includes/site/CachingSiteStore.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 namespace MediaWiki\Site;
  22
  23 use Wikimedia\ObjectCache\BagOStuff;
  24
  25 /**
  26  * Hold a configured list of sites (SiteList), with a caching layer.
  27  *
  28  * @internal For use by core ServiceWiring only. The public interface is SiteStore
  29  * @ingroup Site
  30  * @author Jeroen De Dauw < jeroendedauw@gmail.com >
  31  * @author Katie Filbert < aude.wiki@gmail.com >
  32  */
  33 class CachingSiteStore implements SiteStore {
  34         /** @var SiteStore */
  35         private $siteStore;
  36         /** @var BagOStuff */
  37         private $cache;
  38
  39         /** @var string|null */
  40         private $cacheKey = null;
  41         /** @var SiteList|null */
  42         private $sites = null;
  43
  44         public function __construct(
  45                 SiteStore $siteStore,
  46                 BagOStuff $cache
  47         ) {
  48                 $this->siteStore = $siteStore;
  49                 $this->cache = $cache;
  50         }
  51
  52         /**
  53          * Constructs a cache key to use for caching the list of sites.
  54          *
  55          * This includes the concrete class name of the site list as well as a version identifier
  56          * for the list's serialization, to avoid problems when unserializing site lists serialized
  57          * by an older version, e.g. when reading from a cache.
  58          *
  59          * The cache key also includes information about where the sites were loaded from, e.g.
  60          * the name of a database table.
  61          *
  62          * @see SiteList::getSerialVersionId
  63          *
  64          * @return string The cache key.
  65          */
  66         private function getCacheKey() {
  67                 if ( $this->cacheKey === null ) {
  68                         $version = SiteList::getSerialVersionId();
  69                         $this->cacheKey = $this->cache->makeKey( 'site-SiteList', $version );
  70                 }
  71
  72                 return $this->cacheKey;
  73         }
  74
  75         /**
  76          * @see SiteStore::getSites
  77          *
  78          * @since 1.25
  79          * @return SiteList
  80          */
  81         public function getSites() {
  82                 if ( $this->sites === null ) {
  83                         $this->sites = $this->cache->getWithSetCallback(
  84                                 $this->getCacheKey(),
  85                                 BagOStuff::TTL_HOUR,
  86                                 function () {
  87                                         return $this->siteStore->getSites();
  88                                 }
  89                         );
  90                 }
  91
  92                 return $this->sites;
  93         }
  94
  95         /**
  96          * @see SiteStore::getSite
  97          *
  98          * @since 1.25
  99          * @param string $globalId
 100          * @return Site|null
 101          */
 102         public function getSite( $globalId ) {
 103                 $sites = $this->getSites();
 104
 105                 return $sites->hasSite( $globalId ) ? $sites->getSite( $globalId ) : null;
 106         }
 107
 108         /**
 109          * @see SiteStore::saveSite
 110          *
 111          * @since 1.25
 112          * @param Site $site
 113          * @return bool Success indicator
 114          */
 115         public function saveSite( Site $site ) {
 116                 return $this->saveSites( [ $site ] );
 117         }
 118
 119         /**
 120          * @see SiteStore::saveSites
 121          *
 122          * @since 1.25
 123          * @param Site[] $sites
 124          * @return bool Success indicator
 125          */
 126         public function saveSites( array $sites ) {
 127                 if ( !$sites ) {
 128                         return true;
 129                 }
 130
 131                 $success = $this->siteStore->saveSites( $sites );
 132
 133                 // purge cache
 134                 $this->reset();
 135
 136                 return $success;
 137         }
 138
 139         /**
 140          * Purge the internal and external cache of the site list, forcing the list.
 141          * of sites to be reloaded.
 142          *
 143          * @since 1.25
 144          */
 145         public function reset() {
 146                 $this->cache->delete( $this->getCacheKey() );
 147                 $this->sites = null;
 148         }
 149
 150         /**
 151          * Clears the list of sites stored.
 152          *
 153          * NOTE: The fact that this also clears the in-process cache is an internal
 154          * detail for PHPUnit testing only. The injected cache is generally APCU,
 155          * which is per-server, so the cache reset would not apply to any other web servers.
 156          *
 157          * @see SiteStore::clear()
 158          * @return bool Success
 159          */
 160         public function clear() {
 161                 $this->reset();
 162
 163                 return $this->siteStore->clear();
 164         }
 165
 166 }
 167
 168 /** @deprecated class alias since 1.42 */
 169 class_alias( CachingSiteStore::class, 'CachingSiteStore' );