CRM/Core/BAO/Cache.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 5                                                  |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2018                                |
   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  * BAO object for civicrm_cache table.
  30  *
  31  * This is a database cache and is persisted across sessions. Typically we use
  32  * this to store meta data (like profile fields, custom fields etc).
  33  *
  34  * The group_name column is used for grouping together all cache elements that logically belong to the same set.
  35  * Thus all session cache entries are grouped under 'CiviCRM Session'. This allows us to delete all entries of
  36  * a specific group if needed.
  37  *
  38  * The path column allows us to differentiate between items in that group. Thus for the session cache, the path is
  39  * the unique form name for each form (per user)
  40  */
  41 class CRM_Core_BAO_Cache extends CRM_Core_DAO_Cache {
  42
  43   /**
  44    * When store session/form state, how long should the data be retained?
  45    *
  46    * @var int, number of second
  47    */
  48   const DEFAULT_SESSION_TTL = 172800; // Two days: 2*24*60*60
  49
  50   /**
  51    * @var array ($cacheKey => $cacheValue)
  52    */
  53   static $_cache = NULL;
  54
  55   /**
  56    * Retrieve an item from the DB cache.
  57    *
  58    * @param string $group
  59    *   (required) The group name of the item.
  60    * @param string $path
  61    *   (required) The path under which this item is stored.
  62    * @param int $componentID
  63    *   The optional component ID (so componenets can share the same name space).
  64    *
  65    * @return object
  66    *   The data if present in cache, else null
  67    */
  68   public static function &getItem($group, $path, $componentID = NULL) {
  69     if (self::$_cache === NULL) {
  70       self::$_cache = array();
  71     }
  72
  73     $argString = "CRM_CT_{$group}_{$path}_{$componentID}";
  74     if (!array_key_exists($argString, self::$_cache)) {
  75       $cache = CRM_Utils_Cache::singleton();
  76       $cleanKey = self::cleanKey($argString);
  77       self::$_cache[$argString] = $cache->get($cleanKey);
  78       if (self::$_cache[$argString] === NULL) {
  79         $table = self::getTableName();
  80         $where = self::whereCache($group, $path, $componentID);
  81         $rawData = CRM_Core_DAO::singleValueQuery("SELECT data FROM $table WHERE $where");
  82         $data = $rawData ? self::decode($rawData) : NULL;
  83
  84         self::$_cache[$argString] = $data;
  85         if ($data !== NULL) {
  86           // Do not cache 'null' as that is most likely a cache miss & we shouldn't then cache it.
  87           $cache->set($cleanKey, self::$_cache[$argString]);
  88         }
  89       }
  90     }
  91     return self::$_cache[$argString];
  92   }
  93
  94   /**
  95    * Retrieve all items in a group.
  96    *
  97    * @param string $group
  98    *   (required) The group name of the item.
  99    * @param int $componentID
 100    *   The optional component ID (so componenets can share the same name space).
 101    *
 102    * @return object
 103    *   The data if present in cache, else null
 104    */
 105   public static function &getItems($group, $componentID = NULL) {
 106     if (self::$_cache === NULL) {
 107       self::$_cache = array();
 108     }
 109
 110     $argString = "CRM_CT_CI_{$group}_{$componentID}";
 111     if (!array_key_exists($argString, self::$_cache)) {
 112       $cache = CRM_Utils_Cache::singleton();
 113       $cleanKey = self::cleanKey($argString);
 114       self::$_cache[$argString] = $cache->get($cleanKey);
 115       if (!self::$_cache[$argString]) {
 116         $table = self::getTableName();
 117         $where = self::whereCache($group, NULL, $componentID);
 118         $dao = CRM_Core_DAO::executeQuery("SELECT path, data FROM $table WHERE $where");
 119
 120         $result = array();
 121         while ($dao->fetch()) {
 122           $result[$dao->path] = self::decode($dao->data);
 123         }
 124         $dao->free();
 125
 126         self::$_cache[$argString] = $result;
 127         $cache->set($cleanKey, self::$_cache[$argString]);
 128       }
 129     }
 130
 131     return self::$_cache[$argString];
 132   }
 133
 134   /**
 135    * Store an item in the DB cache.
 136    *
 137    * @param object $data
 138    *   (required) A reference to the data that will be serialized and stored.
 139    * @param string $group
 140    *   (required) The group name of the item.
 141    * @param string $path
 142    *   (required) The path under which this item is stored.
 143    * @param int $componentID
 144    *   The optional component ID (so componenets can share the same name space).
 145    */
 146   public static function setItem(&$data, $group, $path, $componentID = NULL) {
 147     if (self::$_cache === NULL) {
 148       self::$_cache = array();
 149     }
 150
 151     // get a lock so that multiple ajax requests on the same page
 152     // dont trample on each other
 153     // CRM-11234
 154     $lock = Civi::lockManager()->acquire("cache.{$group}_{$path}._{$componentID}");
 155     if (!$lock->isAcquired()) {
 156       CRM_Core_Error::fatal();
 157     }
 158
 159     $table = self::getTableName();
 160     $where = self::whereCache($group, $path, $componentID);
 161     $dataExists = CRM_Core_DAO::singleValueQuery("SELECT COUNT(*) FROM $table WHERE {$where}");
 162     $now = date('Y-m-d H:i:s'); // FIXME - Use SQL NOW() or CRM_Utils_Time?
 163     $dataSerialized = self::encode($data);
 164
 165     // This table has a wonky index, so we cannot use REPLACE or
 166     // "INSERT ... ON DUPE". Instead, use SELECT+(INSERT|UPDATE).
 167     if ($dataExists) {
 168       $sql = "UPDATE $table SET data = %1, created_date = %2 WHERE {$where}";
 169       $args = array(
 170         1 => array($dataSerialized, 'String'),
 171         2 => array($now, 'String'),
 172       );
 173       $dao = CRM_Core_DAO::executeQuery($sql, $args, TRUE, NULL, FALSE, FALSE);
 174     }
 175     else {
 176       $insert = CRM_Utils_SQL_Insert::into($table)
 177         ->row(array(
 178           'group_name' => $group,
 179           'path' => $path,
 180           'component_id' => $componentID,
 181           'data' => $dataSerialized,
 182           'created_date' => $now,
 183         ));
 184       $dao = CRM_Core_DAO::executeQuery($insert->toSQL(), array(), TRUE, NULL, FALSE, FALSE);
 185     }
 186
 187     $lock->release();
 188
 189     $dao->free();
 190
 191     // cache coherency - refresh or remove dependent caches
 192
 193     $argString = "CRM_CT_{$group}_{$path}_{$componentID}";
 194     $cache = CRM_Utils_Cache::singleton();
 195     $data = self::decode($dataSerialized);
 196     self::$_cache[$argString] = $data;
 197     $cache->set(self::cleanKey($argString), $data);
 198
 199     $argString = "CRM_CT_CI_{$group}_{$componentID}";
 200     unset(self::$_cache[$argString]);
 201     $cache->delete(self::cleanKey($argString));
 202   }
 203
 204   /**
 205    * Delete all the cache elements that belong to a group OR delete the entire cache if group is not specified.
 206    *
 207    * @param string $group
 208    *   The group name of the entries to be deleted.
 209    * @param string $path
 210    *   Path of the item that needs to be deleted.
 211    * @param bool $clearAll clear all caches
 212    */
 213   public static function deleteGroup($group = NULL, $path = NULL, $clearAll = TRUE) {
 214     $table = self::getTableName();
 215     $where = self::whereCache($group, $path, NULL);
 216     CRM_Core_DAO::executeQuery("DELETE FROM $table WHERE $where");
 217
 218     if ($clearAll) {
 219       // also reset ACL Cache
 220       CRM_ACL_BAO_Cache::resetCache();
 221
 222       // also reset memory cache if any
 223       CRM_Utils_System::flushCache();
 224     }
 225   }
 226
 227   /**
 228    * The next two functions are internal functions used to store and retrieve session from
 229    * the database cache. This keeps the session to a limited size and allows us to
 230    * create separate session scopes for each form in a tab
 231    */
 232
 233   /**
 234    * This function takes entries from the session array and stores it in the cache.
 235    *
 236    * It also deletes the entries from the $_SESSION object (for a smaller session size)
 237    *
 238    * @param array $names
 239    *   Array of session values that should be persisted.
