com.eucalyptus.reporting.upgrade.UpgradeUtils.java Source code

Introduction

Here is the source code for com.eucalyptus.reporting.upgrade.UpgradeUtils.java

Source

/*************************************************************************
 * Copyright 2009-2012 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 ************************************************************************/
package com.eucalyptus.reporting.upgrade;

import java.util.List;
import javax.annotation.Nullable;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.PersistenceContext;
import com.eucalyptus.entities.PersistenceContexts;
import com.eucalyptus.system.Ats;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;

/**
 *
 */
class UpgradeUtils {

    static boolean transactionalForEntity(final Class entityClass,
            final Function<EntityManager, Boolean> callback) {
        final String context = Ats.inClassHierarchy(entityClass).get(PersistenceContext.class).name();
        final EntityManagerFactory entityManagerFactory = PersistenceContexts.getEntityManagerFactory(context);
        final EntityManager entityManager = entityManagerFactory.createEntityManager();
        final EntityTransaction transaction = entityManager.getTransaction();
        transaction.begin();
        boolean success = false;
        try {
            success = callback.apply(entityManager);
        } finally {
            if (success && !transaction.getRollbackOnly()) {
                transaction.commit();
            } else {
                transaction.rollback();
            }
        }
        return success;
    }

    static Function<EntityManager, Boolean> dropTables(final List<String> dropTables) {
        return new Function<EntityManager, Boolean>() {
            @Override
            public Boolean apply(final EntityManager entityManager) {
                return Iterables.all(dropTables, new Predicate<String>() {
                    @Override
                    public boolean apply(final String table) {
                        entityManager.createNativeQuery("drop table if exists " + table).executeUpdate();
                        return true;
                    }
                });
            }
        };
    }
}