/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2012, 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.engine.internal;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.jboss.logging.Logger;
import org.hibernate.AssertionFailure;
import org.hibernate.cache.spi.NaturalIdCacheKey;
import org.hibernate.cache.spi.access.NaturalIdRegionAccessStrategy;
import org.hibernate.engine.spi.PersistenceContext;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.type.Type;
/**
* Maintains a {@link org.hibernate.engine.spi.PersistenceContext}-level 2-way cross-reference (xref) between the
* identifiers and natural ids of entities associated with the PersistenceContext.
* <p/>
* Most operations resolve the proper {@link NaturalIdResolutionCache} to use based on the persister and
* simply delegate calls there.
*
* @author Steve Ebersole
*/
public class NaturalIdXrefDelegate {
private static final Logger LOG = Logger.getLogger( NaturalIdXrefDelegate.class );
private final StatefulPersistenceContext persistenceContext;
private final Map<EntityPersister, NaturalIdResolutionCache> naturalIdResolutionCacheMap = new ConcurrentHashMap<EntityPersister, NaturalIdResolutionCache>();
public NaturalIdXrefDelegate(StatefulPersistenceContext persistenceContext) {
this.persistenceContext = persistenceContext;
}
/**
* Access to the session (via the PersistenceContext) to which this delegate ultimately belongs.
*
* @return The session
*/
protected SessionImplementor session() {
return persistenceContext.getSession();
}
/**
* Creates needed cross-reference entries between the given primary (pk) and natural (naturalIdValues) key values
* for the given persister. Returns an indication of whether entries were actually made. If those values already
* existed as an entry, {@code false} would be returned here.
*
* @param persister The persister representing the entity type.
* @param pk The primary key value
* @param naturalIdValues The natural id value(s)
*
* @return {@code true} if a new entry was actually added; {@code false} otherwise.
*/
public boolean cacheNaturalIdCrossReference(EntityPersister persister, Serializable pk, Object[] naturalIdValues) {
validateNaturalId( persister, naturalIdValues );
NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
if ( entityNaturalIdResolutionCache == null ) {
entityNaturalIdResolutionCache = new NaturalIdResolutionCache( persister );
naturalIdResolutionCacheMap.put( persister, entityNaturalIdResolutionCache );
}
return entityNaturalIdResolutionCache.cache( pk, naturalIdValues );
}
/**
* Handle removing cross reference entries for the given natural-id/pk combo
*
* @param persister The persister representing the entity type.
* @param pk The primary key value
* @param naturalIdValues The natural id value(s)
*
* @return The cached values, if any. May be different from incoming values.
*/
public Object[] removeNaturalIdCrossReference(EntityPersister persister, Serializable pk, Object[] naturalIdValues) {
persister = locatePersisterForKey( persister );
validateNaturalId( persister, naturalIdValues );
NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
Object[] sessionCachedNaturalIdValues = null;
if ( entityNaturalIdResolutionCache != null ) {
final CachedNaturalId cachedNaturalId = entityNaturalIdResolutionCache.pkToNaturalIdMap
.remove( pk );
if ( cachedNaturalId != null ) {
entityNaturalIdResolutionCache.naturalIdToPkMap.remove( cachedNaturalId );
sessionCachedNaturalIdValues = cachedNaturalId.getValues();
}
}
if ( persister.hasNaturalIdCache() ) {
final NaturalIdRegionAccessStrategy naturalIdCacheAccessStrategy = persister
.getNaturalIdCacheAccessStrategy();
final NaturalIdCacheKey naturalIdCacheKey = new NaturalIdCacheKey( naturalIdValues, persister, session() );
naturalIdCacheAccessStrategy.evict( naturalIdCacheKey );
if ( sessionCachedNaturalIdValues != null
&& !Arrays.equals( sessionCachedNaturalIdValues, naturalIdValues ) ) {
final NaturalIdCacheKey sessionNaturalIdCacheKey = new NaturalIdCacheKey( sessionCachedNaturalIdValues, persister, session() );
naturalIdCacheAccessStrategy.evict( sessionNaturalIdCacheKey );
}
}
return sessionCachedNaturalIdValues;
}
/**
* Are the naturals id values cached here (if any) for the given persister+pk combo the same as the given values?
