/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2000 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.compiler;

import java.util.*;

/** Set that uses == to compare its objects
* WARNING The class does is not consistent with equals
* defined on its items, so it cannot be passed out from the CompilerJob since it's 
* not a well-behaved Collection.
* @author  Jaroslav Tulach
*/
final class IdSet extends AbstractSet {
    HashMap     data;
    
    IdSet() {
        data = new HashMap(17);
    }
    
    /**
     * Assume the added object is a Compiler
     */
    public boolean add(Object o) {
       Object key = new K(o);
       Object old = data.put(key, o);
       if (old == null)
           return true;
       data.put(key, old);
       return false;
    }
    
    public boolean contains(Object o) {
        return data.containsKey(new K(o));
    }
    
    public boolean remove(Object o) {
        return data.remove(new K(o)) != null;
    }
    
    public java.util.Iterator iterator() {
        return data.values().iterator();
    }
    
    public int size() {
        return data.size();
    }
    
    Collection   asImmutableCollection() {
        return Collections.unmodifiableCollection(data.values());
    }
    
    /**
     * Wrapper which "properly" implements hashCode and equals
     */
    static class K {
        Object  key;
        
        K(Object key) {
            this.key = key;
        }
        
        public int hashCode() {
            return key.hashCode();
        }
        
        public boolean equals(Object other) {
            if (!(other instanceof K))
                return false;
            return ((K)other).key == key;
        }
    }
}