gecko-dev/gc/boehm/leaksoup/Histogram.java

/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s):
 *
 * Patrick C. Beard <beard@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU Public License (the "GPL"), in which case the
 * provisions of the GPL are applicable instead of those above.
 * If you wish to allow use of your version of this file only
 * under the terms of the GPL and not to allow others to use your
 * version of this file under the NPL, indicate your decision by
 * deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL.  If you do not delete
 * the provisions above, a recipient may use your version of this
 * file under either the NPL or the GPL.
 */

import java.util.Enumeration;
import java.util.Hashtable;

/**
 * Provides a simple way to tally the occurrence of unique objects.
 */
public class Histogram {
	private static class Bin {
		int count = 0;
	};

	private Hashtable bins = new Hashtable();
	
	public void record(Object object) {
		Bin bin = (Bin) bins.get(object);
		if (bin == null) {
			bin = new Bin();
			bins.put(object, bin);
		}
		++bin.count;
	}
	
	public Object[] objects() {
		int count = bins.size();
		Object[] objects = new Object[count];
		Enumeration e = bins.keys();
		while (e.hasMoreElements())
			objects[--count] = e.nextElement();
		return objects;
	}
	
	public int count(Object object) {
		Bin bin = (Bin) bins.get(object);
		if (bin != null)
			return bin.count;
		else
			return 0;
	}
}