/******************************************************************************* | |
* Copyright (c) 1998, 2013 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 v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* Oracle - initial API and implementation from Oracle TopLink | |
******************************************************************************/ | |
package org.eclipse.persistence.internal.identitymaps; | |
import java.util.*; | |
import org.eclipse.persistence.descriptors.ClassDescriptor; | |
import org.eclipse.persistence.indirection.ValueHolderInterface; | |
import org.eclipse.persistence.internal.sessions.AbstractSession; | |
import org.eclipse.persistence.mappings.ForeignReferenceMapping; | |
/** | |
* <p><b>Purpose</b>: Provide the capability to not cache objects at all. | |
* <p><b>Responsibilities</b>:<ul> | |
* <li> Do nothing when an object is cached. | |
* </ul> | |
* @since TOPLink/Java 1.0 | |
*/ | |
public class NoIdentityMap extends AbstractIdentityMap { | |
public NoIdentityMap(int size, ClassDescriptor descriptor, AbstractSession session, boolean isolated) { | |
super(size, descriptor, session, isolated); | |
} | |
/** | |
* NoIdentityMap has no locks. | |
*/ | |
@Override | |
public void collectLocks(HashMap threadList) { | |
return; | |
} | |
/** | |
* Return an empty enumerator. | |
*/ | |
@Override | |
public Enumeration elements() { | |
return new Vector(0).elements(); | |
} | |
/** | |
* Return null as no objects are cached. | |
*/ | |
@Override | |
public Object get(Object primaryKey) { | |
return null; | |
} | |
/** | |
* Return null as no objects are cached. | |
*/ | |
@Override | |
public CacheKey getCacheKey(Object searchKey, boolean forMerge) { | |
return null; | |
} | |
/** | |
* Return null as no objects are cached. | |
*/ | |
@Override | |
protected CacheKey putCacheKeyIfAbsent(CacheKey cacheKey) { | |
return null; | |
} | |
/** | |
* Return 0 as no objects are cached. | |
*/ | |
@Override | |
public int getSize() { | |
return 0; | |
} | |
/** | |
* Return 0 as no objects are cached. | |
*/ | |
@Override | |
public int getSize(Class myClass, boolean recurse) { | |
return 0; | |
} | |
/** | |
* Return null as no objects are cached. | |
*/ | |
@Override | |
public Object getWriteLockValue(Object primaryKey) { | |
return null; | |
} | |
/** | |
* Return an empty enumerator. | |
*/ | |
@Override | |
public Enumeration keys() { | |
return new Vector(0).elements(); | |
} | |
/** | |
* Return an empty enumerator. | |
*/ | |
public Enumeration keys(boolean checkReadLocks) { | |
return keys(); | |
} | |
/** | |
* Notify the cache that a lazy relationship has been triggered in the object | |
* and the cache may need to be updated | |
*/ | |
public void lazyRelationshipLoaded(Object object, ValueHolderInterface valueHolder, ForeignReferenceMapping mapping){ | |
//NO-OP | |
} | |
/** | |
* Do Nothing. | |
*/ | |
@Override | |
public CacheKey put(Object primaryKey, Object object, Object writeLockValue, long readTime) { | |
return null; | |
} | |
/** | |
* Do Nothing. | |
* Return null, since no objects are cached. | |
*/ | |
@Override | |
public Object remove(Object primaryKey, Object object) { | |
return null; | |
} | |
/** | |
* Do Nothing. | |
* Return null, since no objects are cached. | |
*/ | |
@Override | |
public Object remove(CacheKey searchKey) { | |
return null; | |
} | |
/** | |
* Do Nothing. | |
*/ | |
@Override | |
public void setWriteLockValue(Object primaryKey, Object writeLockValue) { | |
return; | |
} | |
} |