/*
* Created on 13 May 2008
* Created by Allan Crooks
* Copyright (C) 2007 Aelitis, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program 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.
*
* AELITIS, SAS au capital de 46,603.30 euros
* 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
*/
package com.aelitis.azureus.core.util;
import java.util.HashMap;
import java.util.Map;
/**
* @author Allan Crooks
*
*/
public class CopyOnWriteMap {
private volatile Map map;
public CopyOnWriteMap() {
this.map = new HashMap(0);
}
public void put(Object key, Object val) {
synchronized(this) {
HashMap new_map = new HashMap(map);
new_map.put(key, val);
this.map = new_map;
}
}
public Object remove(Object key) {
synchronized(this) {
HashMap new_map = new HashMap(map);
Object res = new_map.remove(key);
this.map = new_map;
return res;
}
}
public Object get(Object key) {
return this.map.get(key);
}
public int size() {
return this.map.size();
}
public boolean isEmpty() {
return this.map.isEmpty();
}
/*
* shouldn't return underlying map directly as open to abuse. either wrap in unmodifyable
* map or implement desired features explicitly
public Map getMap() {
return this.map;
}
*/
}