/* 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.foundation;
public class HashSet4 implements Set4 {
private Hashtable4 _map;
public HashSet4() {
this(1);
}
public HashSet4(int count) {
_map = new Hashtable4(count);
}
public boolean add(Object obj) {
if(_map.containsKey(obj)) {
return false;
}
_map.put(obj, obj);
return true;
}
public void clear() {
_map.clear();
}
public boolean contains(Object obj) {
return _map.containsKey(obj);
}
public boolean isEmpty() {
return _map.size() == 0;
}
public Iterator4 iterator() {
return _map.values().iterator();
}
public boolean remove(Object obj) {
return _map.remove(obj) != null;
}
public int size() {
return _map.size();
}
public String toString() {
return Iterators.join(_map.keys() , "{", "}", ", ");
}
}