includes/cache/localisation/LocalisationCacheBulkLoad.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 /**
  22  * A localisation cache optimised for loading large amounts of data for many
  23  * languages. Used by rebuildLocalisationCache.php.
  24  */
  25 class LocalisationCacheBulkLoad extends LocalisationCache {
  26
  27         /**
  28          * A cache of the contents of data files.
  29          * Core files are serialized to avoid using ~1GB of RAM during a recache.
  30          */
  31         private $fileCache = [];
  32
  33         /**
  34          * Most recently used languages. Uses the linked-list aspect of PHP hashtables
  35          * to keep the most recently used language codes at the end of the array, and
  36          * the language codes that are ready to be deleted at the beginning.
  37          */
  38         private $mruLangs = [];
  39
  40         /**
  41          * Maximum number of languages that may be loaded into $this->data
  42          */
  43         private $maxLoadedLangs = 10;
  44
  45         /**
  46          * @param string $fileName
  47          * @param string $fileType
  48          * @return array|mixed
  49          */
  50         protected function readPHPFile( $fileName, $fileType ) {
  51                 $serialize = $fileType === 'core';
  52                 if ( !isset( $this->fileCache[$fileName][$fileType] ) ) {
  53                         $data = parent::readPHPFile( $fileName, $fileType );
  54
  55                         if ( $serialize ) {
  56                                 $encData = serialize( $data );
  57                         } else {
  58                                 $encData = $data;
  59                         }
  60
  61                         $this->fileCache[$fileName][$fileType] = $encData;
  62
  63                         return $data;
  64                 } elseif ( $serialize ) {
  65                         return unserialize( $this->fileCache[$fileName][$fileType] );
  66                 } else {
  67                         return $this->fileCache[$fileName][$fileType];
  68                 }
  69         }
  70
  71         /**
  72          * @param string $code
  73          * @param string $key
  74          * @return mixed
  75          */
  76         public function getItem( $code, $key ) {
  77                 unset( $this->mruLangs[$code] );
  78                 $this->mruLangs[$code] = true;
  79
  80                 return parent::getItem( $code, $key );
  81         }
  82
  83         /**
  84          * @param string $code
  85          * @param string $key
  86          * @param string $subkey
  87          * @return mixed
  88          */
  89         public function getSubitem( $code, $key, $subkey ) {
  90                 unset( $this->mruLangs[$code] );
  91                 $this->mruLangs[$code] = true;
  92
  93                 return parent::getSubitem( $code, $key, $subkey );
  94         }
  95
  96         /**
  97          * @param string $code
  98          */
  99         public function recache( $code ) {
 100                 parent::recache( $code );
 101                 unset( $this->mruLangs[$code] );
 102                 $this->mruLangs[$code] = true;
 103                 $this->trimCache();
 104         }
 105
 106         /**
 107          * @param string $code
 108          */
 109         public function unload( $code ) {
 110                 unset( $this->mruLangs[$code] );
 111                 parent::unload( $code );
 112         }
 113
 114         /**
 115          * Unload cached languages until there are less than $this->maxLoadedLangs
 116          */
 117         protected function trimCache() {
 118                 while ( count( $this->data ) > $this->maxLoadedLangs && count( $this->mruLangs ) ) {
 119                         reset( $this->mruLangs );
 120                         $code = key( $this->mruLangs );
 121                         wfDebug( __METHOD__ . ": unloading $code\n" );
 122                         $this->unload( $code );
 123                 }
 124         }
 125
 126 }