CRM/Utils/Cache/Memcached.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | Copyright CiviCRM LLC. All rights reserved.                        |
   5  |                                                                    |
   6  | This work is published under the GNU AGPLv3 license with some      |
   7  | permitted exceptions and without any warranty. For full license    |
   8  | and copyright information, see https://civicrm.org/licensing       |
   9  +--------------------------------------------------------------------+
  10  */
  11
  12 /**
  13  *
  14  * @package CRM
  15  * @copyright CiviCRM LLC https://civicrm.org/licensing
  16  */
  17 class CRM_Utils_Cache_Memcached implements CRM_Utils_Cache_Interface {
  18
  19   // TODO Consider native implementation.
  20   use CRM_Utils_Cache_NaiveMultipleTrait;
  21
  22   const DEFAULT_HOST = 'localhost';
  23   const DEFAULT_PORT = 11211;
  24   const DEFAULT_TIMEOUT = 3600;
  25   const DEFAULT_PREFIX = '';
  26   const MAX_KEY_LEN = 200;
  27
  28   /**
  29    * If another process clears namespace, we'll find out in ~5 sec.
  30    */
  31   const NS_LOCAL_TTL = 5;
  32
  33   /**
  34    * The host name of the memcached server
  35    *
  36    * @var string
  37    */
  38   protected $_host = self::DEFAULT_HOST;
  39
  40   /**
  41    * The port on which to connect on
  42    *
  43    * @var int
  44    */
  45   protected $_port = self::DEFAULT_PORT;
  46
  47   /**
  48    * The default timeout to use
  49    *
  50    * @var int
  51    */
  52   protected $_timeout = self::DEFAULT_TIMEOUT;
  53
  54   /**
  55    * The prefix prepended to cache keys.
  56    *
  57    * If we are using the same memcache instance for multiple CiviCRM
  58    * installs, we must have a unique prefix for each install to prevent
  59    * the keys from clobbering each other.
  60    *
  61    * @var string
  62    */
  63   protected $_prefix = self::DEFAULT_PREFIX;
  64
  65   /**
  66    * The actual memcache object.
  67    *
  68    * @var Memcached
  69    */
  70   protected $_cache;
  71
  72   /**
  73    * @var NULL|array
  74    *
  75    * This is the effective prefix. It may be bumped up whenever the dataset is flushed.
  76    *
  77    * @see https://github.com/memcached/memcached/wiki/ProgrammingTricks#deleting-by-namespace
  78    */
  79   protected $_truePrefix = NULL;
  80
  81   /**
  82    * Constructor.
  83    *
  84    * @param array $config
  85    *   An array of configuration params.
  86    *
  87    * @return \CRM_Utils_Cache_Memcached
  88    */
  89   public function __construct($config) {
  90     if (isset($config['host'])) {
  91       $this->_host = $config['host'];
  92     }
  93     if (isset($config['port'])) {
  94       $this->_port = $config['port'];
  95     }
  96     if (isset($config['timeout'])) {
  97       $this->_timeout = $config['timeout'];
  98     }
  99     if (isset($config['prefix'])) {
 100       $this->_prefix = $config['prefix'];
 101     }
 102
 103     $this->_cache = new Memcached();
 104
 105     if (!$this->_cache->addServer($this->_host, $this->_port)) {
 106       // dont use fatal here since we can go in an infinite loop
 107       echo 'Could not connect to Memcached server';
 108       CRM_Utils_System::civiExit();
 109     }
 110   }
 111
 112   /**
 113    * @param $key
 114    * @param $value
 115    * @param null|int|\DateInterval $ttl
 116    *
 117    * @return bool
 118    * @throws Exception
 119    */
 120   public function set($key, $value, $ttl = NULL) {
 121     CRM_Utils_Cache::assertValidKey($key);
 122     if (is_int($ttl) && $ttl <= 0) {
 123       return $this->delete($key);
 124     }
 125     $expires = CRM_Utils_Date::convertCacheTtlToExpires($ttl, $this->_timeout);
 126
 127     $key = $this->cleanKey($key);
 128     if (!$this->_cache->set($key, serialize($value), $expires)) {
 129       if (PHP_SAPI === 'cli' || (Civi\Core\Container::isContainerBooted() && CRM_Core_Permission::check('view debug output'))) {
