includes/libs/objectcache/CachedBagOStuff.php

   1 <?php
   2 /**
   3  * Wrapper around a BagOStuff that caches data in memory
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Cache
  22  */
  23
  24 /**
  25  * Wrapper around a BagOStuff that caches data in memory
  26  *
  27  * The differences between CachedBagOStuff and MultiWriteBagOStuff are:
  28  * * CachedBagOStuff supports only one "backend".
  29  * * There's a flag for writes to only go to the in-memory cache.
  30  * * The in-memory cache is always updated.
  31  * * Locks go to the backend cache (with MultiWriteBagOStuff, it would wind
  32  *   up going to the HashBagOStuff used for the in-memory cache).
  33  *
  34  * @ingroup Cache
  35  */
  36 class CachedBagOStuff extends HashBagOStuff {
  37         /** @var BagOStuff */
  38         protected $backend;
  39
  40         /**
  41          * @param BagOStuff $backend Permanent backend to use
  42          * @param array $params Parameters for HashBagOStuff
  43          */
  44         function __construct( BagOStuff $backend, $params = [] ) {
  45                 unset( $params['reportDupes'] ); // useless here
  46
  47                 parent::__construct( $params );
  48
  49                 $this->backend = $backend;
  50                 $this->attrMap = $backend->attrMap;
  51         }
  52
  53         protected function doGet( $key, $flags = 0 ) {
  54                 $ret = parent::doGet( $key, $flags );
  55                 if ( $ret === false && !$this->hasKey( $key ) ) {
  56                         $ret = $this->backend->doGet( $key, $flags );
  57                         $this->set( $key, $ret, 0, self::WRITE_CACHE_ONLY );
  58                 }
  59                 return $ret;
  60         }
  61
  62         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
  63                 parent::set( $key, $value, $exptime, $flags );
  64                 if ( !( $flags & self::WRITE_CACHE_ONLY ) ) {
  65                         $this->backend->set( $key, $value, $exptime, $flags & ~self::WRITE_CACHE_ONLY );
  66                 }
  67                 return true;
  68         }
  69
  70         public function delete( $key, $flags = 0 ) {
  71                 unset( $this->bag[$key] );
  72                 if ( !( $flags & self::WRITE_CACHE_ONLY ) ) {
  73                         $this->backend->delete( $key );
  74                 }
  75
  76                 return true;
  77         }
  78
  79         public function setDebug( $bool ) {
  80                 parent::setDebug( $bool );
  81                 $this->backend->setDebug( $bool );
  82         }
  83
  84         public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
  85                 return $this->backend->lock( $key, $timeout, $expiry, $rclass );
  86         }
  87
  88         public function unlock( $key ) {
  89                 return $this->backend->unlock( $key );
  90         }
  91
  92         public function deleteObjectsExpiringBefore( $date, $progressCallback = false ) {
  93                 parent::deleteObjectsExpiringBefore( $date, $progressCallback );
  94                 return $this->backend->deleteObjectsExpiringBefore( $date, $progressCallback );
  95         }
  96
  97         public function getLastError() {
  98                 return $this->backend->getLastError();
  99         }
 100
 101         public function clearLastError() {
 102                 $this->backend->clearLastError();
 103         }
 104
 105         public function modifySimpleRelayEvent( array $event ) {
 106                 return $this->backend->modifySimpleRelayEvent( $event );
 107         }
 108
 109 }