monetdb-java: src/main/java/nl/cwi/monetdb/jdbc/MonetConnection.java comparison

comparison src/main/java/nl/cwi/monetdb/jdbc/MonetConnection.java @ 0:a5a898f6886c

Copy of MonetDB java directory changeset e6e32756ad31.

author	Sjoerd Mullender <sjoerd@acm.org>
date	Wed, 21 Sep 2016 09:34:48 +0200 (2016-09-21)
parents
children	a27ee2cb14a0

comparison

equal deleted inserted replaced

--1:000000000000
+:a5a898f6886c
+/*
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0.  If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/.
+*
+* Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
+*/
+package nl.cwi.monetdb.jdbc;
+import java.io.File;
+import java.io.IOException;
+import java.net.SocketException;
+import java.net.SocketTimeoutException;
+import java.sql.Array;
+import java.sql.Blob;
+import java.sql.CallableStatement;
+import java.sql.Clob;
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.NClob;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.SQLFeatureNotSupportedException;
+import java.sql.SQLWarning;
+import java.sql.SQLXML;
+import java.sql.Savepoint;
+import java.sql.Statement;
+import java.sql.Struct;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Properties;
+import java.util.WeakHashMap;
+import java.util.concurrent.Executor;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import nl.cwi.monetdb.jdbc.types.INET;
+import nl.cwi.monetdb.jdbc.types.URL;
+import nl.cwi.monetdb.mcl.MCLException;
+import nl.cwi.monetdb.mcl.io.BufferedMCLReader;
+import nl.cwi.monetdb.mcl.io.BufferedMCLWriter;
+import nl.cwi.monetdb.mcl.net.MapiSocket;
+import nl.cwi.monetdb.mcl.parser.HeaderLineParser;
+import nl.cwi.monetdb.mcl.parser.MCLParseException;
+import nl.cwi.monetdb.mcl.parser.StartOfHeaderParser;
+/**
+* A {@link Connection} suitable for the MonetDB database.
+*
+* This connection represents a connection (session) to a MonetDB
+* database. SQL statements are executed and results are returned within
+* the context of a connection. This Connection object holds a physical
+* connection to the MonetDB database.
+*
+* A Connection object's database should able to provide information
+* describing its tables, its supported SQL grammar, its stored
+* procedures, the capabilities of this connection, and so on. This
+* information is obtained with the getMetaData method.
+*
+* Note: By default a Connection object is in auto-commit mode, which
+* means that it automatically commits changes after executing each
+* statement. If auto-commit mode has been disabled, the method commit
+* must be called explicitly in order to commit changes; otherwise,
+* database changes will not be saved.
+*
+* The current state of this connection is that it nearly implements the
+* whole Connection interface.
+*
+* @author Fabian Groffen
+* @version 1.2
+*/
+public class MonetConnection extends MonetWrapper implements Connection {
+	/** The hostname to connect to */
+	private final String hostname;
+	/** The port to connect on the host to */
+	private final int port;
+	/** The database to use (currently not used) */
+	private final String database;
+	/** The username to use when authenticating */
+	private final String username;
+	/** The password to use when authenticating */
+	private final String password;
+	/** A connection to mserver5 using a TCP socket */
+	private final MapiSocket server;
+	/** The Reader from the server */
+	private final BufferedMCLReader in;
+	/** The Writer to the server */
+	private final BufferedMCLWriter out;
+	/** A StartOfHeaderParser  declared for reuse. */
+	private StartOfHeaderParser sohp = new StartOfHeaderParser();
+	/** Whether this Connection is closed (and cannot be used anymore) */
+	private boolean closed;
+	/** Whether this Connection is in autocommit mode */
+	private boolean autoCommit = true;
+	/** The stack of warnings for this Connection object */
+	private SQLWarning warnings = null;
+	/** The Connection specific mapping of user defined types to Java
+	 * types */
+	private Map<String,Class<?>> typeMap = new HashMap<String,Class<?>>() {/**
+		 *
+		 */
+		private static final long serialVersionUID = 1L;
+		{
+			put("inet", INET.class);
+			put("url",  URL.class);
+		}
+	};
+	// See javadoc for documentation about WeakHashMap if you don't know what
+	// it does !!!NOW!!! (only when you deal with it of course)
+	/** A Map containing all (active) Statements created from this Connection */
+	private Map<Statement,?> statements = new WeakHashMap<Statement, Object>();
+	/** The number of results we receive from the server at once */
+	private int curReplySize = -1;	// the server by default uses -1 (all)
+	/** A template to apply to each query (like pre and post fixes) */
+	String[] queryTempl;
+	/** A template to apply to each command (like pre and post fixes) */
+	String[] commandTempl;
+	/** the SQL language */
+	final static int LANG_SQL = 0;
+	/** the MAL language (officially *NOT* supported) */
+	final static int LANG_MAL = 3;
+	/** an unknown language */
+	final static int LANG_UNKNOWN = -1;
+	/** The language which is used */
+	final int lang;
+	/** Whether or not BLOB is mapped to BINARY within the driver */
+	private final boolean blobIsBinary;
+	/**
+	 * Constructor of a Connection for MonetDB. At this moment the
+	 * current implementation limits itself to storing the given host,
+	 * database, username and password for later use by the
+	 * createStatement() call.  This constructor is only accessible to
+	 * classes from the jdbc package.
+	 *
+	 * @param props a Property hashtable holding the properties needed for
+	 *              connecting
+	 * @throws SQLException if a database error occurs
+	 * @throws IllegalArgumentException is one of the arguments is null or empty
+	 */
+	MonetConnection(Properties props)
+		throws SQLException, IllegalArgumentException
+	{
+		this.hostname = props.getProperty("host");
+		int port;
+		try {
+			port = Integer.parseInt(props.getProperty("port"));
+		} catch (NumberFormatException e) {
+			port = 0;
+		}
+		this.port = port;
+		this.database = props.getProperty("database");
+		this.username = props.getProperty("user");
+		this.password = props.getProperty("password");
+		String language = props.getProperty("language");
+		boolean debug = Boolean.valueOf(props.getProperty("debug")).booleanValue();
+		String hash = props.getProperty("hash");
+		blobIsBinary = Boolean.valueOf(props.getProperty("treat_blob_as_binary")).booleanValue();
+		int sockTimeout = 0;
+		try {
+			sockTimeout = Integer.parseInt(props.getProperty("so_timeout"));
+		} catch (NumberFormatException e) {
+			sockTimeout = 0;
+		}
+		// check input arguments
+		if (hostname == null || hostname.trim().equals(""))
+			throw new IllegalArgumentException("hostname should not be null or empty");
+		if (port == 0)
+			throw new IllegalArgumentException("port should not be 0");
+		if (username == null || username.trim().equals(""))
+			throw new IllegalArgumentException("user should not be null or empty");
+		if (password == null || password.trim().equals(""))
+			throw new IllegalArgumentException("password should not be null or empty");
+		if (language == null || language.trim().equals("")) {
+			language = "sql";
+			addWarning("No language given, defaulting to 'sql'", "M1M05");
+		}
+		// initialise query templates (filled later, but needed below)
+		queryTempl = new String[3]; // pre, post, sep
+		commandTempl = new String[3]; // pre, post, sep
+		server = new MapiSocket();
+		if (hash != null) server.setHash(hash);
+		if (database != null) server.setDatabase(database);
+		server.setLanguage(language);
+		// we're debugging here... uhm, should be off in real life
+		if (debug) {
+			try {
+				String fname = props.getProperty("logfile", "monet_" +
+					System.currentTimeMillis() + ".log");
+				File f = new File(fname);
+				int ext = fname.lastIndexOf(".");
+				if (ext < 0) ext = fname.length();
+				String pre = fname.substring(0, ext);
+				String suf = fname.substring(ext);
+				for (int i = 1; f.exists(); i++) {
+					f = new File(pre + "-" + i + suf);
+				}
+				server.debug(f.getAbsolutePath());
+			} catch (IOException ex) {
+				throw new SQLException("Opening logfile failed: " + ex.getMessage(), "08M01");
+			}
+		}
+		try {
+			List<String> warnings =
+				server.connect(hostname, port, username, password);
+			for (String warning : warnings) {
+				addWarning(warning, "01M02");
+			}
+			// apply NetworkTimeout value from legacy (pre 4.1) driver
+			// so_timeout calls
+			server.setSoTimeout(sockTimeout);
+			in = server.getReader();
+			out = server.getWriter();
+			String error = in.waitForPrompt();
+			if (error != null)
+				throw new SQLException(error.substring(6), "08001");
+		} catch (IOException e) {
+			throw new SQLException("Unable to connect (" + hostname + ":" + port + "): " + e.getMessage(), "08006");
+		} catch (MCLParseException e) {
+			throw new SQLException(e.getMessage(), "08001");
+		} catch (MCLException e) {
+			String[] connex = e.getMessage().split("\n");
+			SQLException sqle = new SQLException(connex[0], "08001", e);
+			for (int i = 1; i < connex.length; i++) {
+				sqle.setNextException(new SQLException(connex[1], "08001"));
+			}
+			throw sqle;
+		}
+		// we seem to have managed to log in, let's store the
+		// language used
+		if ("sql".equals(language)) {
+			lang = LANG_SQL;
+		} else if ("mal".equals(language)) {
+			lang = LANG_MAL;
+		} else {
+			lang = LANG_UNKNOWN;
+		}
+		// fill the query templates
+		if (lang == LANG_SQL) {
+			queryTempl[0] = "s";		// pre
+			queryTempl[1] = "\n;";		// post
+			queryTempl[2] = "\n;\n";	// separator
+			commandTempl[0] = "X";		// pre
+			commandTempl[1] = null;		// post
+			commandTempl[2] = "\nX";	// separator
+		} else if (lang == LANG_MAL) {
+			queryTempl[0] = null;
+			queryTempl[1] = ";\n";
+			queryTempl[2] = ";\n";
+			commandTempl[0] = null;		// pre
+			commandTempl[1] = null;		// post
+			commandTempl[2] = null;		// separator
+		}
+		// the following initialisers are only valid when the language
+		// is SQL...
+		if (lang == LANG_SQL) {
+			// enable auto commit
+			setAutoCommit(true);
+			// set our time zone on the server
+			Calendar cal = Calendar.getInstance();
+			int offset = cal.get(Calendar.ZONE_OFFSET) + cal.get(Calendar.DST_OFFSET);
+			offset /= (60 * 1000); // milliseconds to minutes
+			String tz = offset < 0 ? "-" : "+";
+			tz += (Math.abs(offset) / 60 < 10 ? "0" : "") + (Math.abs(offset) / 60) + ":";
+			offset -= (offset / 60) * 60;
+			tz += (offset < 10 ? "0" : "") + offset;
+			sendIndependentCommand("SET TIME ZONE INTERVAL '" + tz + "' HOUR TO MINUTE");
+		}
+		// we're absolutely not closed, since we're brand new
+		closed = false;
+	}
+	//== methods of interface Connection
+	/**
+	 * Clears all warnings reported for this Connection object. After a
+	 * call to this method, the method getWarnings returns null until a
+	 * new warning is reported for this Connection object.
