Glassfish example source code file (VersionConsistencyCache.java)

This example Glassfish source code file (VersionConsistencyCache.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Glassfish tags/keywords

object, object, statemanager, statemanager, versionconsistencycache, versionconsistencycache

The Glassfish VersionConsistencyCache.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. 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_1_1.html
 * or packager/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 packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [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 com.sun.jdo.spi.persistence.support.sqlstore;

/**
 * A cache of "version consistent" StateManager instances.  These instances
 * are used so that we can avoid loading state from the database.
 *
 * @author Dave Bristor
 */
public interface VersionConsistencyCache {
    /**
     * Puts the given StateManager into a map that is keyed by the given OID.
     * We anticipate that implementations will want to use a two-level map,
     * and so the pc's class can be used as a key into a map to access a
     * second map, which would be that keyed by OID.
     * @param pcType class of instance, used as key in outer map.
     * @param oid Object id, used as key in inner map.
     * @param sm StateManager bound to <code>oid in inner map.
     */
    public StateManager put(Class pcType, Object oid, StateManager sm);

    /**
     * Returns an SM, if found, else null.
     * @param pcType class of instance, used as key in outer map.
     * @param oid Object id, used as key in inner map.
     */
    public StateManager get(Class pcType, Object oid);

    /**
     * Removes entry based on pc and oid.  If map is empty after remove,
     * removes it from its containint map.
     * @param pcType class of instance, used as key in outer map.
     * @param oid Object id, used as key in inner map.
     */
    public StateManager remove(Class pcType, Object oid);

    /**
     * Informs the cache to expect that the given pcType will be used as a key
     * for the outer map in subsequent <code>putEntry operations.
     * @param pcType class of instance, used as key in outer map.
     */
    public void addPCType(Class pcType);

    /**
     * Removes the map for the given pcType and all its elements.
     * @param pcType class of instance, used as key in outer map.
     */
    public void removePCType(Class pcType);
}