/*******************************************************************************
* Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.descriptors.changetracking;
import java.beans.PropertyChangeListener;
import java.util.*;
import org.eclipse.persistence.internal.sessions.ObjectChangeSet;
import org.eclipse.persistence.queries.*;
import org.eclipse.persistence.internal.descriptors.*;
import org.eclipse.persistence.internal.descriptors.changetracking.ObjectChangeListener;
import org.eclipse.persistence.internal.sessions.MergeManager;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.mappings.*;
import org.eclipse.persistence.descriptors.DescriptorEvent;
import org.eclipse.persistence.descriptors.DescriptorEventManager;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork;
import org.eclipse.persistence.internal.sessions.UnitOfWorkChangeSet;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
/**
* PUBLIC:
* A DeferredChangeDetectionPolicy defers all change detection to the UnitOfWork's
* change detection process. Essentially, the calculateChanges() method will run
* for all objects in a UnitOfWork. This is the default ObjectChangePolicy unless weaving is used.
*
* @author Tom Ware
*/
public class DeferredChangeDetectionPolicy implements ObjectChangePolicy, java.io.Serializable {
/**
* INTERNAL:
* PERF: Calculate change for the new object, avoids check for new since already know.
*/
public ObjectChangeSet calculateChangesForNewObject(Object clone, UnitOfWorkChangeSet changeSet, UnitOfWorkImpl unitOfWork, ClassDescriptor descriptor, boolean shouldRaiseEvent) {
return calculateChanges(clone, null, true, changeSet, unitOfWork, descriptor, shouldRaiseEvent);
}
/**
* INTERNAL:
* PERF: Calculate change for the new object, avoids check for new since already know.
*/
public ObjectChangeSet calculateChangesForExistingObject(Object clone, UnitOfWorkChangeSet changeSet, UnitOfWorkImpl unitOfWork, ClassDescriptor descriptor, boolean shouldRaiseEvent) {
return calculateChanges(clone, unitOfWork.getBackupClone(clone, descriptor), false, changeSet, unitOfWork, descriptor, shouldRaiseEvent);
}
/**
* INTERNAL:
* calculateChanges creates a change set for a particular object. In DeferredChangeDetectionPolicy
* all mappings will be compared against a backup copy of the object.
* @return an object change set describing
* the changes to this object
* @param clone the Object to compute a change set for
* @param backUp the old version of the object to use for comparison
* @param changeSet the change set to add changes to
* @param unitOfWork the current session
* @param descriptor the descriptor for this object
* @param shouldRaiseEvent indicates whether PreUpdate event should be risen (usually true)
*/
public ObjectChangeSet calculateChanges(Object clone, Object backUp, boolean isNew, UnitOfWorkChangeSet changeSet, UnitOfWorkImpl unitOfWork, ClassDescriptor descriptor, boolean shouldRaiseEvent) {
// PERF: Avoid events if no listeners.
if (descriptor.getEventManager().hasAnyEventListeners() && shouldRaiseEvent) {
// The query is built for compatibility to old event mechanism.
WriteObjectQuery writeQuery = new WriteObjectQuery(clone.getClass());
writeQuery.setObject(clone);
writeQuery.setBackupClone(backUp);
writeQuery.setSession(unitOfWork);
writeQuery.setDescriptor(descriptor);
descriptor.getEventManager().executeEvent(new DescriptorEvent(DescriptorEventManager.PreWriteEvent, writeQuery));
if (isNew) {
descriptor.getEventManager().executeEvent(new DescriptorEvent(DescriptorEventManager.PreInsertEvent, writeQuery));
} else {
descriptor.getEventManager().executeEvent(new DescriptorEvent(DescriptorEventManager.PreUpdateEvent, writeQuery));
}
}
ObjectChangeSet changes = createObjectChangeSet(clone, backUp, changeSet, isNew, unitOfWork, descriptor);
if(changes.hasChanges() && descriptor.hasMappingsPostCalculateChanges() && ! changes.isNew() && ! unitOfWork.getCommitManager().isActive() && !unitOfWork.isNestedUnitOfWork()) {
// if we are in the commit because of an event skip this postCalculateChanges step as we have already executed it.
int size = descriptor.getMappingsPostCalculateChanges().size();
for(int i=0; i < size; i++) {
DatabaseMapping mapping = descriptor.getMappingsPostCalculateChanges().get(i);
org.eclipse.persistence.sessions.changesets.ChangeRecord record = changes.getChangesForAttributeNamed(mapping.getAttributeName());
if(record != null) {
// Deferred attributes will already have been acted on, therefore we need
// to post calculate changes to ensure orphaned objects are removed.
