/* 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.internal.slots;
import com.db4o.foundation.*;
import com.db4o.internal.*;
/**
* @exclude
*/
public class ReferencedSlot extends TreeInt {
private Slot _slot;
private int _references;
public ReferencedSlot(int a_key) {
super(a_key);
}
public Object shallowClone() {
ReferencedSlot rs = new ReferencedSlot(_key);
rs._slot = _slot;
rs._references = _references;
return super.shallowCloneInternal(rs);
}
public void pointTo(Slot slot) {
_slot = slot;
}
public Tree free(LocalObjectContainer file, Tree treeRoot, Slot slot) {
file.free(_slot.address(), _slot.length());
if (removeReferenceIsLast()) {
if(treeRoot != null){
return treeRoot.removeNode(this);
}
}
pointTo(slot);
return treeRoot;
}
public boolean addReferenceIsFirst() {
_references++;
return (_references == 1);
}
public boolean removeReferenceIsLast() {
_references--;
return _references < 1;
}
public Slot slot() {
return _slot;
}
}