+	 */
+	@Override
+	public void clearWarnings() {
+		warnings = null;
+	}
+	/**
+	 * Releases this Connection object's database and JDBC resources
+	 * immediately instead of waiting for them to be automatically
+	 * released. All Statements created from this Connection will be
+	 * closed when this method is called.
+	 *
+	 * Calling the method close on a Connection object that is already
+	 * closed is a no-op.
+	 */
+	@Override
+	public void close() {
+		synchronized (server) {
+			for (Statement st : statements.keySet()) {
+				try {
+					st.close();
+				} catch (SQLException e) {
+					// better luck next time!
+				}
+			}
+			// close the socket
+			server.close();
+			// close active SendThread if any
+			if (sendThread != null) {
+				sendThread.shutdown();
+				sendThread = null;
+			}
+			// report ourselves as closed
+			closed = true;
+		}
+	}
+	/**
+	 * Makes all changes made since the previous commit/rollback
+	 * permanent and releases any database locks currently held by this
+	 * Connection object.  This method should be used only when
+	 * auto-commit mode has been disabled.
+	 *
+	 * @throws SQLException if a database access error occurs or this
+	 *         Connection object is in auto-commit mode
+	 * @see #setAutoCommit(boolean)
+	 */
+	@Override
+	public void commit() throws SQLException {
+		// note: can't use sendIndependentCommand here because we need
+		// to process the auto_commit state the server gives
+		// create a container for the result
+		ResponseList l = new ResponseList(
+			0,
+			0,
+			ResultSet.FETCH_FORWARD,
+			ResultSet.CONCUR_READ_ONLY
+		);
+		// send commit to the server
+		try {
+			l.processQuery("COMMIT");
+		} finally {
+			l.close();
+		}
+	}
+	/**
+	 * Factory method for creating Array objects.
+	 *
+	 * Note: When createArrayOf is used to create an array object that
+	 * maps to a primitive data type, then it is implementation-defined
+	 * whether the Array object is an array of that primitive data type
+	 * or an array of Object.
+	 *
+	 * Note: The JDBC driver is responsible for mapping the elements
+	 * Object array to the default JDBC SQL type defined in
+	 * java.sql.Types for the given class of Object. The default mapping
+	 * is specified in Appendix B of the JDBC specification. If the
+	 * resulting JDBC type is not the appropriate type for the given
+	 * typeName then it is implementation defined whether an
+	 * SQLException is thrown or the driver supports the resulting
+	 * conversion.
+	 *
+	 * @param typeName the SQL name of the type the elements of the
+	 *        array map to. The typeName is a database-specific name
+	 *        which may be the name of a built-in type, a user-defined
+	 *        type or a standard SQL type supported by this database.
+	 *        This is the value returned by Array.getBaseTypeName
+	 * @return an Array object whose elements map to the specified SQL
+	 *         type
+	 * @throws SQLException if a database error occurs, the JDBC type
+	 *         is not appropriate for the typeName and the conversion is
+	 *         not supported, the typeName is null or this method is
+	 *         called on a closed connection
+	 * @throws SQLFeatureNotSupportedException the JDBC driver does
+	 *         not support this data type
+	 */
+	@Override
+	public Array createArrayOf(String typeName, Object[] elements)
+		throws SQLException
+	{
+		throw new SQLFeatureNotSupportedException("createArrayOf(String, Object[]) not supported", "0A000");
+	}
+	/**
+	 * Creates a Statement object for sending SQL statements to the
+	 * database.  SQL statements without parameters are normally
+	 * executed using Statement objects. If the same SQL statement is
+	 * executed many times, it may be more efficient to use a
+	 * PreparedStatement object.
+	 *
+	 * Result sets created using the returned Statement object will by
+	 * default be type TYPE_FORWARD_ONLY and have a concurrency level of
+	 * CONCUR_READ_ONLY.
+	 *
+	 * @return a new default Statement object
+	 * @throws SQLException if a database access error occurs
+	 */
+	@Override
+	public Statement createStatement() throws SQLException {
+		return createStatement(
+					ResultSet.TYPE_FORWARD_ONLY,
+					ResultSet.CONCUR_READ_ONLY,
+					ResultSet.HOLD_CURSORS_OVER_COMMIT);
+	}
+	/**
+	 * Creates a Statement object that will generate ResultSet objects
+	 * with the given type and concurrency. This method is the same as
+	 * the createStatement method above, but it allows the default
+	 * result set type and concurrency to be overridden.
+	 *
+	 * @param resultSetType a result set type; one of
+	 *        ResultSet.TYPE_FORWARD_ONLY, ResultSet.TYPE_SCROLL_INSENSITIVE,
+	 *        or ResultSet.TYPE_SCROLL_SENSITIVE
+	 * @param resultSetConcurrency a concurrency type; one of
+	 *        ResultSet.CONCUR_READ_ONLY or ResultSet.CONCUR_UPDATABLE
+	 * @return a new Statement object that will generate ResultSet objects with
+	 *         the given type and concurrency
+	 * @throws SQLException if a database access error occurs
+	 */
+	@Override
+	public Statement createStatement(
+			int resultSetType,
+			int resultSetConcurrency)
+		throws SQLException
+	{
+		return createStatement(
+					resultSetType,
+					resultSetConcurrency,
+					ResultSet.HOLD_CURSORS_OVER_COMMIT);
+	}
+	/**
+	 * Creates a Statement object that will generate ResultSet objects
+	 * with the given type, concurrency, and holdability.  This method
+	 * is the same as the createStatement method above, but it allows
+	 * the default result set type, concurrency, and holdability to be
+	 * overridden.
+	 *
+	 * @param resultSetType one of the following ResultSet constants:
+	 * ResultSet.TYPE_FORWARD_ONLY, ResultSet.TYPE_SCROLL_INSENSITIVE,
+	 * or ResultSet.TYPE_SCROLL_SENSITIVE
+	 * @param resultSetConcurrency one of the following ResultSet
+	 * constants: ResultSet.CONCUR_READ_ONLY or
+	 * ResultSet.CONCUR_UPDATABLE
+	 * @param resultSetHoldability one of the following ResultSet
+	 * constants: ResultSet.HOLD_CURSORS_OVER_COMMIT or
+	 * ResultSet.CLOSE_CURSORS_AT_COMMIT
+	 *
+	 * @return a new Statement      object that will generate ResultSet
+	 * objects with the given type, concurrency, and holdability
+	 * @throws SQLException if a database access error occurs or the
+	 * given parameters are not ResultSet constants indicating type,
+	 * concurrency, and holdability
+	 */
+	@Override
+	public Statement createStatement(
+			int resultSetType,
+			int resultSetConcurrency,
+			int resultSetHoldability)
+		throws SQLException
+	{
+		try {
+			Statement ret =
+				new MonetStatement(
+					this,
+					resultSetType,
+					resultSetConcurrency,
+					resultSetHoldability
+				);
+			// store it in the map for when we close...
+			statements.put(ret, null);
+			return ret;
+		} catch (IllegalArgumentException e) {
+			throw new SQLException(e.toString(), "M0M03");
+		}
+		// we don't have to catch SQLException because that is declared to
+		// be thrown
+	}
+	/**
+	 * Constructs an object that implements the Clob interface. The
+	 * object returned initially contains no data. The setAsciiStream,
+	 * setCharacterStream and setString methods of the Clob interface
+	 * may be used to add data to the Clob.
+	 *
+	 * @return a MonetClob instance
+	 * @throws SQLFeatureNotSupportedException the JDBC driver does
+	 *         not support MonetClob objects that can be filled in
+	 */
+	@Override
+	public Clob createClob() throws SQLException {
+		throw new SQLFeatureNotSupportedException("createClob() not supported", "0A000");
+	}
+	/**
+	 * Constructs an object that implements the Blob interface. The
+	 * object returned initially contains no data. The setBinaryStream
+	 * and setBytes methods of the Blob interface may be used to add
+	 * data to the Blob.
+	 *
+	 * @return a MonetBlob instance
+	 * @throws SQLFeatureNotSupportedException the JDBC driver does
+	 *         not support MonetBlob objects that can be filled in
+	 */
+	@Override
+	public Blob createBlob() throws SQLException {
+		throw new SQLFeatureNotSupportedException("createBlob() not supported", "0A000");
+	}
+	/**
+	 * Constructs an object that implements the NClob interface. The
+	 * object returned initially contains no data. The setAsciiStream,
+	 * setCharacterStream and setString methods of the NClob interface
+	 * may be used to add data to the NClob.
+	 *
+	 * @return an NClob instance
+	 * @throws SQLFeatureNotSupportedException the JDBC driver does
+	 *         not support MonetClob objects that can be filled in
+	 */
+	@Override
+	public NClob createNClob() throws SQLException {
+		throw new SQLFeatureNotSupportedException("createNClob() not supported", "0A000");
+	}
+	/**
+	 * Factory method for creating Struct objects.
+	 *
+	 * @param typeName the SQL type name of the SQL structured type that
+	 *        this Struct object maps to. The typeName is the name of a
+	 *        user-defined type that has been defined for this database.
+	 *        It is the value returned by Struct.getSQLTypeName.
+	 * @param attributes the attributes that populate the returned
+	 *        object
+	 * @return a Struct object that maps to the given SQL type and is
+	 *         populated with the given attributes
+	 * @throws SQLException if a database error occurs, the typeName
+	 *         is null or this method is called on a closed connection
+	 * @throws SQLFeatureNotSupportedException the JDBC driver does
+	 *         not support this data type
+	 */
+	@Override
+	public Struct createStruct(String typeName, Object[] attributes)
+		throws SQLException
+	{
+		throw new SQLFeatureNotSupportedException("createStruct() not supported", "0A000");
+	}
+	/**
+	 * Constructs an object that implements the SQLXML interface. The
+	 * object returned initially contains no data. The
+	 * createXmlStreamWriter object and setString method of the SQLXML
+	 * interface may be used to add data to the SQLXML object.
+	 *
+	 * @return An object that implements the SQLXML interface
+	 * @throws SQLFeatureNotSupportedException the JDBC driver does
+	 *         not support this data type
+	 */
+	@Override
+	public SQLXML createSQLXML() throws SQLException {
+		throw new SQLFeatureNotSupportedException("createSQLXML() not supported", "0A000");
+	}
+	/**
+	 * Retrieves the current auto-commit mode for this Connection
+	 * object.
+	 *
+	 * @return the current state of this Connection object's auto-commit
+	 *         mode
+	 * @see #setAutoCommit(boolean)
+	 */
+	@Override
+	public boolean getAutoCommit() throws SQLException {
+		return autoCommit;
+	}
+	/**
+	 * Retrieves this Connection object's current catalog name.
+	 *
+	 * @return the current catalog name or null if there is none
+	 * @throws SQLException if a database access error occurs or the
+	 *         current language is not SQL
+	 */
+	@Override
+	public String getCatalog() throws SQLException {
+		// MonetDB does NOT support catalogs
+		return null;
+	}
+	/**
+	 * Not implemented by MonetDB's JDBC driver.
+	 *
+	 * @param name The name of the client info property to retrieve
+	 * @return The value of the client info property specified
+	 */
+	@Override
+	public String getClientInfo(String name) {
+		// This method will also return null if the specified client
+		// info property name is not supported by the driver.
+		return null;
+	}
+	/**
+	 * Not implemented by MonetDB's JDBC driver.
+	 *
+	 * @return A Properties object that contains the name and current
+	 *         value of each of the client info properties supported by
+	 *         the driver.
+	 */
+	@Override
+	public Properties getClientInfo() {
+		return new Properties();
+	}
+	/**
+	 * Retrieves the current holdability of ResultSet objects created
+	 * using this Connection object.
+	 *
+	 * @return the holdability, one of
+	 *         ResultSet.HOLD_CURSORS_OVER_COMMIT or
+	 *         ResultSet.CLOSE_CURSORS_AT_COMMIT
+	 */
+	@Override
+	public int getHoldability() {
+		// TODO: perhaps it is better to have the server implement
+		//       CLOSE_CURSORS_AT_COMMIT
+		return ResultSet.HOLD_CURSORS_OVER_COMMIT;
+	}
+	/**
+	 * Retrieves a DatabaseMetaData object that contains metadata about
+	 * the database to which this Connection object represents a
+	 * connection. The metadata includes information about the
+	 * database's tables, its supported SQL grammar, its stored
+	 * procedures, the capabilities of this connection, and so on.
+	 *
+	 * @throws SQLException if the current language is not SQL
+	 * @return a DatabaseMetaData object for this Connection object
+	 */
+	@Override
+	public DatabaseMetaData getMetaData() throws SQLException {
+		if (lang != LANG_SQL)
+			throw new SQLException("This method is only supported in SQL mode", "M0M04");
+		return new MonetDatabaseMetaData(this);
+	}
+	/**
+	 * Retrieves this Connection object's current transaction isolation
+	 * level.
+	 *
+	 * @return the current transaction isolation level, which will be
+	 *         Connection.TRANSACTION_SERIALIZABLE
+	 */
+	@Override
+	public int getTransactionIsolation() {
+		return TRANSACTION_SERIALIZABLE;
+	}
+	/**
+	 * Retrieves the Map object associated with this Connection object.
+	 * Unless the application has added an entry, the type map returned
+	 * will be empty.
+	 *
+	 * @return the java.util.Map object associated with this Connection
+	 *         object
+	 */
+	@Override
+	public Map<String,Class<?>> getTypeMap() {
+		return typeMap;
+	}
+	/**
+	 * Retrieves the first warning reported by calls on this Connection
+	 * object.  If there is more than one warning, subsequent warnings
+	 * will be chained to the first one and can be retrieved by calling
+	 * the method SQLWarning.getNextWarning on the warning that was
+	 * retrieved previously.
+	 *
+	 * This method may not be called on a closed connection; doing so
+	 * will cause an SQLException to be thrown.
+	 *
+	 * Note: Subsequent warnings will be chained to this SQLWarning.
+	 *
+	 * @return the first SQLWarning object or null if there are none
+	 * @throws SQLException if a database access error occurs or this method is
+	 *         called on a closed connection
+	 */
+	@Override
+	public SQLWarning getWarnings() throws SQLException {
+		if (closed)
+			throw new SQLException("Cannot call on closed Connection", "M1M20");
+		// if there are no warnings, this will be null, which fits with the
+		// specification.
+		return warnings;
+	}
+	/**
+	 * Retrieves whether this Connection object has been closed.  A
+	 * connection is closed if the method close has been called on it or
+	 * if certain fatal errors have occurred.  This method is guaranteed
+	 * to return true only when it is called after the method
+	 * Connection.close has been called.
+	 *
+	 * This method generally cannot be called to determine whether a
+	 * connection to a database is valid or invalid.  A typical client
+	 * can determine that a connection is invalid by catching any
+	 * exceptions that might be thrown when an operation is attempted.
+	 *
+	 * @return true if this Connection object is closed; false if it is
+	 *         still open
+	 */
+	@Override
+	public boolean isClosed() {
+		return closed;
+	}
+	/**
+	 * Retrieves whether this Connection object is in read-only mode.
+	 * MonetDB currently doesn't support updateable result sets, but
+	 * updates are possible.  Hence the Connection object is never in
+	 * read-only mode.
+	 *
+	 * @return true if this Connection object is read-only; false otherwise
+	 */
+	@Override
+	public boolean isReadOnly() {
+		return false;
+	}
+	/**
+	 * Returns true if the connection has not been closed and is still
+	 * valid. The driver shall submit a query on the connection or use
+	 * some other mechanism that positively verifies the connection is
+	 * still valid when this method is called.
+	 *
+	 * The query submitted by the driver to validate the connection
+	 * shall be executed in the context of the current transaction.
+	 *
+	 * @param timeout The time in seconds to wait for the database
+	 *        operation used to validate the connection to complete. If
+	 *        the timeout period expires before the operation completes,
+	 *        this method returns false. A value of 0 indicates a
+	 *        timeout is not applied to the database operation.
+	 * @return true if the connection is valid, false otherwise
+	 * @throws SQLException if the value supplied for timeout is less
+	 *         than 0
+	 */
+	@Override
+	public boolean isValid(int timeout) throws SQLException {
+		if (timeout < 0)
+			throw new SQLException("timeout is less than 0", "M1M05");
+		if (closed)
+			return false;
+		// ping db using select 1;
+		Statement stmt = null;
+		try {
+			stmt = createStatement();
+			// the timeout parameter is ignored here, since
+			// MonetStatement.setQueryTimeout(timeout) is not supported.
+			stmt.executeQuery("SELECT 1");
+			stmt.close();
+			return true;
+		} catch (Exception e) {
+			if (stmt != null) {
+				try {
+					stmt.close();
+				} catch (Exception e2) {}
+			}
+		}
+		return false;
+	}
+	@Override
+	public String nativeSQL(String sql) {return sql;}
+	@Override
+	public CallableStatement prepareCall(String sql) {return null;}
+	@Override
+	public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) {return null;}
+	@Override
+	public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability) {return null;}
+	/**
+	 * Creates a PreparedStatement object for sending parameterized SQL
+	 * statements to the database.
+	 *
+	 * A SQL statement with or without IN parameters can be pre-compiled
+	 * and stored in a PreparedStatement object. This object can then be
+	 * used to efficiently execute this statement multiple times.
+	 *
+	 * Note: This method is optimized for handling parametric SQL
+	 * statements that benefit from precompilation. If the driver
+	 * supports precompilation, the method prepareStatement will send
+	 * the statement to the database for precompilation. Some drivers
+	 * may not support precompilation. In this case, the statement may
+	 * not be sent to the database until the PreparedStatement object is
+	 * executed. This has no direct effect on users; however, it does
+	 * affect which methods throw certain SQLException objects.
+	 *
+	 * Result sets created using the returned PreparedStatement object
+	 * will by default be type TYPE_FORWARD_ONLY and have a concurrency
+	 * level of CONCUR_READ_ONLY.
+	 *
+	 * @param sql an SQL statement that may contain one or more '?' IN
+	 *        parameter placeholders
+	 * @return a new default PreparedStatement object containing the
+	 *         pre-compiled SQL statement
+	 * @throws SQLException if a database access error occurs
+	 */
+	@Override
+	public PreparedStatement prepareStatement(String sql) throws SQLException {
+		return prepareStatement(
+					sql,
+					ResultSet.TYPE_FORWARD_ONLY,
+					ResultSet.CONCUR_READ_ONLY,
+					ResultSet.HOLD_CURSORS_OVER_COMMIT
+		);
+	}
+	/**
+	 * Creates a PreparedStatement object that will generate ResultSet
+	 * objects with the given type and concurrency.  This method is the
+	 * same as the prepareStatement method above, but it allows the
+	 * default result set type and concurrency to be overridden.
+	 *
+	 * @param sql a String object that is the SQL statement to be sent to the
+	 *            database; may contain one or more ? IN parameters
+	 * @param resultSetType a result set type; one of
+	 *        ResultSet.TYPE_FORWARD_ONLY, ResultSet.TYPE_SCROLL_INSENSITIVE,
+	 *        or ResultSet.TYPE_SCROLL_SENSITIVE
+	 * @param resultSetConcurrency a concurrency type; one of
+	 *        ResultSet.CONCUR_READ_ONLY or ResultSet.CONCUR_UPDATABLE
+	 * @return a new PreparedStatement object containing the pre-compiled SQL
+	 *         statement that will produce ResultSet objects with the given
+	 *         type and concurrency
+	 * @throws SQLException if a database access error occurs or the given
+	 *                      parameters are not ResultSet constants indicating
+	 *                      type and concurrency
+	 */
+	@Override
+	public PreparedStatement prepareStatement(
+			String sql,
+			int resultSetType,
+			int resultSetConcurrency)
+		throws SQLException
+	{
+		return prepareStatement(
+					sql,
+					resultSetType,
+					resultSetConcurrency,
+					ResultSet.HOLD_CURSORS_OVER_COMMIT
+		);
+	}
+	/**
+	 * Creates a PreparedStatement object that will generate ResultSet
+	 * objects with the given type, concurrency, and holdability.
+	 *
+	 * This method is the same as the prepareStatement method above, but
+	 * it allows the default result set type, concurrency, and
+	 * holdability to be overridden.
+	 *
+	 * @param sql a String object that is the SQL statement to be sent
+	 * to the database; may contain one or more ? IN parameters
+	 * @param resultSetType one of the following ResultSet constants:
+	 * ResultSet.TYPE_FORWARD_ONLY, ResultSet.TYPE_SCROLL_INSENSITIVE,
+	 * or ResultSet.TYPE_SCROLL_SENSITIVE
+	 * @param resultSetConcurrency one of the following ResultSet
+	 * constants: ResultSet.CONCUR_READ_ONLY or
+	 * ResultSet.CONCUR_UPDATABLE
+	 * @param resultSetHoldability one of the following ResultSet
+	 * constants: ResultSet.HOLD_CURSORS_OVER_COMMIT or
+	 * ResultSet.CLOSE_CURSORS_AT_COMMIT
+	 * @return a new PreparedStatement object, containing the
+	 * pre-compiled SQL statement, that will generate ResultSet objects
+	 * with the given type, concurrency, and holdability
+	 * @throws SQLException if a database access error occurs or the
+	 * given parameters are not ResultSet constants indicating type,
+	 * concurrency, and holdability
+	 */
+	@Override
+	public PreparedStatement prepareStatement(
+			String sql,
+			int resultSetType,
+			int resultSetConcurrency,
+			int resultSetHoldability)
+		throws SQLException
+	{
+		try {
+			PreparedStatement ret = new MonetPreparedStatement(
+				this,
+				resultSetType,
+				resultSetConcurrency,
+				resultSetHoldability,
+				sql
+			);
+			// store it in the map for when we close...
+			statements.put(ret, null);
+			return ret;
+		} catch (IllegalArgumentException e) {
+			throw new SQLException(e.toString(), "M0M03");
+		}
+		// we don't have to catch SQLException because that is declared to
+		// be thrown
+	}
+	/**
+	 * Creates a default PreparedStatement object that has the
+	 * capability to retrieve auto-generated keys.  The given constant
+	 * tells the driver whether it should make auto-generated keys
+	 * available for retrieval.  This parameter is ignored if the SQL
+	 * statement is not an INSERT statement.
+	 *
+	 * Note: This method is optimized for handling parametric SQL
+	 * statements that benefit from precompilation.  If the driver
+	 * supports precompilation, the method prepareStatement will send
+	 * the statement to the database for precompilation. Some drivers
+	 * may not support precompilation.  In this case, the statement may
+	 * not be sent to the database until the PreparedStatement object is
+	 * executed.  This has no direct effect on users; however, it does
+	 * affect which methods throw certain SQLExceptions.
