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/*
* Copyright (c) 2009-2013 Eike Stepper (Berlin, Germany) and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Eike Stepper - initial API and implementation
*/
package org.eclipse.emf.cdo.server.internal.db.mapping.horizontal;
import org.eclipse.emf.cdo.common.id.CDOID;
import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
import org.eclipse.emf.cdo.server.db.IIDHandler;
import java.sql.Connection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* @author Eike Stepper
* @since 4.0
*/
public class ObjectTypeCache extends DelegatingObjectTypeMapper
{
public static final int DEFAULT_CACHE_CAPACITY = 100000;
private Map<CDOID, CDOID> memoryCache;
private int cacheSize;
public ObjectTypeCache(int cacheSize)
{
this.cacheSize = cacheSize;
}
@Override
protected CDOID doGetObjectType(IDBStoreAccessor accessor, CDOID id)
{
return memoryCache.get(id);
}
@Override
protected boolean doPutObjectType(IDBStoreAccessor accessor, CDOID id, CDOID type)
{
return memoryCache.put(id, type) == null;
}
@Override
protected boolean doRemoveObjectType(IDBStoreAccessor accessor, CDOID id)
{
return memoryCache.remove(id) != null;
}
@Override
protected CDOID doGetMaxID(Connection connection, IIDHandler idHandler)
{
return null;
}
@Override
protected void doActivate() throws Exception
{
super.doActivate();
memoryCache = Collections.synchronizedMap(new MemoryCache(cacheSize));
}
@Override
protected void doDeactivate() throws Exception
{
memoryCache = null;
super.doDeactivate();
}
/**
* @author Stefan Winkler
*/
private static final class MemoryCache extends LinkedHashMap<CDOID, CDOID>
{
private static final long serialVersionUID = 1L;
private int capacity;
public MemoryCache(int capacity)
{
super(capacity, 0.75f, true);
this.capacity = capacity;
}
@Override
protected boolean removeEldestEntry(java.util.Map.Entry<CDOID, CDOID> eldest)
{
return size() > capacity;
}
}
}
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