/**
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 Mar 1, 2012
*/
package com.bigdata.rdf.sparql.ast.service;
import java.util.UUID;
import org.eclipse.jetty.client.HttpClient;
import org.openrdf.query.BindingSet;
import org.openrdf.query.QueryEvaluationException;
import org.openrdf.query.TupleQueryResult;
import com.bigdata.rdf.sail.Sesame2BigdataIterator;
import com.bigdata.rdf.sail.webapp.client.ConnectOptions;
import com.bigdata.rdf.sail.webapp.client.RemoteRepositoryManager;
import cutthecrap.utils.striterators.ICloseableIterator;
/**
* This class handles vectored remote service invocation by generating an
* appropriate SPARQL query (with BINDINGS) and an appropriate HTTP request. The
* behavior of this class may be configured in the {@link ServiceRegistry} by
* adjusting the {@link RemoteServiceOptions} for the service URI.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class RemoteServiceCallImpl implements RemoteServiceCall {
// private static final Logger log = Logger
// .getLogger(RemoteServiceCallImpl.class);
private final ServiceCallCreateParams params;
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append(getClass().getName());
sb.append("{params=" + params);
sb.append("}");
return sb.toString();
}
public RemoteServiceCallImpl(final ServiceCallCreateParams params) {
if (params == null)
throw new IllegalArgumentException();
this.params = params;
}
@Override
public RemoteServiceOptions getServiceOptions() {
return (RemoteServiceOptions) params.getServiceOptions();
}
@Override
public ICloseableIterator<BindingSet> call(final BindingSet[] bindingSets)
throws Exception {
final String uriStr = params.getServiceURI().stringValue();
final RemoteServiceOptions serviceOptions = getServiceOptions();
final ConnectOptions o = new ConnectOptions(uriStr);
{
final String acceptHeader = serviceOptions.getAcceptHeader();
if (acceptHeader != null) {
o.setAcceptHeader(acceptHeader);
} else {
o.setAcceptHeader(ConnectOptions.DEFAULT_SOLUTIONS_ACCEPT_HEADER);
}
}
o.method = serviceOptions.isGET() ? "GET" : "POST";
/*
* Note: This uses a factory pattern to handle each of the possible ways
* in which we have to vector solutions to the service end point.
*/
final IRemoteSparqlQueryBuilder queryBuilder = RemoteSparqlBuilderFactory
.get(serviceOptions, params.getServiceNode(), bindingSets);
final String queryStr = queryBuilder.getSparqlQuery(bindingSets);
final UUID queryId = UUID.randomUUID();
o.addRequestParam("query", queryStr);
o.addRequestParam("queryId", queryId.toString());
final HttpClient client = params.getClientConnectionManager();
/*
* Note: While this constructs one instance per remote SERVICE call, the
* instance uses the existing HTTPClient and Executor and is basically
* flyweight as a result.
*/
final RemoteRepositoryManager repo = new RemoteRepositoryManager(//
uriStr,//
params.getServiceOptions().isBigdataLBS(),// useLBS
client,
params.getTripleStore().getExecutorService()
);
/*
* Note: This does not stream chunks back. The ServiceCallJoin currently
* materializes all solutions from the service in a single chunk, so
* there is no point doing something incremental here unless it is
* coordinated with the ServiceCallJoin.
*/
final TupleQueryResult queryResult;
try {
queryResult = repo.tupleResults(o, queryId, null);
} finally {
repo.close();
}
return new Sesame2BigdataIterator<BindingSet, QueryEvaluationException>(
queryResult);
}
}