/* * * $Id: MessengerState.java,v 1.4 2005/12/20 18:30:01 bondolo Exp $ * * Copyright (c) 2004 Sun Microsystems, Inc.  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 *       Sun Microsystems, Inc. for Project JXTA." *    Alternately, this acknowledgment may appear in the software itself, *    if and wherever such third-party acknowledgments normally appear. * * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" *    must not be used to endorse or promote products derived from this *    software without prior written permission. For written *    permission, please contact Project JXTA at http://www.jxta.org. * * 5. Products derived from this software may not be called "JXTA", *    nor may "JXTA" appear in their name, without prior written *    permission of Sun. * * 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 SUN MICROSYSTEMS 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. * * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of Project JXTA.  For more * information on Project JXTA, please see * <http://www.jxta.org/>. * * This license is based on the BSD license adopted by the Apache Foundation. */package net.jxta.endpoint;/** *  The complete standard messenger life cycle state machine that all messengers  *  must obey. Compliant messengers can be built by implementing and using this  *  class as an engine to orchestrate discrete operations. * *  <p/>In order to use this class, one must implement the various abstract  *  Action methods, so that they trigger the required operations. * *  <p/>Synchronization has to be externally provided and usualy needs to extend *  around sections wider than just the invocation of this class' methods. For  *  example, if the user of this class maintains a queue, the state of the *  queue must be kept consistent with the invocation of {@link #msgsEvent},  *  {@link #saturatedEvent}, and {@link #idleEvent}, which all denote different *  states of that queue. It is suggested to use the instance of this class as *  the synchronization object. **/public abstract class MessengerState {        // All the transition map setup is rather terse because java tends to make     // it extremely verbose. We do not want to end up with 1000 lines of code     // for what amounts to initializing a table.        // Below is a method reference. It permits to put "what to do" in a variable.    // The <tt>doIt</tt> method is given the target object because we want our    // entire transition table to be a static singleton. Otherwise it would cost    // too much initializing each instance of this class.        private interface Action {        public void doIt(MessengerState s);    }        // Action method "pointers".    // The transition table is static. Otherwise it would cost too much initializing each instance of this class.        private final static Action Connect   = new Action(){public void doIt(MessengerState s){s.connectAction();}                         };    private final static Action Closein   = new Action(){public void doIt(MessengerState s){s.closeInputAction();}                      };    private final static Action Start     = new Action(){public void doIt(MessengerState s){s.startAction();}                           };    private final static Action Closeout  = new Action(){public void doIt(MessengerState s){s.closeOutputAction();}                     };    private final static Action Failall   = new Action(){public void doIt(MessengerState s){s.failAllAction();}                         };    private final static Action Closeio   = new Action(){public void doIt(MessengerState s){s.closeInputAction();s.closeOutputAction();}};    private final static Action Closefail = new Action(){public void doIt(MessengerState s){s.closeInputAction();s.failAllAction();}    };    private final static Action Nop       = new Action(){public void doIt(MessengerState s){};                                          };        // A state: what transition each event causes when in that state.    private static class State {        int number;        State stResolve   ; Action acResolve   ;        State stMsgs      ; Action acMsgs      ;        State stSaturated ; Action acSaturated ;        State stClose     ; Action acClose     ;        State stShutdown  ; Action acShutdown  ;        State stUp        ; Action acUp        ;        State stDown      ; Action acDown      ;        State stIdle      ; Action acIdle      ;                void init(int stateNum, Object[] data) {            number = stateNum;            stResolve   = (State) data[0];  acResolve   = (Action) data[1];            stMsgs      = (State) data[2];  acMsgs      = (Action) data[3];            stSaturated = (State) data[4];  acSaturated = (Action) data[5];            stClose     = (State) data[6];  acClose     = (Action) data[7];            stShutdown  = (State) data[8];  acShutdown  = (Action) data[9];            stUp        = (State) data[10]; acUp        = (Action) data[11];            stDown      = (State) data[12]; acDown      = (Action) data[13];            stIdle      = (State) data[14]; acIdle      = (Action) data[15];        }    }            // All the states. (We put them together in a class essentially to simplify initialization).    private static class TransitionMap {                final static State Unresolved  = new State();        final static State ResPending  = new State();        final static State Resolving   = new State();        final static State ResolSat    = new State();        final static State Connected   = new State();        final static State Disconned   = new State();        final static State Reconning   = new State();        final static State ReconSat    = new State();        final static State Sending     = new State();        final static State SendingSat  = new State();        final static State ResClosing  = new State();        final static State ReconClosing= new State();        final static State Closing     = new State();