/**
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
*/
package com.bigdata.rdf.sail;
import java.util.Collection;
import java.util.LinkedList;
import java.util.UUID;
import java.util.concurrent.Future;
import org.apache.log4j.Logger;
import com.bigdata.bop.engine.IRunningQuery;
import com.bigdata.bop.engine.QueryEngine;
import com.bigdata.rdf.sail.model.RunningQuery;
/**
*
* This class encapsulate functionality that is common to the REST API and
* Embedded Graph deployments.
*
* @author beebs
*
*/
public class QueryCancellationHelper {
static private final transient Logger log = Logger
.getLogger(QueryCancellationHelper.class);
public static void cancelQuery(final UUID queryId,
final QueryEngine queryEngine) {
final Collection<UUID> queryIds = new LinkedList<UUID>();
queryIds.add(queryId);
cancelQueries(queryIds, queryEngine);
}
public static void cancelQueries(final Collection<UUID> queryIds,
final QueryEngine queryEngine) {
for (UUID queryId : queryIds) {
if (!tryCancelQuery(queryEngine, queryId)) {
//TODO: BLZG-1464 Unify Embedded and REST cancellation
if (!tryCancelUpdate(queryEngine,queryId,null)) {
queryEngine.addPendingCancel(queryId);
if (log.isInfoEnabled()) {
log.info("No such QUERY or UPDATE: " + queryId);
}
}
}
}
}
/**
* Attempt to cancel a running SPARQL Query
*
* @param queryEngine
* @param queryId
* @return
*/
public static boolean tryCancelQuery(final QueryEngine queryEngine,
final UUID queryId) {
final IRunningQuery q;
try {
q = queryEngine.getRunningQuery(queryId);
} catch (RuntimeException ex) {
/*
* Ignore.
*
* Either the IRunningQuery has already terminated or this is an
* UPDATE rather than a QUERY.
*/
return false;
}
if (q != null && q.cancel(true/* mayInterruptIfRunning */)) {
if (log.isInfoEnabled())
log.info("Cancelled query: " + queryId);
return true;
}
return false;
}
/**
* Attempt to cancel a running SPARQL UPDATE request.
* @param context
* @param queryId
* @return
*/
//This should not be used for the StatusServlet until the Embedded and REST API are unified.
public static boolean tryCancelUpdate(final QueryEngine queryEngine,
RunningQuery query) {
if (query != null) {
final IRunningQuery q;
try {
q = queryEngine.getRunningQuery(query.getQueryUuid());
if(q != null && q.cancel(true /* interrupt when running */)) {
return true;
}
} catch (RuntimeException ex) {
/*
* Ignore.
*
* Either the IRunningQuery has already terminated or this is an
* UPDATE rather than a QUERY.
*/
return false;
}
}
//
// if (query.queryTask instanceof UpdateTask) {
//
// final Future<Void> f = ((UpdateTask) query.queryTask).updateFuture;
//
// if (f != null) {
//
// if (f.cancel(true/* mayInterruptIfRunning */)) {
//
// return true;
//
// }
//
// }
//
// }
//
// }
//
// Either not found or found but not running when cancelled.
return false;
}
//TODO: Unify the webapp and embedded
//This should not be used for the StatusServlet until the Embedded and REST API are unified.
public static boolean tryCancelUpdate(final QueryEngine queryEngine,
final UUID queryId, final Future<Void> f) {
final IRunningQuery q;
try {
q = queryEngine.getRunningQuery(queryId);
if (q != null && q.cancel(true /* interrupt when running */)) {
return true;
}
} catch (RuntimeException ex) {
/*
* Ignore.
*
* Either the IRunningQuery has already terminated or this is an
* UPDATE rather than a QUERY.
*/
return false;
}
if (f != null) {
if (f.cancel(true/* mayInterruptIfRunning */)) {
return true;
}
}
// Either not found or found but not running when cancelled.
return false;
}
}