/*
* 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.engine;
import java.io.Serializable;
import org.hibernate.AssertionFailure;
import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.collection.PersistentCollection;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.pretty.MessageHelper;
import org.hibernate.type.CollectionType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Implements book-keeping for the collection persistence by reachability algorithm
* @author Gavin King
*/
public final class Collections {
private Collections() {}
private static final Logger log = LoggerFactory.getLogger(Collections.class);
/**
* record the fact that this collection was dereferenced
*
* @param coll The collection to be updated by unreachability.
* @throws HibernateException
*/
public static void processUnreachableCollection(PersistentCollection coll, SessionImplementor session)
throws HibernateException {
if ( coll.getOwner()==null ) {
processNeverReferencedCollection(coll, session);
}
else {
processDereferencedCollection(coll, session);
}
}
private static void processDereferencedCollection(PersistentCollection coll, SessionImplementor session)
throws HibernateException {
final PersistenceContext persistenceContext = session.getPersistenceContext();
CollectionEntry entry = persistenceContext.getCollectionEntry(coll);
final CollectionPersister loadedPersister = entry.getLoadedPersister();
if ( log.isDebugEnabled() && loadedPersister != null )
log.debug(
"Collection dereferenced: " +
MessageHelper.collectionInfoString(
loadedPersister,
entry.getLoadedKey(),
session.getFactory()
)
);
// do a check
boolean hasOrphanDelete = loadedPersister != null &&
loadedPersister.hasOrphanDelete();
if (hasOrphanDelete) {
Serializable ownerId = loadedPersister.getOwnerEntityPersister()
.getIdentifier( coll.getOwner(), session.getEntityMode() );
if ( ownerId == null ) {
// the owning entity may have been deleted and its identifier unset due to
// identifier-rollback; in which case, try to look up its identifier from
// the persistence context
if ( session.getFactory().getSettings().isIdentifierRollbackEnabled() ) {
EntityEntry ownerEntry = persistenceContext.getEntry( coll.getOwner() );
if ( ownerEntry != null ) {
ownerId = ownerEntry.getId();
}
}
if ( ownerId == null ) {
throw new AssertionFailure( "Unable to determine collection owner identifier for orphan-delete processing" );
}
}
EntityKey key = new EntityKey(
ownerId,
loadedPersister.getOwnerEntityPersister(),
session.getEntityMode()
);
Object owner = persistenceContext.getEntity(key);
if ( owner == null ) {
throw new AssertionFailure(
"collection owner not associated with session: " +
loadedPersister.getRole()
);
}
EntityEntry e = persistenceContext.getEntry(owner);
//only collections belonging to deleted entities are allowed to be dereferenced in the case of orphan delete
if ( e != null && e.getStatus() != Status.DELETED && e.getStatus() != Status.GONE ) {
throw new HibernateException(
"A collection with cascade=\"all-delete-orphan\" was no longer referenced by the owning entity instance: " +
loadedPersister.getRole()
);
}
}
// do the work
entry.setCurrentPersister(null);
entry.setCurrentKey(null);
prepareCollectionForUpdate( coll, entry, session.getEntityMode(), session.getFactory() );
}
private static void processNeverReferencedCollection(PersistentCollection coll, SessionImplementor session)
throws HibernateException {
final PersistenceContext persistenceContext = session.getPersistenceContext();
CollectionEntry entry = persistenceContext.getCollectionEntry(coll);
log.debug(
"Found collection with unloaded owner: " +
MessageHelper.collectionInfoString(
entry.getLoadedPersister(),
entry.getLoadedKey(),
session.getFactory()
)
);
entry.setCurrentPersister( entry.getLoadedPersister() );
entry.setCurrentKey( entry.getLoadedKey() );
prepareCollectionForUpdate( coll, entry, session.getEntityMode(), session.getFactory() );
}
/**
* Initialize the role of the collection.
*
* @param collection The collection to be updated by reachibility.
* @param type The type of the collection.
* @param entity The owner of the collection.
* @throws HibernateException
*/
public static void processReachableCollection(
PersistentCollection collection,
CollectionType type,
Object entity,
SessionImplementor session)
throws HibernateException {
collection.setOwner(entity);
CollectionEntry ce = session.getPersistenceContext().getCollectionEntry(collection);
if ( ce == null ) {
// refer to comment in StatefulPersistenceContext.addCollection()
throw new HibernateException(
"Found two representations of same collection: " +
type.getRole()
);
}
// The CollectionEntry.isReached() stuff is just to detect any silly users
// who set up circular or shared references between/to collections.
if ( ce.isReached() ) {
// We've been here before
throw new HibernateException(
"Found shared references to a collection: " +
type.getRole()
);
}
ce.setReached(true);
SessionFactoryImplementor factory = session.getFactory();
CollectionPersister persister = factory.getCollectionPersister( type.getRole() );
ce.setCurrentPersister(persister);
ce.setCurrentKey( type.getKeyOfOwner(entity, session) ); //TODO: better to pass the id in as an argument?
if ( log.isDebugEnabled() ) {
log.debug(
"Collection found: " +
MessageHelper.collectionInfoString( persister, ce.getCurrentKey(), factory ) +
", was: " +
MessageHelper.collectionInfoString( ce.getLoadedPersister(), ce.getLoadedKey(), factory ) +
( collection.wasInitialized() ? " (initialized)" : " (uninitialized)" )
);
}
prepareCollectionForUpdate( collection, ce, session.getEntityMode(), factory );
}
/**
* 1. record the collection role that this collection is referenced by
* 2. decide if the collection needs deleting/creating/updating (but
* don't actually schedule the action yet)
*/
private static void prepareCollectionForUpdate(
PersistentCollection collection,
CollectionEntry entry,
EntityMode entityMode,
SessionFactoryImplementor factory)
throws HibernateException {
if ( entry.isProcessed() ) {
throw new AssertionFailure( "collection was processed twice by flush()" );
}
entry.setProcessed(true);
final CollectionPersister loadedPersister = entry.getLoadedPersister();
final CollectionPersister currentPersister = entry.getCurrentPersister();
if ( loadedPersister != null || currentPersister != null ) { // it is or was referenced _somewhere_
boolean ownerChanged = loadedPersister != currentPersister || // if either its role changed,
!currentPersister
.getKeyType().isEqual( // or its key changed
entry.getLoadedKey(),
entry.getCurrentKey(),
entityMode, factory
);
if (ownerChanged) {
// do a check
final boolean orphanDeleteAndRoleChanged = loadedPersister != null &&
currentPersister != null &&
loadedPersister.hasOrphanDelete();
if (orphanDeleteAndRoleChanged) {
throw new HibernateException(
"Don't change the reference to a collection with cascade=\"all-delete-orphan\": " +
loadedPersister.getRole()
);
}
// do the work
if ( currentPersister != null ) {
entry.setDorecreate(true); // we will need to create new entries
}
if ( loadedPersister != null ) {
entry.setDoremove(true); // we will need to remove ye olde entries
if ( entry.isDorecreate() ) {
log.trace( "Forcing collection initialization" );
collection.forceInitialization(); // force initialize!
}
}
}
else if ( collection.isDirty() ) { // else if it's elements changed
entry.setDoupdate(true);
}
}
}
}