001/*
002 * HA-JDBC: High-Availability JDBC
003 * Copyright (c) 2004-2007 Paul Ferraro
004 * 
005 * This library is free software; you can redistribute it and/or modify it 
006 * under the terms of the GNU Lesser General Public License as published by the 
007 * Free Software Foundation; either version 2.1 of the License, or (at your 
008 * option) any later version.
009 * 
010 * This library is distributed in the hope that it will be useful, but WITHOUT
011 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
012 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License 
013 * for more details.
014 * 
015 * You should have received a copy of the GNU Lesser General Public License
016 * along with this library; if not, write to the Free Software Foundation, 
017 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
018 * 
019 * Contact: ferraro@users.sourceforge.net
020 */
021package net.sf.hajdbc;
022
023import java.util.Set;
024
025/**
026 * @author Paul Ferraro
027 *
028 */
029public interface StateManager extends DatabaseActivationListener, DatabaseDeactivationListener, Lifecycle
030{
031        /**
032         * Returns the initial state of the cluster.
033         * @return a set of database identifiers, or null, if no initial cluster state was found.
034         */
035        public Set<String> getInitialState();
036        
037        /**
038         * Detects whether or not the membership of this state manager is empty.
039         * Used during cluster panic detection.
040         * @return true, if membership is empty, false otherwise
041         */
042        public boolean isMembershipEmpty();
043}