 240    *                     This is either a form name + qfKey or just a form name
 241    *                     (in the case of profile)
 242    * @param bool $resetSession
 243    *   Should session state be reset on completion of DB store?.
 244    */
 245   public static function storeSessionToCache($names, $resetSession = TRUE) {
 246     foreach ($names as $key => $sessionName) {
 247       if (is_array($sessionName)) {
 248         $value = NULL;
 249         if (!empty($_SESSION[$sessionName[0]][$sessionName[1]])) {
 250           $value = $_SESSION[$sessionName[0]][$sessionName[1]];
 251         }
 252         $key = "{$sessionName[0]}_{$sessionName[1]}";
 253         Civi::cache('session')->set($key, $value, self::pickSessionTtl($key));
 254         if ($resetSession) {
 255           $_SESSION[$sessionName[0]][$sessionName[1]] = NULL;
 256           unset($_SESSION[$sessionName[0]][$sessionName[1]]);
 257         }
 258       }
 259       else {
 260         $value = NULL;
 261         if (!empty($_SESSION[$sessionName])) {
 262           $value = $_SESSION[$sessionName];
 263         }
 264         Civi::cache('session')->set($sessionName, $value, self::pickSessionTtl($sessionName));
 265         if ($resetSession) {
 266           $_SESSION[$sessionName] = NULL;
 267           unset($_SESSION[$sessionName]);
 268         }
 269       }
 270     }
 271
 272     self::cleanup();
 273   }
 274
 275   /* Retrieve the session values from the cache and populate the $_SESSION array
 276    *
 277    * @param array $names
 278    *   Array of session values that should be persisted.
 279    *                     This is either a form name + qfKey or just a form name
 280    *                     (in the case of profile)
 281    */
 282
 283   /**
 284    * Restore session from cache.
 285    *
 286    * @param string $names
 287    */
 288   public static function restoreSessionFromCache($names) {
 289     foreach ($names as $key => $sessionName) {
 290       if (is_array($sessionName)) {
 291         $value = Civi::cache('session')->get("{$sessionName[0]}_{$sessionName[1]}");
 292         if ($value) {
 293           $_SESSION[$sessionName[0]][$sessionName[1]] = $value;
 294         }
 295       }
 296       else {
 297         $value = Civi::cache('session')->get($sessionName);
 298         if ($value) {
 299           $_SESSION[$sessionName] = $value;
 300         }
 301       }
 302     }
 303   }
 304
 305   /**
 306    * Determine how long session-state should be retained.
 307    *
 308    * @param string $sessionKey
 309    *   Ex: '_CRM_Admin_Form_Preferences_Display_f1a5f232e3d850a29a7a4d4079d7c37b_4654_container'
 310    *   Ex: 'CiviCRM_CRM_Admin_Form_Preferences_Display_f1a5f232e3d850a29a7a4d4079d7c37b_4654'
 311    * @return int
 312    *   Number of seconds.
 313    */
 314   protected static function pickSessionTtl($sessionKey) {
 315     $secureSessionTimeoutMinutes = (int) Civi::settings()->get('secure_cache_timeout_minutes');
 316     if ($secureSessionTimeoutMinutes) {
 317       $transactionPages = array(
 318         'CRM_Contribute_Controller_Contribution',
 319         'CRM_Event_Controller_Registration',
 320       );
 321       foreach ($transactionPages as $transactionPage) {
 322         if (strpos($sessionKey, $transactionPage) !== FALSE) {
 323           return $secureSessionTimeoutMinutes * 60;
 324         }
 325       }
 326     }
 327
 328     return self::DEFAULT_SESSION_TTL;
 329   }
 330
 331   /**
 332    * Do periodic cleanup of the CiviCRM session table.
 333    *
 334    * Also delete all session cache entries which are a couple of days old.
 335    * This keeps the session cache to a manageable size
 336    * Delete Contribution page session caches more energetically.
