includes/site/FileBasedSiteLookup.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  * @license GNU GPL v2+
  21  */
  22
  23 /**
  24  * Provides a file-based cache of a SiteStore. The sites are stored in
  25  * a json file. (see docs/sitescache.txt regarding format)
  26  *
  27  * The cache can be built with the rebuildSitesCache.php maintenance script,
  28  * and a MediaWiki instance can be setup to use this by setting the
  29  * 'wgSitesCacheFile' configuration to the cache file location.
  30  *
  31  * @since 1.25
  32  */
  33 class FileBasedSiteLookup implements SiteLookup {
  34
  35         /**
  36          * @var SiteList
  37          */
  38         private $sites = null;
  39
  40         /**
  41          * @var string
  42          */
  43         private $cacheFile;
  44
  45         /**
  46          * @param string $cacheFile
  47          */
  48         public function __construct( $cacheFile ) {
  49                 $this->cacheFile = $cacheFile;
  50         }
  51
  52         /**
  53          * @since 1.25
  54          *
  55          * @return SiteList
  56          */
  57         public function getSites() {
  58                 if ( $this->sites === null ) {
  59                         $this->sites = $this->loadSitesFromCache();
  60                 }
  61
  62                 return $this->sites;
  63         }
  64
  65         /**
  66          * @param string $globalId
  67          *
  68          * @since 1.25
  69          *
  70          * @return Site|null
  71          */
  72         public function getSite( $globalId ) {
  73                 $sites = $this->getSites();
  74
  75                 return $sites->hasSite( $globalId ) ? $sites->getSite( $globalId ) : null;
  76         }
  77
  78         /**
  79          * @return SiteList
  80          */
  81         private function loadSitesFromCache() {
  82                 $data = $this->loadJsonFile();
  83
  84                 $sites = new SiteList();
  85
  86                 // @todo lazy initialize the site objects in the site list (e.g. only when needed to access)
  87                 foreach ( $data['sites'] as $siteArray ) {
  88                         $sites[] = $this->newSiteFromArray( $siteArray );
  89                 }
  90
  91                 return $sites;
  92         }
  93
  94         /**
  95          * @throws MWException
  96          * @return array see docs/sitescache.txt for format of the array.
  97          */
  98         private function loadJsonFile() {
  99                 if ( !is_readable( $this->cacheFile ) ) {
 100                         throw new MWException( 'SiteList cache file not found.' );
 101                 }
 102
 103                 $contents = file_get_contents( $this->cacheFile );
 104                 $data = json_decode( $contents, true );
 105
 106                 if ( !is_array( $data ) || !is_array( $data['sites'] )
 107                         || !array_key_exists( 'sites', $data )
 108                 ) {
 109                         throw new MWException( 'SiteStore json cache data is invalid.' );
 110                 }
 111
 112                 return $data;
 113         }
 114
 115         /**
 116          * @param array $data
 117          *
 118          * @return Site
 119          */
 120         private function newSiteFromArray( array $data ) {
 121                 $siteType = array_key_exists( 'type', $data ) ? $data['type'] : Site::TYPE_UNKNOWN;
 122                 $site = Site::newForType( $siteType );
 123
 124                 $site->setGlobalId( $data['globalid'] );
 125                 $site->setForward( $data['forward'] );
 126                 $site->setGroup( $data['group'] );
 127                 $site->setLanguageCode( $data['language'] );
 128                 $site->setSource( $data['source'] );
 129                 $site->setExtraData( $data['data'] );
 130                 $site->setExtraConfig( $data['config'] );
 131
 132                 foreach ( $data['identifiers'] as $identifier ) {
 133                         $site->addLocalId( $identifier['type'], $identifier['key'] );
 134                 }
 135
 136                 return $site;
 137         }
 138
 139 }