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HHH-11032 performance improvements of PersistentBag.equalsSnapshot 

(cherry picked from commit f096445ccc)
This commit is contained in:
Gail Badner 2019-07-10 19:22:09 -07:00 committed by gbadner
parent 3aeb7719d7
commit b99160d12f
1 changed files with 15 additions and 15 deletions
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30
hibernate-core/src/main/java/org/hibernate/collection/internal/PersistentBag.java
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@ -12,7 +12,6 @@ import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
@ -137,34 +136,35 @@ public class PersistentBag extends AbstractPersistentCollection implements List
@Override
@SuppressWarnings( "unchecked" )
public boolean equalsSnapshot(CollectionPersister persister) throws HibernateException {
Type elementType = persister.getElementType();
List<Object> sn = (List<Object>) getSnapshot();
final Type elementType = persister.getElementType();
final List<Object> sn = (List<Object>) getSnapshot();
if ( sn.size() != bag.size() ) {
return false;
}
// HHH-11032 - Group objects by Type.getHashCode() to reduce the complexity of the search
Map<Integer, List<Object>> instanceCountBag = groupByEqualityHash( bag, elementType );
Map<Integer, List<Object>> instanceCountSn = groupByEqualityHash( sn, elementType );
if ( instanceCountBag.size() != instanceCountSn.size() ) {
final Map<Integer, List<Object>> hashToInstancesBag = groupByEqualityHash( bag, elementType );
final Map<Integer, List<Object>> HashToInstancesSn = groupByEqualityHash( sn, elementType );
if ( hashToInstancesBag.size() != HashToInstancesSn.size() ) {
return false;
}
for ( Object elt : bag ) {
List<Object> candidatesBag = getItemsWithSameHash( instanceCountBag, elt, elementType );
List<Object> candidatesSn = getItemsWithSameHash( instanceCountSn, elt, elementType );
if ( countOccurrences( elt, candidatesBag, elementType ) != countOccurrences( elt, candidatesSn, elementType ) ) {
for ( Map.Entry<Integer, List<Object>> hashToInstancesBagEntry : hashToInstancesBag.entrySet() ) {
final int hash = hashToInstancesBagEntry.getKey();
final List<Object> instancesBag = hashToInstancesBagEntry.getValue();
final List<Object> instancesSn = HashToInstancesSn.getOrDefault( hash, Collections.emptyList() );
if ( instancesBag.size() != instancesSn.size() ) {
return false;
}
for ( Object instance : instancesBag ) {
if ( countOccurrences( instance, instancesBag, elementType ) != countOccurrences( instance, instancesSn, elementType ) ) {
return false;
}
}
}
return true;
}
private List<Object> getItemsWithSameHash(Map<Integer, List<Object>> instanceCountBag, Object elt, Type elementType) {
return instanceCountBag.getOrDefault( elementType.getHashCode( elt ), Collections.emptyList() );
}
/**
* Groups items in searchedBag according to persistence "equality" as defined in Type.isSame and Type.getHashCode
*