mapping.postCalculateChanges(record, unitOfWork);
}
}
}
//Check if the user set the PK to null and throw an exception (bug# 4569755)
if (changes.getId() == null && !isNew && !changes.isAggregate()) {
if(!(unitOfWork.isNestedUnitOfWork()) || (unitOfWork.isNestedUnitOfWork() && !(unitOfWork.isNewObjectInParent(clone)|| unitOfWork.isUnregisteredNewObjectInParent(unitOfWork.getCloneToOriginals().get(clone))))) {
Object id = descriptor.getObjectBuilder().extractPrimaryKeyFromObject(clone, unitOfWork, false);
throw ValidationException.nullPrimaryKeyInUnitOfWorkClone(clone, id);
}
}
// if forceUpdate or optimistic read locking is on, mark changeSet. This is to force it
// to be stored and used for writing out SQL later on
if ((descriptor.getCMPPolicy() != null) && (descriptor.getCMPPolicy().getForceUpdate())) {
changes.setHasCmpPolicyForcedUpdate(true);
}
if (!changes.hasForcedChangesFromCascadeLocking() && unitOfWork.hasOptimisticReadLockObjects()) {
Boolean modifyVersionField = (Boolean)unitOfWork.getOptimisticReadLockObjects().get(clone);
if ((modifyVersionField != null) && (unitOfWork instanceof RepeatableWriteUnitOfWork) && (((RepeatableWriteUnitOfWork)unitOfWork).getCumulativeUOWChangeSet() != null)) {
// modify the version field if the UOW cumulative change set does not contain a changeset for this clone
if (((RepeatableWriteUnitOfWork)unitOfWork).getCumulativeUOWChangeSet().getObjectChangeSetForClone(clone) == null) {
modifyVersionField = Boolean.TRUE;
}
}
changes.setShouldModifyVersionField(modifyVersionField);
}
if (changes.hasChanges() || changes.hasForcedChanges()) {
return changes;
}
return null;
}
/**
* INTERNAL:
* This is a place holder for reseting the listener on one of the subclasses
*/
public void clearChanges(Object object, UnitOfWorkImpl uow, ClassDescriptor descriptor, boolean forRefresh) {
}
/**
* INTERNAL:
* Create ObjectChangeSet
*/
public ObjectChangeSet createObjectChangeSet(Object clone, Object backUp, org.eclipse.persistence.internal.sessions.UnitOfWorkChangeSet changeSet, boolean isNew, AbstractSession session, ClassDescriptor descriptor) {
return this.createObjectChangeSetThroughComparison(clone, backUp, changeSet, isNew, session, descriptor);
}
/**
* INTERNAL:
* Create ObjectChangeSet
*/
public ObjectChangeSet createObjectChangeSetThroughComparison(Object clone, Object backUp, org.eclipse.persistence.internal.sessions.UnitOfWorkChangeSet changeSet, boolean isNew, AbstractSession session, ClassDescriptor descriptor) {
ObjectBuilder builder = descriptor.getObjectBuilder();
ObjectChangeSet changes = builder.createObjectChangeSet(clone, changeSet, isNew, true, session);
// The following code deals with reads that force changes to the flag associated with optimistic locking.
FetchGroup fetchGroup = null;
// The flag indicates whether should get fetch group - to avoid doing
// that twice. Useful because fetchGroup may be null.
boolean shouldGetFetchGroup = true;
if ((descriptor.usesOptimisticLocking()) && (changes.getId() != null)) {
if (descriptor.hasFetchGroupManager()) {
fetchGroup = descriptor.getFetchGroupManager().getObjectFetchGroup(clone);
}
if (fetchGroup == null || fetchGroup != descriptor.getFetchGroupManager().getIdEntityFetchGroup()) {
changes.setOptimisticLockingPolicyAndInitialWriteLockValue(descriptor.getOptimisticLockingPolicy(), session);
}
// already tried to get the fetch group - no need to do that again.
shouldGetFetchGroup = false;
}
// PERF: Do not create change records for new objects.
if (!isNew || descriptor.shouldUseFullChangeSetsForNewObjects() || descriptor.isDescriptorTypeAggregate()) {
// PERF: Avoid synchronized enumerator as is concurrency bottleneck.