*
* @param persister The persister representing the entity type.
* @param pk The primary key value
* @param naturalIdValues The natural id value(s) to check
*
* @return {@code true} if the given naturalIdValues match the current cached values; {@code false} otherwise.
*/
public boolean sameAsCached(EntityPersister persister, Serializable pk, Object[] naturalIdValues) {
NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
return entityNaturalIdResolutionCache != null
&& entityNaturalIdResolutionCache.sameAsCached( pk, naturalIdValues );
}
/**
* It is only valid to define natural ids at the root of an entity hierarchy. This method makes sure we are
* using the root persister.
*
* @param persister The persister representing the entity type.
*
* @return The root persister.
*/
protected EntityPersister locatePersisterForKey(EntityPersister persister) {
return persistenceContext.getSession().getFactory().getEntityPersister( persister.getRootEntityName() );
}
/**
* Invariant validate of the natural id. Checks include<ul>
* <li>that the entity defines a natural id</li>
* <li>the number of natural id values matches the expected number</li>
* </ul>
*
* @param persister The persister representing the entity type.
* @param naturalIdValues The natural id values
*/
protected void validateNaturalId(EntityPersister persister, Object[] naturalIdValues) {
if ( !persister.hasNaturalIdentifier() ) {
throw new IllegalArgumentException( "Entity did not define a natrual-id" );
}
if ( persister.getNaturalIdentifierProperties().length != naturalIdValues.length ) {
throw new IllegalArgumentException( "Mismatch between expected number of natural-id values and found." );
}
}
/**
* Given a persister and primary key, find the locally cross-referenced natural id.
*
* @param persister The persister representing the entity type.
* @param pk The entity primary key
*
* @return The corresponding cross-referenced natural id values, or {@code null} if none
*/
public Object[] findCachedNaturalId(EntityPersister persister, Serializable pk) {
persister = locatePersisterForKey( persister );
final NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
if ( entityNaturalIdResolutionCache == null ) {
return null;
}
final CachedNaturalId cachedNaturalId = entityNaturalIdResolutionCache.pkToNaturalIdMap.get( pk );
if ( cachedNaturalId == null ) {
return null;
}
return cachedNaturalId.getValues();
}
/**
* Given a persister and natural-id value(s), find the locally cross-referenced primary key. Will return
* {@link PersistenceContext.NaturalIdHelper#INVALID_NATURAL_ID_REFERENCE} if the given natural ids are known to
* be invalid (see {@link #stashInvalidNaturalIdReference}).
*
* @param persister The persister representing the entity type.
* @param naturalIdValues The natural id value(s)
*
* @return The corresponding cross-referenced primary key,
* {@link PersistenceContext.NaturalIdHelper#INVALID_NATURAL_ID_REFERENCE},
* or {@code null} if none
*/
public Serializable findCachedNaturalIdResolution(EntityPersister persister, Object[] naturalIdValues) {
persister = locatePersisterForKey( persister );
validateNaturalId( persister, naturalIdValues );
NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
Serializable pk;
final CachedNaturalId cachedNaturalId = new CachedNaturalId( persister, naturalIdValues );
if ( entityNaturalIdResolutionCache != null ) {
pk = entityNaturalIdResolutionCache.naturalIdToPkMap.get( cachedNaturalId );
// Found in session cache
if ( pk != null ) {
if ( LOG.isTraceEnabled() ) {
LOG.trace(
"Resolved natural key -> primary key resolution in session cache: " +
persister.getRootEntityName() + "#[" +
Arrays.toString( naturalIdValues ) + "]"
);
}
return pk;
}
// if we did not find a hit, see if we know about these natural ids as invalid...
