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