/* Copyright (C) 2004 - 2008  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
package com.db4o.internal.classindex;

import com.db4o.*;
import com.db4o.internal.*;

/**
 * @exclude
 */
public abstract class AbstractClassIndexStrategy implements ClassIndexStrategy {

	protected final ClassMetadata _yapClass;

	public AbstractClassIndexStrategy(ClassMetadata yapClass) {
		_yapClass = yapClass;
	}

	protected int yapClassID() {
		return _yapClass.getID();
	}

	public int ownLength() {
		return Const4.ID_LENGTH;
	}

	protected abstract void internalAdd(Transaction trans, int id);

	public final void add(Transaction trans, int id) {
		if (DTrace.enabled) {
	        DTrace.ADD_TO_CLASS_INDEX.log(id);
	    }
		checkId(id);
		internalAdd(trans, id);
	}	

	protected abstract void internalRemove(Transaction ta, int id);

	public final void remove(Transaction ta, int id) {
	    if (DTrace.enabled){
	        DTrace.REMOVE_FROM_CLASS_INDEX.log(id);
	    }
	    checkId(id);
	    internalRemove(ta, id);
	}
	
	private void checkId(int id) {
		if (Deploy.debug) {
            if (id == 0) {
                throw new IllegalArgumentException("id can't be zero");
            }
        }
	}
}