 337    *
 338    * @param bool $session
 339    * @param bool $table
 340    * @param bool $prevNext
 341    */
 342   public static function cleanup($session = FALSE, $table = FALSE, $prevNext = FALSE, $expired = FALSE) {
 343     // clean up the session cache every $cacheCleanUpNumber probabilistically
 344     $cleanUpNumber = 757;
 345
 346     // clean up all sessions older than $cacheTimeIntervalDays days
 347     $timeIntervalDays = 2;
 348
 349     if (mt_rand(1, 100000) % $cleanUpNumber == 0) {
 350       $expired = $session = $table = $prevNext = TRUE;
 351     }
 352
 353     if (!$session && !$table && !$prevNext && !$expired) {
 354       return;
 355     }
 356
 357     if ($prevNext) {
 358       // delete all PrevNext caches
 359       CRM_Core_BAO_PrevNextCache::cleanupCache();
 360     }
 361
 362     if ($table) {
 363       CRM_Core_Config::clearTempTables($timeIntervalDays . ' day');
 364     }
 365
 366     if ($session) {
 367       // Session caches are just regular caches, so they expire naturally per TTL.
 368       $expired = TRUE;
 369     }
 370
 371     if ($expired) {
 372       $sql = "DELETE FROM civicrm_cache WHERE expired_date < %1";
 373       $params = [
 374         1 => [date(CRM_Utils_Cache_SqlGroup::TS_FMT, CRM_Utils_Time::getTimeRaw()), 'String'],
 375       ];
 376       CRM_Core_DAO::executeQuery($sql, $params);
 377     }
 378   }
 379
 380   /**
 381    * (Quasi-private) Encode an object/array/string/int as a string.
 382    *
 383    * @param $mixed
 384    * @return string
 385    */
 386   public static function encode($mixed) {
 387     return base64_encode(serialize($mixed));
 388   }
 389
 390   /**
 391    * (Quasi-private) Decode an object/array/string/int from a string.
 392    *
 393    * @param $string
 394    * @return mixed
 395    */
 396   public static function decode($string) {
 397     // Upgrade support -- old records (serialize) always have this punctuation,
 398     // and new records (base64) never do.
 399     if (strpos($string, ':') !== FALSE || strpos($string, ';') !== FALSE) {
 400       return unserialize($string);
 401     }
 402     else {
 403       return unserialize(base64_decode($string));
 404     }
 405   }
 406
 407   /**
 408    * Compose a SQL WHERE clause for the cache.
 409    *
 410    * Note: We need to use the cache during bootstrap, so we don't have
 411    * full access to DAO services.
 412    *
 413    * @param string $group
 414    * @param string|NULL $path
 415    *   Filter by path. If NULL, then return any paths.
 416    * @param int|NULL $componentID
 417    *   Filter by component. If NULL, then look for explicitly NULL records.
 418    * @return string
 419    */
 420   protected static function whereCache($group, $path, $componentID) {
 421     $clauses = array();
 422     $clauses[] = ('group_name = "' . CRM_Core_DAO::escapeString($group) . '"');
 423     if ($path) {
 424       $clauses[] = ('path = "' . CRM_Core_DAO::escapeString($path) . '"');
 425     }
 426     if ($componentID && is_numeric($componentID)) {
 427       $clauses[] = ('component_id = ' . (int) $componentID);
 428     }
 429     return $clauses ? implode(' AND ', $clauses) : '(1)';
 430   }
 431
 432   /**
 433    * Normalize a cache key.
 434    *
 435    * This bridges an impedance mismatch between our traditional caching
 436    * and PSR-16 -- PSR-16 accepts a narrower range of cache keys.
 437    *
 438    * @param string $key
 439    *   Ex: 'ab/cd:ef'
 440    * @return string
 441    *   Ex: '_abcd1234abcd1234' or 'ab_xx/cd_xxef'.
 442    *   A similar key, but suitable for use with PSR-16-compliant cache providers.
 443    */
 444   public static function cleanKey($key) {
 445     if (!is_string($key) && !is_int($key)) {
 446       throw new \RuntimeException("Malformed cache key");
 447     }
 448
 449     $maxLen = 64;
 450     $escape = '-';
 451
 452     if (strlen($key) >= $maxLen) {
 453       return $escape . md5($key);
 454     }
 455
 456     $r = preg_replace_callback(';[^A-Za-z0-9_\.];', function($m) use ($escape) {
 457       return $escape . dechex(ord($m[0]));
 458     }, $key);
 459
 460     return strlen($r) >= $maxLen ? $escape . md5($key) : $r;
 461   }
 462
 463 }