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  * @TODO: Make this class use composition instead of calling super
  36  */
  37 class CachedBagOStuff extends HashBagOStuff {
  38         /** @var BagOStuff */
  39         protected $backend;
  40
  41         /**
  42          * @param BagOStuff $backend Permanent backend to use
  43          * @param array $params Parameters for HashBagOStuff
  44          */
  45         function __construct( BagOStuff $backend, $params = [] ) {
  46                 unset( $params['reportDupes'] ); // useless here
  47
  48                 parent::__construct( $params );
  49
  50                 $this->backend = $backend;
  51                 $this->attrMap = $backend->attrMap;
  52         }
  53
  54         public function get( $key, $flags = 0 ) {
  55                 $ret = parent::get( $key, $flags );
  56                 if ( $ret === false && !$this->hasKey( $key ) ) {
  57                         $ret = $this->backend->get( $key, $flags );
  58                         $this->set( $key, $ret, 0, self::WRITE_CACHE_ONLY );
  59                 }
  60                 return $ret;
  61         }
  62
  63         public function set( $key, $value, $exptime = 0, $flags = 0 ) {
  64                 parent::set( $key, $value, $exptime, $flags );
  65                 if ( !( $flags & self::WRITE_CACHE_ONLY ) ) {
  66                         $this->backend->set( $key, $value, $exptime, $flags & ~self::WRITE_CACHE_ONLY );
  67                 }
  68                 return true;
  69         }
  70
  71         public function delete( $key, $flags = 0 ) {
  72                 parent::delete( $key, $flags );
  73                 if ( !( $flags & self::WRITE_CACHE_ONLY ) ) {
  74                         $this->backend->delete( $key );
  75                 }
  76
  77                 return true;
  78         }
  79
  80         public function setDebug( $bool ) {
  81                 parent::setDebug( $bool );
  82                 $this->backend->setDebug( $bool );
  83         }
  84
  85         public function deleteObjectsExpiringBefore(
  86                 $timestamp,
  87                 callable $progressCallback = null,
  88                 $limit = INF
  89         ) {
  90                 parent::deleteObjectsExpiringBefore( $timestamp, $progressCallback, $limit );
  91
  92                 return $this->backend->deleteObjectsExpiringBefore(
  93                         $timestamp,
  94                         $progressCallback,
  95                         $limit
  96                 );
  97         }
  98
  99         public function makeKeyInternal( $keyspace, $args ) {
 100                 return $this->backend->makeKeyInternal( ...func_get_args() );
 101         }
 102
 103         public function makeKey( $class, $component = null ) {
 104                 return $this->backend->makeKey( ...func_get_args() );
 105         }
 106
 107         public function makeGlobalKey( $class, $component = null ) {
 108                 return $this->backend->makeGlobalKey( ...func_get_args() );
 109         }
 110
 111         // These just call the backend (tested elsewhere)
 112         // @codeCoverageIgnoreStart
 113
 114         public function add( $key, $value, $exptime = 0, $flags = 0 ) {
 115                 if ( $this->get( $key ) === false ) {
 116                         return $this->set( $key, $value, $exptime, $flags );
 117                 }
 118
 119                 return false; // key already set
 120         }
 121
 122         public function incr( $key, $value = 1 ) {
 123                 $n = $this->backend->incr( $key, $value );
 124                 parent::delete( $key );
 125
 126                 return $n;
 127         }
 128
 129         public function lock( $key, $timeout = 6, $expiry = 6, $rclass = '' ) {
 130                 return $this->backend->lock( $key, $timeout, $expiry, $rclass );
 131         }
 132
 133         public function unlock( $key ) {
 134                 return $this->backend->unlock( $key );
 135         }
 136
 137         public function getLastError() {
 138                 return $this->backend->getLastError();
 139         }
 140
 141         public function clearLastError() {
 142                 return $this->backend->clearLastError();
 143         }
 144
 145         // @codeCoverageIgnoreEnd
 146 }