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         /**
  45          * @param SiteStore $siteStore
  46          * @param BagOStuff $cache
  47          */
  48         public function __construct(
  49                 SiteStore $siteStore,
  50                 BagOStuff $cache
  51         ) {
  52                 $this->siteStore = $siteStore;
  53                 $this->cache = $cache;
  54         }
  55
  56         /**
  57          * Constructs a cache key to use for caching the list of sites.
  58          *
  59          * This includes the concrete class name of the site list as well as a version identifier
  60          * for the list's serialization, to avoid problems when unserializing site lists serialized
  61          * by an older version, e.g. when reading from a cache.
  62          *
  63          * The cache key also includes information about where the sites were loaded from, e.g.
  64          * the name of a database table.
  65          *
  66          * @see SiteList::getSerialVersionId
  67          *
  68          * @return string The cache key.
  69          */
  70         private function getCacheKey() {
  71                 if ( $this->cacheKey === null ) {
  72                         $version = SiteList::getSerialVersionId();
  73                         $this->cacheKey = $this->cache->makeKey( 'site-SiteList', $version );
  74                 }
  75
  76                 return $this->cacheKey;
  77         }
  78
  79         /**
  80          * @see SiteStore::getSites
  81          *
  82          * @since 1.25
  83          * @return SiteList
  84          */
  85         public function getSites() {
  86                 if ( $this->sites === null ) {
  87                         $this->sites = $this->cache->getWithSetCallback(
  88                                 $this->getCacheKey(),
  89                                 BagOStuff::TTL_HOUR,
  90                                 function () {
  91                                         return $this->siteStore->getSites();
  92                                 }
  93                         );
  94                 }
  95
  96                 return $this->sites;
  97         }
  98
  99         /**
 100          * @see SiteStore::getSite
 101          *
 102          * @since 1.25
 103          * @param string $globalId
 104          * @return Site|null
 105          */
 106         public function getSite( $globalId ) {
 107                 $sites = $this->getSites();
 108
 109                 return $sites->hasSite( $globalId ) ? $sites->getSite( $globalId ) : null;
 110         }
 111
 112         /**
 113          * @see SiteStore::saveSite
 114          *
 115          * @since 1.25
 116          * @param Site $site
 117          * @return bool Success indicator
 118          */
 119         public function saveSite( Site $site ) {
 120                 return $this->saveSites( [ $site ] );
 121         }
 122
 123         /**
 124          * @see SiteStore::saveSites
 125          *
 126          * @since 1.25
 127          * @param Site[] $sites
 128          * @return bool Success indicator
 129          */
 130         public function saveSites( array $sites ) {
 131                 if ( !$sites ) {
 132                         return true;
 133                 }
 134
 135                 $success = $this->siteStore->saveSites( $sites );
 136
 137                 // purge cache
 138                 $this->reset();
 139
 140                 return $success;
 141         }
 142
 143         /**
 144          * Purge the internal and external cache of the site list, forcing the list.
 145          * of sites to be reloaded.
 146          *
 147          * @since 1.25
 148          */
 149         public function reset() {
 150                 $this->cache->delete( $this->getCacheKey() );
 151                 $this->sites = null;
 152         }
 153
 154         /**
 155          * Clears the list of sites stored.
 156          *
 157          * NOTE: The fact that this also clears the in-process cache is an internal
 158          * detail for PHPUnit testing only. The injected cache is generally APCU,
 159          * which is per-server, so the cache reset would not apply to any other web servers.
 160          *
 161          * @see SiteStore::clear()
 162          * @return bool Success
 163          */
 164         public function clear() {
 165                 $this->reset();
 166
 167                 return $this->siteStore->clear();
 168         }
 169
 170 }
 171
 172 /** @deprecated class alias since 1.42 */
 173 class_alias( CachingSiteStore::class, 'CachingSiteStore' );