+	 *
+	 * Result sets created using the returned PreparedStatement object
+	 * will by default be type TYPE_FORWARD_ONLY and have a concurrency
+	 * level of CONCUR_READ_ONLY.
+	 *
+	 * @param sql an SQL statement that may contain one or more '?' IN
+	 *        parameter placeholders
+	 * @param autoGeneratedKeys a flag indicating whether auto-generated
+	 *        keys should be returned; one of
+	 *        Statement.RETURN_GENERATED_KEYS or
+	 *        Statement.NO_GENERATED_KEYS
+	 * @return a new PreparedStatement object, containing the
+	 *         pre-compiled SQL statement, that will have the capability
+	 *         of returning auto-generated keys
+	 * @throws SQLException - if a database access error occurs or the
+	 *         given parameter is not a Statement  constant indicating
+	 *         whether auto-generated keys should be returned
+	 */
+	@Override
+	public PreparedStatement prepareStatement(
+			String sql,
+			int autoGeneratedKeys)
+		throws SQLException
+	{
+		if (autoGeneratedKeys != Statement.RETURN_GENERATED_KEYS &&
+				autoGeneratedKeys != Statement.NO_GENERATED_KEYS)
+			throw new SQLException("Invalid argument, expected RETURN_GENERATED_KEYS or NO_GENERATED_KEYS", "M1M05");
+		/* MonetDB has no way to disable this, so just do the normal
+		 * thing ;) */
+		return prepareStatement(
+					sql,
+					ResultSet.TYPE_FORWARD_ONLY,
+					ResultSet.CONCUR_READ_ONLY
+		);
+	}
+	@Override
+	public PreparedStatement prepareStatement(String sql, int[] columnIndexes) {return null;}
+	@Override
+	public PreparedStatement prepareStatement(String sql, String[] columnNames) {return null;}
+	/**
+	 * Removes the given Savepoint object from the current transaction.
+	 * Any reference to the savepoint after it have been removed will
+	 * cause an SQLException to be thrown.
+	 *
+	 * @param savepoint the Savepoint object to be removed
+	 * @throws SQLException if a database access error occurs or the given
+	 *         Savepoint object is not a valid savepoint in the current
+	 *         transaction
+	 */
+	@Override
+	public void releaseSavepoint(Savepoint savepoint) throws SQLException {
+		if (!(savepoint instanceof MonetSavepoint)) throw
+			new SQLException("This driver can only handle savepoints it created itself", "M0M06");
+		MonetSavepoint sp = (MonetSavepoint)savepoint;
+		// note: can't use sendIndependentCommand here because we need
+		// to process the auto_commit state the server gives
+		// create a container for the result
+		ResponseList l = new ResponseList(
+			0,
+			0,
+			ResultSet.FETCH_FORWARD,
+			ResultSet.CONCUR_READ_ONLY
+		);
+		// send the appropriate query string to the database
+		try {
+			l.processQuery("RELEASE SAVEPOINT " + sp.getName());
+		} finally {
+			l.close();
+		}
+	}
+	/**
+	 * Undoes all changes made in the current transaction and releases
+	 * any database locks currently held by this Connection object. This
+	 * method should be used only when auto-commit mode has been
+	 * disabled.
+	 *
+	 * @throws SQLException if a database access error occurs or this
+	 *         Connection object is in auto-commit mode
+	 * @see #setAutoCommit(boolean)
+	 */
+	@Override
+	public void rollback() throws SQLException {
+		// note: can't use sendIndependentCommand here because we need
+		// to process the auto_commit state the server gives
+		// create a container for the result
+		ResponseList l = new ResponseList(
+			0,
+			0,
+			ResultSet.FETCH_FORWARD,
+			ResultSet.CONCUR_READ_ONLY
+		);
+		// send rollback to the server
+		try {
+			l.processQuery("ROLLBACK");
+		} finally {
+			l.close();
+		}
+	}
+	/**
+	 * Undoes all changes made after the given Savepoint object was set.
+	 *
+	 * This method should be used only when auto-commit has been
+	 * disabled.
+	 *
+	 * @param savepoint the Savepoint object to roll back to
+	 * @throws SQLException if a database access error occurs, the
+	 *         Savepoint object is no longer valid, or this Connection
+	 *         object is currently in auto-commit mode
+	 */
+	@Override
+	public void rollback(Savepoint savepoint) throws SQLException {
+		if (!(savepoint instanceof MonetSavepoint)) throw
+			new SQLException("This driver can only handle savepoints it created itself", "M0M06");
+		MonetSavepoint sp = (MonetSavepoint)savepoint;
+		// note: can't use sendIndependentCommand here because we need
+		// to process the auto_commit state the server gives
+		// create a container for the result
+		ResponseList l = new ResponseList(
+			0,
+			0,
+			ResultSet.FETCH_FORWARD,
+			ResultSet.CONCUR_READ_ONLY
+		);
+		// send the appropriate query string to the database
+		try {
+			l.processQuery("ROLLBACK TO SAVEPOINT " + sp.getName());
+		} finally {
+			l.close();
+		}
+	}
+	/**
+	 * Sets this connection's auto-commit mode to the given state. If a
+	 * connection is in auto-commit mode, then all its SQL statements
+	 * will be executed and committed as individual transactions.
+	 * Otherwise, its SQL statements are grouped into transactions that
+	 * are terminated by a call to either the method commit or the
+	 * method rollback. By default, new connections are in auto-commit
+	 * mode.
+	 *
+	 * The commit occurs when the statement completes or the next
+	 * execute occurs, whichever comes first. In the case of statements
+	 * returning a ResultSet object, the statement completes when the
+	 * last row of the ResultSet object has been retrieved or the
+	 * ResultSet object has been closed. In advanced cases, a single
+	 * statement may return multiple results as well as output parameter
+	 * values. In these cases, the commit occurs when all results and
+	 * output parameter values have been retrieved.
+	 *
+	 * NOTE: If this method is called during a transaction, the
+	 * transaction is committed.
+	 *
+	 * @param autoCommit true to enable auto-commit mode; false to disable it
+	 * @throws SQLException if a database access error occurs
+	 * @see #getAutoCommit()
+	 */
+	@Override
+	public void setAutoCommit(boolean autoCommit) throws SQLException {
+		if (this.autoCommit != autoCommit) {
+			sendControlCommand("auto_commit " + (autoCommit ? "1" : "0"));
+			this.autoCommit = autoCommit;
+		}
+	}
+	/**
+	 * Sets the given catalog name in order to select a subspace of this
+	 * Connection object's database in which to work.  If the driver
+	 * does not support catalogs, it will silently ignore this request.
+	 */
+	@Override
+	public void setCatalog(String catalog) throws SQLException {
+		// silently ignore this request as MonetDB does not support catalogs
+	}
+	/**
+	 * Not implemented by MonetDB's JDBC driver.
+	 *
+	 * @param name The name of the client info property to set
+	 * @param value The value to set the client info property to. If the
+	 *        value is null, the current value of the specified property
+	 *        is cleared.
+	 */
+	@Override
+	public void setClientInfo(String name, String value) {
+		addWarning("clientInfo: " + name + "is not a recognised property", "01M07");
+	}
+	/**
+	 * Not implemented by MonetDB's JDBC driver.
+	 *
+	 * @param props The list of client info properties to set
+	 */
+	@Override
+	public void setClientInfo(Properties props) {
+		for (Entry<Object, Object> entry : props.entrySet()) {
+			setClientInfo(entry.getKey().toString(),
+					entry.getValue().toString());
+		}
+	}
+	@Override
+	public void setHoldability(int holdability) {}
+	/**
+	 * Puts this connection in read-only mode as a hint to the driver to
+	 * enable database optimizations.  MonetDB doesn't support any mode
+	 * here, hence an SQLWarning is generated if attempted to set
+	 * to true here.
+	 *
+	 * @param readOnly true enables read-only mode; false disables it
+	 * @throws SQLException if a database access error occurs or this
+	 *         method is called during a transaction.
+	 */
+	@Override
+	public void setReadOnly(boolean readOnly) throws SQLException {
+		if (readOnly == true)
+			addWarning("cannot setReadOnly(true): read-only Connection mode not supported", "01M08");
+	}
+	/**
+	 * Creates an unnamed savepoint in the current transaction and
+	 * returns the new Savepoint object that represents it.
+	 *
+	 * @return the new Savepoint object
+	 * @throws SQLException if a database access error occurs or this Connection
+	 *         object is currently in auto-commit mode
+	 */
+	@Override
+	public Savepoint setSavepoint() throws SQLException {
+		// create a new Savepoint object
+		MonetSavepoint sp = new MonetSavepoint();
+		// note: can't use sendIndependentCommand here because we need
+		// to process the auto_commit state the server gives
+		// create a container for the result
+		ResponseList l = new ResponseList(
+			0,
+			0,
+			ResultSet.FETCH_FORWARD,
+			ResultSet.CONCUR_READ_ONLY
+		);
+		// send the appropriate query string to the database
+		try {
+			l.processQuery("SAVEPOINT " + sp.getName());
+		} finally {
+			l.close();
+		}
+		return sp;
+	}
+	/**
+	 * Creates a savepoint with the given name in the current
+	 * transaction and returns the new Savepoint object that represents
+	 * it.
+	 *
+	 * @param name a String containing the name of the savepoint
+	 * @return the new Savepoint object
+	 * @throws SQLException if a database access error occurs or this Connection
+	 *         object is currently in auto-commit mode
+	 */
+	@Override
+	public Savepoint setSavepoint(String name) throws SQLException {
+		// create a new Savepoint object
+		MonetSavepoint sp;
+		try {
+			sp = new MonetSavepoint(name);
+		} catch (IllegalArgumentException e) {
+			throw new SQLException(e.getMessage(), "M0M03");
+		}
+		// note: can't use sendIndependentCommand here because we need
+		// to process the auto_commit state the server gives
+		// create a container for the result
+		ResponseList l = new ResponseList(
+			0,
+			0,
+			ResultSet.FETCH_FORWARD,
+			ResultSet.CONCUR_READ_ONLY
+		);
+		// send the appropriate query string to the database
+		try {
+			l.processQuery("SAVEPOINT " + sp.getName());
+		} finally {
+			l.close();
+		}
+		return sp;
+	}
+	/**
+	 * Attempts to change the transaction isolation level for this
+	 * Connection object to the one given.  The constants defined in the
+	 * interface Connection are the possible transaction isolation
+	 * levels.
+	 *
+	 * @param level one of the following Connection constants:
+	 *        Connection.TRANSACTION_READ_UNCOMMITTED,
+	 *        Connection.TRANSACTION_READ_COMMITTED,
+	 *        Connection.TRANSACTION_REPEATABLE_READ, or
+	 *        Connection.TRANSACTION_SERIALIZABLE.
+	 */
+	@Override
+	public void setTransactionIsolation(int level) {
+		if (level != TRANSACTION_SERIALIZABLE) {
+			addWarning("MonetDB only supports fully serializable " +
+					"transactions, continuing with transaction level " +
+					"raised to TRANSACTION_SERIALIZABLE", "01M09");
+		}
+	}
+	/**
+	 * Installs the given TypeMap object as the type map for this
+	 * Connection object. The type map will be used for the custom
+	 * mapping of SQL structured types and distinct types.
+	 *
+	 * @param map the java.util.Map object to install as the replacement for
+	 *        this Connection  object's default type map
+	 */
+	@Override
+	public void setTypeMap(Map<String, Class<?>> map) {
+		typeMap = map;
+	}
+	/**
+	 * Returns a string identifying this Connection to the MonetDB
+	 * server.
+	 *
+	 * @return a String representing this Object
+	 */
+	@Override
+	public String toString() {
+		return "MonetDB Connection (" + getJDBCURL() + ") " +
+				(closed ? "connected" : "disconnected");
+	}
+	//== 1.7 methods (JDBC 4.1)
+	/**
+	 * Sets the given schema name to access.
+	 *
+	 * @param schema the name of a schema in which to work
+	 * @throws SQLException if a database access error occurs or this
+	 *         method is called on a closed connection
+	 */
+	@Override
+	public void setSchema(String schema) throws SQLException {
+		if (closed)
+			throw new SQLException("Cannot call on closed Connection", "M1M20");
+		if (schema != null)
+			createStatement().execute("SET SCHEMA \"" + schema + "\"");
+	}
+	/**
+	 * Retrieves this Connection object's current schema name.
+	 *
+	 * @return the current schema name or null if there is none
+	 * @throws SQLException if a database access error occurs or this
+	 *         method is called on a closed connection
+	 */
+	@Override
+	public String getSchema() throws SQLException {
+		if (closed)
+			throw new SQLException("Cannot call on closed Connection", "M1M20");
+		String cur_schema;
+		Statement st = createStatement();
+		ResultSet rs = null;
+		try {
+			rs = st.executeQuery("SELECT CURRENT_SCHEMA");
+			if (!rs.next())
+				throw new SQLException("Row expected", "02000");
+			cur_schema = rs.getString(1);
+		} finally {
+			if (rs != null)
+				rs.close();
+			st.close();
+		}
+		return cur_schema;
+	}
+	/**
+	 * Terminates an open connection. Calling abort results in:
+	 *  * The connection marked as closed
+	 *  * Closes any physical connection to the database
+	 *  * Releases resources used by the connection
+	 *  * Insures that any thread that is currently accessing the
+	 *    connection will either progress to completion or throw an
+	 *    SQLException.
+	 * Calling abort marks the connection closed and releases any
+	 * resources. Calling abort on a closed connection is a no-op.
+	 *
+	 * @param executor The Executor implementation which will be used by
+	 *        abort
+	 * @throws SQLException if a database access error occurs or the
+	 *         executor is null
+	 * @throws SecurityException if a security manager exists and
+	 *         its checkPermission method denies calling abort
+	 */
+	@Override
+	public void abort(Executor executor) throws SQLException {
+		if (closed)
+			return;
+		if (executor == null)
+			throw new SQLException("executor is null", "M1M05");
+		// this is really the simplest thing to do, it destroys
+		// everything (in particular the server connection)
+		close();
+	}
+	/**
+	 * Sets the maximum period a Connection or objects created from the
+	 * Connection will wait for the database to reply to any one
+	 * request. If any request remains unanswered, the waiting method
+	 * will return with a SQLException, and the Connection or objects
+	 * created from the Connection will be marked as closed. Any
+	 * subsequent use of the objects, with the exception of the close,
+	 * isClosed or Connection.isValid methods, will result in a
+	 * SQLException.
+	 *
+	 * @param executor The Executor implementation which will be used by
+	 *        setNetworkTimeout
+	 * @param millis The time in milliseconds to wait for the
+	 *        database operation to complete
+	 * @throws SQLException if a database access error occurs, this
+	 *         method is called on a closed connection, the executor is
+	 *         null, or the value specified for seconds is less than 0.
+	 */
+	@Override
+	public void setNetworkTimeout(Executor executor, int millis)
+		throws SQLException
+	{
+		if (closed)
+			throw new SQLException("Cannot call on closed Connection", "M1M20");
+		if (executor == null)
+			throw new SQLException("executor is null", "M1M05");
+		if (millis < 0)
+			throw new SQLException("milliseconds is less than zero", "M1M05");
+		try {
+			server.setSoTimeout(millis);
+		} catch (SocketException e) {
+			throw new SQLException(e.getMessage(), "08000");
+		}
+	}
+	/**
+	 * Retrieves the number of milliseconds the driver will wait for a
+	 * database request to complete. If the limit is exceeded, a
+	 * SQLException is thrown.
+	 *
+	 * @return the current timeout limit in milliseconds; zero means
+	 *         there is no limit
+	 * @throws SQLException if a database access error occurs or
+	 *         this method is called on a closed Connection
+	 */
+	@Override
+	public int getNetworkTimeout() throws SQLException {
+		if (closed)
+			throw new SQLException("Cannot call on closed Connection", "M1M20");
+		try {
+			return server.getSoTimeout();
+		} catch (SocketException e) {
+			throw new SQLException(e.getMessage(), "08000");
+		}
+	}
+	//== end methods of interface Connection
+	public String getJDBCURL() {
+		String language = "";
+		if (lang == LANG_MAL)
+			language = "?language=mal";
+		return "jdbc:monetdb://" + hostname + ":" + port + "/" +
+			database + language;
+	}
+	/**
+	 * Returns whether the BLOB type should be mapped to BINARY type.
+	 */
+	boolean getBlobAsBinary() {
+		return blobIsBinary;
+	}
+	/**
+	 * Sends the given string to MonetDB as regular statement, making
+	 * sure there is a prompt after the command is sent.  All possible
+	 * returned information is discarded.  Encountered errors are
+	 * reported.
+	 *
+	 * @param command the exact string to send to MonetDB
+	 * @throws SQLException if an IO exception or a database error occurs
+	 */
+	void sendIndependentCommand(String command) throws SQLException {
+		synchronized (server) {
+			try {
+				out.writeLine(
+						(queryTempl[0] == null ? "" : queryTempl[0]) +
+						command +
+						(queryTempl[1] == null ? "" : queryTempl[1]));
+				String error = in.waitForPrompt();
+				if (error != null)
+					throw new SQLException(error.substring(6),
+							error.substring(0, 5));
+			} catch (SocketTimeoutException e) {
+				close(); // JDBC 4.1 semantics: abort()
+				throw new SQLException("connection timed out", "08M33");
+			} catch (IOException e) {
+				throw new SQLException(e.getMessage(), "08000");
+			}
+		}
+	}
+	/**
+	 * Sends the given string to MonetDB as control statement, making
+	 * sure there is a prompt after the command is sent.  All possible
+	 * returned information is discarded.  Encountered errors are
+	 * reported.
+	 *
+	 * @param command the exact string to send to MonetDB
+	 * @throws SQLException if an IO exception or a database error occurs
+	 */
+	void sendControlCommand(String command) throws SQLException {
+		// send X command
+		synchronized (server) {
+			try {
+				out.writeLine(
+						(commandTempl[0] == null ? "" : commandTempl[0]) +
+						command +
+						(commandTempl[1] == null ? "" : commandTempl[1]));
+				String error = in.waitForPrompt();
+				if (error != null)
+					throw new SQLException(error.substring(6),
+							error.substring(0, 5));
+			} catch (SocketTimeoutException e) {
+				close(); // JDBC 4.1 semantics, abort()
+				throw new SQLException("connection timed out", "08M33");
+			} catch (IOException e) {
+				throw new SQLException(e.getMessage(), "08000");
+			}
+		}
+	}
+	/**
+	 * Adds a warning to the pile of warnings this Connection object
+	 * has.  If there were no warnings (or clearWarnings was called)
+	 * this warning will be the first, otherwise this warning will get
+	 * appended to the current warning.
+	 *
+	 * @param reason the warning message
+	 */
+	void addWarning(String reason, String sqlstate) {
+		if (warnings == null) {
+			warnings = new SQLWarning(reason, sqlstate);
+		} else {
+			warnings.setNextWarning(new SQLWarning(reason, sqlstate));
+		}
+	}
+	/** the default number of rows that are (attempted to) read at once */
+	private final static int DEF_FETCHSIZE = 250;
+	/** The sequence counter */
+	private static int seqCounter = 0;
+	/** An optional thread that is used for sending large queries */
+	private SendThread sendThread = null;
+	/**
+	 * A Response is a message sent by the server to indicate some
+	 * action has taken place, and possible results of that action.
+	 */
+	// {{{ interface Response
+	interface Response {
+		/**
+		 * Adds a line to the underlying Response implementation.
+		 *
+		 * @param line the header line as String
+		 * @param linetype the line type according to the MAPI protocol
+		 * @return a non-null String if the line is invalid,
+		 *         or additional lines are not allowed.
+		 */
+		public abstract String addLine(String line, int linetype);
+		/**
+		 * Returns whether this Reponse expects more lines to be added
+		 * to it.
+		 *
+		 * @return true if a next line should be added, false otherwise
+		 */
+		public abstract boolean wantsMore();
+		/**
+		 * Indicates that no more header lines will be added to this
+		 * Response implementation.
+		 *
+		 * @throws SQLException if the contents of the Response is not
+		 *         consistent or sufficient.
+		 */
+		public abstract void complete() throws SQLException;
+		/**
+		 * Instructs the Response implementation to close and do the
+		 * necessary clean up procedures.
+		 *
+		 * @throws SQLException
+		 */
+		public abstract void close();
+	}
+	// }}}
+	/**
+	 * The ResultSetResponse represents a tabular result sent by the
+	 * server.  This is typically an SQL table.  The MAPI headers of the
+	 * Response look like:
+	 * <pre>
+	 * &amp;1 1 28 2 10
+	 * # name,     value # name
+	 * # varchar,  varchar # type
+	 * </pre>
+	 * there the first line consists out of<br />
+	 * <tt>&amp;"qt" "id" "tc" "cc" "rc"</tt>.
+	 */
+	// {{{ ResultSetResponse class implementation
+	class ResultSetResponse implements Response {
+		/** The number of columns in this result */
+		public final int columncount;
+		/** The total number of rows this result set has */
+		public final int tuplecount;
+		/** The numbers of rows to retrieve per DataBlockResponse */
+		private int cacheSize;
+		/** The table ID of this result */
+		public final int id;
+		/** The names of the columns in this result */
+		private String[] name;
+		/** The types of the columns in this result */
+		private String[] type;
+		/** The max string length for each column in this result */
+		private int[] columnLengths;
+		/** The table for each column in this result */
+		private String[] tableNames;
+		/** The query sequence number */
+		private final int seqnr;
+		/** A List of result blocks (chunks of size fetchSize/cacheSize) */
+		private DataBlockResponse[] resultBlocks;
+		/** A bitmap telling whether the headers are set or not */
+		private boolean[] isSet;
+		/** Whether this Response is closed */
+		private boolean closed;
+		/** The Connection that we should use when requesting a new block */
+		private MonetConnection.ResponseList parent;
+		/** Whether the fetchSize was explitly set by the user */
+		private boolean cacheSizeSetExplicitly = false;
+		/** Whether we should send an Xclose command to the server
+		 *  if we close this Response */
+		private boolean destroyOnClose;
+		/** the offset to be used on Xexport queries */
+		private int blockOffset = 0;
+		/** A parser for header lines */
+		HeaderLineParser hlp;
+		private final static int NAMES	= 0;
+		private final static int TYPES	= 1;
+		private final static int TABLES	= 2;
+		private final static int LENS	= 3;
+		/**
+		 * Sole constructor, which requires a MonetConnection parent to
+		 * be given.
+		 *
+		 * @param id the ID of the result set
+		 * @param tuplecount the total number of tuples in the result set
+		 * @param columncount the number of columns in the result set
+		 * @param rowcount the number of rows in the current block
+		 * @param parent the parent that created this Response and will
+		 *               supply new result blocks when necessary
+		 * @param seq the query sequence number
+		 */
+		ResultSetResponse(
+				int id,
+				int tuplecount,
+				int columncount,
+				int rowcount,
+				MonetConnection.ResponseList parent,
+				int seq)
+			throws SQLException
+		{
+			isSet = new boolean[7];
+			this.parent = parent;
+			if (parent.cachesize == 0) {
+				/* Below we have to calculate how many "chunks" we need
+				 * to allocate to store the entire result.  However, if
+				 * the user didn't set a cache size, as in this case, we
+				 * need to stick to our defaults. */
+				cacheSize = MonetConnection.DEF_FETCHSIZE;
+				cacheSizeSetExplicitly = false;
+			} else {
+				cacheSize = parent.cachesize;
+				cacheSizeSetExplicitly = true;
+			}
+			/* So far, so good.  Now the problem with EXPLAIN, DOT, etc
+			 * queries is, that they don't support any block fetching,
+			 * so we need to always fetch everything at once.  For that
+			 * reason, the cache size is here set to the rowcount if
+			 * it's larger, such that we do a full fetch at once.
+			 * (Because we always set a reply_size, we can only get a
+			 * larger rowcount from the server if it doesn't paginate,
+			 * because it's a pseudo SQL result.) */
+			if (rowcount > cacheSize)
+				cacheSize = rowcount;
+			seqnr = seq;
+			closed = false;
+			destroyOnClose = id > 0 && tuplecount > rowcount;
+			this.id = id;
+			this.tuplecount = tuplecount;
+			this.columncount = columncount;
+			this.resultBlocks =
+				new DataBlockResponse[(tuplecount / cacheSize) + 1];
+			hlp = new HeaderLineParser(columncount);
+			resultBlocks[0] = new DataBlockResponse(
+				rowcount,
+				parent.rstype == ResultSet.TYPE_FORWARD_ONLY
+			);
+		}
+		/**
+		 * Parses the given string and changes the value of the matching
+		 * header appropriately, or passes it on to the underlying
+		 * DataResponse.
+		 *
+		 * @param tmpLine the string that contains the header
+		 * @return a non-null String if the header cannot be parsed or
+		 *         is unknown
+		 */
+		// {{{ addLine
+		@Override
+		public String addLine(String tmpLine, int linetype) {
+			if (isSet[LENS] && isSet[TYPES] && isSet[TABLES] && isSet[NAMES]) {
+				return resultBlocks[0].addLine(tmpLine, linetype);
+			}
+			if (linetype != BufferedMCLReader.HEADER)
+				return "header expected, got: " + tmpLine;
+			// depending on the name of the header, we continue
+			try {
+				switch (hlp.parse(tmpLine)) {
+					case HeaderLineParser.NAME:
+						name = hlp.values.clone();
+						isSet[NAMES] = true;
+					break;
+					case HeaderLineParser.LENGTH:
+						columnLengths = hlp.intValues.clone();
+						isSet[LENS] = true;
+					break;
+					case HeaderLineParser.TYPE:
+						type = hlp.values.clone();
+						isSet[TYPES] = true;
+					break;
+					case HeaderLineParser.TABLE:
+						tableNames = hlp.values.clone();
+						isSet[TABLES] = true;
+					break;
+				}
+			} catch (MCLParseException e) {
+				return e.getMessage();
+			}
+			// all is well
+			return null;
+		}
+		// }}}
+		/**
+		 * Returns whether this ResultSetResponse needs more lines.
+		 * This method returns true if not all headers are set, or the
+		 * first DataBlockResponse reports to want more.
+		 */
+		@Override
+		public boolean wantsMore() {
+			if (isSet[LENS] && isSet[TYPES] && isSet[TABLES] && isSet[NAMES]) {
+				return resultBlocks[0].wantsMore();
+			} else {
+				return true;
+			}
+		}
+		/**
+		 * Returns an array of Strings containing the values between
+		 * ',\t' separators.
+		 *
+		 * @param chrLine a character array holding the input data
+		 * @param start where the relevant data starts
+		 * @param stop where the relevant data stops
+		 * @return an array of Strings
+		 */
+		final private String[] getValues(char[] chrLine, int start, int stop) {
+			int elem = 0;
+			String[] values = new String[columncount];
+			for (int i = start; i < stop; i++) {
+				if (chrLine[i] == '\t' && chrLine[i - 1] == ',') {
+					values[elem++] =
+						new String(chrLine, start, i - 1 - start);
+					start = i + 1;
+				}
+			}
+			// at the left over part
+			values[elem++] = new String(chrLine, start, stop - start);
+			return values;
+		}
+		/**
+		 * Adds the given DataBlockResponse to this ResultSetResponse at
+		 * the given block position.
+		 *
+		 * @param offset the offset number of rows for this block
+		 * @param rr the DataBlockResponse to add
+		 */
+		void addDataBlockResponse(int offset, DataBlockResponse rr) {
+			int block = (offset - blockOffset) / cacheSize;
+			resultBlocks[block] = rr;
+		}
+		/**
+		 * Marks this Response as being completed.  A complete Response
+		 * needs to be consistent with regard to its internal data.
+		 *
+		 * @throws SQLException if the data currently in this Response is not
+		 *                      sufficient to be consistant
+		 */
+		@Override
+		public void complete() throws SQLException {
+			String error = "";
+			if (!isSet[NAMES]) error += "name header missing\n";
+			if (!isSet[TYPES]) error += "type header missing\n";
+			if (!isSet[TABLES]) error += "table name header missing\n";
+			if (!isSet[LENS]) error += "column width header missing\n";
+			if (error != "") throw new SQLException(error, "M0M10");
+		}
+		/**
+		 * Returns the names of the columns
+		 *
+		 * @return the names of the columns
+		 */
+		String[] getNames() {
+			return name;
+		}
+		/**
+		 * Returns the types of the columns
+		 *
+		 * @return the types of the columns
+		 */
+		String[] getTypes() {
+			return type;
+		}
+		/**
+		 * Returns the tables of the columns
+		 *
+		 * @return the tables of the columns
+		 */
+		String[] getTableNames() {
+			return tableNames;
+		}
+		/**
+		 * Returns the lengths of the columns
+		 *
+		 * @return the lengths of the columns
+		 */
+		int[] getColumnLengths() {
+			return columnLengths;
+		}
+		/**
+		 * Returns the cache size used within this Response
+		 *
+		 * @return the cache size
+		 */
+		int getCacheSize() {
+			return cacheSize;
+		}
+		/**
+		 * Returns the current block offset
+		 *
+		 * @return the current block offset
+		 */
+		int getBlockOffset() {
+			return blockOffset;
+		}
+		/**
+		 * Returns the ResultSet type, FORWARD_ONLY or not.
+		 *
+		 * @return the ResultSet type
+		 */
+		int getRSType() {
+			return parent.rstype;
+		}
+		/**
+		 * Returns the concurrency of the ResultSet.
+		 *
+		 * @return the ResultSet concurrency
+		 */
+		int getRSConcur() {
+			return parent.rsconcur;
+		}
+		/**
+		 * Returns a line from the cache. If the line is already present in the
+		 * cache, it is returned, if not apropriate actions are taken to make
+		 * sure the right block is being fetched and as soon as the requested
+		 * line is fetched it is returned.
+		 *
+		 * @param row the row in the result set to return
+		 * @return the exact row read as requested or null if the requested row
+		 *         is out of the scope of the result set
+		 * @throws SQLException if an database error occurs
+		 */
+		String getLine(int row) throws SQLException {
+			if (row >= tuplecount || row < 0)
+				return null;
+			int block = (row - blockOffset) / cacheSize;
+			int blockLine = (row - blockOffset) % cacheSize;
+			// do we have the right block loaded? (optimistic try)
+			DataBlockResponse rawr;
+			// load block if appropriate
+			if ((rawr = resultBlocks[block]) == null) {
+				/// TODO: ponder about a maximum number of blocks to keep
+				///       in memory when dealing with random access to
+				///       reduce memory blow-up
+				// if we're running forward only, we can discard the old
+				// block loaded
+				if (parent.rstype == ResultSet.TYPE_FORWARD_ONLY) {
+					for (int i = 0; i < block; i++)
+						resultBlocks[i] = null;
+					if (MonetConnection.seqCounter - 1 == seqnr &&
+							!cacheSizeSetExplicitly &&
+							tuplecount - row > cacheSize &&
+							cacheSize < MonetConnection.DEF_FETCHSIZE * 10)
+					{
+						// there has no query been issued after this
+						// one, so we can consider this an uninterrupted
+						// continuation request.  Let's once increase
+						// the cacheSize as it was not explicitly set,
+						// since the chances are high that we won't
+						// bother anyone else by doing so, and just
+						// gaining some performance.
+						// store the previous position in the
+						// blockOffset variable
+						blockOffset += cacheSize;
+						// increase the cache size (a lot)
+						cacheSize *= 10;
+						// by changing the cacheSize, we also
+						// change the block measures.  Luckily
+						// we don't care about previous blocks
+						// because we have a forward running
+						// pointer only.  However, we do have
+						// to recalculate the block number, to
+						// ensure the next call to find this
+						// new block.
+						block = (row - blockOffset) / cacheSize;
+						blockLine = (row - blockOffset) % cacheSize;
+					}
+				}
+				// ok, need to fetch cache block first
+				parent.executeQuery(
+						commandTempl,
+						"export " + id + " " + ((block * cacheSize) + blockOffset) + " " + cacheSize
+				);
+				rawr = resultBlocks[block];
+				if (rawr == null) throw
+					new AssertionError("block " + block + " should have been fetched by now :(");
+			}
+			return rawr.getRow(blockLine);
+		}
+		/**
+		 * Closes this Response by sending an Xclose to the server indicating
+		 * that the result can be closed at the server side as well.
+		 */
+		@Override
+		public void close() {
+			if (closed) return;
+			// send command to server indicating we're done with this
+			// result only if we had an ID in the header and this result
+			// was larger than the reply size
+			try {
+				if (destroyOnClose) sendControlCommand("close " + id);
+			} catch (SQLException e) {
+				// probably a connection error...
+			}
+			// close the data block associated with us
+			for (int i = 1; i < resultBlocks.length; i++) {
+				DataBlockResponse r = resultBlocks[i];
+				if (r != null) r.close();
+			}
+			closed = true;
+		}
+		/**
+		 * Returns whether this Response is closed
+		 *
+		 * @return whether this Response is closed
+		 */
+		boolean isClosed() {
+			return closed;
+		}
+	}
+	// }}}
+	/**
+	 * The DataBlockResponse is tabular data belonging to a
+	 * ResultSetResponse.  Tabular data from the server typically looks
+	 * like:
+	 * <pre>
+	 * [ "value",	56	]
+	 * </pre>
+	 * where each column is separated by ",\t" and each tuple surrounded
+	 * by brackets ("[" and "]").  A DataBlockResponse object holds the
+	 * raw data as read from the server, in a parsed manner, ready for
+	 * easy retrieval.
