1: <?php
  2: /**
  3:  * A Horde_Injector based factory for the IMP_Imap_Tree object.
  4:  *
  5:  * PHP version 5
  6:  *
  7:  * @author   Michael Slusarz <slusarz@horde.org>
  8:  * @category Horde
  9:  * @license  http://www.horde.org/licenses/gpl GPL
 10:  * @link     http://pear.horde.org/index.php?package=IMP
 11:  * @package  IMP
 12:  */
 13: 
 14: /**
 15:  * A Horde_Injector based factory for the IMP_Imap_Tree object.
 16:  *
 17:  * Copyright 2010-2012 Horde LLC (http://www.horde.org/)
 18:  *
 19:  * See the enclosed file COPYING for license information (GPL). If you
 20:  * did not receive this file, see http://www.horde.org/licenses/gpl.
 21:  *
 22:  * @author   Michael Slusarz <slusarz@horde.org>
 23:  * @category Horde
 24:  * @license  http://www.horde.org/licenses/gpl GPL
 25:  * @link     http://pear.horde.org/index.php?package=IMP
 26:  * @package  IMP
 27:  */
 28: class IMP_Factory_Imaptree extends Horde_Core_Factory_Injector
 29: {
 30:     /**
 31:      * Indicates that the tree object is being initialized.
 32:      *
 33:      * @var boolean
 34:      */
 35:     static private $_isInit = false;
 36: 
 37:     /**
 38:      * Return the IMP_Imap_Tree object.
 39:      *
 40:      * @return IMP_Imap_Tree  The singleton instance.
 41:      */
 42:     public function create(Horde_Injector $injector)
 43:     {
 44:         global $session;
 45: 
 46:         $instance = null;
 47: 
 48:         /* If an IMP_Imap_Tree object is currently stored in the cache,
 49:          * re-create that object.  Else, create a new instance. */
 50:         if ($session->exists('imp', 'treeob')) {
 51:             /* Since IMAP tree generation is so expensive/time-consuming,
 52:              * fallback to storing in the session even if no permanent cache
 53:              * backend is setup. */
 54:             $cache = $injector->getInstance('Horde_Cache');
 55:             if ($cache instanceof Horde_Cache_Null) {
 56:                 $instance = $session->retrieve('imp_imaptree');
 57:             } else {
 58:                 try {
 59:                     $instance = @unserialize($cache->get($session->get('imp', 'treeob'), 86400));
 60:                 } catch (Exception $e) {
 61:                     Horde::logMessage('Could not unserialize stored IMP_Imap_Tree object.', 'DEBUG');
 62:                 }
 63:             }
 64:         } else {
 65:             $session->set('imp', 'treeob', strval(new Horde_Support_Randomid()));
 66:         }
 67: 
 68:         if (!($instance instanceof IMP_Imap_Tree)) {
 69:             self::$_isInit = true;
 70:             $instance = new IMP_Imap_Tree();
 71:             self::$_isInit = false;
 72:         }
 73: 
 74:         register_shutdown_function(array($this, 'shutdown'), $instance, $injector);
 75: 
 76:         return $instance;
 77:     }
 78: 
 79:     /**
 80:      * Store serialized version of object in the current session.
 81:      *
 82:      * @param IMP_Imap_Tree $instance   Tree object.
 83:      * @param Horde_Injector $injector  Injector object.
 84:      */
 85:     public function shutdown($instance, $injector)
 86:     {
 87:         global $session;
 88: 
 89:         /* Only need to store the object if the tree has changed. */
 90:         if ($instance->changed) {
 91:             $cache = $injector->getInstance('Horde_Cache');
 92:             if ($cache instanceof Horde_Cache_Null) {
 93:                 $session->store($instance, true, 'imp_imaptree');
 94:             } else {
 95:                 $cache->set($GLOBALS['session']->get('imp', 'treeob'), serialize($instance), 86400);
 96:             }
 97:         }
 98:     }
 99: 
100:     /**
101:      * Static method: determines if IMP_Imap_Tree has already been initialized
102:      * in this session.
103:      *
104:      * @return boolean  True if the tree object has been initialized.
105:      */
106:     static public function initialized()
107:     {
108:         return (!self::$_isInit &&
109:                 $GLOBALS['session']->exists('imp', 'treeob'));
110:     }
111: 
112: }
113: