tikhomirov@264: /*
tikhomirov@264:  * Copyright (c) 2011 TMate Software Ltd
tikhomirov@264:  *  
tikhomirov@264:  * This program is free software; you can redistribute it and/or modify
tikhomirov@264:  * it under the terms of the GNU General Public License as published by
tikhomirov@264:  * the Free Software Foundation; version 2 of the License.
tikhomirov@264:  *
tikhomirov@264:  * This program is distributed in the hope that it will be useful,
tikhomirov@264:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@264:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@264:  * GNU General Public License for more details.
tikhomirov@264:  *
tikhomirov@264:  * For information on how to redistribute this software under
tikhomirov@264:  * the terms of a license other than GNU General Public License
tikhomirov@264:  * contact TMate Software at support@hg4j.com
tikhomirov@264:  */
tikhomirov@264: package org.tmatesoft.hg.internal;
tikhomirov@264: 
tikhomirov@431: import org.tmatesoft.hg.util.Convertor;
tikhomirov@304: import org.tmatesoft.hg.util.DirectHashSet;
tikhomirov@304: 
tikhomirov@264: 
tikhomirov@264: /**
tikhomirov@264:  *
tikhomirov@264:  * @author Artem Tikhomirov
tikhomirov@264:  * @author TMate Software Ltd.
tikhomirov@264:  */
tikhomirov@431: public class IdentityPool<T> implements Convertor<T> {
tikhomirov@304: 	private final DirectHashSet<T> unify = new DirectHashSet<T>();
tikhomirov@264: 	
tikhomirov@431: 	public IdentityPool() {
tikhomirov@264: 	}
tikhomirov@264: 	
tikhomirov@431: 	public IdentityPool(int sizeHint) {
tikhomirov@264: 	}
tikhomirov@264: 	
tikhomirov@431: 	public T mangle(T t) {
tikhomirov@431: 		return unify(t);
tikhomirov@431: 	}
tikhomirov@431: 
tikhomirov@264: 	public T unify(T t) {
tikhomirov@264: 		T rv = unify.get(t);
tikhomirov@264: 		if (rv == null) {
tikhomirov@264: 			// first time we see a new value
tikhomirov@264: 			unify.put(t);
tikhomirov@264: 			rv = t;
tikhomirov@264: 		}
tikhomirov@264: 		return rv;
tikhomirov@264: 	}
tikhomirov@264: 	
tikhomirov@264: 	public boolean contains(T t) {
tikhomirov@264: 		return unify.get(t) != null;
tikhomirov@264: 	}
tikhomirov@264: 	
tikhomirov@264: 	public void record(T t) {
tikhomirov@264: 		unify.put(t);
tikhomirov@264: 	}
tikhomirov@264: 	
tikhomirov@264: 	public void clear() {
tikhomirov@264: 		unify.clear();
tikhomirov@264: 	}
tikhomirov@264: 
tikhomirov@264: 	public int size() {
tikhomirov@264: 		return unify.size();
tikhomirov@264: 	}
tikhomirov@264: 
tikhomirov@264: 	@Override
tikhomirov@264: 	public String toString() {
tikhomirov@264: 		StringBuilder sb = new StringBuilder();
tikhomirov@431: 		sb.append(IdentityPool.class.getSimpleName());
tikhomirov@264: 		sb.append('@');
tikhomirov@264: 		sb.append(Integer.toString(System.identityHashCode(this)));
tikhomirov@264: 		sb.append(' ');
tikhomirov@264: 		sb.append(unify.toString());
tikhomirov@264: 		return sb.toString();
tikhomirov@264: 	}
tikhomirov@264: }