+	 *
+	 * This object is not intended to be queried by multiple threads
+	 * synchronously. It is designed to work for one thread retrieving
+	 * rows from it.  When multiple threads will retrieve rows from this
+	 * object, it is possible for threads to get the same data.
+	 */
+	// {{{ DataBlockResponse class implementation
+	static class DataBlockResponse implements Response {
+		/** The String array to keep the data in */
+		private final String[] data;
+		/** The counter which keeps the current position in the data array */
+		private int pos;
+		/** Whether we can discard lines as soon as we have read them */
+		private boolean forwardOnly;
+		/**
+		 * Constructs a DataBlockResponse object
+		 * @param size the size of the data array to create
+		 * @param forward whether this is a forward only result
+		 */
+		DataBlockResponse(int size, boolean forward) {
+			pos = -1;
+			data = new String[size];
+			forwardOnly = forward;
+		}
+		/**
+		 * addLine adds a String of data to this object's data array.
+		 * Note that an IndexOutOfBoundsException can be thrown when an
+		 * attempt is made to add more than the original construction size
+		 * specified.
+		 *
+		 * @param line the header line as String
+		 * @param linetype the line type according to the MAPI protocol
+		 * @return a non-null String if the line is invalid,
+		 *         or additional lines are not allowed.
+		 */
+		@Override
+		public String addLine(String line, int linetype) {
+			if (linetype != BufferedMCLReader.RESULT)
+				return "protocol violation: unexpected line in data block: " + line;
+			// add to the backing array
+			data[++pos] = line;
+			// all is well
+			return null;
+		}
+		/**
+		 * Returns whether this Reponse expects more lines to be added
+		 * to it.
+		 *
+		 * @return true if a next line should be added, false otherwise
+		 */
+		@Override
+		public boolean wantsMore() {
+			// remember: pos is the value already stored
+			return pos + 1 < data.length;
+		}
+		/**
+		 * Indicates that no more header lines will be added to this
+		 * Response implementation.  In most cases this is a redundant
+		 * operation because the data array is full.  However... it can
+		 * happen that this is NOT the case!
+		 *
+		 * @throws SQLException if not all rows are filled
+		 */
+		@Override
+		public void complete() throws SQLException {
+			if ((pos + 1) != data.length) throw
+				new SQLException("Inconsistent state detected!  Current block capacity: " + data.length + ", block usage: " + (pos + 1) + ".  Did MonetDB send what it promised to?", "M0M10");
+		}
+		/**
+		 * Instructs the Response implementation to close and do the
+		 * necessary clean up procedures.
+		 *
+		 * @throws SQLException
+		 */
+		@Override
+		public void close() {
+			// feed all rows to the garbage collector
+			for (int i = 0; i < data.length; i++) data[i] = null;
+		}
+		/**
+		 * Retrieves the required row.  Warning: if the requested rows
+		 * is out of bounds, an IndexOutOfBoundsException will be
+		 * thrown.
+		 *
+		 * @param line the row to retrieve
+		 * @return the requested row as String
+		 */
+		String getRow(int line) {
+			if (forwardOnly) {
+				String ret = data[line];
+				data[line] = null;
+				return ret;
+			} else {
+				return data[line];
+			}
+		}
+	}
+	// }}}
+	/**
+	 * The UpdateResponse represents an update statement response.  It
+	 * is issued on an UPDATE, INSERT or DELETE SQL statement.  This
+	 * response keeps a count field that represents the affected rows
+	 * and a field that contains the last inserted auto-generated ID, or
+	 * -1 if not applicable.<br />
+	 * <tt>&amp;2 0 -1</tt>
+	 */
+	// {{{ UpdateResponse class implementation
+	static class UpdateResponse implements Response {
+		public final int count;
+		public final String lastid;
+		public UpdateResponse(int cnt, String id) {
+			// fill the blank finals
+			this.count = cnt;
+			this.lastid = id;
+		}
+		@Override
+		public String addLine(String line, int linetype) {
+			return "Header lines are not supported for an UpdateResponse";
+		}
+		@Override
+		public boolean wantsMore() {
+			return false;
+		}
+		@Override
+		public void complete() {
+			// empty, because there is nothing to check
+		}
+		@Override
+		public void close() {
+			// nothing to do here...
+		}
+	}
+	// }}}
+	/**
+	 * The SchemaResponse represents an schema modification response.
+	 * It is issued on statements like CREATE, DROP or ALTER TABLE.
+	 * This response keeps a field that represents the success state, as
+	 * defined by JDBC, which is currently in MonetDB's case alwats
+	 * SUCCESS_NO_INFO.  Note that this state is not sent by the
+	 * server.<br />
+	 * <tt>&amp;3</tt>
+	 */
+	// {{{ SchemaResponse class implementation
+	class SchemaResponse implements Response {
+		public final int state = Statement.SUCCESS_NO_INFO;
+		@Override
+		public String addLine(String line, int linetype) {
+			return "Header lines are not supported for a SchemaResponse";
+		}
+		@Override
+		public boolean wantsMore() {
+			return false;
+		}
+		@Override
+		public void complete() {
+			// empty, because there is nothing to check
+		}
+		@Override
+		public void close() {
+			// nothing to do here...
+		}
+	}
+	// }}}
+	/**
+	 * The AutoCommitResponse represents a transaction message.  It
+	 * stores (a change in) the server side auto commit mode.<br />
+	 * <tt>&amp;4 (t|f)</tt>
+	 */
+	// {{{ AutoCommitResponse class implementation
+	class AutoCommitResponse extends SchemaResponse {
+		public final boolean autocommit;
+		public AutoCommitResponse(boolean ac) {
+			// fill the blank final
+			this.autocommit = ac;
+		}
+	}
+	// }}}
+	/**
+	 * A list of Response objects.  Responses are added to this list.
+	 * Methods of this class are not synchronized.  This is left as
+	 * responsibility to the caller to prevent concurrent access.
+	 */
+	// {{{ ResponseList class implementation
+	class ResponseList {
+		/** The cache size (number of rows in a DataBlockResponse object) */
+		final int cachesize;
+		/** The maximum number of results for this query */
+		final int maxrows;
+		/** The ResultSet type to produce */
+		final int rstype;
+		/** The ResultSet concurrency to produce */
+		final int rsconcur;
+		/** The sequence number of this ResponseList */
+		final int seqnr;
+		/** A list of the Responses associated with the query,
+		 *  in the right order */
+		private List<Response> responses;
+		/** A map of ResultSetResponses, used for additional
+		 *  DataBlockResponse mapping */
+		private Map<Integer, ResultSetResponse> rsresponses;
+		/** The current header returned by getNextResponse() */
+		private int curResponse;
+		/**
+		 * Main constructor.  The query argument can either be a String
+		 * or List.  An SQLException is thrown if another object
+		 * instance is supplied.
+		 *
+		 * @param cachesize overall cachesize to use
+		 * @param maxrows maximum number of rows to allow in the set
+		 * @param rstype the type of result sets to produce
+		 * @param rsconcur the concurrency of result sets to produce
+		 */
+		ResponseList(
+				int cachesize,
+				int maxrows,
+				int rstype,
+				int rsconcur
+		) throws SQLException {
+			this.cachesize = cachesize;
+			this.maxrows = maxrows;
+			this.rstype = rstype;
+			this.rsconcur = rsconcur;
+			responses = new ArrayList<Response>();
+			curResponse = -1;
+			seqnr = MonetConnection.seqCounter++;
+		}
+		/**
+		 * Retrieves the next available response, or null if there are
+		 * no more responses.
+		 *
+		 * @return the next Response available or null
+		 */
+		Response getNextResponse() throws SQLException {
+			if (rstype == ResultSet.TYPE_FORWARD_ONLY) {
+				// free resources if we're running forward only
+				if (curResponse >= 0 && curResponse < responses.size()) {
+					Response tmp = responses.get(curResponse);
+					if (tmp != null) tmp.close();
+					responses.set(curResponse, null);
+				}
+			}
+			curResponse++;
+			if (curResponse >= responses.size()) {
+				// ResponseList is obviously completed so, there are no
+				// more responses
+				return null;
+			} else {
+				// return this response
+				return responses.get(curResponse);
+			}
+		}
+		/**
+		 * Closes the Reponse at index i, if not null.
+		 *
+		 * @param i the index position of the header to close
+		 */
+		void closeResponse(int i) {
+			if (i < 0 || i >= responses.size()) return;
+			Response tmp = responses.set(i, null);
+			if (tmp != null)
+				tmp.close();
+		}
+		/**
+		 * Closes the current response.
+		 */
+		void closeCurrentResponse() {
+			closeResponse(curResponse);
+		}
+		/**
+		 * Closes the current and previous responses.
+		 */
+		void closeCurOldResponses() {
+			for (int i = curResponse; i >= 0; i--) {
+				closeResponse(i);
+			}
+		}
+		/**
+		 * Closes this ResponseList by closing all the Responses in this
+		 * ResponseList.
+		 */
+		void close() {
+			for (int i = 0; i < responses.size(); i++) {
+				closeResponse(i);
+			}
+		}
+		/**
+		 * Returns whether this ResponseList has still unclosed
+		 * Responses.
+		 */
+		boolean hasUnclosedResponses() {
+			for (Response r : responses) {
+				if (r != null)
+					return true;
+			}
+			return false;
+		}
+		/**
+		 * Executes the query contained in this ResponseList, and
+		 * stores the Responses resulting from this query in this
+		 * ResponseList.
+		 *
+		 * @throws SQLException if a database error occurs
+		 */
+		void processQuery(String query) throws SQLException {
+			executeQuery(queryTempl, query);
+		}
+		/**
+		 * Internal executor of queries.
+		 *
+		 * @param templ the template to fill in
+		 * @param the query to execute
+		 * @throws SQLException if a database error occurs
+		 */
+		@SuppressWarnings("fallthrough")
+		void executeQuery(String[] templ, String query)
+			throws SQLException
+		{
+			boolean sendThreadInUse = false;
+			String error = null;
+			try {
+				synchronized (server) {
+					// make sure we're ready to send query; read data till we
+					// have the prompt it is possible (and most likely) that we
+					// already have the prompt and do not have to skip any
+					// lines.  Ignore errors from previous result sets.
+					in.waitForPrompt();
+					// {{{ set reply size
+					/**
+					 * Change the reply size of the server.  If the given
+					 * value is the same as the current value known to use,
+					 * then ignore this call.  If it is set to 0 we get a
+					 * prompt after the server sent it's header.
+					 */
+					int size = cachesize == 0 ? DEF_FETCHSIZE : cachesize;
+					size = maxrows != 0 ? Math.min(maxrows, size) : size;
+					// don't do work if it's not needed
+					if (lang == LANG_SQL && size != curReplySize && templ != commandTempl) {
+						sendControlCommand("reply_size " + size);
+						// store the reply size after a successful change
+						curReplySize = size;
+					}
+					// }}} set reply size
+					// If the query is larger than the TCP buffer size, use a
+					// special send thread to avoid deadlock with the server due
+					// to blocking behaviour when the buffer is full.  Because
+					// the server will be writing back results to us, it will
+					// eventually block as well when its TCP buffer gets full,
+					// as we are blocking an not consuming from it.  The result
+					// is a state where both client and server want to write,
+					// but block.
