/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.marmotta.platform.backend.titan;
import com.thinkaurelius.titan.core.TitanFactory;
import com.thinkaurelius.titan.core.TitanGraph;
import com.tinkerpop.blueprints.oupls.sail.GraphSail;
import org.apache.commons.configuration.BaseConfiguration;
import org.apache.commons.configuration.Configuration;
import org.apache.marmotta.platform.core.api.config.ConfigurationService;
import org.apache.marmotta.platform.core.api.triplestore.SesameService;
import org.apache.marmotta.platform.core.api.triplestore.StoreProvider;
import org.apache.marmotta.platform.core.events.ConfigurationChangedEvent;
import org.openrdf.repository.sail.SailRepository;
import org.openrdf.sail.NotifyingSail;
import org.openrdf.sail.Sail;
import org.slf4j.Logger;
import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.event.Observes;
import javax.inject.Inject;
import java.util.List;
/**
* A store provider implementation for Apache Marmotta providing instances of Titan.
*
* @author Viktor Gal
*/
@ApplicationScoped
public class TitanStoreProvider implements StoreProvider {
@Inject
private Logger log;
@Inject
private ConfigurationService configurationService;
@Inject
private SesameService sesameService;
/**
* Create the store provided by this SailProvider
*
* @return a new instance of the store
*/
@Override
public NotifyingSail createStore() {
log.info("Initializing Backend: Titan Store");
final TitanGraph graph = createTitanGraph();
return new GraphSail(graph);
}
public void configurationChanged(@Observes ConfigurationChangedEvent e) {
if(e.containsChangedKeyWithPrefix("titan")) {
sesameService.restart();
}
}
/**
* Create the repository using the sail given as argument.
* This method is needed because some backends
* use custom implementations of SailRepository.
*
* @param sail
* @return
*/
@Override
public SailRepository createRepository(Sail sail) {
return new SailRepository(sail);
}
/**
* Create a TitanGraph from the configuration
*
* @return TitanGraph
*/
public TitanGraph createTitanGraph() {
Configuration conf = new BaseConfiguration();
List<String> titanConf = configurationService.listConfigurationKeys("titan");
for (String key : titanConf) {
String titanKey = key.replaceFirst("^titan\\.", "");
conf.setProperty(titanKey, configurationService.getStringConfiguration(key));
}
return TitanFactory.open(conf);
}
/**
* Return the name of the provider. Used e.g. for displaying status information or logging.
*
* @return
*/
@Override
public String getName() {
return "Titan Store";
}
/**
* Return true if this sail provider is enabled in the configuration.
*
* @return
*/
@Override
public boolean isEnabled() {
return true;
}
}