if ( entityNaturalIdResolutionCache.containsInvalidNaturalIdReference( naturalIdValues ) ) {
return PersistenceContext.NaturalIdHelper.INVALID_NATURAL_ID_REFERENCE;
}
}
// Session cache miss, see if second-level caching is enabled
if ( !persister.hasNaturalIdCache() ) {
return null;
}
// Try resolution from second-level cache
final NaturalIdCacheKey naturalIdCacheKey = new NaturalIdCacheKey( naturalIdValues, persister, session() );
final NaturalIdRegionAccessStrategy naturalIdCacheAccessStrategy = persister.getNaturalIdCacheAccessStrategy();
pk = CacheHelper.fromSharedCache( session(), naturalIdCacheKey, naturalIdCacheAccessStrategy );
// Found in second-level cache, store in session cache
final SessionFactoryImplementor factory = session().getFactory();
if ( pk != null ) {
if ( factory.getStatistics().isStatisticsEnabled() ) {
factory.getStatisticsImplementor().naturalIdCacheHit(
naturalIdCacheAccessStrategy.getRegion().getName()
);
}
if ( LOG.isTraceEnabled() ) {
// protected to avoid Arrays.toString call unless needed
LOG.tracef(
"Found natural key [%s] -> primary key [%s] xref in second-level cache for %s",
Arrays.toString( naturalIdValues ),
pk,
persister.getRootEntityName()
);
}
if ( entityNaturalIdResolutionCache == null ) {
entityNaturalIdResolutionCache = new NaturalIdResolutionCache( persister );
naturalIdResolutionCacheMap.put( persister, entityNaturalIdResolutionCache );
}
entityNaturalIdResolutionCache.pkToNaturalIdMap.put( pk, cachedNaturalId );
entityNaturalIdResolutionCache.naturalIdToPkMap.put( cachedNaturalId, pk );
}
else if ( factory.getStatistics().isStatisticsEnabled() ) {
factory.getStatisticsImplementor().naturalIdCacheMiss( naturalIdCacheAccessStrategy.getRegion().getName() );
}
return pk;
}
/**
* Return all locally cross-referenced primary keys for the given persister. Used as part of load
* synchronization process.
*
* @param persister The persister representing the entity type.
*
* @return The primary keys
*
* @see org.hibernate.NaturalIdLoadAccess#setSynchronizationEnabled
*/
public Collection<Serializable> getCachedPkResolutions(EntityPersister persister) {
persister = locatePersisterForKey( persister );
Collection<Serializable> pks = null;
NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
if ( entityNaturalIdResolutionCache != null ) {
pks = entityNaturalIdResolutionCache.pkToNaturalIdMap.keySet();
}
if ( pks == null || pks.isEmpty() ) {
return java.util.Collections.emptyList();
}
else {
return java.util.Collections.unmodifiableCollection( pks );
}
}
/**
* As part of "load synchronization process", if a particular natural id is found to have changed we need to track
* its invalidity until after the next flush. This method lets the "load synchronization process" indicate
* when it has encountered such changes.
*
* @param persister The persister representing the entity type.
* @param invalidNaturalIdValues The "old" natural id values.
*
* @see org.hibernate.NaturalIdLoadAccess#setSynchronizationEnabled
*/
public void stashInvalidNaturalIdReference(EntityPersister persister, Object[] invalidNaturalIdValues) {
persister = locatePersisterForKey( persister );
final NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
if ( entityNaturalIdResolutionCache == null ) {
throw new AssertionFailure( "Expecting NaturalIdResolutionCache to exist already for entity " + persister.getEntityName() );
}
entityNaturalIdResolutionCache.stashInvalidNaturalIdReference( invalidNaturalIdValues );
}
/**
* Again, as part of "load synchronization process" we need to also be able to clear references to these
* known-invalid natural-ids after flush. This method exposes that capability.
*/
public void unStashInvalidNaturalIdReferences() {
for ( NaturalIdResolutionCache naturalIdResolutionCache : naturalIdResolutionCacheMap.values() ) {
naturalIdResolutionCache.unStashInvalidNaturalIdReferences();
}
}
/**
* Used to put natural id values into collections. Useful mainly to apply equals/hashCode implementations.
