/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.envers.synchronization.work;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.hibernate.Session;
import org.hibernate.collection.spi.PersistentCollection;
import org.hibernate.engine.spi.CollectionEntry;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.envers.RevisionType;
import org.hibernate.envers.configuration.AuditConfiguration;
import org.hibernate.envers.configuration.AuditEntitiesConfiguration;
import org.hibernate.envers.entities.mapper.PersistentCollectionChangeData;
/**
* @author Adam Warski (adam at warski dot org)
*/
public class PersistentCollectionChangeWorkUnit extends AbstractAuditWorkUnit implements AuditWorkUnit {
private final List<PersistentCollectionChangeData> collectionChanges;
private final String referencingPropertyName;
public PersistentCollectionChangeWorkUnit(SessionImplementor sessionImplementor, String entityName,
AuditConfiguration auditCfg, PersistentCollection collection,
CollectionEntry collectionEntry, Serializable snapshot, Serializable id,
String referencingPropertyName) {
super(sessionImplementor, entityName, auditCfg, new PersistentCollectionChangeWorkUnitId(id, collectionEntry.getRole()), RevisionType.MOD);
this.referencingPropertyName = referencingPropertyName;
collectionChanges = auditCfg.getEntCfg().get(getEntityName()).getPropertyMapper()
.mapCollectionChanges(referencingPropertyName, collection, snapshot, id);
}
public PersistentCollectionChangeWorkUnit(SessionImplementor sessionImplementor, String entityName,
AuditConfiguration verCfg, Serializable id,
List<PersistentCollectionChangeData> collectionChanges,
String referencingPropertyName) {
super(sessionImplementor, entityName, verCfg, id, RevisionType.MOD);
this.collectionChanges = collectionChanges;
this.referencingPropertyName = referencingPropertyName;
}
public boolean containsWork() {
return collectionChanges != null && collectionChanges.size() != 0;
}
public Map<String, Object> generateData(Object revisionData) {
throw new UnsupportedOperationException("Cannot generate data for a collection change work unit!");
}
@SuppressWarnings({"unchecked"})
public void perform(Session session, Object revisionData) {
AuditEntitiesConfiguration entitiesCfg = verCfg.getAuditEntCfg();
for (PersistentCollectionChangeData persistentCollectionChangeData : collectionChanges) {
// Setting the revision number
((Map<String, Object>) persistentCollectionChangeData.getData().get(entitiesCfg.getOriginalIdPropName()))
.put(entitiesCfg.getRevisionFieldName(), revisionData);
auditStrategy.performCollectionChange(session, verCfg, persistentCollectionChangeData, revisionData);
}
}
public String getReferencingPropertyName() {
return referencingPropertyName;
}
public List<PersistentCollectionChangeData> getCollectionChanges() {
return collectionChanges;
}
public AuditWorkUnit merge(AddWorkUnit second) {
return null;
}
public AuditWorkUnit merge(ModWorkUnit second) {
return null;
}
public AuditWorkUnit merge(DelWorkUnit second) {
return null;
}
public AuditWorkUnit merge(CollectionChangeWorkUnit second) {
return null;
}
public AuditWorkUnit merge(FakeBidirectionalRelationWorkUnit second) {
return null;
}
public AuditWorkUnit dispatch(WorkUnitMergeVisitor first) {
if (first instanceof PersistentCollectionChangeWorkUnit) {
PersistentCollectionChangeWorkUnit original = (PersistentCollectionChangeWorkUnit) first;
// Merging the collection changes in both work units.
// First building a map from the ids of the collection-entry-entities from the "second" collection changes,
// to the PCCD objects. That way, we will be later able to check if an "original" collection change
// should be added, or if it is overshadowed by a new one.
Map<Object, PersistentCollectionChangeData> newChangesIdMap = new HashMap<Object, PersistentCollectionChangeData>();
for (PersistentCollectionChangeData persistentCollectionChangeData : getCollectionChanges()) {
newChangesIdMap.put(
getOriginalId(persistentCollectionChangeData),
persistentCollectionChangeData);
}
// This will be the list with the resulting (merged) changes.
List<PersistentCollectionChangeData> mergedChanges = new ArrayList<PersistentCollectionChangeData>();
// Including only those original changes, which are not overshadowed by new ones.
for (PersistentCollectionChangeData originalCollectionChangeData : original.getCollectionChanges()) {
Object originalOriginalId = getOriginalId(originalCollectionChangeData);
if (!newChangesIdMap.containsKey(originalOriginalId)) {
mergedChanges.add(originalCollectionChangeData);
} else {
// If the changes collide, checking if the first one isn't a DEL, and the second a subsequent ADD
// If so, removing the change alltogether.
String revTypePropName = verCfg.getAuditEntCfg().getRevisionTypePropName();
if (RevisionType.ADD.equals(newChangesIdMap.get(originalOriginalId).getData().get(
revTypePropName)) && RevisionType.DEL.equals(originalCollectionChangeData.getData().get(
revTypePropName))) {
newChangesIdMap.remove(originalOriginalId);
}
}
}
// Finally adding all of the new changes to the end of the list (the map values may differ from
// getCollectionChanges() because of the last operation above).
mergedChanges.addAll(newChangesIdMap.values());
return new PersistentCollectionChangeWorkUnit(sessionImplementor, entityName, verCfg, id, mergedChanges,
referencingPropertyName);
} else {
throw new RuntimeException("Trying to merge a " + first + " with a PersitentCollectionChangeWorkUnit. " +
"This is not really possible.");
}
}
private Object getOriginalId(PersistentCollectionChangeData persistentCollectionChangeData) {
return persistentCollectionChangeData.getData().get(verCfg.getAuditEntCfg().getOriginalIdPropName());
}
/**
* A unique identifier for a collection work unit. Consists of an id of the owning entity and the name of
* the entity plus the name of the field (the role). This is needed because such collections aren't entities
* in the "normal" mapping, but they are entities for Envers.
*/
public static class PersistentCollectionChangeWorkUnitId implements Serializable {
private static final long serialVersionUID = -8007831518629167537L;
private final Serializable ownerId;
private final String role;
public PersistentCollectionChangeWorkUnitId(Serializable ownerId, String role) {
this.ownerId = ownerId;
this.role = role;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
PersistentCollectionChangeWorkUnitId that = (PersistentCollectionChangeWorkUnitId) o;
if (ownerId != null ? !ownerId.equals(that.ownerId) : that.ownerId != null) return false;
//noinspection RedundantIfStatement
if (role != null ? !role.equals(that.role) : that.role != null) return false;
return true;
}
@Override
public int hashCode() {
int result = ownerId != null ? ownerId.hashCode() : 0;
result = 31 * result + (role != null ? role.hashCode() : 0);
return result;
}
public Serializable getOwnerId() {
return ownerId;
}
}
}