1: <?php
  2: 
  3: /**
  4:  * This file is part of the Nette Framework (https://nette.org)
  5:  *
  6:  * Copyright (c) 2004 David Grudl (http://davidgrudl.com)
  7:  *
  8:  * For the full copyright and license information, please view
  9:  * the file license.txt that was distributed with this source code.
 10:  * @package Nette\Caching
 11:  */
 12: 
 13: 
 14: 
 15: /**
 16:  * Memcached storage.
 17:  *
 18:  * @author     David Grudl
 19:  * @package Nette\Caching
 20:  */
 21: class NMemcachedStorage extends NObject implements ICacheStorage
 22: {
 23:     /**#@+ @internal cache structure */
 24:     const META_CALLBACKS = 'callbacks';
 25:     const META_DATA = 'data';
 26:     const META_DELTA = 'delta';
 27:     /**#@-*/
 28: 
 29:     /** @var NMemcache */
 30:     private $memcache;
 31: 
 32:     /** @var string */
 33:     private $prefix;
 34: 
 35: 
 36: 
 37:     /**
 38:      * Checks if Memcached extension is available.
 39:      * @return bool
 40:      */
 41:     public static function isAvailable()
 42:     {
 43:         return extension_loaded('memcache');
 44:     }
 45: 
 46: 
 47: 
 48:     public function __construct($host = 'localhost', $port = 11211, $prefix = '')
 49:     {
 50:         if (!self::isAvailable()) {
 51:             throw new Exception("PHP extension 'memcache' is not loaded.");
 52:         }
 53: 
 54:         $this->prefix = $prefix;
 55:         $this->memcache = new Memcache;
 56:         $this->memcache->connect($host, $port);
 57:     }
 58: 
 59: 
 60: 
 61:     /**
 62:      * Read from cache.
 63:      * @param  string key
 64:      * @return mixed|NULL
 65:      */
 66:     public function read($key)
 67:     {
 68:         $key = $this->prefix . $key;
 69:         $meta = $this->memcache->get($key);
 70:         if (!$meta) return NULL;
 71: 
 72:         // meta structure:
 73:         // array(
 74:         //     data => stored data
 75:         //     delta => relative (sliding) expiration
 76:         //     callbacks => array of callbacks (function, args)
 77:         // )
 78: 
 79:         // verify dependencies
 80:         if (!empty($meta[self::META_CALLBACKS]) && !NCache::checkCallbacks($meta[self::META_CALLBACKS])) {
 81:             $this->memcache->delete($key, 0);
 82:             return NULL;
 83:         }
 84: 
 85:         if (!empty($meta[self::META_DELTA])) {
 86:             $this->memcache->replace($key, $meta, 0, $meta[self::META_DELTA] + time());
 87:         }
 88: 
 89:         return $meta[self::META_DATA];
 90:     }
 91: 
 92: 
 93: 
 94:     /**
 95:      * Writes item into the cache.
 96:      * @param  string key
 97:      * @param  mixed  data
 98:      * @param  array  dependencies
 99:      * @return void
100:      */
101:     public function write($key, $data, array $dp)
102:     {
103:         if (!empty($dp[NCache::TAGS]) || isset($dp[NCache::PRIORITY]) || !empty($dp[NCache::ITEMS])) {
104:             throw new NotSupportedException('Tags, priority and dependent items are not supported by MemcachedStorage.');
105:         }
106: 
107:         $meta = array(
108:             self::META_DATA => $data,
109:         );
110: 
111:         $expire = 0;
112:         if (isset($dp[NCache::EXPIRATION])) {
113:             $expire = (int) $dp[NCache::EXPIRATION];
114:             if (!empty($dp[NCache::SLIDING])) {
115:                 $meta[self::META_DELTA] = $expire; // sliding time
116:             }
117:         }
118: 
119:         if (isset($dp[NCache::CALLBACKS])) {
120:             $meta[self::META_CALLBACKS] = $dp[NCache::CALLBACKS];
121:         }
122: 
123:         $this->memcache->set($this->prefix . $key, $meta, 0, $expire);
124:     }
125: 
126: 
127: 
128:     /**
129:      * Removes item from the cache.
130:      * @param  string key
131:      * @return void
132:      */
133:     public function remove($key)
134:     {
135:         $this->memcache->delete($this->prefix . $key, 0);
136:     }
137: 
138: 
139: 
140:     /**
141:      * Removes items from the cache by conditions & garbage collector.
142:      * @param  array  conditions
143:      * @return void
144:      */
145:     public function clean(array $conds)
146:     {
147:         if (!empty($conds[NCache::ALL])) {
148:             $this->memcache->flush();
149: 
150:         } elseif (isset($conds[NCache::TAGS]) || isset($conds[NCache::PRIORITY])) {
151:             throw new NotSupportedException('Tags and priority is not supported by MemcachedStorage.');
152:         }
153:     }
154: 
155: }
156: