CRM/Utils/Cache/Memcache.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 5                                                  |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2019                                |
   7  +--------------------------------------------------------------------+
   8  | This file is a part of CiviCRM.                                    |
   9  |                                                                    |
  10  | CiviCRM is free software; you can copy, modify, and distribute it  |
  11  | under the terms of the GNU Affero General Public License           |
  12  | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
  13  |                                                                    |
  14  | CiviCRM is distributed in the hope that it will be useful, but     |
  15  | WITHOUT ANY WARRANTY; without even the implied warranty of         |
  16  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
  17  | See the GNU Affero General Public License for more details.        |
  18  |                                                                    |
  19  | You should have received a copy of the GNU Affero General Public   |
  20  | License and the CiviCRM Licensing Exception along                  |
  21  | with this program; if not, contact CiviCRM LLC                     |
  22  | at info[AT]civicrm[DOT]org. If you have questions about the        |
  23  | GNU Affero General Public License or the licensing of CiviCRM,     |
  24  | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
  25  +--------------------------------------------------------------------+
  26  */
  27
  28 /**
  29  *
  30  * @package CRM
  31  * @copyright CiviCRM LLC (c) 2004-2019
  32  */
  33 class CRM_Utils_Cache_Memcache implements CRM_Utils_Cache_Interface {
  34
  35   // TODO Consider native implementation.
  36   use CRM_Utils_Cache_NaiveMultipleTrait;
  37
  38   const DEFAULT_HOST = 'localhost';
  39   const DEFAULT_PORT = 11211;
  40   const DEFAULT_TIMEOUT = 3600;
  41   const DEFAULT_PREFIX = '';
  42
  43   /**
  44    * If another process clears namespace, we'll find out in ~5 sec.
  45    */
  46   const NS_LOCAL_TTL = 5;
  47
  48   /**
  49    * The host name of the memcached server.
  50    *
  51    * @var string
  52    */
  53   protected $_host = self::DEFAULT_HOST;
  54
  55   /**
  56    * The port on which to connect on.
  57    *
  58    * @var int
  59    */
  60   protected $_port = self::DEFAULT_PORT;
  61
  62   /**
  63    * The default timeout to use.
  64    *
  65    * @var int
  66    */
  67   protected $_timeout = self::DEFAULT_TIMEOUT;
  68
  69   /**
  70    * The prefix prepended to cache keys.
  71    *
  72    * If we are using the same memcache instance for multiple CiviCRM
  73    * installs, we must have a unique prefix for each install to prevent
  74    * the keys from clobbering each other.
  75    *
  76    * @var string
  77    */
  78   protected $_prefix = self::DEFAULT_PREFIX;
  79
  80   /**
  81    * The actual memcache object.
  82    *
  83    * @var Memcache
  84    */
  85   protected $_cache;
  86
  87   /**
  88    * @var NULL|array
  89    *
  90    * This is the effective prefix. It may be bumped up whenever the dataset is flushed.
  91    *
  92    * @see https://github.com/memcached/memcached/wiki/ProgrammingTricks#deleting-by-namespace
  93    */
  94   protected $_truePrefix = NULL;
  95
  96   /**
  97    * Constructor.
  98    *
  99    * @param array $config
 100    *   An array of configuration params.
 101    *
 102    * @return \CRM_Utils_Cache_Memcache
 103    */
 104   public function __construct($config) {
 105     if (isset($config['host'])) {
 106       $this->_host = $config['host'];
 107     }
 108     if (isset($config['port'])) {
 109       $this->_port = $config['port'];
 110     }
 111     if (isset($config['timeout'])) {
 112       $this->_timeout = $config['timeout'];
 113     }
 114     if (isset($config['prefix'])) {
 115       $this->_prefix = $config['prefix'];
 116     }
 117
 118     $this->_cache = new Memcache();
 119
 120     if (!$this->_cache->connect($this->_host, $this->_port)) {
 121       // dont use fatal here since we can go in an infinite loop
 122       echo 'Could not connect to Memcached server';
 123       CRM_Utils_System::civiExit();
 124     }
 125   }
 126
 127   /**
 128    * @param $key
 129    * @param $value
 130    * @param null|int|\DateInterval $ttl
 131    *
 132    * @return bool
 133    */
 134   public function set($key, $value, $ttl = NULL) {
 135     CRM_Utils_Cache::assertValidKey($key);
 136     if (is_int($ttl) && $ttl <= 0) {
 137       return $this->delete($key);
 138     }
 139     $expires = CRM_Utils_Date::convertCacheTtlToExpires($ttl, $this->_timeout);
 140     return $this->_cache->set($this->getTruePrefix() . $key, serialize($value), FALSE, $expires);
 141   }
 142
 143   /**
 144    * @param $key
 145    * @param mixed $default
 146    *
 147    * @return mixed
 148    */
 149   public function get($key, $default = NULL) {
 150     CRM_Utils_Cache::assertValidKey($key);
 151     $result = $this->_cache->get($this->getTruePrefix() . $key);
 152     return ($result === FALSE) ? $default : unserialize($result);
 153   }
 154
 155   /**
 156    * @param string $key
 157    *
 158    * @return bool
 159    * @throws \Psr\SimpleCache\CacheException
 160    */
 161   public function has($key) {
 162     CRM_Utils_Cache::assertValidKey($key);
 163     $result = $this->_cache->get($this->getTruePrefix() . $key);
 164     return ($result !== FALSE);
 165   }
 166
 167   /**
 168    * @param $key
 169    *
 170    * @return bool
 171    */
 172   public function delete($key) {
 173     CRM_Utils_Cache::assertValidKey($key);
 174     $this->_cache->delete($this->getTruePrefix() . $key);
 175     return TRUE;
 176   }
 177
 178   /**
 179    * @return bool
 180    */
 181   public function flush() {
 182     $this->_truePrefix = NULL;
 183     $this->_cache->delete($this->_prefix);
 184     return TRUE;
 185   }
 186
 187   public function clear() {
 188     return $this->flush();
 189   }
 190
 191   protected function getTruePrefix() {
 192     if ($this->_truePrefix === NULL || $this->_truePrefix['expires'] < time()) {
 193       $key = $this->_prefix;
 194       $value = $this->_cache->get($key);
 195       if ($value === FALSE) {
 196         $value = uniqid();
 197         // Indefinite.
 198         $this->_cache->set($key, $value, FALSE, 0);
 199       }
 200       $this->_truePrefix = [
 201         'value' => $value,
 202         'expires' => time() + self::NS_LOCAL_TTL,
 203       ];
 204     }
 205     return $this->_prefix . $this->_truePrefix['value'] . '/';
 206   }
 207
 208 }