Propel.php

<?php

/**
 * This file is part of the Propel package.
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @license    MIT License
 */

/**
 * Propel's main resource pool and initialization & configuration class.
 *
 * This static class is used to handle Propel initialization and to maintain all of the
 * open database connections and instantiated database maps.
 *
 * @author     Hans Lellelid <hans@xmpl.rg> (Propel)
 * @author     Daniel Rall <dlr@finemaltcoding.com> (Torque)
 * @author     Magnús Þór Torfason <magnus@handtolvur.is> (Torque)
 * @author     Jason van Zyl <jvanzyl@apache.org> (Torque)
 * @author     Rafal Krzewski <Rafal.Krzewski@e-point.pl> (Torque)
 * @author     Martin Poeschl <mpoeschl@marmot.at> (Torque)
 * @author     Henning P. Schmiedehausen <hps@intermeta.de> (Torque)
 * @author     Kurt Schrader <kschrader@karmalab.org> (Torque)
 * @version    $Revision$
 * @package    propel.runtime
 */
class Propel
{
    /**
     * The Propel version.
     */
    const VERSION = '1.6.9';

    /**
     * A constant for <code>default</code>.
     */
    const DEFAULT_NAME = "default";

    /**
     * A constant defining 'System is unusuable' logging level
     */
    const LOG_EMERG = 0;

    /**
     * A constant defining 'Immediate action required' logging level
     */
    const LOG_ALERT = 1;

    /**
     * A constant defining 'Critical conditions' logging level
     */
    const LOG_CRIT = 2;

    /**
     * A constant defining 'Error conditions' logging level
     */
    const LOG_ERR = 3;

    /**
     * A constant defining 'Warning conditions' logging level
     */
    const LOG_WARNING = 4;

    /**
     * A constant defining 'Normal but significant' logging level
     */
    const LOG_NOTICE = 5;

    /**
     * A constant defining 'Informational' logging level
     */
    const LOG_INFO = 6;

    /**
     * A constant defining 'Debug-level messages' logging level
     */
    const LOG_DEBUG = 7;

    /**
     * The class name for a PDO object.
     */
    const CLASS_PDO = 'PDO';

    /**
     * The class name for a PropelPDO object.
     */
    const CLASS_PROPEL_PDO = 'PropelPDO';

    /**
     * The class name for a DebugPDO object.
     */
    const CLASS_DEBUG_PDO = 'DebugPDO';

    /**
     * Constant used to request a READ connection (applies to replication).
     */
    const CONNECTION_READ = 'read';

    /**
     * Constant used to request a WRITE connection (applies to replication).
     */
    const CONNECTION_WRITE = 'write';

    /**
     * @var        string The db name that is specified as the default in the property file
     */
    private static $defaultDBName;

    /**
     * @var        array The global cache of database maps
     */
    private static $dbMaps = array();

    /**
     * @var        array The cache of DB adapter keys
     */
    private static $adapterMap = array();

    /**
     * @var        array Cache of established connections (to eliminate overhead).
     */
    private static $connectionMap = array();

    /**
     * @var        PropelConfiguration Propel-specific configuration.
     */
    private static $configuration;

    /**
     * @var        bool flag to set to true once this class has been initialized
     */
    private static $isInit = false;

    /**
     * @var        Log optional logger
     */
    private static $logger = null;

    /**
     * @var        string The name of the database mapper class
     */
    private static $databaseMapClass = 'DatabaseMap';

    /**
     * @var        bool Whether the object instance pooling is enabled
     */
    private static $instancePoolingEnabled = true;

    /**
     * @var        bool For replication, whether to force the use of master connection.
     */
    private static $forceMasterConnection = false;

    /**
     * @var        string Base directory to use for autoloading. Initialized in self::initBaseDir()
     */
    protected static $baseDir;

    /**
     * @var        array A map of class names and their file paths for autoloading
     */
    protected static $autoloadMap = array(

