CRM/Utils/Cache/Memcached.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_Memcached implements CRM_Utils_Cache_Interface {
  34
  35   use CRM_Utils_Cache_NaiveMultipleTrait; // TODO Consider native implementation.
  36
  37   const DEFAULT_HOST = 'localhost';
  38   const DEFAULT_PORT = 11211;
  39   const DEFAULT_TIMEOUT = 3600;
  40   const DEFAULT_PREFIX = '';
  41   const MAX_KEY_LEN = 200;
  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 Memcached
  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 $config
 100    *   An array of configuration params.
 101    *
 102    * @return \CRM_Utils_Cache_Memcached
 103    */
 104   public function __construct($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     $this->_cache = new Memcached();
 119
 120     if (!$this->_cache->addServer($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 $ttl
 131    *
 132    * @return bool
 133    * @throws Exception
 134    */
 135   public function set($key, $value, $ttl = NULL) {
 136     CRM_Utils_Cache::assertValidKey($key);
 137     if (is_int($ttl) && $ttl <= 0) {
 138       return $this->delete($key);
 139     }
 140     $expires = CRM_Utils_Date::convertCacheTtlToExpires($ttl, $this->_timeout);
 141
 142     $key = $this->cleanKey($key);
 143     if (!$this->_cache->set($key, serialize($value), $expires)) {
 144       if (PHP_SAPI === 'cli' || (Civi\Core\Container::isContainerBooted() && CRM_Core_Permission::check('view debug output'))) {
 145         throw new CRM_Utils_Cache_CacheException("Memcached::set($key) failed: " . $this->_cache->getResultMessage());
 146       }
 147       else {
 148         Civi::log()->error("Memcached::set($key) failed: " . $this->_cache->getResultMessage());
 149         throw new CRM_Utils_Cache_CacheException("Memcached::set($key) failed");
 150       }
 151       return FALSE;
 152
 153     }
 154     return TRUE;
 155   }
 156
 157   /**
 158    * @param $key
 159    * @param mixed $default
 160    *
 161    * @return mixed
 162    */
 163   public function get($key, $default = NULL) {
 164     CRM_Utils_Cache::assertValidKey($key);
 165     $key = $this->cleanKey($key);
 166     $result = $this->_cache->get($key);
 167     switch ($this->_cache->getResultCode()) {
 168       case Memcached::RES_SUCCESS:
 169         return unserialize($result);
 170
 171       case Memcached::RES_NOTFOUND:
 172         return $default;
 173
 174       default:
 175         Civi::log()->error("Memcached::get($key) failed: " . $this->_cache->getResultMessage());
 176         throw new CRM_Utils_Cache_CacheException("Memcached set ($key) failed");
 177     }
 178   }
 179
 180   /**
 181    * @param string $key
 182    *
 183    * @return bool
 184    * @throws \Psr\SimpleCache\CacheException
 185    */
 186   public function has($key) {
 187     CRM_Utils_Cache::assertValidKey($key);
 188     $key = $this->cleanKey($key);
 189     if ($this->_cache->get($key) !== FALSE) {
 190       return TRUE;
 191     }
 192     switch ($this->_cache->getResultCode()) {
 193       case Memcached::RES_NOTFOUND:
 194         return FALSE;
 195
 196       case Memcached::RES_SUCCESS:
 197         return TRUE;
 198
 199       default:
 200         Civi::log()->error("Memcached::has($key) failed: " . $this->_cache->getResultMessage());
 201         throw new CRM_Utils_Cache_CacheException("Memcached set ($key) failed");
 202     }
 203   }
 204
 205   /**
 206    * @param $key
 207    *
 208    * @return mixed
 209    */
 210   public function delete($key) {
 211     CRM_Utils_Cache::assertValidKey($key);
 212     $key = $this->cleanKey($key);
 213     if ($this->_cache->delete($key)) {
 214       return TRUE;
 215     }
 216     $code = $this->_cache->getResultCode();
 217     return ($code == Memcached::RES_DELETED || $code == Memcached::RES_NOTFOUND);
 218   }
 219
 220   /**
 221    * @param $key
 222    *
 223    * @return mixed|string
 224    */
 225   public function cleanKey($key) {
 226     $truePrefix = $this->getTruePrefix();
 227     $maxLen = self::MAX_KEY_LEN - strlen($truePrefix);
 228     $key = preg_replace('/\s+|\W+/', '_', $key);
 229     if (strlen($key) > $maxLen) {
 230       $md5Key = md5($key);  // this should be 32 characters in length
 231       $subKeyLen = $maxLen - 1 - strlen($md5Key);
 232       $key = substr($key, 0, $subKeyLen) . "_" . $md5Key;
 233     }
 234     return $truePrefix . $key;
 235   }
 236
 237   /**
 238    * @return bool
 239    */
 240   public function flush() {
 241     $this->_truePrefix = NULL;
 242     if ($this->_cache->delete($this->_prefix)) {
 243       return TRUE;
 244     }
 245     $code = $this->_cache->getResultCode();
 246     return ($code == Memcached::RES_DELETED || $code == Memcached::RES_NOTFOUND);
 247   }
 248
 249   public function clear() {
 250     return $this->flush();
 251   }
 252
 253   protected function getTruePrefix() {
 254     if ($this->_truePrefix === NULL || $this->_truePrefix['expires'] < time()) {
 255       $key = $this->_prefix;
 256       $value = $this->_cache->get($key);
 257       if ($this->_cache->getResultCode() === Memcached::RES_NOTFOUND) {
 258         $value = uniqid();
 259         $this->_cache->add($key, $value, 0); // Indefinite.
 260       }
 261       $this->_truePrefix = [
 262         'value' => $value,
 263         'expires' => time() + self::NS_LOCAL_TTL,
 264       ];
 265     }
 266     return $this->_prefix . $this->_truePrefix['value'] . '/';
 267   }
 268
 269 }