*/
private static class CachedNaturalId {
private final EntityPersister persister;
private final Object[] values;
private final Type[] naturalIdTypes;
private int hashCode;
public CachedNaturalId(EntityPersister persister, Object[] values) {
this.persister = persister;
this.values = values;
final int prime = 31;
int hashCodeCalculation = 1;
hashCodeCalculation = prime * hashCodeCalculation + persister.hashCode();
final int[] naturalIdPropertyIndexes = persister.getNaturalIdentifierProperties();
naturalIdTypes = new Type[ naturalIdPropertyIndexes.length ];
int i = 0;
for ( int naturalIdPropertyIndex : naturalIdPropertyIndexes ) {
final Type type = persister.getPropertyType( persister.getPropertyNames()[ naturalIdPropertyIndex ] );
naturalIdTypes[i] = type;
int elementHashCode = values[i] == null ? 0 :type.getHashCode( values[i], persister.getFactory() );
hashCodeCalculation = prime * hashCodeCalculation + elementHashCode;
i++;
}
this.hashCode = hashCodeCalculation;
}
public Object[] getValues() {
return values;
}
@Override
public int hashCode() {
return this.hashCode;
}
@Override
public boolean equals(Object obj) {
if ( this == obj ) {
return true;
}
if ( obj == null ) {
return false;
}
if ( getClass() != obj.getClass() ) {
return false;
}
final CachedNaturalId other = (CachedNaturalId) obj;
return persister.equals( other.persister ) && isSame(other.values );
}
private boolean isSame(Object[] otherValues) {
// lengths have already been verified at this point
for ( int i = 0; i < naturalIdTypes.length; i++ ) {
if ( ! naturalIdTypes[i].isEqual( values[i], otherValues[i], persister.getFactory() ) ) {
return false;
}
}
return true;
}
}
/**
* Represents the persister-specific cross-reference cache.
*/
private static class NaturalIdResolutionCache implements Serializable {
private final EntityPersister persister;
private final Type[] naturalIdTypes;
private Map<Serializable, CachedNaturalId> pkToNaturalIdMap = new ConcurrentHashMap<Serializable, CachedNaturalId>();
private Map<CachedNaturalId, Serializable> naturalIdToPkMap = new ConcurrentHashMap<CachedNaturalId, Serializable>();
private List<CachedNaturalId> invalidNaturalIdList;
private NaturalIdResolutionCache(EntityPersister persister) {
this.persister = persister;
final int[] naturalIdPropertyIndexes = persister.getNaturalIdentifierProperties();
naturalIdTypes = new Type[ naturalIdPropertyIndexes.length ];
int i = 0;
for ( int naturalIdPropertyIndex : naturalIdPropertyIndexes ) {
naturalIdTypes[i++] = persister.getPropertyType( persister.getPropertyNames()[ naturalIdPropertyIndex ] );
}
}
public EntityPersister getPersister() {
return persister;
}
public boolean sameAsCached(Serializable pk, Object[] naturalIdValues) {
if ( pk == null ) {
return false;
}
final CachedNaturalId initial = pkToNaturalIdMap.get( pk );
if ( initial != null ) {
if ( initial.isSame( naturalIdValues ) ) {
return true;
}
}
return false;
}
public boolean cache(Serializable pk, Object[] naturalIdValues) {
if ( pk == null ) {
return false;
}
final CachedNaturalId initial = pkToNaturalIdMap.get( pk );
if ( initial != null ) {
if ( initial.isSame( naturalIdValues ) ) {
return false;
}
naturalIdToPkMap.remove( initial );
}
final CachedNaturalId cachedNaturalId = new CachedNaturalId( persister, naturalIdValues );
pkToNaturalIdMap.put( pk, cachedNaturalId );
naturalIdToPkMap.put( cachedNaturalId, pk );
return true;
}
public void stashInvalidNaturalIdReference(Object[] invalidNaturalIdValues) {
if ( invalidNaturalIdList == null ) {
invalidNaturalIdList = new ArrayList<CachedNaturalId>();
}
invalidNaturalIdList.add( new CachedNaturalId( persister, invalidNaturalIdValues ) );
}
public boolean containsInvalidNaturalIdReference(Object[] naturalIdValues) {
return invalidNaturalIdList != null
&& invalidNaturalIdList.contains( new CachedNaturalId( persister, naturalIdValues ) );
}
public void unStashInvalidNaturalIdReferences() {
if ( invalidNaturalIdList != null ) {
invalidNaturalIdList.clear();
}
}
}
public void clear() {
naturalIdResolutionCacheMap.clear();
}
}