VirtDataSource.java

/*
 *  $Id$
 *
 *  This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
 *  project.
 *
 *  Copyright (C) 1998-2012 OpenLink Software
 *
 *  This project 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; only version 2 of the License, dated June 1991.
 *
 *  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.,
 *  51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 */
package virtuoso.jena.driver;

import java.sql.ResultSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import virtuoso.jdbc4.VirtuosoDataSource;

import com.hp.hpl.jena.graph.Graph;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.query.Dataset;
import com.hp.hpl.jena.query.LabelExistsException;
import com.hp.hpl.jena.query.ReadWrite;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.shared.JenaException;
import com.hp.hpl.jena.shared.Lock;
import com.hp.hpl.jena.sparql.core.DatasetGraph;
import com.hp.hpl.jena.sparql.core.Quad;
import com.hp.hpl.jena.sparql.util.Context;

public class VirtDataSource extends VirtGraph implements Dataset {

	/**
	 * Default model - may be null - according to Javadoc
	 */
	Model defaultModel = null;

	public VirtDataSource() {
		super();
	}

	public VirtDataSource(String _graphName, VirtuosoDataSource _ds) {
		super(_graphName, _ds);
	}

	protected VirtDataSource(VirtGraph g) {
		this.graphName = g.getGraphName();
		setReadFromAllGraphs(g.getReadFromAllGraphs());
		this.url_hostlist = g.getGraphUrl();
		this.user = g.getGraphUser();
		this.password = g.getGraphPassword();
		this.roundrobin = g.roundrobin;
		setFetchSize(g.getFetchSize());
		this.connection = g.getConnection();
	}

	public VirtDataSource(String url_hostlist, String user, String password) {
		super(url_hostlist, user, password);
	}

	/** Set the background graph. Can be set to null for none. */
	public void setDefaultModel(Model model) {
		if (!(model instanceof VirtDataSource))
			throw new IllegalArgumentException(
					"VirtDataSource supports only VirtModel as default model");
		defaultModel = model;
	}

	/** Set a named graph. */
	public void addNamedModel(String name, Model model)
			throws LabelExistsException {
		String query = "select count(*) from (sparql select * where { graph `iri(??)` { ?s ?p ?o }})f";
		ResultSet rs = null;
		int ret = 0;

		checkOpen();
		try {
			java.sql.PreparedStatement ps = prepareStatement(query);
			ps.setString(1, name);
			rs = ps.executeQuery();
			if (rs.next())
				ret = rs.getInt(1);
			rs.close();
			ps.close();
		} catch (Exception e) {
			throw new JenaException(e);
		}

		try {
			if (ret != 0)
				throw new LabelExistsException("A model with ID '" + name
						+ "' already exists.");
			Graph g = model.getGraph();
			int count = 0;
			java.sql.PreparedStatement ps = prepareStatement(sinsert);

			for (Iterator i = g.find(Node.ANY, Node.ANY, Node.ANY); i.hasNext();) {
				Triple t = (Triple) i.next();

				ps.setString(1, name);
				bindSubject(ps, 2, t.getSubject());
				bindPredicate(ps, 3, t.getPredicate());
				bindObject(ps, 4, t.getObject());
				ps.addBatch();
				count++;
				if (count > BATCH_SIZE) {
					ps.executeBatch();
					ps.clearBatch();
					count = 0;
				}
			}
			if (count > 0) {
				ps.executeBatch();
				ps.clearBatch();
			}
			ps.close();
		} catch (Exception e) {
			throw new JenaException(e);
		}
	}

	/** Remove a named graph. */
	public void removeNamedModel(String name) {
		String exec_text = "sparql clear graph <" + name + ">";

		checkOpen();
		try {
			java.sql.Statement stmt = createStatement();
			stmt.executeQuery(exec_text);
			stmt.close();
		} catch (Exception e) {
			throw new JenaException(e);
		}
	}

	/** Change a named graph for another uisng the same name */
	public void replaceNamedModel(String name, Model model) {
		try {
			getConnection().setAutoCommit(false);
			removeNamedModel(name);
			addNamedModel(name, model);
			getConnection().commit();
			getConnection().setAutoCommit(true);
		} catch (Exception e) {
			try {
				getConnection().rollback();
			} catch (Exception e2) {
				throw new JenaException(
						"Could not replace model, and could not rollback!", e2);
			}
			throw new JenaException("Could not replace model:", e);
		}
	}

	/** Get the default graph as a Jena Model */
	public Model getDefaultModel() {
		return defaultModel;
	}

	/** Get a graph by name as a Jena Model */
	public Model getNamedModel(String name) {
		try {
			VirtuosoDataSource _ds = getDataSource();
			if (_ds != null)
				return new VirtModel(new VirtGraph(name, _ds));
			else
				return new VirtModel(new VirtGraph(name, this.getGraphUrl(),
						this.getGraphUser(), this.getGraphPassword()));
		} catch (Exception e) {
			throw new JenaException(e);
		}
	}

