DataModelNeo4jProcessor.java

/**
 * This file is part of d:swarm graph extension.
 *
 * d:swarm graph extension 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * d:swarm graph extension 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 d:swarm graph extension.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.dswarm.graph;

import java.util.Map;
import java.util.Optional;

import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Relationship;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.dswarm.graph.hash.HashUtils;
import org.dswarm.graph.index.NamespaceIndex;
import org.dswarm.graph.model.GraphStatics;
import org.dswarm.graph.tx.TransactionHandler;
import org.dswarm.graph.versioning.VersionHandler;
import org.dswarm.graph.versioning.VersioningStatics;

/**
 * @author tgaengler
 */
public class DataModelNeo4jProcessor extends BasicNeo4jProcessor {

	private static final Logger LOG = LoggerFactory.getLogger(DataModelNeo4jProcessor.class);

	private final String prefixedDataModelURI;

	public DataModelNeo4jProcessor(final GraphDatabaseService database, final TransactionHandler txArg, final NamespaceIndex namespaceIndex,
	                               final String prefixedDataModelURIArg) throws DMPGraphException {

		super(database, txArg, namespaceIndex);

		prefixedDataModelURI = prefixedDataModelURIArg;
	}

	public String getPrefixedDataModelURI() {

		return prefixedDataModelURI;
	}

	@Override
	public void addObjectToResourceWDataModelIndex(final Node node, final String URI, final Optional<String> optionalPrefixedDataModelURI) {

		final String finalPrefixedDataModelURI = getPrefixedDataModelURI(optionalPrefixedDataModelURI);
		final long resourceUriDataModelUriHash = generateResourceHash(URI, Optional.of(finalPrefixedDataModelURI));

		addNodeToResourcesWDataModelIndex(URI, resourceUriDataModelUriHash, node);
	}

	@Override
	public void handleObjectDataModel(final Node node, final Optional<String> optionalPrefixedDataModelURI) {

		final String finalPrefixedDataModelURI = getPrefixedDataModelURI(optionalPrefixedDataModelURI);

		node.setProperty(GraphStatics.DATA_MODEL_PROPERTY, finalPrefixedDataModelURI);
	}

	@Override
	public void handleSubjectDataModel(final Node node, String prefixedURI, final Optional<String> optionalPrefixedDataModelURI) {

		final String finalPrefixedDataModelURI = getPrefixedDataModelURI(optionalPrefixedDataModelURI);
		final long resourceUriDataModelUriHash = generateResourceHash(prefixedURI, Optional.of(finalPrefixedDataModelURI));

		node.setProperty(GraphStatics.DATA_MODEL_PROPERTY, finalPrefixedDataModelURI);
		addNodeToResourcesWDataModelIndex(prefixedURI, resourceUriDataModelUriHash, node);
	}

	@Override
	public Optional<Node> getResourceNodeHits(final String prefixedResourceURI) {

		final long resourceUriDataModelUriHash = generateResourceHash(prefixedResourceURI, Optional.of(prefixedDataModelURI));

		return getNodeFromResourcesWDataModelIndex(resourceUriDataModelUriHash);
	}

	@Override
	public long generateResourceHash(final String prefixedResourceURI, final Optional<String> optionalPrefixedDataModelURI) {

		final String finalPrefixedDataModelURI = getPrefixedDataModelURI(optionalPrefixedDataModelURI);

		final String hashString = prefixedResourceURI + finalPrefixedDataModelURI;

		return HashUtils.generateHash(hashString);
	}

	@Override
	protected String putSaltToStatementHash(final String hash) {

		return hash + " " + this.prefixedDataModelURI;
	}

	@Override
	public Relationship prepareRelationship(final Node subjectNode, final String predicateURI, final Node objectNode, final long statementUUID,
	                                        final Optional<Map<String, Object>> qualifiedAttributes, final Optional<Long> optionalIndex, final VersionHandler versionHandler) {

		final Relationship rel = super.prepareRelationship(subjectNode, predicateURI, objectNode, statementUUID, qualifiedAttributes, optionalIndex, versionHandler);

		rel.setProperty(GraphStatics.DATA_MODEL_PROPERTY, prefixedDataModelURI);

		rel.setProperty(VersioningStatics.VALID_FROM_PROPERTY, versionHandler.getRange().from());
		rel.setProperty(VersioningStatics.VALID_TO_PROPERTY, versionHandler.getRange().to());

		return rel;
	}

	private String getPrefixedDataModelURI(final Optional<String> optionalPrefixedDataModelURI) {

		if (optionalPrefixedDataModelURI.isPresent()) {

			return optionalPrefixedDataModelURI.get();
		}

		return prefixedDataModelURI;
	}
}