Mercurial > hg > blitz_condensed
diff src/com/go/trove/util/UsageSet.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
---|---|
date | Sat, 21 Mar 2009 11:00:06 +0000 |
parents | |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/com/go/trove/util/UsageSet.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,107 @@ +/* ==================================================================== + * 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 that orders its elements based on how recently they have been used. + * Most recently used elements appear first in the Set. Elements are marked as + * being used whenever they are added to the Set. To re-position an element, + * re-add it. + * + * @author Brian S O'Neill + * @version + * <!--$$Revision:--> 16 <!-- $-->, <!--$$JustDate:--> 9/07/00 <!-- $--> + */ +public class UsageSet extends MapBackedSet { + /** + * Creates a UsageSet in forward order, MRU first. + */ + public UsageSet() { + this(new HashMap()); + } + + /** + * @param backingMap map to use for storage + */ + public UsageSet(Map backingMap) { + super(new UsageMap(backingMap)); + } + + /** + * With reverse order, elements are ordered least recently used first. The + * ordering of the elements will be consistent with the order they were + * added in. Switching to and from reverse order is performed quickly + * and is not affected by the current size of the set. + */ + public void setReverseOrder(boolean reverse) { + ((UsageMap)mMap).setReverseOrder(reverse); + } + + /** + * Returns the first element in the set, the most recently used. If reverse + * order, then the least recently used is returned. + */ + public Object first() throws NoSuchElementException { + return ((UsageMap)mMap).firstKey(); + } + + /** + * Returns the last element in the set, the least recently used. If reverse + * order, then the most recently used is returned. + */ + public Object last() throws NoSuchElementException { + return ((UsageMap)mMap).lastKey(); + } +}