1: <?php
  2: 
  3: /*
  4:  * This file is part of SwiftMailer.
  5:  * (c) 2004-2009 Chris Corbyn
  6:  *
  7:  * For the full copyright and license information, please view the LICENSE
  8:  * file that was distributed with this source code.
  9:  */
 10: 
 11: /**
 12:  * Throttles the rate at which emails are sent.
 13:  * @package Swift
 14:  * @subpackage Plugins
 15:  * @author Chris Corbyn
 16:  */
 17: class Swift_Plugins_ThrottlerPlugin extends Swift_Plugins_BandwidthMonitorPlugin implements Swift_Plugins_Sleeper, Swift_Plugins_Timer
 18: {
 19:     /** Flag for throttling in bytes per minute */
 20:     const BYTES_PER_MINUTE = 0x01;
 21: 
 22:     /** Flag for throttling in emails per minute */
 23:     const MESSAGES_PER_MINUTE = 0x10;
 24: 
 25:     /**
 26:      * The Sleeper instance for sleeping.
 27:      * @var Swift_Plugins_Sleeper
 28:      * @access private
 29:      */
 30:     private $_sleeper;
 31: 
 32:     /**
 33:      * The Timer instance which provides the timestamp.
 34:      * @var Swift_Plugins_Timer
 35:      * @access private
 36:      */
 37:     private $_timer;
 38: 
 39:     /**
 40:      * The time at which the first email was sent.
 41:      * @var int
 42:      * @access private
 43:      */
 44:     private $_start;
 45: 
 46:     /**
 47:      * The rate at which messages should be sent.
 48:      * @var int
 49:      * @access private
 50:      */
 51:     private $_rate;
 52: 
 53:     /**
 54:      * The mode for throttling.
 55:      * This is {@link BYTES_PER_MINUTE} or {@link MESSAGES_PER_MINUTE}
 56:      * @var int
 57:      * @access private
 58:      */
 59:     private $_mode;
 60: 
 61:     /**
 62:      * An internal counter of the number of messages sent.
 63:      * @var int
 64:      * @access private
 65:      */
 66:     private $_messages = 0;
 67: 
 68:     /**
 69:      * Create a new ThrottlerPlugin.
 70:      * @param int                   $rate
 71:      * @param int                   $mode,   defaults to {@link BYTES_PER_MINUTE}
 72:      * @param Swift_Plugins_Sleeper $sleeper (only needed in testing)
 73:      * @param Swift_Plugins_Timer   $timer   (only needed in testing)
 74:      */
 75:     public function __construct($rate, $mode = self::BYTES_PER_MINUTE, Swift_Plugins_Sleeper $sleeper = null, Swift_Plugins_Timer $timer = null)
 76:     {
 77:         $this->_rate = $rate;
 78:         $this->_mode = $mode;
 79:         $this->_sleeper = $sleeper;
 80:         $this->_timer = $timer;
 81:     }
 82: 
 83:     /**
 84:      * Invoked immediately before the Message is sent.
 85:      * @param Swift_Events_SendEvent $evt
 86:      */
 87:     public function beforeSendPerformed(Swift_Events_SendEvent $evt)
 88:     {
 89:         $time = $this->getTimestamp();
 90:         if (!isset($this->_start)) {
 91:             $this->_start = $time;
 92:         }
 93:         $duration = $time - $this->_start;
 94: 
 95:         if (self::BYTES_PER_MINUTE == $this->_mode) {
 96:             $sleep = $this->_throttleBytesPerMinute($duration);
 97:         } else {
 98:             $sleep = $this->_throttleMessagesPerMinute($duration);
 99:         }
100: 
101:         if ($sleep > 0) {
102:             $this->sleep($sleep);
103:         }
104:     }
105: 
106:     /**
107:      * Invoked when a Message is sent.
108:      * @param Swift_Events_SendEvent $evt
109:      */
110:     public function sendPerformed(Swift_Events_SendEvent $evt)
111:     {
112:         parent::sendPerformed($evt);
113:         ++$this->_messages;
114:     }
115: 
116:     /**
117:      * Sleep for $seconds.
118:      * @param int $seconds
119:      */
120:     public function sleep($seconds)
121:     {
122:         if (isset($this->_sleeper)) {
123:             $this->_sleeper->sleep($seconds);
124:         } else {
125:             sleep($seconds);
126:         }
127:     }
128: 
129:     /**
130:      * Get the current UNIX timestamp
131:      * @return int
132:      */
133:     public function getTimestamp()
134:     {
135:         if (isset($this->_timer)) {
136:             return $this->_timer->getTimestamp();
137:         } else {
138:             return time();
139:         }
140:     }
141: 
142:     // -- Private methods
143: 
144:     /**
145:      * Get a number of seconds to sleep for.
146:      * @param  int $timePassed
147:      * @return int
148:      * @access private
149:      */
150:     private function _throttleBytesPerMinute($timePassed)
151:     {
152:         $expectedDuration = $this->getBytesOut() / ($this->_rate / 60);
153: 
154:         return (int) ceil($expectedDuration - $timePassed);
155:     }
156: 
157:     /**
158:      * Get a number of seconds to sleep for.
159:      * @param  int $timePassed
160:      * @return int
161:      * @access private
162:      */
163:     private function _throttleMessagesPerMinute($timePassed)
164:     {
165:         $expectedDuration = $this->_messages / ($this->_rate / 60);
166: 
167:         return (int) ceil($expectedDuration - $timePassed);
168:     }
169: }
170: