WriteContext.java

/* This file is part of the db4o object database http://www.db4o.com

Copyright (C) 2004 - 2011  Versant Corporation http://www.versant.com

db4o is free software; you can redistribute it and/or modify it under
the terms of version 3 of the GNU General Public License as published
by the Free Software Foundation.

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, see http://www.gnu.org/licenses/. */
package com.db4o.marshall;

import com.db4o.typehandlers.*;


/**
 * this interface is passed to internal class {@link TypeHandler4} during marshaling
 * and provides methods to marshal objects. 
 */
public interface WriteContext extends Context, WriteBuffer {

    /**
     * makes sure the object is stored and writes the ID of
     * the object to the context.
     * Use this method for first class objects only (objects that
     * have an identity in the database). If the object can potentially
     * be a primitive type, do not use this method but use 
     * a matching {@link WriteBuffer} method instead.
     * @param obj the object to write.
     */
    void writeObject(Object obj);

    /**
     * writes sub-objects, in cases where the {@link TypeHandler4} is known.
     * 
     * @param handler typehandler to be used to write the object.
     * @param obj the object to write
     */
    void writeObject(TypeHandler4 handler, Object obj);

    /**
     * reserves a buffer with a specific length at the current
     * position, to be written in a later step.
     * @param length the length to be reserved. 
     * @return the ReservedBuffer
     */
    ReservedBuffer reserve(int length);
    
}