CRM/Utils/Cache/Memcached.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 5                                                  |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2020                                |
   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) 2004-2020
  32  */
  33 class CRM_Utils_Cache_Memcached 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   const MAX_KEY_LEN = 200;
  43
  44   /**
  45    * If another process clears namespace, we'll find out in ~5 sec.
  46    */
  47   const NS_LOCAL_TTL = 5;
  48
  49   /**
  50    * The host name of the memcached server
  51    *
  52    * @var string
  53    */
  54   protected $_host = self::DEFAULT_HOST;
  55
  56   /**
  57    * The port on which to connect on
  58    *
  59    * @var int
  60    */
  61   protected $_port = self::DEFAULT_PORT;
  62
  63   /**
  64    * The default timeout to use
  65    *
  66    * @var int
  67    */
  68   protected $_timeout = self::DEFAULT_TIMEOUT;
  69
  70   /**
  71    * The prefix prepended to cache keys.
  72    *
  73    * If we are using the same memcache instance for multiple CiviCRM
  74    * installs, we must have a unique prefix for each install to prevent
  75    * the keys from clobbering each other.
  76    *
  77    * @var string
  78    */
  79   protected $_prefix = self::DEFAULT_PREFIX;
  80
  81   /**
  82    * The actual memcache object.
  83    *
  84    * @var Memcached
  85    */
  86   protected $_cache;
  87
  88   /**
  89    * @var NULL|array
  90    *
  91    * This is the effective prefix. It may be bumped up whenever the dataset is flushed.
  92    *
  93    * @see https://github.com/memcached/memcached/wiki/ProgrammingTricks#deleting-by-namespace
  94    */
  95   protected $_truePrefix = NULL;
  96
  97   /**
  98    * Constructor.
  99    *
 100    * @param array $config
 101    *   An array of configuration params.
 102    *
 103    * @return \CRM_Utils_Cache_Memcached
 104    */
 105   public function __construct($config) {
 106     if (isset($config['host'])) {
 107       $this->_host = $config['host'];
 108     }
 109     if (isset($config['port'])) {
 110       $this->_port = $config['port'];
 111     }
 112     if (isset($config['timeout'])) {
 113       $this->_timeout = $config['timeout'];
 114     }
 115     if (isset($config['prefix'])) {
 116       $this->_prefix = $config['prefix'];
 117     }
 118
 119     $this->_cache = new Memcached();
 120
 121     if (!$this->_cache->addServer($this->_host, $this->_port)) {
 122       // dont use fatal here since we can go in an infinite loop
 123       echo 'Could not connect to Memcached server';
 124       CRM_Utils_System::civiExit();
 125     }
 126   }
 127
 128   /**
 129    * @param $key
 130    * @param $value
 131    * @param null|int|\DateInterval $ttl
 132    *
 133    * @return bool
 134    * @throws Exception
 135    */
 136   public function set($key, $value, $ttl = NULL) {
 137     CRM_Utils_Cache::assertValidKey($key);
 138     if (is_int($ttl) && $ttl <= 0) {
 139       return $this->delete($key);
 140     }
 141     $expires = CRM_Utils_Date::convertCacheTtlToExpires($ttl, $this->_timeout);
 142
 143     $key = $this->cleanKey($key);
 144     if (!$this->_cache->set($key, serialize($value), $expires)) {
 145       if (PHP_SAPI === 'cli' || (Civi\Core\Container::isContainerBooted() && CRM_Core_Permission::check('view debug output'))) {
 146         throw new CRM_Utils_Cache_CacheException("Memcached::set($key) failed: " . $this->_cache->getResultMessage());
 147       }
 148       else {
 149         Civi::log()->error("Memcached::set($key) failed: " . $this->_cache->getResultMessage());
 150         throw new CRM_Utils_Cache_CacheException("Memcached::set($key) failed");
