/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.engine.jdbc.connections.internal;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.SQLException;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.hibernate.HibernateException;
import org.hibernate.boot.registry.classloading.spi.ClassLoaderService;
import org.hibernate.cfg.AvailableSettings;
import org.hibernate.cfg.Environment;
import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
import org.hibernate.internal.CoreLogging;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.internal.util.ReflectHelper;
import org.hibernate.internal.util.config.ConfigurationHelper;
import org.hibernate.service.UnknownUnwrapTypeException;
import org.hibernate.service.spi.Configurable;
import org.hibernate.service.spi.ServiceException;
import org.hibernate.service.spi.ServiceRegistryAwareService;
import org.hibernate.service.spi.ServiceRegistryImplementor;
import org.hibernate.service.spi.Stoppable;
/**
* A connection provider that uses the {@link java.sql.DriverManager} directly to open connections and provides
* a very rudimentary connection pool.
* <p/>
* IMPL NOTE : not intended for production use!
* <p/>
* Thanks to Oleg Varaksin and his article on object pooling using the {@link java.util.concurrent} package, from
* which much of the pooling code here is derived. See http://ovaraksin.blogspot.com/2013/08/simple-and-lightweight-pool.html
*
* @author Gavin King
* @author Steve Ebersole
*/
public class DriverManagerConnectionProviderImpl
implements ConnectionProvider, Configurable, Stoppable, ServiceRegistryAwareService {
private static final CoreMessageLogger log = CoreLogging.messageLogger( DriverManagerConnectionProviderImpl.class );
public static final String MIN_SIZE = "hibernate.connection.min_pool_size";
public static final String INITIAL_SIZE = "hibernate.connection.initial_pool_size";
// in TimeUnit.SECONDS
public static final String VALIDATION_INTERVAL = "hibernate.connection.pool_validation_interval";
private boolean active = true;
private ConcurrentLinkedQueue<Connection> connections = new ConcurrentLinkedQueue<Connection>();
private ConnectionCreator connectionCreator;
private ScheduledExecutorService executorService;
// create the pool ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
private ServiceRegistryImplementor serviceRegistry;
@Override
public void injectServices(ServiceRegistryImplementor serviceRegistry) {
this.serviceRegistry = serviceRegistry;
}
@Override
public void configure(Map configurationValues) {
log.usingHibernateBuiltInConnectionPool();
connectionCreator = buildCreator( configurationValues );
final int minSize = ConfigurationHelper.getInt( MIN_SIZE, configurationValues, 1 );
final int maxSize = ConfigurationHelper.getInt( AvailableSettings.POOL_SIZE, configurationValues, 20 );
final int initialSize = ConfigurationHelper.getInt( INITIAL_SIZE, configurationValues, minSize );
final long validationInterval = ConfigurationHelper.getLong( VALIDATION_INTERVAL, configurationValues, 30 );
log.hibernateConnectionPoolSize( maxSize, minSize );
log.debugf( "Initializing Connection pool with %s Connections", initialSize );
for ( int i = 0; i < initialSize; i++ ) {
connections.add( connectionCreator.createConnection() );
}
executorService = Executors.newSingleThreadScheduledExecutor();
executorService.scheduleWithFixedDelay(
new Runnable() {
private boolean primed;
@Override
public void run() {
int size = connections.size();
if ( !primed && size >= minSize ) {
// IMPL NOTE : the purpose of primed is to allow the pool to lazily reach its
// defined min-size.
log.debug( "Connection pool now considered primed; min-size will be maintained" );
primed = true;
}
if ( size < minSize && primed ) {
int numberToBeAdded = minSize - size;
log.debugf( "Adding %s Connections to the pool", numberToBeAdded );
for (int i = 0; i < numberToBeAdded; i++) {
connections.add( connectionCreator.createConnection() );
}
}
else if ( size > maxSize ) {
int numberToBeRemoved = size - maxSize;
log.debugf( "Removing %s Connections from the pool", numberToBeRemoved );
for ( int i = 0; i < numberToBeRemoved; i++ ) {
Connection connection = connections.poll();
try {
connection.close();
}
catch (SQLException e) {
log.unableToCloseConnection( e );
}
}
}
}
},
validationInterval,
validationInterval,
TimeUnit.SECONDS
);
}
private ConnectionCreator buildCreator(Map configurationValues) {
final ConnectionCreatorBuilder connectionCreatorBuilder = new ConnectionCreatorBuilder( serviceRegistry );
final String driverClassName = (String) configurationValues.get( AvailableSettings.DRIVER );
connectionCreatorBuilder.setDriver( loadDriverIfPossible( driverClassName ) );
final String url = (String) configurationValues.get( AvailableSettings.URL );
if ( url == null ) {
final String msg = log.jdbcUrlNotSpecified( AvailableSettings.URL );
log.error( msg );
throw new HibernateException( msg );
}
connectionCreatorBuilder.setUrl( url );
log.usingDriver( driverClassName, url );
final Properties connectionProps = ConnectionProviderInitiator.getConnectionProperties( configurationValues );
// if debug level is enabled, then log the password, otherwise mask it
if ( log.isDebugEnabled() ) {
log.connectionProperties( connectionProps );
}
else {
log.connectionProperties( ConfigurationHelper.maskOut( connectionProps, "password" ) );
}
connectionCreatorBuilder.setConnectionProps( connectionProps );
final boolean autoCommit = ConfigurationHelper.getBoolean( AvailableSettings.AUTOCOMMIT, configurationValues, false );
log.autoCommitMode( autoCommit );
connectionCreatorBuilder.setAutoCommit( autoCommit );
final Integer isolation = ConfigurationHelper.getInteger( AvailableSettings.ISOLATION, configurationValues );
if ( isolation != null ) {
log.jdbcIsolationLevel( Environment.isolationLevelToString( isolation ) );
}
connectionCreatorBuilder.setIsolation( isolation );
return connectionCreatorBuilder.build();
}
private Driver loadDriverIfPossible(String driverClassName) {
if ( driverClassName == null ) {
log.debug( "No driver class specified" );
return null;
}
if ( serviceRegistry != null ) {
final ClassLoaderService classLoaderService = serviceRegistry.getService( ClassLoaderService.class );
final Class<Driver> driverClass = classLoaderService.classForName( driverClassName );
try {
return driverClass.newInstance();
}
catch ( Exception e ) {
throw new ServiceException( "Specified JDBC Driver " + driverClassName + " could not be loaded", e );
}
}
try {
return (Driver) Class.forName( driverClassName ).newInstance();
}
catch ( Exception e1 ) {
try{
return (Driver) ReflectHelper.classForName( driverClassName ).newInstance();
}
catch ( Exception e2 ) {
throw new ServiceException( "Specified JDBC Driver " + driverClassName + " could not be loaded", e2 );
}
}
}
// use the pool ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public Connection getConnection() throws SQLException {
if ( !active ) {
throw new HibernateException( "Connection pool is no longer active" );
}
Connection connection;
if ( (connection = connections.poll()) == null ) {
connection = connectionCreator.createConnection();
}
return connection;
}
@Override
public void closeConnection(Connection conn) throws SQLException {
if (conn == null) {
return;
}
this.connections.offer( conn );
}
@Override
public boolean supportsAggressiveRelease() {
return false;
}
@Override
public boolean isUnwrappableAs(Class unwrapType) {
return ConnectionProvider.class.equals( unwrapType ) ||
DriverManagerConnectionProviderImpl.class.isAssignableFrom( unwrapType );
}
@Override
@SuppressWarnings( {"unchecked"})
public <T> T unwrap(Class<T> unwrapType) {
if ( ConnectionProvider.class.equals( unwrapType ) ||
DriverManagerConnectionProviderImpl.class.isAssignableFrom( unwrapType ) ) {
return (T) this;
}
else {
throw new UnknownUnwrapTypeException( unwrapType );
}
}
// destroy the pool ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@Override
public void stop() {
if ( !active ) {
return;
}
log.cleaningUpConnectionPool( connectionCreator.getUrl() );
active = false;
if ( executorService != null ) {
executorService.shutdown();
}
executorService = null;
for ( Connection connection : connections ) {
try {
connection.close();
}
catch (SQLException e) {
log.unableToClosePooledConnection( e );
}
}
}
@Override
protected void finalize() throws Throwable {
if ( active ) {
stop();
}
super.finalize();
}
}