1: <?php
  2: /**
  3:  * Memcache storage engine for cache
  4:  *
  5:  *
  6:  * PHP versions 4 and 5
  7:  *
  8:  * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
  9:  * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 10:  *
 11:  * Licensed under The MIT License
 12:  * Redistributions of files must retain the above copyright notice.
 13:  *
 14:  * @copyright     Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 15:  * @link          http://cakephp.org CakePHP(tm) Project
 16:  * @package       cake
 17:  * @subpackage    cake.cake.libs.cache
 18:  * @since         CakePHP(tm) v 1.2.0.4933
 19:  * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 20:  */
 21: 
 22: /**
 23:  * Memcache storage engine for cache.  Memcache has some limitations in the amount of 
 24:  * control you have over expire times far in the future.  See MemcacheEngine::write() for
 25:  * more information.
 26:  *
 27:  * @package       cake
 28:  * @subpackage    cake.cake.libs.cache
 29:  */
 30: class MemcacheEngine extends CacheEngine {
 31: 
 32: /**
 33:  * Memcache wrapper.
 34:  *
 35:  * @var Memcache
 36:  * @access private
 37:  */
 38:     var $__Memcache = null;
 39: 
 40: /**
 41:  * Settings
 42:  *
 43:  *  - servers = string or array of memcache servers, default => 127.0.0.1. If an
 44:  *    array MemcacheEngine will use them as a pool.
 45:  *  - compress = boolean, default => false
 46:  *
 47:  * @var array
 48:  * @access public
 49:  */
 50:     var $settings = array();
 51: 
 52: /**
 53:  * Initialize the Cache Engine
 54:  *
 55:  * Called automatically by the cache frontend
 56:  * To reinitialize the settings call Cache::engine('EngineName', [optional] settings = array());
 57:  *
 58:  * @param array $setting array of setting for the engine
 59:  * @return boolean True if the engine has been successfully initialized, false if not
 60:  * @access public
 61:  */
 62:     function init($settings = array()) {
 63:         if (!class_exists('Memcache')) {
 64:             return false;
 65:         }
 66:         parent::init(array_merge(array(
 67:             'engine'=> 'Memcache', 
 68:             'prefix' => Inflector::slug(APP_DIR) . '_', 
 69:             'servers' => array('127.0.0.1'),
 70:             'compress'=> false,
 71:             'persistent' => true
 72:             ), $settings)
 73:         );
 74: 
 75:         if ($this->settings['compress']) {
 76:             $this->settings['compress'] = MEMCACHE_COMPRESSED;
 77:         }
 78:         if (!is_array($this->settings['servers'])) {
 79:             $this->settings['servers'] = array($this->settings['servers']);
 80:         }
 81:         if (!isset($this->__Memcache)) {
 82:             $return = false;
 83:             $this->__Memcache =& new Memcache();
 84:             foreach ($this->settings['servers'] as $server) {
 85:                 list($host, $port) = $this->_parseServerString($server);
 86:                 if ($this->__Memcache->addServer($host, $port, $this->settings['persistent'])) {
 87:                     $return = true;
 88:                 }
 89:             }
 90:             return $return;
 91:         }
 92:         return true;
 93:     }
 94: 
 95: /**
 96:  * Parses the server address into the host/port.  Handles both IPv6 and IPv4
 97:  * addresses and Unix sockets
 98:  *
 99:  * @param string $server The server address string.
100:  * @return array Array containing host, port
101:  */
102:     function _parseServerString($server) {
103:         if ($server[0] == 'u') {
104:             return array($server, 0);
105:         }
106:         if (substr($server, 0, 1) == '[') {
107:             $position = strpos($server, ']:');
108:             if ($position !== false) {
109:                 $position++;
110:             }
111:         } else {
112:             $position = strpos($server, ':');
113:         }
114:         $port = 11211;
115:         $host = $server;
116:         if ($position !== false) {
117:             $host = substr($server, 0, $position);
118:             $port = substr($server, $position + 1);
119:         }
120:         return array($host, $port);
121:     }
122: 
123: /**
124:  * Write data for key into cache.  When using memcache as your cache engine
125:  * remember that the Memcache pecl extension does not support cache expiry times greater 
126:  * than 30 days in the future. Any duration greater than 30 days will be treated as never expiring.
127:  *
128:  * @param string $key Identifier for the data
129:  * @param mixed $value Data to be cached
130:  * @param integer $duration How long to cache the data, in seconds
131:  * @return boolean True if the data was succesfully cached, false on failure
132:  * @see http://php.net/manual/en/memcache.set.php
133:  * @access public
134:  */
135:     function write($key, &$value, $duration) {
136:         if ($duration > 30 * DAY) {
137:             $duration = 0;
138:         }
139:         return $this->__Memcache->set($key, $value, $this->settings['compress'], $duration);
140:     }
141: 
142: /**
143:  * Read a key from the cache
144:  *
145:  * @param string $key Identifier for the data
146:  * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
147:  * @access public
148:  */
149:     function read($key) {
150:         return $this->__Memcache->get($key);
151:     }
152: 
153: /**
154:  * Increments the value of an integer cached key
155:  *
156:  * @param string $key Identifier for the data
157:  * @param integer $offset How much to increment
158:  * @param integer $duration How long to cache the data, in seconds
159:  * @return New incremented value, false otherwise
160:  * @access public
161:  */
162:     function increment($key, $offset = 1) {
163:         if ($this->settings['compress']) {
164:             trigger_error(sprintf(__('Method increment() not implemented for compressed cache in %s', true), get_class($this)), E_USER_ERROR);
165:         }
166:         return $this->__Memcache->increment($key, $offset);
167:     }
168: 
169: /**
170:  * Decrements the value of an integer cached key
171:  *
172:  * @param string $key Identifier for the data
173:  * @param integer $offset How much to substract
174:  * @param integer $duration How long to cache the data, in seconds
175:  * @return New decremented value, false otherwise
176:  * @access public
177:  */
178:     function decrement($key, $offset = 1) {
179:         if ($this->settings['compress']) {
180:             trigger_error(sprintf(__('Method decrement() not implemented for compressed cache in %s', true), get_class($this)), E_USER_ERROR);
181:         }
182:         return $this->__Memcache->decrement($key, $offset);
183:     }
184: 
185: /**
186:  * Delete a key from the cache
187:  *
188:  * @param string $key Identifier for the data
189:  * @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
190:  * @access public
191:  */
192:     function delete($key) {
193:         return $this->__Memcache->delete($key);
194:     }
195: 
196: /**
197:  * Delete all keys from the cache
198:  *
199:  * @return boolean True if the cache was succesfully cleared, false otherwise
200:  * @access public
201:  */
202:     function clear() {
203:         return $this->__Memcache->flush();
204:     }
205: 
206: /**
207:  * Connects to a server in connection pool
208:  *
209:  * @param string $host host ip address or name
210:  * @param integer $port Server port
211:  * @return boolean True if memcache server was connected
212:  * @access public
213:  */
214:     function connect($host, $port = 11211) {
215:         if ($this->__Memcache->getServerStatus($host, $port) === 0) {
216:             if ($this->__Memcache->connect($host, $port)) {
217:                 return true;
218:             }
219:             return false;
220:         }
221:         return true;
222:     }
223: }
224: