/*
* 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.event.def;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.hibernate.HibernateException;
import org.hibernate.action.CollectionRecreateAction;
import org.hibernate.action.CollectionRemoveAction;
import org.hibernate.action.CollectionUpdateAction;
import org.hibernate.collection.PersistentCollection;
import org.hibernate.engine.ActionQueue;
import org.hibernate.engine.Cascade;
import org.hibernate.engine.CascadingAction;
import org.hibernate.engine.CollectionEntry;
import org.hibernate.engine.CollectionKey;
import org.hibernate.engine.Collections;
import org.hibernate.engine.EntityEntry;
import org.hibernate.engine.PersistenceContext;
import org.hibernate.engine.Status;
import org.hibernate.event.EventSource;
import org.hibernate.event.FlushEntityEvent;
import org.hibernate.event.FlushEntityEventListener;
import org.hibernate.event.FlushEvent;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.pretty.Printer;
import org.hibernate.util.IdentityMap;
import org.hibernate.util.LazyIterator;
/**
* A convenience base class for listeners whose functionality results in flushing.
*
* @author Steve Eberole
*/
public abstract class AbstractFlushingEventListener implements Serializable {
private static final Logger log = LoggerFactory.getLogger(AbstractFlushingEventListener.class);
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// 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);
// we could move this inside if we wanted to
// tolerate collection initializations during
// collection dirty checking:
prepareCollectionFlushes(session);
// 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);
flushCollections(session);
}
finally {
persistenceContext.setFlushing(false);
}
//some statistics
if ( log.isDebugEnabled() ) {
log.debug( "Flushed: " +
session.getActionQueue().numberOfInsertions() + " insertions, " +
session.getActionQueue().numberOfUpdates() + " updates, " +
session.getActionQueue().numberOfDeletions() + " deletions to " +
persistenceContext.getEntityEntries().size() + " objects"
);
log.debug( "Flushed: " +
session.getActionQueue().numberOfCollectionCreations() + " (re)creations, " +
session.getActionQueue().numberOfCollectionUpdates() + " updates, " +
session.getActionQueue().numberOfCollectionRemovals() + " removals to " +
persistenceContext.getCollectionEntries().size() + " collections"
);
new Printer( session.getFactory() ).toString(
persistenceContext.getEntitiesByKey().values().iterator(),
session.getEntityMode()
);
}
}
/**
* 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) throws HibernateException {
log.debug("processing flush-time cascades");
final Map.Entry[] list = IdentityMap.concurrentEntries( session.getPersistenceContext().getEntityEntries() );
//safe from concurrent modification because of how entryList() is implemented on IdentityMap
final int size = list.length;
final Object anything = getAnything();
for ( int i=0; i<size; i++ ) {
Map.Entry me = list[i];
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(SessionImplementor session) throws HibernateException {
// Initialize dirty flags for arrays + collections with composite elements
// and reset reached, doupdate, etc.
log.debug("dirty checking collections");
final List list = IdentityMap.entries( session.getPersistenceContext().getCollectionEntries() );
final int size = list.size();
for ( int i = 0; i < size; i++ ) {
Map.Entry e = ( Map.Entry ) list.get( i );
( (CollectionEntry) e.getValue() ).preFlush( (PersistentCollection) e.getKey() );
}
}
/**
* 1. detect any dirty entities
* 2. schedule any entity updates
* 3. search out any reachable collections
*/
private void flushEntities(FlushEvent event) throws HibernateException {
log.trace("Flushing entities and processing referenced collections");
// 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()
final EventSource source = event.getSession();
final Map.Entry[] list = IdentityMap.concurrentEntries( source.getPersistenceContext().getEntityEntries() );
final int size = list.length;
for ( int i = 0; i < size; i++ ) {
// Update the status of the object and if necessary, schedule an update
Map.Entry me = list[i];
EntityEntry entry = (EntityEntry) me.getValue();
Status status = entry.getStatus();
if ( status != Status.LOADING && status != Status.GONE ) {
FlushEntityEvent entityEvent = new FlushEntityEvent( source, me.getKey(), entry );
FlushEntityEventListener[] listeners = source.getListeners().getFlushEntityEventListeners();
for ( int j = 0; j < listeners.length; j++ ) {
listeners[j].onFlushEntity(entityEvent);
}
}
}
source.getActionQueue().sortActions();
}
/**
* process any unreferenced collections and then inspect all known collections,
* scheduling creates/removes/updates
*/
private void flushCollections(EventSource session) throws HibernateException {
log.trace("Processing unreferenced collections");
List list = IdentityMap.entries( session.getPersistenceContext().getCollectionEntries() );
int size = list.size();
for ( int i = 0; i < size; i++ ) {
Map.Entry me = ( Map.Entry ) list.get( i );
CollectionEntry ce = (CollectionEntry) me.getValue();
if ( !ce.isReached() && !ce.isIgnore() ) {
Collections.processUnreachableCollection( (PersistentCollection) me.getKey(), session );
}
}
// Schedule updates to collections:
log.trace( "Scheduling collection removes/(re)creates/updates" );
list = IdentityMap.entries( session.getPersistenceContext().getCollectionEntries() );
size = list.size();
ActionQueue actionQueue = session.getActionQueue();
for ( int i = 0; i < size; i++ ) {
Map.Entry me = (Map.Entry) list.get(i);
PersistentCollection coll = (PersistentCollection) me.getKey();
CollectionEntry ce = (CollectionEntry) 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>
*/
protected void performExecutions(EventSource session) throws HibernateException {
log.trace("executing flush");
try {
session.getJDBCContext().getConnectionManager().flushBeginning();
// we need to lock the collection caches before
// executing entity inserts/updates in order to
// account for bidi associations
session.getActionQueue().prepareActions();
session.getActionQueue().executeActions();
}
finally {
session.getJDBCContext().getConnectionManager().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
Iterator iter = persistenceContext.getCollectionEntries().entrySet().iterator();
while ( iter.hasNext() ) {
Map.Entry me = (Map.Entry) iter.next();
CollectionEntry collectionEntry = (CollectionEntry) me.getValue();
PersistentCollection 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(),
session.getEntityMode()
);
persistenceContext.getCollectionsByKey()
.put(collectionKey, persistentCollection);
}
}
session.getInterceptor().postFlush( new LazyIterator( persistenceContext.getEntitiesByKey() ) );
}
}