/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
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* or http://forgerock.org/license/CDDLv1.0.html.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at legal-notices/CDDLv1_0.txt.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Copyright 2008 Sun Microsystems, Inc.
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*/
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package org.opends.server.replication.common;
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/**
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* This class contains static methods to implement the DS status state machine.
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* They are used to validate the transitions of the state machine according to
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* the current status and event, and to compute the new status.
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* - Status (states of the state machine) are defined in ServerStatus enum
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* - Events are defined in StateMachineEvent enum
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*/
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public class StatusMachine
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{
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/**
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* Checks if a given status is valid as an entering status for the state
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* machine.
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* @param initStatus Initial status to check.
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* @return True if the passed status is a valid initial status.
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*/
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public static boolean isValidInitialStatus(ServerStatus initStatus)
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{
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switch (initStatus)
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{
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case NORMAL_STATUS:
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case DEGRADED_STATUS:
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case BAD_GEN_ID_STATUS:
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return true;
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}
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return false;
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}
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/**
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* Computes the new status of the state machine according to the current
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* status and the new generated event.
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* @param curStatus The current status we start from.
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* @param event The event that must make the current status evolve.
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* @return The newly computed status. If the state transition is impossible
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* according to state machine, special INVALID_STATUS is returned.
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*/
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public static ServerStatus computeNewStatus(ServerStatus curStatus,
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StatusMachineEvent event)
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{
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switch (curStatus)
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{
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// From NOT_CONNECTED_STATUS
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case NOT_CONNECTED_STATUS:
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switch (event)
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{
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case TO_NOT_CONNECTED_STATUS_EVENT:
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return ServerStatus.NOT_CONNECTED_STATUS;
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case TO_NORMAL_STATUS_EVENT:
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return ServerStatus.NORMAL_STATUS;
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case TO_DEGRADED_STATUS_EVENT:
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return ServerStatus.DEGRADED_STATUS;
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case TO_BAD_GEN_ID_STATUS_EVENT:
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return ServerStatus.BAD_GEN_ID_STATUS;
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default:
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return ServerStatus.INVALID_STATUS;
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}
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// From NORMAL_STATUS
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case NORMAL_STATUS:
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switch (event)
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{
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case TO_NOT_CONNECTED_STATUS_EVENT:
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return ServerStatus.NOT_CONNECTED_STATUS;
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case TO_NORMAL_STATUS_EVENT:
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return ServerStatus.NORMAL_STATUS;
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case TO_DEGRADED_STATUS_EVENT:
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return ServerStatus.DEGRADED_STATUS;
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case TO_FULL_UPDATE_STATUS_EVENT:
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return ServerStatus.FULL_UPDATE_STATUS;
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case TO_BAD_GEN_ID_STATUS_EVENT:
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return ServerStatus.BAD_GEN_ID_STATUS;
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default:
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return ServerStatus.INVALID_STATUS;
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}
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// From DEGRADED_STATUS
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case DEGRADED_STATUS:
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switch (event)
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{
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case TO_NOT_CONNECTED_STATUS_EVENT:
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return ServerStatus.NOT_CONNECTED_STATUS;
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case TO_NORMAL_STATUS_EVENT:
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return ServerStatus.NORMAL_STATUS;
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case TO_DEGRADED_STATUS_EVENT:
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return ServerStatus.DEGRADED_STATUS;
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case TO_FULL_UPDATE_STATUS_EVENT:
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return ServerStatus.FULL_UPDATE_STATUS;
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case TO_BAD_GEN_ID_STATUS_EVENT:
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return ServerStatus.BAD_GEN_ID_STATUS;
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default:
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return ServerStatus.INVALID_STATUS;
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}
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// From FULL_UPDATE_STATUS
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case FULL_UPDATE_STATUS:
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switch (event)
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{
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case TO_NOT_CONNECTED_STATUS_EVENT:
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return ServerStatus.NOT_CONNECTED_STATUS;
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case TO_FULL_UPDATE_STATUS_EVENT:
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return ServerStatus.FULL_UPDATE_STATUS;
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default:
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return ServerStatus.INVALID_STATUS;
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}
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// From BAD_GEN_ID_STATUS
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case BAD_GEN_ID_STATUS:
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switch (event)
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{
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case TO_NOT_CONNECTED_STATUS_EVENT:
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return ServerStatus.NOT_CONNECTED_STATUS;
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case TO_FULL_UPDATE_STATUS_EVENT:
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return ServerStatus.FULL_UPDATE_STATUS;
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case TO_BAD_GEN_ID_STATUS_EVENT:
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return ServerStatus.BAD_GEN_ID_STATUS;
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default:
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return ServerStatus.INVALID_STATUS;
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}
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default:
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return ServerStatus.INVALID_STATUS;
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}
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}
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}
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