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/*
* Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.config;
/**
* FlushClearCache persistence property
* defines modes of cache handling after em.flush call followed by em.clear call.
* This property could be specified while creating either EntityManagerFactory
* (createEntityManagerFactory or persistence.xml)
* or EntityManager (createEntityManager); the latter overrides the former.
*
* JPA persistence property Usage:
*
*
properties.add(PersistenceUnitProperties.FLUSH_CLEAR_CACHE, FlushClearCache.Drop);
*
*
Values are case-insensitive.
* "" could be used instead of default value FlushClearCache.DEFAULT.
*/
public class FlushClearCache {
/** Call to clear method causes to drop from EntityManager cache only the objects that haven't been flushed.
* This is the most accurate mode: shared cache is perfect after commit;
* but the least memory effective: smbd repeatedly using flush followed by clear
* may eventually run out of memory in a huge transaction.
*/
public static final String Merge = "Merge";
/** Call to clear method causes to drop the whole EntityManager cache.
* This is the fasteset and using the least memory mode -
* but after commit the shared cache potentially contains stale data.
*/
public static final String Drop = "Drop";
/** Call to clear method causes to drops the whole EntityManager cache,
* on commit the classes that have at least one object updated or deleted
* are invalidated in the shared cache.
* This is a compromise mode: potentially a bit slower than drop,
* but has virtually the same memory efficiency.
* After commit all potentially stale data is invalidated in the shared cache.
*/
public static final String DropInvalidate = "DropInvalidate";
public static final String DEFAULT = DropInvalidate;
}