List mappings = descriptor.getMappings();
int mappingsSize = mappings.size();
if(shouldGetFetchGroup && descriptor.hasFetchGroupManager()) {
fetchGroup = descriptor.getFetchGroupManager().getObjectFetchGroup(clone);
}
for (int index = 0; index < mappingsSize; index++) {
DatabaseMapping mapping = (DatabaseMapping)mappings.get(index);
if ((fetchGroup == null) || fetchGroup.containsAttributeInternal(mapping.getAttributeName())) {
changes.addChange(mapping.compareForChange(clone, backUp, changes, session));
}
}
}
return changes;
}
/**
* INTERNAL:
* This method is used to disable changetracking temporarily
*/
public void dissableEventProcessing(Object changeTracker){
//no-op
}
/**
* INTERNAL:
* This method is used to enable changetracking temporarily
*/
public void enableEventProcessing(Object changeTracker){
//no-op
}
/**
* INTERNAL:
* Return true if the Object should be compared, false otherwise. In DeferredChangeDetectionPolicy,
* true is always returned since always allow the UnitOfWork to calculate changes.
* @param object the object that will be compared
* @param unitOfWork the active unitOfWork
* @param descriptor the descriptor for the current object
*/
public boolean shouldCompareExistingObjectForChange(Object object, UnitOfWorkImpl unitOfWork, ClassDescriptor descriptor) {
return true;
}
/**
* INTERNAL:
* Build back up clone. Used if clone is new because listener should not be set.
*/
public Object buildBackupClone(Object clone, ObjectBuilder builder, UnitOfWorkImpl uow) {
return builder.buildBackupClone(clone, uow);
}
/**
* INTERNAL:
* Assign ChangeListener to an aggregate object
*/
public void setAggregateChangeListener(Object parent, Object aggregate, UnitOfWorkImpl uow, ClassDescriptor descriptor, String mappingAttribute){
//no-op
}
/**
* INTERNAL:
* Set ChangeListener for the clone
*/
public PropertyChangeListener setChangeListener(Object clone, UnitOfWorkImpl uow, ClassDescriptor descriptor) {
return null;
}
/**
* INTERNAL:
* Set the ObjectChangeSet on the Listener, initially used for aggregate support
*/
public void setChangeSetOnListener(ObjectChangeSet objectChangeSet, Object clone){
//no-op
}
/**
* INTERNAL:
* Clear changes in the ChangeListener of the clone
*/
public void updateWithChanges(Object clone, ObjectChangeSet objectChangeSet, UnitOfWorkImpl uow, ClassDescriptor descriptor) {
if (objectChangeSet == null) {
return;
}
Object backupClone = uow.getCloneMapping().get(clone);
if (backupClone != null) {
// If new just re-build the backup clone, otherwise use MergeManager (should be a special merge though, not the default constructor like it is...)
if (objectChangeSet.isNew()) {
uow.getCloneMapping().put(clone, descriptor.getObjectBuilder().buildBackupClone(clone, uow));
} else {
MergeManager mergeManager = new MergeManager(uow);
mergeManager.setCascadePolicy(MergeManager.NO_CASCADE);
descriptor.getObjectBuilder().mergeChangesIntoObject(backupClone, objectChangeSet, clone, mergeManager, mergeManager.getSession());
}
}
clearChanges(clone, uow, descriptor, false);
}
/**
* INTERNAL:
* This may cause a property change event to be raised to a listener in the case that a listener exists.
* If there is no listener then this call is a no-op
*/
public void raiseInternalPropertyChangeEvent(Object source, String propertyName, Object oldValue, Object newValue){
//no-op
}
/**
* INTERNAL:
* This method is used to revert an object within the unit of work
* @param cloneMapping may not be the same as what is in the uow
*/
public void revertChanges(Object clone, ClassDescriptor descriptor, UnitOfWorkImpl uow, Map cloneMapping, boolean forRefresh) {
cloneMapping.put(clone, buildBackupClone(clone, descriptor.getObjectBuilder(), uow));
clearChanges(clone, uow, descriptor, forRefresh);
}
/**
* INTERNAL:
* initialize the Policy
*/
public void initialize(AbstractSession session, ClassDescriptor descriptor) {
//do nothing
}
/**
* Used to track instances of the change policies without doing an instance of check
*/
public boolean isDeferredChangeDetectionPolicy(){
return true;
}
/**
* Used to track instances of the change policies without doing an instance of check
*/
public boolean isObjectChangeTrackingPolicy(){
return false;
}
/**
* Used to track instances of the change policies without doing an instance of check
*/
public boolean isAttributeChangeTrackingPolicy(){
return false;
}
/**
* INTERNAL:
* In cases where a relationship with detached or new entities is merged into itself previous changes may have been recorded for
* the detached/new entity that need to be updated.
*/
public void updateListenerForSelfMerge(ObjectChangeListener listener, ForeignReferenceMapping mapping, Object source, Object target, UnitOfWorkImpl unitOfWork) {
//not applicable for this change detection type.
}
}