1: <?php
  2: /**
  3:  * Horde_Scheduler
  4:  *
  5:  * @package Scheduler
  6:  */
  7: class Horde_Scheduler
  8: {
  9:     /**
 10:      * Name of the sleep function.
 11:      *
 12:      * @var string
 13:      */
 14:     protected $_sleep;
 15: 
 16:     /**
 17:      * Adjustment factor to sleep in microseconds.
 18:      *
 19:      * @var integer
 20:      */
 21:     protected $_sleep_adj;
 22: 
 23:     /**
 24:      * Attempts to return a concrete Horde_Scheduler instance based on $driver.
 25:      *
 26:      * @param string $driver The type of concrete subclass to return.
 27:      * @param array $params  A hash containing any additional configuration or
 28:      *                       connection parameters a subclass might need.
 29:      *
 30:      * @return Horde_Scheduler  The newly created concrete instance.
 31:      * @throws Horde_Scheduler_Exception
 32:      */
 33:     static public function factory($driver, $params = null)
 34:     {
 35:         $driver = basename($driver);
 36:         $class = 'Horde_Scheduler_' . $driver;
 37: 
 38:         if (class_exists($class)) {
 39:             return new $class($params);
 40:         }
 41: 
 42:         throw new Horde_Scheduler_Exception('Class definition of ' . $class . ' not found.');
 43:     }
 44: 
 45:     /**
 46:      * Constructor.
 47:      *
 48:      * Figures out how we can best sleep with microsecond precision
 49:      * based on what platform we're running on.
 50:      */
 51:     public function __construct()
 52:     {
 53:         if (!strncasecmp(PHP_OS, 'WIN', 3)) {
 54:             $this->_sleep = 'sleep';
 55:             $this->_sleep_adj = 1000000;
 56:         } else {
 57:             $this->_sleep = 'usleep';
 58:             $this->_sleep_adj = 1;
 59:         }
 60:     }
 61: 
 62:     /**
 63:      * Main loop/action function.
 64:      */
 65:     public function run()
 66:     {
 67:     }
 68: 
 69:     /**
 70:      * Preserve the internal state of the scheduler object that we are
 71:      * passed, and save it to the Horde VFS backend. Horde_Scheduler
 72:      * objects should define __sleep() and __wakeup() serialization
 73:      * callbacks for anything that needs to be done at object
 74:      * serialization or deserialization - handling database
 75:      * connections, etc.
 76:      *
 77:      * @param string $id  An id to uniquely identify this scheduler from
 78:      *                    others of the same class.
 79:      *
 80:      * @return boolean  Success result.
 81:      */
 82:     public function serialize($id = '')
 83:     {
 84:         try {
 85:             $vfs = $GLOBALS['injector']->getInstance('Horde_Core_Factory_Vfs')->create();
 86:             $vfs->writeData('.horde/scheduler', Horde_String::lower(get_class($this)) . $id, serialize($this), true);
 87:             return true;
 88:         } catch (Horde_Vfs_Exception $e) {
 89:             Horde::logMessage($e, 'ERR');
 90:             return false;
 91:         }
 92:     }
 93: 
 94:     /**
 95:      * Restore a Horde_Scheduler object from the cache.
 96:      *
 97:      * @param string $class      The name of the object to restore.
 98:      * @param string $id         An id to uniquely identify this
 99:      *                           scheduler from others of the same class.
100:      * @param boolean $autosave  Automatically store (serialize) the returned
101:      *                           object at script shutdown.
102:      *
103:      * @see Horde_Scheduler::serialize()
104:      */
105:     public function unserialize($class, $id = '', $autosave = true)
106:     {
107:         /* Need a lowercase version of the classname, and a default instance of
108:          * the scheduler object in case we can't retrieve one. */
109:         $scheduler = new $class;
110: 
111:         try {
112:             $vfs = $GLOBALS['injector']->getInstance('Horde_Core_Factory_Vfs')->create();
113:             $data = $vfs->read('.horde/scheduler', $class . $id);
114:             if ($tmp = @unserialize($data)) {
115:                 $scheduler = $tmp;
116:             }
117:         } catch (Horde_Vfs_Exception $e) {
118:             Horde::logMessage($e, 'ERR');
119:         }
120: 
121:         if ($autosave) {
122:             register_shutdown_function(array($scheduler, 'serialize'));
123:         }
124: 
125:         return $scheduler;
126:     }
127: 
128:     /**
129:      * Platform-independant sleep $msec microseconds.
130:      *
131:      * @param integer $msec  Microseconds to sleep.
132:      */
133:     public function sleep($msec)
134:     {
135:         call_user_func($this->_sleep, $msec / $this->_sleep_adj);
136:     }
137: 
138: }
139: