/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
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
*/
/*
* Created on Nov 1, 2013
*/
package com.bigdata.ha;
import java.util.ArrayList;
import com.bigdata.util.concurrent.ExecutionExceptions;
/**
* Response for a 2-phase commit.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class CommitResponse {
/**
* The COMMIT message.
*/
private final CommitRequest req;
/**
* An array of the root cause exceptions for any errors encountered when
* instructing the services to execute the COMMIT message. The indices into
* this collection are correlated with the service join order and the
* PREPARE vote order. The leader is always at index zero.
*/
private final ArrayList<Throwable> causes;
/**
* The number of COMMIT messages that are known to have been processed
* successfully.
*/
private final int nok;
/**
* The number of COMMIT messages that were issued and which failed.
*/
private final int nfail;
public CommitResponse(final CommitRequest req,
final ArrayList<Throwable> causes) {
this.req = req;
this.causes = causes;
int nok = 0, nfail = 0;
for (Throwable t : causes) {
if (t == null)
nok++; // request issued and was Ok.
else
nfail++; // request issued and failed.
}
this.nok = nok;
this.nfail = nfail;
}
public boolean isLeaderOk() {
return causes.get(0) == null;
}
/**
* Number of COMMIT messages that were generated and succeeded.
*/
public int getNOk() {
return nok;
}
/**
* Number of COMMIT messages that were generated and failed.
*/
public int getNFail() {
return nfail;
}
/**
* Return the root cause for the ith service -or- <code>null</code> if the
* COMMIT did not produce an exception for that service.
*/
public Throwable getCause(final int i) {
return causes.get(i);
}
/**
* Throw out the exception(s).
* <p>
* Note: This method is guaranteed to not return normally!
*
* @throws Exception
* if one or more services that voted YES failed the COMMIT.
*
* @throws IllegalStateException
* if all services that voted YES succeeded.
*/
public void throwCauses() throws Exception {
if (causes.isEmpty()) {
// There were no errors.
throw new IllegalStateException();
}
// Throw exception back to the leader.
if (causes.size() == 1)
throw new Exception(causes.get(0));
final int k = req.getPrepareResponse().replicationFactor();
throw new Exception("replicationFactor=" + k + ", nok=" + nok
+ ", nfail=" + nfail, new ExecutionExceptions(causes));
}
}