1: <?php
 2: /**
 3:  * Pastie_Driver:: defines an API for implementing storage backends for
 4:  * Pastie.
 5:  *
 6:  * Copyright 2007-2012 Horde LLC (http://www.horde.org/)
 7:  *
 8:  * See the enclosed file COPYING for license information (GPL). If you
 9:  * did not receive this file, see http://www.horde.org/licenses/gpl.
10:  *
11:  * @author  Ben Klang <ben@alkaloid.net>
12:  * @package Pastie
13:  */
14: class Pastie_Driver
15: {
16:     /**
17:      * Attempts to return a concrete instance based on $driver.
18:      *
19:      * @param string $driver  The type of the concrete subclass to return.
20:      *                        The class name is based on the storage driver
21:      *                        ($driver).  The code is dynamically included.
22:      *
23:      * @param array $params   A hash containing any additional configuration
24:      *                        or connection parameters a subclass might need.
25:      *
26:      * @return Pastie_Driver  The newly created concrete instance.
27:      * @throws Horde_Exception
28:      */
29:     static public function factory($driver = null, $params = null)
30:     {
31:         if (is_null($driver)) {
32:             $driver = $GLOBALS['conf']['storage']['params']['driver'];
33:         }
34: 
35:         if (is_null($params)) {
36:             $params = Horde::getDriverConfig('storage', $driver);
37:         }
38: 
39:         $driver = ucfirst(basename($driver));
40:         $class = 'Pastie_Driver_' . $driver;
41:         if (class_exists($class)) {
42:             return new $class($params);
43:         }
44: 
45:         throw new Horde_Exception('Could not find driver ' . $class);
46:     }
47: 
48:     /**
49:      * Attempts to return a reference to a concrete Pastie_Driver instance based
50:      * on $driver.
51:      *
52:      * It will only create a new instance if no Pastie_Driver instance with the
53:      * same parameters currently exists.
54:      *
55:      * This should be used if multiple storage sources are required.
56:      *
57:      * This method must be invoked as: $var = &Pastie_Driver::singleton()
58:      *
59:      * @param string    $notepad    The name of the current notepad.
60:      *
61:      * @param string    $driver     The type of concrete Pastie_Driver subclass
62:      *                              to return.  The is based on the storage
63:      *                              driver ($driver).  The code is dynamically
64:      *                              included.
65:      *
66:      * @param array     $params     (optional) A hash containing any additional
67:      *                              configuration or connection parameters a
68:      *                              subclass might need.
69:      *
70:      * @return mixed    The created concrete Pastie_Driver instance, or false
71:      *                  on error.
72:      */
73:     function &singleton($bin = '', $driver = null, $params = null)
74:     {
75:         static $instances = array();
76:         if (is_null($driver)) {
77:             $driver = $GLOBALS['conf']['storage']['driver'];
78:         }
79: 
80:         if (is_null($params)) {
81:             $params = Horde::getDriverConfig('storage', $driver);
82:         }
83: 
84:         $signature = serialize(array($notepad, $driver, $params));
85:         if (!isset($instances[$signature])) {
86:             $instances[$signature] = &Pastie_Driver::factory($notepad, $driver, $params);
87:         }
88: 
89:         return $instances[$signature];
90:     }
91: 
92: }
93: