      Flag used to determine if any private parts should be cascaded

    • shouldCascadeReferences

      public boolean shouldCascadeReferences()
      Refreshes are based on the objects row, so all attributes of the object must be refreshed. However merging from RMI, normally reference are made transient, so should not be merge unless specified.

    • shouldMergeChangesIntoDistributedCache

      public boolean shouldMergeChangesIntoDistributedCache()
      INTERNAL: This happens when changes from an UnitOfWork is propagated to a distributed class.

    • shouldMergeCloneIntoWorkingCopy

      public boolean shouldMergeCloneIntoWorkingCopy()
      This can be used by the user for merging clones from RMI into the unit of work.

    • shouldMergeCloneWithReferencesIntoWorkingCopy

      public boolean shouldMergeCloneWithReferencesIntoWorkingCopy()
      This can be used by the user for merging remote EJB objects into the unit of work.

    • shouldMergeOriginalIntoWorkingCopy

      public boolean shouldMergeOriginalIntoWorkingCopy()
      This is used to revert changes to objects, or during refreshes.

    • shouldMergeWorkingCopyIntoOriginal

      public boolean shouldMergeWorkingCopyIntoOriginal()
      This is used during the unit of work commit to merge changes into the parent.

    • shouldMergeWorkingCopyIntoRemote

      public boolean shouldMergeWorkingCopyIntoRemote()
      INTERNAL: This happens when serialized remote unit of work has to be merged with local remote unit of work.

    • shouldRefreshRemoteObject

      public boolean shouldRefreshRemoteObject()
      INTERNAL: This is used to refresh objects on the remote session

    • shouldForceCascade

      public boolean shouldForceCascade()
      This is used to cascade merge even if a clone is already registered.

    • getMergedNewObjects

      public IdentityHashMap<Object,Object> getMergedNewObjects()
      INTERNAL: Used to return a map containing new objects found through the registerObjectForMergeCloneIntoWorkingCopy method.
      Returns:
      Map

    • transitionToDeferredLocks

      public void transitionToDeferredLocks()
      INTERNAL: Records that this merge manager has transitioned to use deferred locks during the merge.

    • updateCacheKeyProperties

      protected void updateCacheKeyProperties(UnitOfWorkImpl unitOfWork, CacheKey cacheKey, Object original, Object clone, ObjectChangeSet objectChangeSet, ClassDescriptor descriptor)
      INTERNAL: Update CacheKey properties with new information. This method is called if this code actually merges

    • getLockThread

      public Thread getLockThread()
      INTERNAL:
      Returns:
      lockThread

    • setLockThread

      public void setLockThread(Thread lockThread)
      INTERNAL: Save the currentThread for later comparison to the activeThread in case they don't match