/*
* 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</code> 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</code> 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);
}