/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * // Copyright (c) 1998, 2007, Oracle. All rights reserved.
 * 
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
package oracle.toplink.essentials.internal.sequencing;

import oracle.toplink.essentials.internal.sessions.AbstractSession;
import oracle.toplink.essentials.internal.sessions.DatabaseSessionImpl;
import oracle.toplink.essentials.threetier.ClientSession;

/**
 * SequencingFactory is private to TopLink.
 * It instantiates sequencing classes for sessions.
 * It allows sequencing classes to be incupsulated in
 * this package.
 *
 * @see ClientSessionSequencing
 * @see RemoteConnectionSequencing
 * @see SessionBrokerSequencing
 * @see SequencingManager
 *
 */
public class SequencingFactory {

    /**
    * INTERNAL:
    * Takes a potential owner - a Session, returns Sequencing object.
    * Note that before creating a Sequencing object there is a check performed
    * to determine whether the object could be created.
    */
    public static Sequencing createSequencing(AbstractSession session) {
        Sequencing sequencing = null;
        if (session.isClientSession()) {
            ClientSession cs = (ClientSession)session;
            if (ClientSessionSequencing.sequencingServerExists(cs)) {
                sequencing = new ClientSessionSequencing(cs);
            }
        }
        return sequencing;
    }

    /**
    * INTERNAL:
    * Takes a potential owner - a DatabaseSession, returns SequencingHome object.
    * Only DatabaseSession and ServerSession should be passed (not SessionBroker).
    */
    public static SequencingHome createSequencingHome(DatabaseSessionImpl ownerSession) {
        SequencingHome home = null;
        if (!ownerSession.isBroker()) {
            home = new SequencingManager(ownerSession);
        }
        return home;
    }
}