 151       }
 152       return FALSE;
 153
 154     }
 155     return TRUE;
 156   }
 157
 158   /**
 159    * @param $key
 160    * @param mixed $default
 161    *
 162    * @return mixed
 163    */
 164   public function get($key, $default = NULL) {
 165     CRM_Utils_Cache::assertValidKey($key);
 166     $key = $this->cleanKey($key);
 167     $result = $this->_cache->get($key);
 168     switch ($this->_cache->getResultCode()) {
 169       case Memcached::RES_SUCCESS:
 170         return unserialize($result);
 171
 172       case Memcached::RES_NOTFOUND:
 173         return $default;
 174
 175       default:
 176         Civi::log()->error("Memcached::get($key) failed: " . $this->_cache->getResultMessage());
 177         throw new CRM_Utils_Cache_CacheException("Memcached set ($key) failed");
 178     }
 179   }
 180
 181   /**
 182    * @param string $key
 183    *
 184    * @return bool
 185    * @throws \Psr\SimpleCache\CacheException
 186    */
 187   public function has($key) {
 188     CRM_Utils_Cache::assertValidKey($key);
 189     $key = $this->cleanKey($key);
 190     if ($this->_cache->get($key) !== FALSE) {
 191       return TRUE;
 192     }
 193     switch ($this->_cache->getResultCode()) {
 194       case Memcached::RES_NOTFOUND:
 195         return FALSE;
 196
 197       case Memcached::RES_SUCCESS:
 198         return TRUE;
 199
 200       default:
 201         Civi::log()->error("Memcached::has($key) failed: " . $this->_cache->getResultMessage());
 202         throw new CRM_Utils_Cache_CacheException("Memcached set ($key) failed");
 203     }
 204   }
 205
 206   /**
 207    * @param $key
 208    *
 209    * @return mixed
 210    */
 211   public function delete($key) {
 212     CRM_Utils_Cache::assertValidKey($key);
 213     $key = $this->cleanKey($key);
 214     if ($this->_cache->delete($key)) {
 215       return TRUE;
 216     }
 217     $code = $this->_cache->getResultCode();
 218     return ($code == Memcached::RES_DELETED || $code == Memcached::RES_NOTFOUND);
 219   }
 220
 221   /**
 222    * @param $key
 223    *
 224    * @return mixed|string
 225    */
 226   public function cleanKey($key) {
 227     $truePrefix = $this->getTruePrefix();
 228     $maxLen = self::MAX_KEY_LEN - strlen($truePrefix);
 229     $key = preg_replace('/\s+|\W+/', '_', $key);
 230     if (strlen($key) > $maxLen) {
 231       // this should be 32 characters in length
 232       $md5Key = md5($key);
 233       $subKeyLen = $maxLen - 1 - strlen($md5Key);
 234       $key = substr($key, 0, $subKeyLen) . "_" . $md5Key;
 235     }
 236     return $truePrefix . $key;
 237   }
 238
 239   /**
 240    * @return bool
 241    */
 242   public function flush() {
 243     $this->_truePrefix = NULL;
 244     if ($this->_cache->delete($this->_prefix)) {
 245       return TRUE;
 246     }
 247     $code = $this->_cache->getResultCode();
 248     return ($code == Memcached::RES_DELETED || $code == Memcached::RES_NOTFOUND);
 249   }
 250
 251   public function clear() {
 252     return $this->flush();
 253   }
 254
 255   protected function getTruePrefix() {
 256     if ($this->_truePrefix === NULL || $this->_truePrefix['expires'] < time()) {
 257       $key = $this->_prefix;
 258       $value = $this->_cache->get($key);
 259       if ($this->_cache->getResultCode() === Memcached::RES_NOTFOUND) {
 260         $value = uniqid();
 261         // Indefinite.
 262         $this->_cache->add($key, $value, 0);
 263       }
 264       $this->_truePrefix = [
 265         'value' => $value,
 266         'expires' => time() + self::NS_LOCAL_TTL,
 267       ];
 268     }
 269     return $this->_prefix . $this->_truePrefix['value'] . '/';
 270   }
 271
 272 }