        'DBAdapter'           => 'adapter/DBAdapter.php',
        'DBMSSQL'             => 'adapter/DBMSSQL.php',
        'MssqlPropelPDO'      => 'adapter/MSSQL/MssqlPropelPDO.php',
        'MssqlDebugPDO'       => 'adapter/MSSQL/MssqlDebugPDO.php',
        'MssqlDateTime'       => 'adapter/MSSQL/MssqlDateTime.class.php',
        'DBMySQL'             => 'adapter/DBMySQL.php',
        'DBMySQLi'            => 'adapter/DBMySQLi.php',
        'DBNone'              => 'adapter/DBNone.php',
        'DBOracle'            => 'adapter/DBOracle.php',
        'DBPostgres'          => 'adapter/DBPostgres.php',
        'DBSQLite'            => 'adapter/DBSQLite.php',
        'DBSybase'            => 'adapter/DBSybase.php',
        'DBSQLSRV'            => 'adapter/DBSQLSRV.php',

        'PropelArrayCollection' => 'collection/PropelArrayCollection.php',
        'PropelCollection'    => 'collection/PropelCollection.php',
        'PropelObjectCollection' => 'collection/PropelObjectCollection.php',
        'PropelOnDemandCollection' => 'collection/PropelOnDemandCollection.php',
        'PropelOnDemandIterator' => 'collection/PropelOnDemandIterator.php',

        'PropelConfiguration' => 'config/PropelConfiguration.php',
        'PropelConfigurationIterator' => 'config/PropelConfigurationIterator.php',

        'PropelPDO'           => 'connection/PropelPDO.php',
        'DebugPDO'            => 'connection/DebugPDO.php',
        'DebugPDOStatement'   => 'connection/DebugPDOStatement.php',

        'PropelException'     => 'exception/PropelException.php',

        'ModelWith'           => 'formatter/ModelWith.php',
        'PropelArrayFormatter' => 'formatter/PropelArrayFormatter.php',
        'PropelFormatter'     => 'formatter/PropelFormatter.php',
        'PropelObjectFormatter' => 'formatter/PropelObjectFormatter.php',
        'PropelOnDemandFormatter' => 'formatter/PropelOnDemandFormatter.php',
        'PropelStatementFormatter' => 'formatter/PropelStatementFormatter.php',
        'PropelSimpleArrayFormatter' => 'formatter/PropelSimpleArrayFormatter.php',

        'BasicLogger'         => 'logger/BasicLogger.php',
        'MojaviLogAdapter'    => 'logger/MojaviLogAdapter.php',

        'ColumnMap'           => 'map/ColumnMap.php',
        'DatabaseMap'         => 'map/DatabaseMap.php',
        'TableMap'            => 'map/TableMap.php',
        'RelationMap'         => 'map/RelationMap.php',
        'ValidatorMap'        => 'map/ValidatorMap.php',

        'BaseObject'          => 'om/BaseObject.php',
        'NodeObject'          => 'om/NodeObject.php',
        'Persistent'          => 'om/Persistent.php',
        'PreOrderNodeIterator' => 'om/PreOrderNodeIterator.php',
        'NestedSetPreOrderNodeIterator' => 'om/NestedSetPreOrderNodeIterator.php',
        'NestedSetRecursiveIterator' => 'om/NestedSetRecursiveIterator.php',

        'PropelCSVParser'     => 'parser/PropelCSVParser.php',
        'PropelJSONParser'    => 'parser/PropelJSONParser.php',
        'PropelParser'        => 'parser/PropelParser.php',
        'PropelXMLParser'     => 'parser/PropelXMLParser.php',
        'PropelYAMLParser'    => 'parser/PropelYAMLParser.php',

        'Criteria'            => 'query/Criteria.php',
        'Criterion'           => 'query/Criterion.php',
        'CriterionIterator'   => 'query/CriterionIterator.php',
        'Join'                => 'query/Join.php',
        'ModelCriteria'       => 'query/ModelCriteria.php',
        'ModelCriterion'      => 'query/ModelCriterion.php',
        'ModelJoin'           => 'query/ModelJoin.php',
        'PropelQuery'         => 'query/PropelQuery.php',

        'BasePeer'            => 'util/BasePeer.php',
        'NodePeer'            => 'util/NodePeer.php',
        'PeerInfo'            => 'util/PeerInfo.php',
        'PropelAutoloader'    => 'util/PropelAutoloader.php',
        'PropelColumnTypes'   => 'util/PropelColumnTypes.php',
        'PropelConditionalProxy' => 'util/PropelConditionalProxy.php',
        'PropelModelPager'    => 'util/PropelModelPager.php',
        'PropelPager'         => 'util/PropelPager.php',
        'PropelDateTime'      => 'util/PropelDateTime.php',

        'BasicValidator'      => 'validator/BasicValidator.php',
        'MatchValidator'      => 'validator/MatchValidator.php',
        'MaxLengthValidator'  => 'validator/MaxLengthValidator.php',
        'MaxValueValidator'   => 'validator/MaxValueValidator.php',
        'MinLengthValidator'  => 'validator/MinLengthValidator.php',
        'MinValueValidator'   => 'validator/MinValueValidator.php',
        'NotMatchValidator'   => 'validator/NotMatchValidator.php',
        'RequiredValidator'   => 'validator/RequiredValidator.php',
        'TypeValidator'       => 'validator/TypeValidator.php',
        'UniqueValidator'     => 'validator/UniqueValidator.php',
        'ValidValuesValidator' => 'validator/ValidValuesValidator.php',
        'ValidationFailed'    => 'validator/ValidationFailed.php',
    );

    /**
     * Initializes Propel
     *
     * @throws PropelException Any exceptions caught during processing will be
     *                             rethrown wrapped into a PropelException.
     */
    public static function initialize()
    {
        if (self::$configuration === null) {
            throw new PropelException("Propel cannot be initialized without a valid configuration. Please check the log files for further details.");
        }

        self::configureLogging();

        // check whether the generated model has the same version as the runtime, see gh-#577
        // we need to check for existance first, because tasks which rely on the runtime.xml conf will not provide a generator_version
        if (isset(self::$configuration['generator_version']) && self::$configuration['generator_version'] != self::VERSION) {
            $warning = "Version mismatch: The generated model was build using propel '". self::$configuration['generator_version'] ."' while the current runtime is at version '". self::VERSION ."'";
            if (self::$logger) {
                self::$logger->warning($warning);
            } else {
                trigger_error($warning, E_USER_WARNING);
            }
        }

        // reset the connection map (this should enable runtime changes of connection params)
        self::$connectionMap = array();

        if (isset(self::$configuration['classmap']) && is_array(self::$configuration['classmap'])) {
            PropelAutoloader::getInstance()->addClassPaths(self::$configuration['classmap']);
            PropelAutoloader::getInstance()->register();
        }

        self::$isInit = true;
    }

    /**
     * Configure Propel a PHP (array) config file.
     *
     * @param      string Path (absolute or relative to include_path) to config file.
     *
     * @throws PropelException If configuration file cannot be opened.
     *                             (E_WARNING probably will also be raised by PHP)
     */
    public static function configure($configFile)
    {
        $configuration = include($configFile);
        if ($configuration === false) {
            throw new PropelException("Unable to open configuration file: " . var_export($configFile, true));
        }
        self::setConfiguration($configuration);
    }

    /**
     * Configure the logging system, if config is specified in the runtime configuration.
     */
    protected static function configureLogging()
    {
        if (self::$logger === null) {
            if (isset(self::$configuration['log']) && is_array(self::$configuration['log']) && count(self::$configuration['log'])) {
                include_once 'Log.php'; // PEAR Log class
                $c = self::$configuration['log'];
                $type = isset($c['type']) ? $c['type'] : 'file';
                $name = isset($c['name']) ? $c['name'] : './propel.log';
                $ident = isset($c['ident']) ? $c['ident'] : 'propel';
                $conf = isset($c['conf']) ? $c['conf'] : array();
                $level = isset($c['level']) ? $c['level'] : PEAR_LOG_DEBUG;
                self::$logger = Log::singleton($type, $name, $ident, $conf, $level);
            } // if isset()
        }
    }

    /**
     * Initialization of Propel a PHP (array) configuration file.
     *
     * @param string $c The Propel configuration file path.
     *
     * @throws PropelException Any exceptions caught during processing will be
     *                             rethrown wrapped into a PropelException.
     */
    public static function init($c)
    {
        self::configure($c);
        self::initialize();
    }

    /**
     * Determine whether Propel has already been initialized.
     *
     * @return bool True if Propel is already initialized.
     */
    public static function isInit()
    {
        return self::$isInit;
    }

    /**
     * Sets the configuration for Propel and all dependencies.
     *
     * @param      mixed The Configuration (array or PropelConfiguration)
     */
    public static function setConfiguration($c)
    {
        if (is_array($c)) {
            if (isset($c['propel']) && is_array($c['propel'])) {
                $c = $c['propel'];
            }
            $c = new PropelConfiguration($c);
        }
        self::$configuration = $c;
    }

    /**
     * Get the configuration for this component.
     *
     * @param      int - PropelConfiguration::TYPE_ARRAY: return the configuration as an array
     *                   (for backward compatibility this is the default)
     *                 - PropelConfiguration::TYPE_ARRAY_FLAT: return the configuration as a flat array
     *                   ($config['name.space.item'])
     *                 - PropelConfiguration::TYPE_OBJECT: return the configuration as a PropelConfiguration instance
     * @return mixed The Configuration (array or PropelConfiguration)
     */
    public static function getConfiguration($type = PropelConfiguration::TYPE_ARRAY)
    {
        return self::$configuration->getParameters($type);
    }

    /**
     * Override the configured logger.
     *
     * This is primarily for things like unit tests / debugging where
     * you want to change the logger without altering the configuration file.
     *
     * You can use any logger class that implements the propel.logger.BasicLogger
     * interface.  This interface is based on PEAR::Log, so you can also simply pass
     * a PEAR::Log object to this method.
     *
     * @param      object The new logger to use. ([PEAR] Log or BasicLogger)
     */
    public static function setLogger($logger)
    {
        self::$logger = $logger;
    }

    /**
     * Returns true if a logger, for example PEAR::Log, has been configured,
     * otherwise false.
     *
     * @return bool True if Propel uses logging
     */
    public static function hasLogger()
    {
        return (self::$logger !== null);
    }

    /**
     * Get the configured logger.
     *
     * @return object Configured log class ([PEAR] Log or BasicLogger).
     */
    public static function logger()
    {
        return self::$logger;
    }

    /**
     * Logs a message
     * If a logger has been configured, the logger will be used, otherwrise the
     * logging message will be discarded without any further action
     *
     * @param      string The message that will be logged.
     * @param      string The logging level.
     *
     * @return bool True if the message was logged successfully or no logger was used.
     */
    public static function log($message, $level = self::LOG_DEBUG)
    {
        if (self::hasLogger()) {
            $logger = self::logger();
            switch ($level) {
            case self::LOG_EMERG:
                return $logger->log($message, $level);
            case self::LOG_ALERT:
                return $logger->alert($message);
            case self::LOG_CRIT:
                return $logger->crit($message);
            case self::LOG_ERR:
                return $logger->err($message);
            case self::LOG_WARNING:
                return $logger->warning($message);
            case self::LOG_NOTICE:
                return $logger->notice($message);
            case self::LOG_INFO:
                return $logger->info($message);
            default:
                return $logger->debug($message);
            }
        }

        return true;
    }

    /**
     * Returns the database map information. Name relates to the name
     * of the connection pool to associate with the map.
     *
     * The database maps are "registered" by the generated map builder classes.
     *
     * @param      string The name of the database corresponding to the DatabaseMap to retrieve.
     *
     * @return DatabaseMap The named <code>DatabaseMap</code>.
     *
     * @throws PropelException - if database map is null or propel was not initialized properly.
     */
    public static function getDatabaseMap($name = null)
    {
        if ($name === null) {
            $name = self::getDefaultDB();
            if ($name === null) {
                throw new PropelException("DatabaseMap name is null!");
            }
        }

        if (!isset(self::$dbMaps[$name])) {
            $clazz = self::$databaseMapClass;
            self::$dbMaps[$name] = new $clazz($name);
        }

        return self::$dbMaps[$name];
    }

    /**
     * Sets the database map object to use for specified datasource.
     *
     * @param string      $name The datasource name.
     * @param DatabaseMap $map  The database map object to use for specified datasource.
     */
    public static function setDatabaseMap($name, DatabaseMap $map)
    {
        if ($name === null) {
            $name = self::getDefaultDB();
        }
        self::$dbMaps[$name] = $map;
    }

    /**
     * For replication, set whether to always force the use of a master connection.
     *
     * @param boolean $bit True or False
     */
    public static function setForceMasterConnection($bit)
    {
        self::$forceMasterConnection = (bool) $bit;
    }

    /**
     * For replication, whether to always force the use of a master connection.
     *
     * @return boolean
     */
    public static function getForceMasterConnection()
    {
        return self::$forceMasterConnection;
    }

    /**
     * Sets a Connection for specified datasource name.
     *
     * @param string    $name The datasource name for the connection being set.
     * @param PropelPDO $con  The PDO connection.
     * @param string    $mode Whether this is a READ or WRITE connection (Propel::CONNECTION_READ, Propel::CONNECTION_WRITE)
     */
    public static function setConnection($name, PropelPDO $con, $mode = Propel::CONNECTION_WRITE)
    {
        if ($name === null) {
            $name = self::getDefaultDB();
        }
        if ($mode == Propel::CONNECTION_READ) {
            self::$connectionMap[$name]['slave'] = $con;
        } else {
            self::$connectionMap[$name]['master'] = $con;
        }
    }

    /**
     * Gets an already-opened PDO connection or opens a new one for passed-in db name.
     *
     * @param string $name The datasource name that is used to look up the DSN from the runtime configuation file.
     * @param string $mode The connection mode (this applies to replication systems).
     *
     * @return PDO A database connection
     *
     * @throws PropelException - if connection cannot be configured or initialized.
     */
    public static function getConnection($name = null, $mode = Propel::CONNECTION_WRITE)
    {
        if ($name === null) {
            $name = self::getDefaultDB();
        }

        // IF a WRITE-mode connection was requested
        // or Propel is configured to always use the master connection
        // THEN return the master connection.
        if ($mode != Propel::CONNECTION_READ || self::$forceMasterConnection) {
            return self::getMasterConnection($name);
        } else {
            return self::getSlaveConnection($name);
        }

    }

    /**
     * Gets an already-opened write PDO connection or opens a new one for passed-in db name.
     *
     * @param string $name The datasource name that is used to look up the DSN
     *                          from the runtime configuation file. Empty name not allowed.
     *
     * @return PDO A database connection
     *
     * @throws PropelException - if connection cannot be configured or initialized.
     */
    public static function getMasterConnection($name)
    {
        if (!isset(self::$connectionMap[$name]['master'])) {
            // load connection parameter for master connection
            $conparams = isset(self::$configuration['datasources'][$name]['connection']) ? self::$configuration['datasources'][$name]['connection'] : null;
            if (empty($conparams)) {
                throw new PropelException('No connection information in your runtime configuration file for datasource ['.$name.']');
            }
            // initialize master connection
            $con = Propel::initConnection($conparams, $name);
            self::$connectionMap[$name]['master'] = $con;
        }

        return self::$connectionMap[$name]['master'];
    }

    /**
     * Gets an already-opened read PDO connection or opens a new one for passed-in db name.
     *
     * @param string $name The datasource name that is used to look up the DSN
     *                          from the runtime configuation file. Empty name not allowed.
     *
     * @return PDO A database connection
     *
     * @throws PropelException - if connection cannot be configured or initialized.
     */
    public static function getSlaveConnection($name)
    {
        if (!isset(self::$connectionMap[$name]['slave'])) {

            $slaveconfigs = isset(self::$configuration['datasources'][$name]['slaves']) ? self::$configuration['datasources'][$name]['slaves'] : null;

            if (empty($slaveconfigs)) {
                // no slaves configured for this datasource
                // fallback to the master connection
                self::$connectionMap[$name]['slave'] = self::getMasterConnection($name);
            } else {
                // Initialize a new slave
                if (isset($slaveconfigs['connection']['dsn'])) {
                    // only one slave connection configured
                    $conparams = $slaveconfigs['connection'];
                } else {
                    // more than one sleve connection configured
                    // pickup a random one
                    $randkey = array_rand($slaveconfigs['connection']);
                    $conparams = $slaveconfigs['connection'][$randkey];
                    if (empty($conparams)) {
                        throw new PropelException('No connection information in your runtime configuration file for SLAVE ['.$randkey.'] to datasource ['.$name.']');
                    }
                }

                // initialize slave connection
                $con = Propel::initConnection($conparams, $name);
                self::$connectionMap[$name]['slave'] = $con;
            }

        } // if datasource slave not set

        return self::$connectionMap[$name]['slave'];
    }

    /**
     * Opens a new PDO connection for passed-in db name.
     *
     * @param array  $conparams    Connection paramters.
     * @param string $name         Datasource name.
     * @param string $defaultClass The PDO subclass to instantiate if there is no explicit classname
     * 									specified in the connection params (default is Propel::CLASS_PROPEL_PDO)
     *
     * @return PDO A database connection of the given class (PDO, PropelPDO, SlavePDO or user-defined)
     *
     * @throws PropelException - if lower-level exception caught when trying to connect.
     */
    public static function initConnection($conparams, $name, $defaultClass = Propel::CLASS_PROPEL_PDO)
    {
        $adapter = self::getDB($name);

        if (null === $conparams['dsn']) {
            throw new PropelException('No dsn specified in your connection parameters for datasource ['.$name.']');
        }

