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