org.hibernate.id.SequenceHiLoGenerator.java Source code

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Here is the source code for org.hibernate.id.SequenceHiLoGenerator.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.id;

import java.io.Serializable;
import java.util.Properties;

import org.hibernate.MappingException;
import org.hibernate.engine.spi.SharedSessionContractImplementor;
import org.hibernate.id.enhanced.AccessCallback;
import org.hibernate.id.enhanced.LegacyHiLoAlgorithmOptimizer;
import org.hibernate.internal.util.config.ConfigurationHelper;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.type.Type;

/**
 * <b>seqhilo</b><br>
 * <br>
 * An <tt>IdentifierGenerator</tt> that combines a hi/lo algorithm with an underlying
 * oracle-style sequence that generates hi values. The user may specify a
 * maximum lo value to determine how often new hi values are fetched.<br>
 * <br>
 * Mapping parameters supported: sequence, max_lo, parameters.
 *
 * @author Gavin King
 *
 * @deprecated See deprecation discussion on {@link SequenceGenerator}
 */
@Deprecated
public class SequenceHiLoGenerator extends SequenceGenerator {
    public static final String MAX_LO = "max_lo";

    private int maxLo;

    private LegacyHiLoAlgorithmOptimizer hiloOptimizer;

    @Override
    public void configure(Type type, Properties params, ServiceRegistry serviceRegistry) throws MappingException {
        super.configure(type, params, serviceRegistry);

        maxLo = ConfigurationHelper.getInt(MAX_LO, params, 9);

        if (maxLo >= 1) {
            hiloOptimizer = new LegacyHiLoAlgorithmOptimizer(getIdentifierType().getReturnedClass(), maxLo);
        }
    }

    @Override
    public synchronized Serializable generate(final SharedSessionContractImplementor session, Object obj) {
        // maxLo < 1 indicates a hilo generator with no hilo :?
        if (maxLo < 1) {
            //keep the behavior consistent even for boundary usages
            IntegralDataTypeHolder value = null;
            while (value == null || value.lt(0)) {
                value = super.generateHolder(session);
            }
            return value.makeValue();
        }

        return hiloOptimizer.generate(new AccessCallback() {
            @Override
            public IntegralDataTypeHolder getNextValue() {
                return generateHolder(session);
            }

            @Override
            public String getTenantIdentifier() {
                return session.getTenantIdentifier();
            }
        });
    }

    /**
     * For testing/assertion purposes
     *
     * @return The optimizer
     */
    LegacyHiLoAlgorithmOptimizer getHiloOptimizer() {
        return hiloOptimizer;
    }
}