        $conparams = $adapter->prepareParams($conparams);

        if (isset($conparams['classname']) && !empty($conparams['classname'])) {
            $classname = $conparams['classname'];
            if (!class_exists($classname)) {
                throw new PropelException('Unable to load specified PDO subclass: ' . $classname);
            }
        } else {
            $classname = $defaultClass;
        }

        $dsn	  = $conparams['dsn'];
        $user	  = isset($conparams['user']) ? $conparams['user'] : null;
        $password = isset($conparams['password']) ? $conparams['password'] : null;

        // load any driver options from the config file
        // driver options are those PDO settings that have to be passed during the connection construction
        $driver_options = array();
        if ( isset($conparams['options']) && is_array($conparams['options']) ) {
            try {
                self::processDriverOptions( $conparams['options'], $driver_options );
            } catch (PropelException $e) {
                throw new PropelException('Error processing driver options for datasource ['.$name.']', $e);
            }
        }

        try {
            $con = new $classname($dsn, $user, $password, $driver_options);
            $con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            $con->setAttribute(PropelPDO::PROPEL_ATTR_CONNECTION_NAME, $name);
        } catch (PDOException $e) {
            throw new PropelException("Unable to open PDO connection", $e);
        }

        // load any connection options from the config file
        // connection attributes are those PDO flags that have to be set on the initialized connection
        if (isset($conparams['attributes']) && is_array($conparams['attributes'])) {
            $attributes = array();
            try {
                self::processDriverOptions( $conparams['attributes'], $attributes );
            } catch (PropelException $e) {
                throw new PropelException('Error processing connection attributes for datasource ['.$name.']', $e);
            }
            foreach ($attributes as $key => $value) {
                $con->setAttribute($key, $value);
            }
        }

        // initialize the connection using the settings provided in the config file. this could be a "SET NAMES <charset>" query for MySQL, for instance
        $adapter->initConnection($con, isset($conparams['settings']) && is_array($conparams['settings']) ? $conparams['settings'] : array());

        return $con;
    }

    /**
     * Internal function to handle driver options or conneciton attributes in PDO.
     *
     * Process the INI file flags to be passed to each connection.
     *
     * @param      array Where to find the list of constant flags and their new setting.
     * @param      array Put the data into here
     *
     * @throws PropelException If invalid options were specified.
     */
    private static function processDriverOptions($source, &$write_to)
    {
        foreach ($source as $option => $optiondata) {
            if (is_string($option) && strpos($option, '::') !== false) {
                $key = $option;
            } elseif (is_string($option)) {
                $key = 'PropelPDO::' . $option;
            }
            if (!defined($key)) {
                throw new PropelException("Invalid PDO option/attribute name specified: ".$key);
            }
            $key = constant($key);

            $value = $optiondata['value'];
            if (is_string($value) && strpos($value, '::') !== false) {
                if (!defined($value)) {
                    throw new PropelException("Invalid PDO option/attribute value specified: ".$value);
                }
                $value = constant($value);
            }

            $write_to[$key] = $value;
        }
    }

    /**
     * Returns database adapter for a specific datasource.
     *
     * @param      string The datasource name.
     *
     * @return DBAdapter The corresponding database adapter.
     *
     * @throws PropelException If unable to find DBdapter for specified db.
     */
    public static function getDB($name = null)
    {
        if ($name === null) {
            $name = self::getDefaultDB();
        }

        if (!isset(self::$adapterMap[$name])) {
            if (!isset(self::$configuration['datasources'][$name]['adapter'])) {
                throw new PropelException("Unable to find adapter for datasource [" . $name . "].");
            }
            $db = DBAdapter::factory(self::$configuration['datasources'][$name]['adapter']);
            // register the adapter for this name
            self::$adapterMap[$name] = $db;
        }

        return self::$adapterMap[$name];
    }

    /**
     * Sets a database adapter for specified datasource.
     *
     * @param string    $name    The datasource name.
     * @param DBAdapter $adapter The DBAdapter implementation to use.
     */
    public static function setDB($name, DBAdapter $adapter)
    {
        if ($name === null) {
            $name = self::getDefaultDB();
        }
        self::$adapterMap[$name] = $adapter;
    }

