Source of file Connection_Manager.php

<?php

/**

 * Query

 *

 * Free Query Builder / Database Abstraction Layer

 *

 * @package		Query

 * @author		Timothy J. Warren

 * @copyright	Copyright (c) 2012 - 2014

 * @link 		https://github.com/aviat4ion/Query

 * @license		http://philsturgeon.co.uk/code/dbad-license

 */

// --------------------------------------------------------------------------

namespace Query;

/**

 * Connection manager class to manage connections for the

 * Query method

 *

 * @package Query

 * @subpackage Core

 */

final class Connection_Manager {

	/**

	 * Map of named database connections

	 * @var array

	 */

	private $connections = array();

	/**

	 * Class instance variable

	 * @var Connection_Manager

	 */

	private static $instance = null;

	// --------------------------------------------------------------------------

	/**

	 * Private constructor to prevent multiple instances

	 * @codeCoverageIgnore

	 */

	private function __construct() {}

	// --------------------------------------------------------------------------

	/**

	 * Private clone method to prevent cloning

	 * @throws \DomainException

	 */

	public function __clone()

	{

		throw new \DomainException("Can't clone singleton");

	}

	// --------------------------------------------------------------------------

	/**

	 * Prevent serialization of this object

	 * @throws \DomainException

	 */

	public function __sleep()

	{

		throw new \DomainException("No serializing of singleton");

	}

	// --------------------------------------------------------------------------

	/**

	 * Make sure serialize/deserialize doesn't work

	 * @throws \DomainException

	 */

	public function __wakeup()

	{

		throw new \DomainException("Can't unserialize singleton");

	}

	// --------------------------------------------------------------------------

	/**

	 * Return  a connection manager instance

	 *

	 * @staticvar null $instance

	 * @return Connection_Manager

	 */

	public static function get_instance()

	{

		if (self::$instance === null) self::$instance = new self();

		return self::$instance;

	}

	// --------------------------------------------------------------------------

	/**

	 * Returns the connection specified by the name given

	 *

	 * @param string|array|object $name

	 * @return Query_Builder

	 * @throws \InvalidArgumentException

	 */

	public function get_connection($name = '')

	{

		// If the parameter is a string, use it as an array index

		if (is_scalar($name) && isset($this->connections[$name]))

		{

			return $this->connections[$name];

		}

		elseif (empty($name) && ! empty($this->connections)) // Otherwise, return the last one

		{

			return end($this->connections);

		}

		// You should actually connect before trying to get a connection...

		throw new \InvalidArgumentException("The specified connection does not exist");

	}

	// --------------------------------------------------------------------------

	/**

	 * Parse the passed parameters and return a connection

	 *

	 * @param \stdClass $params

	 * @return Query_Builder

	 */

	public function connect(\stdClass $params)

	{

		list($dsn, $dbtype, $params, $options) = $this->parse_params($params);

		$dbtype = ucfirst($dbtype);

		$driver = "\\Query\\Drivers\\{$dbtype}\\Driver";

		// Create the database connection

		$db = ( ! empty($params->user))

			? new $driver($dsn, $params->user, $params->pass, $options)

			: new $driver($dsn, '', '', $options);

		// Set the table prefix, if it exists

		if (isset($params->prefix))

		{

			$db->set_table_prefix($params->prefix);

		}

		// Create Query Builder object

		$conn = new Query_Builder($db, new Query_Parser($db));

		// Save it for later

		if (isset($params->alias))

		{

			$this->connections[$params->alias] = $conn;

		}

		else

		{

			$this->connections[] = $conn;

		}

		return $conn;

	}

	// --------------------------------------------------------------------------

	/**

	 * Parses params into a dsn and option array

	 *

	 * @param \stdClass $params

	 * @return array

	 * @throws BadDBDriverException

	 */

	public function parse_params(\stdClass $params)

	{

		$params->type = strtolower($params->type);

		$dbtype = ($params->type !== 'postgresql') ? $params->type : 'pgsql';

		$dbtype = ucfirst($dbtype);

		// Make sure the class exists

		if ( ! class_exists("\\Query\\Drivers\\{$dbtype}\\Driver"))

		{

			throw new BadDBDriverException('Database driver does not exist, or is not supported');

		}

		// Set additional PDO options

		$options = array();

		if (isset($params->options))

		{

			$options = (array) $params->options;

		}

		// Create the dsn for the database to connect to

		if (strtolower($dbtype) === 'firebird')

		{

			$dsn = "{$params->host}:{$params->file}";

		}

		else if(strtolower($dbtype) === 'sqlite')

		{

			$dsn = $params->file;

		}

		else

		{

			$dsn = $this->create_dsn($dbtype, $params);

		}

		return array($dsn, $dbtype, $params, $options);

	}

	// --------------------------------------------------------------------------

	/**

	 * Create the dsn from the db type and params

	 *

	 * @param string $dbtype

	 * @param \stdClass $params

	 * @return string

	 */

	private function create_dsn($dbtype, \stdClass $params)

	{

		if (strtolower($dbtype) === 'pdo_firebird') $dbtype = 'firebird';

		$pairs = array();

		if ( ! empty($params->database))

		{

			$pairs[] = implode('=', array('dbname', $params->database));

		}

		$skip = array(

			'name' => 'name',

			'pass' => 'pass',

			'user' => 'user',

			'type' => 'type',

			'prefix' => 'prefix',

			'options' => 'options',

			'database' => 'database',

			'alias' => 'alias'

		);

		foreach($params as $key => $val)

		{

			if (( ! array_key_exists($key, $skip)) && ( ! empty($val)))

			{

				$pairs[] = implode('=', array($key, $val));

			}

		}

		return strtolower($dbtype) . ':' . implode(';', $pairs);

	}

}

// End of connection_manager.php