001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.ade.configuration;
029
030import java.util.HashSet;
031import java.util.Set;
032
033/**
034 * Helper class which keeps track of a set of updates to be performed in a different thread.
035 *
036 * New updates can be added, and all updates can be fetched and removed at the same time.
037 *
038 * @param <U> the type representing the updates
039 */
040public class CmsSynchronizedUpdateSet<U> {
041
042    /** The set of updates to perform. */
043    private Set<U> m_set = new HashSet<U>();
044
045    /**
046     * Adds a new update.<p>
047     *
048     * @param update the update
049     */
050    public synchronized void add(U update) {
051
052        m_set.add(update);
053    }
054
055    /**
056     * Removes all updates from the internal set and returns a new set containing the removed updates.<p>
057     *
058     * @return the removed updates
059     */
060    public synchronized Set<U> removeAll() {
061
062        Set<U> result = new HashSet<U>(m_set);
063        m_set.clear();
064        return result;
065    }
066
067}