Mercurial > hg > blitz_condensed
view src/com/go/trove/util/MapBackedSet.java @ 34:6f68e94c1fb8 default tip
Add CondensedStats monitoring utility, equivalent to vmstat
author | Dominic Cleal <dominic-cleal@cdo2.com> |
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date | Thu, 05 Aug 2010 11:07:25 +0100 |
parents | 3dc0c5604566 |
children |
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/* ==================================================================== * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group * ==================================================================== * The Tea Software License, Version 1.1 * * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the * Walt Disney Internet Group (http://opensource.go.com/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must * not be used to endorse or promote products derived from this * software without prior written permission. For written * permission, please contact opensource@dig.com. * * 5. Products derived from this software may not be called "Tea", * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior * written permission of the Walt Disney Internet Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * For more information about Tea, please see http://opensource.go.com/. */ package com.go.trove.util; import java.util.*; /****************************************************************************** * A set implementation that is backed by any map. * * @author Brian S O'Neill * @version * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 9/07/00 <!-- $--> */ public class MapBackedSet extends AbstractSet implements java.io.Serializable { // Dummy value to associate with an Object in the backing Map private static final Object PRESENT = new Object(); protected final Map mMap; /** * @param map The map to back this set. */ public MapBackedSet(Map map) { mMap = map; } /** * Returns an iterator over the elements in this set. The elements * are returned in the order determined by the backing map. * * @return an Iterator over the elements in this set. * @see ConcurrentModificationException */ public Iterator iterator() { return mMap.keySet().iterator(); } /** * Returns the number of elements in this set (its cardinality). * * @return the number of elements in this set (its cardinality). */ public int size() { return mMap.size(); } /** * Returns true if this set contains no elements. * * @return true if this set contains no elements. */ public boolean isEmpty() { return mMap.isEmpty(); } /** * Returns true if this set contains the specified element. * * @return true if this set contains the specified element. */ public boolean contains(Object obj) { return mMap.containsKey(obj); } /** * Adds the specified element to this set if it is not already * present. * * @param obj element to be added to this set. * @return true if the set did not already contain the specified element. */ public boolean add(Object obj) { return mMap.put(obj, PRESENT) == null; } /** * Removes the given element from this set if it is present. * * @param obj object to be removed from this set, if present. * @return true if the set contained the specified element. */ public boolean remove(Object obj) { return mMap.remove(obj) == PRESENT; } /** * Removes all of the elements from this set. */ public void clear() { mMap.clear(); } }