 130         throw new CRM_Utils_Cache_CacheException("Memcached::set($key) failed: " . $this->_cache->getResultMessage());
 131       }
 132       else {
 133         Civi::log()->error("Memcached::set($key) failed: " . $this->_cache->getResultMessage());
 134         throw new CRM_Utils_Cache_CacheException("Memcached::set($key) failed");
 135       }
 136       return FALSE;
 137
 138     }
 139     return TRUE;
 140   }
 141
 142   /**
 143    * @param $key
 144    * @param mixed $default
 145    *
 146    * @return mixed
 147    */
 148   public function get($key, $default = NULL) {
 149     CRM_Utils_Cache::assertValidKey($key);
 150     $key = $this->cleanKey($key);
 151     $result = $this->_cache->get($key);
 152     switch ($this->_cache->getResultCode()) {
 153       case Memcached::RES_SUCCESS:
 154         return unserialize($result);
 155
 156       case Memcached::RES_NOTFOUND:
 157         return $default;
 158
 159       default:
 160         Civi::log()->error("Memcached::get($key) failed: " . $this->_cache->getResultMessage());
 161         throw new CRM_Utils_Cache_CacheException("Memcached set ($key) failed");
 162     }
 163   }
 164
 165   /**
 166    * @param string $key
 167    *
 168    * @return bool
 169    * @throws \Psr\SimpleCache\CacheException
 170    */
 171   public function has($key) {
 172     CRM_Utils_Cache::assertValidKey($key);
 173     $key = $this->cleanKey($key);
 174     if ($this->_cache->get($key) !== FALSE) {
 175       return TRUE;
 176     }
 177     switch ($this->_cache->getResultCode()) {
 178       case Memcached::RES_NOTFOUND:
 179         return FALSE;
 180
 181       case Memcached::RES_SUCCESS:
 182         return TRUE;
 183
 184       default:
 185         Civi::log()->error("Memcached::has($key) failed: " . $this->_cache->getResultMessage());
 186         throw new CRM_Utils_Cache_CacheException("Memcached set ($key) failed");
 187     }
 188   }
 189
 190   /**
 191    * @param $key
 192    *
 193    * @return mixed
 194    */
 195   public function delete($key) {
 196     CRM_Utils_Cache::assertValidKey($key);
 197     $key = $this->cleanKey($key);
 198     if ($this->_cache->delete($key)) {
 199       return TRUE;
 200     }
 201     $code = $this->_cache->getResultCode();
 202     return ($code == Memcached::RES_DELETED || $code == Memcached::RES_NOTFOUND);
 203   }
 204
 205   /**
 206    * @param $key
 207    *
 208    * @return mixed|string
 209    */
 210   public function cleanKey($key) {
 211     $truePrefix = $this->getTruePrefix();
 212     $maxLen = self::MAX_KEY_LEN - strlen($truePrefix);
 213     $key = preg_replace('/\s+|\W+/', '_', $key);
 214     if (strlen($key) > $maxLen) {
 215       // this should be 32 characters in length
 216       $md5Key = md5($key);
 217       $subKeyLen = $maxLen - 1 - strlen($md5Key);
 218       $key = substr($key, 0, $subKeyLen) . "_" . $md5Key;
 219     }
 220     return $truePrefix . $key;
 221   }
 222
 223   /**
 224    * @return bool
 225    */
 226   public function flush() {
 227     $this->_truePrefix = NULL;
 228     if ($this->_cache->delete($this->_prefix)) {
 229       return TRUE;
 230     }
 231     $code = $this->_cache->getResultCode();
 232     return ($code == Memcached::RES_DELETED || $code == Memcached::RES_NOTFOUND);
 233   }
 234
 235   public function clear() {
 236     return $this->flush();
 237   }
 238
 239   protected function getTruePrefix() {
 240     if ($this->_truePrefix === NULL || $this->_truePrefix['expires'] < time()) {
 241       $key = $this->_prefix;
 242       $value = $this->_cache->get($key);
 243       if ($this->_cache->getResultCode() === Memcached::RES_NOTFOUND) {
 244         $value = uniqid();
 245         // Indefinite.
 246         $this->_cache->add($key, $value, 0);
 247       }
 248       $this->_truePrefix = [
 249         'value' => $value,
 250         'expires' => time() + self::NS_LOCAL_TTL,
 251       ];
 252     }
 253     return $this->_prefix . $this->_truePrefix['value'] . '/';
 254   }
 255
 256 }