/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008-2011, Red Hat Inc. 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 Inc.
*
* 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.event.internal;
import java.io.Serializable;
import java.util.Map;
import org.jboss.logging.Logger;
import org.hibernate.HibernateException;
import org.hibernate.action.internal.CollectionRecreateAction;
import org.hibernate.action.internal.CollectionRemoveAction;
import org.hibernate.action.internal.CollectionUpdateAction;
import org.hibernate.collection.spi.PersistentCollection;
import org.hibernate.engine.internal.Cascade;
import org.hibernate.engine.internal.Collections;
import org.hibernate.engine.spi.ActionQueue;
import org.hibernate.engine.spi.CascadingAction;
import org.hibernate.engine.spi.CollectionEntry;
import org.hibernate.engine.spi.CollectionKey;
import org.hibernate.engine.spi.EntityEntry;
import org.hibernate.engine.spi.PersistenceContext;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.engine.spi.Status;
import org.hibernate.event.service.spi.EventListenerRegistry;
import org.hibernate.event.spi.EventSource;
import org.hibernate.event.spi.EventType;
import org.hibernate.event.spi.FlushEntityEvent;
import org.hibernate.event.spi.FlushEntityEventListener;
import org.hibernate.event.spi.FlushEvent;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.internal.util.EntityPrinter;
import org.hibernate.internal.util.collections.IdentityMap;
import org.hibernate.internal.util.collections.LazyIterator;
import org.hibernate.persister.entity.EntityPersister;
/**
* A convenience base class for listeners whose functionality results in flushing.
*
* @author Steve Ebersole
*/
public abstract class AbstractFlushingEventListener implements Serializable {
private static final CoreMessageLogger LOG = Logger.getMessageLogger( CoreMessageLogger.class, AbstractFlushingEventListener.class.getName() );
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Pre-flushing section
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/**
* Coordinates the processing necessary to get things ready for executions
* as db calls by preping the session caches and moving the appropriate
* entities and collections to their respective execution queues.
*
* @param event The flush event.
* @throws HibernateException Error flushing caches to execution queues.
*/
protected void flushEverythingToExecutions(FlushEvent event) throws HibernateException {
LOG.trace( "Flushing session" );
EventSource session = event.getSession();
final PersistenceContext persistenceContext = session.getPersistenceContext();
session.getInterceptor().preFlush( new LazyIterator( persistenceContext.getEntitiesByKey() ) );
prepareEntityFlushes( session, persistenceContext );
// we could move this inside if we wanted to
// tolerate collection initializations during
// collection dirty checking:
prepareCollectionFlushes( persistenceContext );
// now, any collections that are initialized
// inside this block do not get updated - they
// are ignored until the next flush
persistenceContext.setFlushing(true);
try {
flushEntities( event, persistenceContext );
flushCollections( session, persistenceContext );
}
finally {
persistenceContext.setFlushing(false);
}
//some statistics
logFlushResults( event );
}
@SuppressWarnings( value = {"unchecked"} )
private void logFlushResults(FlushEvent event) {
if ( !LOG.isDebugEnabled() ) {
return;
}
final EventSource session = event.getSession();
final PersistenceContext persistenceContext = session.getPersistenceContext();
LOG.debugf(
"Flushed: %s insertions, %s updates, %s deletions to %s objects",
session.getActionQueue().numberOfInsertions(),
session.getActionQueue().numberOfUpdates(),
session.getActionQueue().numberOfDeletions(),
persistenceContext.getEntityEntries().size()
);
LOG.debugf(
"Flushed: %s (re)creations, %s updates, %s removals to %s collections",
session.getActionQueue().numberOfCollectionCreations(),
session.getActionQueue().numberOfCollectionUpdates(),
session.getActionQueue().numberOfCollectionRemovals(),
persistenceContext.getCollectionEntries().size()
);
new EntityPrinter( session.getFactory() ).toString(
persistenceContext.getEntitiesByKey().entrySet()
);
}
/**
* process cascade save/update at the start of a flush to discover
* any newly referenced entity that must be passed to saveOrUpdate(),
* and also apply orphan delete
*/
private void prepareEntityFlushes(EventSource session, PersistenceContext persistenceContext) throws HibernateException {
LOG.debug( "Processing flush-time cascades" );
final Object anything = getAnything();
//safe from concurrent modification because of how concurrentEntries() is implemented on IdentityMap
for ( Map.Entry me : IdentityMap.concurrentEntries( persistenceContext.getEntityEntries() ) ) {
EntityEntry entry = (EntityEntry) me.getValue();
Status status = entry.getStatus();
if ( status == Status.MANAGED || status == Status.SAVING || status == Status.READ_ONLY ) {
cascadeOnFlush( session, entry.getPersister(), me.getKey(), anything );
}
}
}
private void cascadeOnFlush(EventSource session, EntityPersister persister, Object object, Object anything)
throws HibernateException {
session.getPersistenceContext().incrementCascadeLevel();
try {
new Cascade( getCascadingAction(), Cascade.BEFORE_FLUSH, session )
.cascade( persister, object, anything );
}
finally {
session.getPersistenceContext().decrementCascadeLevel();
}
}
protected Object getAnything() { return null; }
protected CascadingAction getCascadingAction() {
return CascadingAction.SAVE_UPDATE;
}
/**
* Initialize the flags of the CollectionEntry, including the
* dirty check.
*/
private void prepareCollectionFlushes(PersistenceContext persistenceContext) throws HibernateException {
// Initialize dirty flags for arrays + collections with composite elements
// and reset reached, doupdate, etc.
LOG.debug( "Dirty checking collections" );
for ( Map.Entry<PersistentCollection,CollectionEntry> entry :
IdentityMap.concurrentEntries( (Map<PersistentCollection,CollectionEntry>) persistenceContext.getCollectionEntries() )) {
entry.getValue().preFlush( entry.getKey() );
}
}
/**
* 1. detect any dirty entities
* 2. schedule any entity updates
* 3. search out any reachable collections
*/
private void flushEntities(final FlushEvent event, final PersistenceContext persistenceContext) throws HibernateException {
LOG.trace( "Flushing entities and processing referenced collections" );
final EventSource source = event.getSession();
final Iterable<FlushEntityEventListener> flushListeners = source
.getFactory()
.getServiceRegistry()
.getService( EventListenerRegistry.class )
.getEventListenerGroup( EventType.FLUSH_ENTITY )
.listeners();
// Among other things, updateReachables() will recursively load all
// collections that are moving roles. This might cause entities to
// be loaded.
// So this needs to be safe from concurrent modification problems.
// It is safe because of how IdentityMap implements entrySet()
for ( Map.Entry me : IdentityMap.concurrentEntries( persistenceContext.getEntityEntries() ) ) {
// Update the status of the object and if necessary, schedule an update
EntityEntry entry = (EntityEntry) me.getValue();
Status status = entry.getStatus();
if ( status != Status.LOADING && status != Status.GONE ) {
final FlushEntityEvent entityEvent = new FlushEntityEvent( source, me.getKey(), entry );
for ( FlushEntityEventListener listener : flushListeners ) {
listener.onFlushEntity( entityEvent );
}
}
}
source.getActionQueue().sortActions();
}
/**
* process any unreferenced collections and then inspect all known collections,
* scheduling creates/removes/updates
*/
private void flushCollections(final EventSource session, final PersistenceContext persistenceContext) throws HibernateException {
LOG.trace( "Processing unreferenced collections" );
for ( Map.Entry<PersistentCollection,CollectionEntry> me :
IdentityMap.concurrentEntries( (Map<PersistentCollection,CollectionEntry>) persistenceContext.getCollectionEntries() )) {
CollectionEntry ce = me.getValue();
if ( !ce.isReached() && !ce.isIgnore() ) {
Collections.processUnreachableCollection( me.getKey(), session );
}
}
// Schedule updates to collections:
LOG.trace( "Scheduling collection removes/(re)creates/updates" );
ActionQueue actionQueue = session.getActionQueue();
for ( Map.Entry<PersistentCollection,CollectionEntry> me :
IdentityMap.concurrentEntries( (Map<PersistentCollection,CollectionEntry>) persistenceContext.getCollectionEntries() )) {
PersistentCollection coll = me.getKey();
CollectionEntry ce = me.getValue();
if ( ce.isDorecreate() ) {
session.getInterceptor().onCollectionRecreate( coll, ce.getCurrentKey() );
actionQueue.addAction(
new CollectionRecreateAction(
coll,
ce.getCurrentPersister(),
ce.getCurrentKey(),
session
)
);
}
if ( ce.isDoremove() ) {
session.getInterceptor().onCollectionRemove( coll, ce.getLoadedKey() );
actionQueue.addAction(
new CollectionRemoveAction(
coll,
ce.getLoadedPersister(),
ce.getLoadedKey(),
ce.isSnapshotEmpty(coll),
session
)
);
}
if ( ce.isDoupdate() ) {
session.getInterceptor().onCollectionUpdate( coll, ce.getLoadedKey() );
actionQueue.addAction(
new CollectionUpdateAction(
coll,
ce.getLoadedPersister(),
ce.getLoadedKey(),
ce.isSnapshotEmpty(coll),
session
)
);
}
}
actionQueue.sortCollectionActions();
}
/**
* Execute all SQL (and second-level cache updates) in a special order so that foreign-key constraints cannot
* be violated: <ol>
* <li> Inserts, in the order they were performed
* <li> Updates
* <li> Deletion of collection elements
* <li> Insertion of collection elements
* <li> Deletes, in the order they were performed
* </ol>
*
* @param session The session being flushed
*/
protected void performExecutions(EventSource session) {
LOG.trace( "Executing flush" );
// IMPL NOTE : here we alter the flushing flag of the persistence context to allow
// during-flush callbacks more leniency in regards to initializing proxies and
// lazy collections during their processing.
// For more information, see HHH-2763
try {
session.getTransactionCoordinator().getJdbcCoordinator().flushBeginning();
session.getPersistenceContext().setFlushing( true );
// we need to lock the collection caches before executing entity inserts/updates in order to
// account for bi-directional associations
session.getActionQueue().prepareActions();
session.getActionQueue().executeActions();
}
finally {
session.getPersistenceContext().setFlushing( false );
session.getTransactionCoordinator().getJdbcCoordinator().flushEnding();
}
}
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// Post-flushing section
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/**
* 1. Recreate the collection key -> collection map
* 2. rebuild the collection entries
* 3. call Interceptor.postFlush()
*/
protected void postFlush(SessionImplementor session) throws HibernateException {
LOG.trace( "Post flush" );
final PersistenceContext persistenceContext = session.getPersistenceContext();
persistenceContext.getCollectionsByKey().clear();
persistenceContext.getBatchFetchQueue()
.clearSubselects(); //the database has changed now, so the subselect results need to be invalidated
for ( Map.Entry<PersistentCollection, CollectionEntry> me : IdentityMap.concurrentEntries( persistenceContext.getCollectionEntries() ) ) {
CollectionEntry collectionEntry = me.getValue();
PersistentCollection persistentCollection = me.getKey();
collectionEntry.postFlush(persistentCollection);
if ( collectionEntry.getLoadedPersister() == null ) {
//if the collection is dereferenced, remove from the session cache
//iter.remove(); //does not work, since the entrySet is not backed by the set
persistenceContext.getCollectionEntries()
.remove(persistentCollection);
}
else {
//otherwise recreate the mapping between the collection and its key
CollectionKey collectionKey = new CollectionKey(
collectionEntry.getLoadedPersister(),
collectionEntry.getLoadedKey()
);
persistenceContext.getCollectionsByKey().put(collectionKey, persistentCollection);
}
}
session.getInterceptor().postFlush( new LazyIterator( persistenceContext.getEntitiesByKey() ) );
}
}