+					if (query.length() > MapiSocket.BLOCK) {
+						// get a reference to the send thread
+						if (sendThread == null)
+							sendThread = new SendThread(out);
+						// tell it to do some work!
+						sendThread.runQuery(templ, query);
+						sendThreadInUse = true;
+					} else {
+						// this is a simple call, which is a lot cheaper and will
+						// always succeed for small queries.
+						out.writeLine(
+								(templ[0] == null ? "" : templ[0]) +
+								query +
+								(templ[1] == null ? "" : templ[1]));
+					}
+					// go for new results
+					String tmpLine = in.readLine();
+					int linetype = in.getLineType();
+					Response res = null;
+					while (linetype != BufferedMCLReader.PROMPT) {
+						// each response should start with a start of header
+						// (or error)
+						switch (linetype) {
+							case BufferedMCLReader.SOHEADER:
+								// make the response object, and fill it
+								try {
+									switch (sohp.parse(tmpLine)) {
+										case StartOfHeaderParser.Q_PARSE:
+											throw new MCLParseException("Q_PARSE header not allowed here", 1);
+										case StartOfHeaderParser.Q_TABLE:
+										case StartOfHeaderParser.Q_PREPARE: {
+											int id = sohp.getNextAsInt();
+											int tuplecount = sohp.getNextAsInt();
+											int columncount = sohp.getNextAsInt();
+											int rowcount = sohp.getNextAsInt();
+											// enforce the maxrows setting
+											if (maxrows != 0 && tuplecount > maxrows)
+												tuplecount = maxrows;
+											res = new ResultSetResponse(
+													id,
+													tuplecount,
+													columncount,
+													rowcount,
+													this,
+													seqnr
+											);
+											// only add this resultset to
+											// the hashmap if it can possibly
+											// have an additional datablock
+											if (rowcount < tuplecount) {
+												if (rsresponses == null)
+													rsresponses = new HashMap<Integer, ResultSetResponse>();
+												rsresponses.put(
+														Integer.valueOf(id),
+														(ResultSetResponse) res
+												);
+											}
+										} break;
+										case StartOfHeaderParser.Q_UPDATE:
+											res = new UpdateResponse(
+													sohp.getNextAsInt(),   // count
+													sohp.getNextAsString() // key-id
+													);
+										break;
+										case StartOfHeaderParser.Q_SCHEMA:
+											res = new SchemaResponse();
+										break;
+										case StartOfHeaderParser.Q_TRANS:
+											boolean ac = sohp.getNextAsString().equals("t") ? true : false;
+											if (autoCommit && ac) {
+												addWarning("Server enabled auto commit " +
+														"mode while local state " +
+														"already was auto commit.", "01M11"
+														);
+											}
+											autoCommit = ac;
+											res = new AutoCommitResponse(ac);
+										break;
+										case StartOfHeaderParser.Q_BLOCK: {
+											// a new block of results for a
+											// response...
+											int id = sohp.getNextAsInt();
+											sohp.getNextAsInt();	// columncount
+											int rowcount = sohp.getNextAsInt();
+											int offset = sohp.getNextAsInt();
+											ResultSetResponse t =
+												rsresponses.get(Integer.valueOf(id));
+											if (t == null) {
+												error = "M0M12!no ResultSetResponse with id " + id + " found";
+												break;
+											}
+											DataBlockResponse r =
+												new DataBlockResponse(
+													rowcount,	// rowcount
+													t.getRSType() == ResultSet.TYPE_FORWARD_ONLY
+												);
+											t.addDataBlockResponse(offset, r);
+											res = r;
+										} break;
+									}
+								} catch (MCLParseException e) {
+									error = "M0M10!error while parsing start of header:\n" +
+										e.getMessage() +
+										" found: '" + tmpLine.charAt(e.getErrorOffset()) + "'" +
+										" in: \"" + tmpLine + "\"" +
+										" at pos: " + e.getErrorOffset();
+									// flush all the rest
+									in.waitForPrompt();
+									linetype = in.getLineType();
+									break;
+								}
+								// immediately handle errors after parsing
+								// the header (res may be null)
+								if (error != null) {
+									in.waitForPrompt();
+									linetype = in.getLineType();
+									break;
+								}
+								// here we have a res object, which
+								// we can start filling
+								while (res.wantsMore()) {
+									error = res.addLine(
+											in.readLine(),
+											in.getLineType()
+									);
+									if (error != null) {
+										// right, some protocol violation,
+										// skip the rest of the result
+										error = "M0M10!" + error;
+										in.waitForPrompt();
+										linetype = in.getLineType();
+										break;
+									}
+								}
+								if (error != null)
+									break;
+								// it is of no use to store
+								// DataBlockReponses, you never want to
+								// retrieve them directly anyway
+								if (!(res instanceof DataBlockResponse))
+									responses.add(res);
+								// read the next line (can be prompt, new
+								// result, error, etc.) before we start the
+								// loop over
+								tmpLine = in.readLine();
+								linetype = in.getLineType();
+							break;
+							case BufferedMCLReader.INFO:
+								addWarning(tmpLine.substring(1), "01000");
+								// read the next line (can be prompt, new
+								// result, error, etc.) before we start the
+								// loop over
+								tmpLine = in.readLine();
+								linetype = in.getLineType();
+							break;
+							default:	// Yeah... in Java this is correct!
+								// we have something we don't
+								// expect/understand, let's make it an error
+								// message
+								tmpLine = "!M0M10!protocol violation, unexpected line: " + tmpLine;
+								// don't break; fall through...
+							case BufferedMCLReader.ERROR:
+								// read everything till the prompt (should be
+								// error) we don't know if we ignore some
+								// garbage here... but the log should reveal
+								// that
+								error = in.waitForPrompt();
+								linetype = in.getLineType();
+								if (error != null) {
+									error = tmpLine.substring(1) + "\n" + error;
+								} else {
+									error = tmpLine.substring(1);
+								}
+							break;
+						}
+					}
+				}
+				// if we used the sendThread, make sure it has finished
+				if (sendThreadInUse) {
+					String tmp = sendThread.getErrors();
+					if (tmp != null) {
+						if (error == null) {
+							error = "08000!" + tmp;
+						} else {
+							error += "\n08000!" + tmp;
+						}
+					}
+				}
+				if (error != null) {
+					SQLException ret = null;
+					String[] errors = error.split("\n");
+					for (int i = 0; i < errors.length; i++) {
+						if (ret == null) {
+							ret = new SQLException(errors[i].substring(6),
+									errors[i].substring(0, 5));
+						} else {
+							ret.setNextException(new SQLException(
+										errors[i].substring(6),
+										errors[i].substring(0, 5)));
+						}
+					}
+					throw ret;
+				}
+			} catch (SocketTimeoutException e) {
+				close(); // JDBC 4.1 semantics, abort()
+				throw new SQLException("connection timed out", "08M33");
+			} catch (IOException e) {
+				closed = true;
+				throw new SQLException(e.getMessage() + " (mserver still alive?)", "08000");
+			}
+		}
+	}
+	// }}}
+	/**
+	 * A thread to send a query to the server.  When sending large
+	 * amounts of data to a server, the output buffer of the underlying
+	 * communication socket may overflow.  In such case the sending
+	 * process blocks.  In order to prevent deadlock, it might be
+	 * desirable that the driver as a whole does not block.  This thread
+	 * facilitates the prevention of such 'full block', because this
+	 * separate thread only will block.<br />
+	 * This thread is designed for reuse, as thread creation costs are
+	 * high.
+	 */
+	// {{{ SendThread class implementation
+	static class SendThread extends Thread {
+		/** The state WAIT represents this thread to be waiting for
+		 *  something to do */
+		private final static int WAIT = 0;
+		/** The state QUERY represents this thread to be executing a query */
+		private final static int QUERY = 1;
+		/** The state SHUTDOWN is the final state that ends this thread */
+		private final static int SHUTDOWN = -1;
+		private String[] templ;
+		private String query;
+		private BufferedMCLWriter out;
+		private String error;
+		private int state = WAIT;
+		final Lock sendLock = new ReentrantLock();
+		final Condition queryAvailable = sendLock.newCondition();
+		final Condition waiting = sendLock.newCondition();
+		/**
+		 * Constructor which immediately starts this thread and sets it
+		 * into daemon mode.
+		 *
+		 * @param monet the socket to write to
+		 */
+		public SendThread(BufferedMCLWriter out) {
+			super("SendThread");
+			setDaemon(true);
+			this.out = out;
+			start();
+		}
+		@Override
+		public void run() {
+			sendLock.lock();
+			try {
+				while (true) {
+					while (state == WAIT) {
+						try {
+							queryAvailable.await();
+						} catch (InterruptedException e) {
+							// woken up, eh?
+						}
+					}
+					if (state == SHUTDOWN)
+						break;
+					// state is QUERY here
+					try {
+						out.writeLine(
+								(templ[0] == null ? "" : templ[0]) +
+								query +
+								(templ[1] == null ? "" : templ[1]));
+					} catch (IOException e) {
+						error = e.getMessage();
+					}
+					// update our state, and notify, maybe someone is waiting
+					// for us in throwErrors
+					state = WAIT;
+					waiting.signal();
+				}
+			} finally {
+				sendLock.unlock();
+			}
+		}
+		/**
+		 * Starts sending the given query over the given socket.  Beware
+		 * that the thread should be finished (can be assured by calling
+		 * throwErrors()) before this method is called!
+		 *
+		 * @param templ the query template
+		 * @param query the query itself
+		 * @throws SQLException if this SendThread is already in use
+		 */
+		public void runQuery(String[] templ, String query) throws SQLException {
+			sendLock.lock();
+			try {
+				if (state != WAIT)
+					throw new SQLException("SendThread already in use or shutting down!", "M0M03");
+				this.templ = templ;
+				this.query = query;
+				// let the thread know there is some work to do
+				state = QUERY;
+				queryAvailable.signal();
+			} finally {
+				sendLock.unlock();
+			}
+		}
+		/**
+		 * Returns errors encountered during the sending process.
+		 *
+		 * @return the errors or null if none
+		 */
+		public String getErrors() {
+			sendLock.lock();
+			try {
+				// make sure the thread is in WAIT state, not QUERY
+				while (state == QUERY) {
+					try {
+						waiting.await();
+					} catch (InterruptedException e) {
+						// just try again
+					}
+				}
+				if (state == SHUTDOWN)
+					error = "SendThread is shutting down";
+			} finally {
+				sendLock.unlock();
+			}
+			return error;
+		}
+		/**
+		 * Requests this SendThread to stop.
+		 */
+		public void shutdown() {
+			sendLock.lock();
+			state = SHUTDOWN;
+			sendLock.unlock();
+			this.interrupt();  // break any wait conditions
+		}
+	}
+	// }}}
+}

Mercurial > hg > monetdb-java

comparison src/main/java/nl/cwi/monetdb/jdbc/MonetConnection.java @ 0:a5a898f6886c