com.bigdata.journal.RunState Maven / Gradle / Ivy
/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
[email protected]
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.bigdata.journal;
/**
* Enum of transaction run states.
*
* @author Bryan Thompson
* @version $Id$
*/
public enum RunState {
Active("Active"),
Prepared("Prepared"),
Committed("Committed"),
Aborted("Aborted");
private final String name;
RunState(String name) {
this.name = name;
}
public String toString() {
return name;
}
/**
* Return true iff a transition is allowable from the current
* {@link RunState} to the proposed {@link RunState}.
*
* Note: Only certain state transitions are allowed. These are:
* {Active->Prepared, Active->Aborted, Active->Committed;
* Prepared->Committed, Prepared->Aborted}. Both Committed and Aborted are
* absorbing states.
*
* Note: A transition to the same state is always allowed.
*
* @param newval
* The proposed {@link RunState}.
*
* @return true iff that state transition is allowed.
*/
public boolean isTransitionAllowed(final RunState newval) {
if (newval == null)
throw new IllegalArgumentException();
if (this.equals(newval))
return true;
if (this.equals(Active)) {
if (newval.equals(Prepared))
return true;
if (newval.equals(RunState.Aborted))
return true;
if (newval.equals(Committed))
return true;
return false;
} else if (this.equals(RunState.Prepared)) {
if (newval.equals(Aborted))
return true;
if (newval.equals(Committed))
return true;
return false;
}
return false;
}
}