Query/docs/files/core/connection_manager.php.txt

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<?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;
/**
* Generic exception for bad drivers
*
* @package Query
* @subpackage Core
*/
class BadDBDriverException extends \InvalidArgumentException {}
// --------------------------------------------------------------------------
/**
* 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
* @codeCoverageIgnore
*/
private function __clone() {}
// --------------------------------------------------------------------------
/**
* Make sure serialize/deserialize doesn't work
* @codeCoverageIgnore
* @throws \DomainException
*/
private function __wakeup()
{
throw new \DomainException("Can't unserialize singleton");
}
// --------------------------------------------------------------------------
/**
* Return a connection manager instance
*
* @staticvar null $instance
* @return Connection_Manager
*/
public static function get_instance()
{
// @codeCoverageIgnoreStart
if (self::$instance === null)
{
self::$instance = new self();
}
// @codeCoverageIgnoreEnd
return self::$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 \ArrayObject $params
* @return Query_Builder
*/
public function connect(\ArrayObject $params)
{
list($dsn, $dbtype, $params, $options) = $this->parse_params($params);
$driver = "\\Query\\Driver\\{$dbtype}";
// 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->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 \ArrayObject $params
* @return array
* @throws BadDBDriverException
*/
private function parse_params(\ArrayObject $params)
{
$params->type = strtolower($params->type);
$dbtype = ($params->type !== 'postgresql') ? $params->type : 'pgsql';
// Make sure the class exists
if ( ! class_exists("Query\\Driver\\{$dbtype}"))
{
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
$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 \ArrayObject $params
* @return string
*/
private function create_dsn($dbtype, \ArrayObject $params)
{
if ($dbtype === 'firebird') $dsn = "{$params->host}:{$params->file}";
elseif ($dbtype === 'sqlite') $dsn = $params->file;
else
{
$dsn = strtolower($dbtype) . ':';
if ( ! empty($params->database))
{
$dsn .= "dbname={$params->database}";
}
$skip = array(
'name' => 'name',
'pass' => 'pass',
'user' => 'user',
'file' => 'file',
'type' => 'type',
'prefix' => 'prefix',
'options' => 'options',
'database' => 'database'
);
foreach($params as $key => $val)
{
if ( ! isset($skip[$key]))
{
$dsn .= ";{$key}={$val}";
}
}
}
return $dsn;
}
}
// End of connection_manager.php