org.hibernate.id.enhanced.LegacyHiLoAlgorithmOptimizer Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2013, 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.id.enhanced;
import java.io.Serializable;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.hibernate.HibernateException;
import org.hibernate.id.IntegralDataTypeHolder;
import org.jboss.logging.Logger;
/**
* Slight variation from {@link HiLoOptimizer}, maintaining compatibility with the values generated by the
* legacy Hibernate hilo based generators.
*
* @author Steve Ebersole
*/
public class LegacyHiLoAlgorithmOptimizer extends AbstractOptimizer {
private static final Logger log = Logger.getLogger( LegacyHiLoAlgorithmOptimizer.class );
private final long initialMaxLo;
private static class GenerationState {
private long maxLo;
private long lo;
private IntegralDataTypeHolder hi;
private IntegralDataTypeHolder lastSourceValue;
private IntegralDataTypeHolder value;
}
/**
* Constructs a LegacyHiLoAlgorithmOptimizer
*
* @param returnClass The Java type of the values to be generated
* @param incrementSize The increment size.
*/
public LegacyHiLoAlgorithmOptimizer(Class returnClass, int incrementSize) {
super( returnClass, incrementSize );
if ( incrementSize < 1 ) {
throw new HibernateException( "increment size cannot be less than 1" );
}
if ( log.isTraceEnabled() ) {
log.tracev( "Creating hilo optimizer (legacy) with [incrementSize={0}; returnClass={1}]", incrementSize, returnClass.getName() );
}
initialMaxLo = incrementSize;
}
@Override
public synchronized Serializable generate(AccessCallback callback) {
final GenerationState generationState = locateGenerationState( callback.getTenantIdentifier() );
if ( generationState.lo > generationState.maxLo ) {
generationState.lastSourceValue = callback.getNextValue();
generationState.lo = generationState.lastSourceValue.eq( 0 ) ? 1 : 0;
generationState.hi = generationState.lastSourceValue.copy().multiplyBy( generationState.maxLo + 1 );
}
generationState.value = generationState.hi.copy().add( generationState.lo++ );
return generationState.value.makeValue();
}
private GenerationState noTenantState;
private Map tenantSpecificState;
private GenerationState locateGenerationState(String tenantIdentifier) {
if ( tenantIdentifier == null ) {
if ( noTenantState == null ) {
noTenantState = createGenerationState();
}
return noTenantState;
}
else {
GenerationState state;
if ( tenantSpecificState == null ) {
tenantSpecificState = new ConcurrentHashMap();
state = createGenerationState();
tenantSpecificState.put( tenantIdentifier, state );
}
else {
state = tenantSpecificState.get( tenantIdentifier );
if ( state == null ) {
state = createGenerationState();
tenantSpecificState.put( tenantIdentifier, state );
}
}
return state;
}
}
private GenerationState createGenerationState() {
final GenerationState state = new GenerationState();
state.maxLo = initialMaxLo;
state.lo = initialMaxLo + 1;
return state;
}
private GenerationState noTenantGenerationState() {
if ( noTenantState == null ) {
throw new IllegalStateException( "Could not locate previous generation state for no-tenant" );
}
return noTenantState;
}
@Override
public synchronized IntegralDataTypeHolder getLastSourceValue() {
return noTenantGenerationState().lastSourceValue.copy();
}
@Override
public boolean applyIncrementSizeToSourceValues() {
return false;
}
/**
* Getter for property 'lastValue'.
*
* Exposure intended for testing purposes.
*
* @return Value for property 'lastValue'.
*/
@SuppressWarnings( {"UnusedDeclaration"})
public synchronized IntegralDataTypeHolder getLastValue() {
return noTenantGenerationState().value;
}
}