	/** Does the dataset contain a model with the name supplied? */
	public boolean containsNamedModel(String name) {
		String query = "select count(*) from (sparql select * where { graph `iri(??)` { ?s ?p ?o }})f";
		ResultSet rs = null;
		int ret = 0;

		checkOpen();
		try {
			java.sql.PreparedStatement ps = prepareStatement(query);
			ps.setString(1, name);
			rs = ps.executeQuery();
			if (rs.next())
				ret = rs.getInt(1);
			rs.close();
			ps.close();
		} catch (Exception e) {
			throw new JenaException(e);
		}
		return (ret != 0);
	}

	/** List the names */
	public Iterator<String> listNames() {
		String exec_text = "DB.DBA.SPARQL_SELECT_KNOWN_GRAPHS()";
		ResultSet rs = null;
		int ret = 0;

		checkOpen();
		try {
			List<String> names = new LinkedList();

			java.sql.Statement stmt = createStatement();
			rs = stmt.executeQuery(exec_text);
			while (rs.next())
				names.add(rs.getString(1));
			rs.close();
			stmt.close();
			return names.iterator();
		} catch (Exception e) {
			throw new JenaException(e);
		}
	}

	Lock lock = null;

	/** Get the lock for this dataset */
	public Lock getLock() {
		if (lock == null)
			lock = new com.hp.hpl.jena.shared.LockNone();
		return lock;
	}

	/** Get the dataset in graph form */
	public DatasetGraph asDatasetGraph() {
		return new VirtDataSetGraph(this);
	}

	public class VirtDataSetGraph implements DatasetGraph {

		VirtDataSource vd = null;

		public VirtDataSetGraph(VirtDataSource vds) {
			vd = vds;
		}

		public Graph getDefaultGraph() {
			return vd;
		}

		public Graph getGraph(Node graphNode) {
			try {
				return new VirtGraph(graphNode.toString(), vd.getGraphUrl(),
						vd.getGraphUser(), vd.getGraphPassword());
			} catch (Exception e) {
				throw new JenaException(e);
			}
		}

		public boolean containsGraph(Node graphNode) {
			return containsNamedModel(graphNode.toString());
		}

		public Iterator<Node> listGraphNodes() {
			String exec_text = "DB.DBA.SPARQL_SELECT_KNOWN_GRAPHS()";
			ResultSet rs = null;
			int ret = 0;

			vd.checkOpen();
			try {
				List<Node> names = new LinkedList();

				java.sql.Statement stmt = vd.createStatement();
				rs = stmt.executeQuery(exec_text);
				while (rs.next())
					names.add(Node.createURI(rs.getString(1)));
				rs.close();
				stmt.close();
				return names.iterator();
			} catch (Exception e) {
				throw new JenaException(e);
			}
		}

		public Lock getLock() {
			return vd.getLock();
		}

		public long size() {
			return vd.size();
		}

		public void close() {
			vd.close();
		}

		public void add(Quad arg0) {
			// TODO Auto-generated method stub

		}

		public void add(Node arg0, Node arg1, Node arg2, Node arg3) {
			// TODO Auto-generated method stub

		}

		public void addGraph(Node arg0, Graph arg1) {
			// TODO Auto-generated method stub

		}

		public boolean contains(Quad arg0) {
			// TODO Auto-generated method stub
			return false;
		}

		public boolean contains(Node arg0, Node arg1, Node arg2, Node arg3) {
			// TODO Auto-generated method stub
			return false;
		}

		public void delete(Quad arg0) {
			// TODO Auto-generated method stub

		}

		public void delete(Node arg0, Node arg1, Node arg2, Node arg3) {
			// TODO Auto-generated method stub

		}

		public void deleteAny(Node arg0, Node arg1, Node arg2, Node arg3) {
			// TODO Auto-generated method stub

		}

		public Iterator<Quad> find() {
			// TODO Auto-generated method stub
			return null;
		}

		public Iterator<Quad> find(Quad arg0) {
			// TODO Auto-generated method stub
			return null;
		}

		public Iterator<Quad> find(Node arg0, Node arg1, Node arg2, Node arg3) {
			// TODO Auto-generated method stub
			return null;
		}

		public Iterator<Quad> findNG(Node arg0, Node arg1, Node arg2, Node arg3) {
			// TODO Auto-generated method stub
			return null;
		}

		public Context getContext() {
			// TODO Auto-generated method stub
			return null;
		}

		public boolean isEmpty() {
			// TODO Auto-generated method stub
			return false;
		}

		public void removeGraph(Node arg0) {
			// TODO Auto-generated method stub

		}

		public void setDefaultGraph(Graph arg0) {
			// TODO Auto-generated method stub

		}

	}

	public void abort() {
		// TODO Auto-generated method stub

	}

	public void begin(ReadWrite arg0) {
		// TODO Auto-generated method stub

	}

	public void commit() {
		// TODO Auto-generated method stub

	}

	public void end() {
		// TODO Auto-generated method stub

	}

	public Context getContext() {
		// TODO Auto-generated method stub
		return null;
	}

	public boolean isInTransaction() {
		// TODO Auto-generated method stub
		return false;
	}

	public boolean supportsTransactions() {
		// TODO Auto-generated method stub
		return false;
	}

}