    /**
     * Returns the name of the default database.
     *
     * @return string Name of the default DB
     */
    public static function getDefaultDB()
    {
        if (self::$defaultDBName === null) {
            // Determine default database name.
            self::$defaultDBName = isset(self::$configuration['datasources']['default']) && is_scalar(self::$configuration['datasources']['default']) ? self::$configuration['datasources']['default'] : self::DEFAULT_NAME;
        }

        return self::$defaultDBName;
    }

    /**
     * Closes any associated resource handles.
     *
     * This method frees any database connection handles that have been
     * opened by the getConnection() method.
     */
    public static function close()
    {
        foreach (self::$connectionMap as $idx => $cons) {
            // Propel::log("Closing connections for " . $idx, Propel::LOG_DEBUG);
            unset(self::$connectionMap[$idx]);
        }
    }

    /**
     * Autoload function for loading propel dependencies.
     *
     * @param      string The class name needing loading.
     *
     * @return boolean TRUE if the class was loaded, false otherwise.
     */
    public static function autoload($className)
    {
        if (isset(self::$autoloadMap[$className])) {
            require self::$baseDir . self::$autoloadMap[$className];

            return true;
        }

        return false;
    }

    /**
     * Initialize the base directory for the autoloader.
     * Avoids a call to dirname(__FILE__) each time self::autoload() is called.
     * FIXME put in the constructor if the Propel class ever becomes a singleton
     */
    public static function initBaseDir()
    {
        self::$baseDir = dirname(__FILE__) . '/';
    }

    /**
     * Include once a file specified in DOT notation and return unqualified classname.
     *
     * Typically, Propel uses autoload is used to load classes and expects that all classes
     * referenced within Propel are included in Propel's autoload map.  This method is only
     * called when a specific non-Propel classname was specified -- for example, the
     * classname of a validator in the schema.xml.  This method will attempt to include that
     * class via autoload and then relative to a location on the include_path.
     *
     * @param  string $class dot-path to clas (e.g. path.to.my.ClassName).
     * @return string unqualified classname
     *
     * @throws PropelException
     */
    public static function importClass($path)
    {
        // extract classname
        if (($pos = strrpos($path, '.')) === false) {
            $class = $path;
        } else {
            $class = substr($path, $pos + 1);
        }

        // check if class exists, using autoloader to attempt to load it.
        if (class_exists($class, $useAutoload=true)) {
            return $class;
        }

        // turn to filesystem path
        $path = strtr($path, '.', DIRECTORY_SEPARATOR) . '.php';

        // include class
        $ret = include_once($path);
        if ($ret === false) {
            throw new PropelException("Unable to import class: " . $class . " from " . $path);
        }

        // return qualified name
        return $class;
    }

    /**
     * Set your own class-name for Database-Mapping. Then
     * you can change the whole TableMap-Model, but keep its
     * functionality for Criteria.
     *
     * @param      string The name of the class.
     */
    public static function setDatabaseMapClass($name)
    {
        self::$databaseMapClass = $name;
    }

    /**
     * Disable instance pooling.
     *
     * @return boolean true if the method changed the instance pooling state,
     *                 false if it was already disabled
     */
    public static function disableInstancePooling()
    {
        if (!self::$instancePoolingEnabled) {
            return false;
        }
        self::$instancePoolingEnabled = false;

        return true;
    }

    /**
     * Enable instance pooling (enabled by default).
     *
     * @return boolean true if the method changed the instance pooling state,
     *                 false if it was already enabled
     */
    public static function enableInstancePooling()
    {
        if (self::$instancePoolingEnabled) {
            return false;
        }
        self::$instancePoolingEnabled = true;

        return true;
    }

    /**
     *  the instance pooling behaviour. True by default.
     *
     * @return boolean Whether the pooling is enabled or not.
     */
    public static function isInstancePoolingEnabled()
    {
        return self::$instancePoolingEnabled;
    }
}

// Since the Propel class is not a true singleton, this code cannot go into the __construct()
Propel::initBaseDir();
spl_autoload_register(array('Propel', 'autoload'));