extensions/Gadgets/includes/GadgetDefinitionNamespaceRepo.php

   1 <?php
   2
   3 use MediaWiki\MediaWikiServices;
   4
   5 /**
   6  * GadgetRepo implementation where each gadget has a page in
   7  * the Gadget definition namespace, and scripts and styles are
   8  * located in the Gadget namespace.
   9  */
  10 class GadgetDefinitionNamespaceRepo extends GadgetRepo {
  11         /**
  12          * How long in seconds the list of gadget ids and
  13          * individual gadgets should be cached for (1 day)
  14          */
  15         const CACHE_TTL = 86400;
  16
  17         /**
  18          * @var WANObjectCache
  19          */
  20         private $wanCache;
  21
  22         public function __construct() {
  23                 $this->wanCache = MediaWikiServices::getInstance()->getMainWANObjectCache();
  24         }
  25
  26         /**
  27          * Get a list of gadget ids from cache/database
  28          *
  29          * @return string[]
  30          */
  31         public function getGadgetIds() {
  32                 $key = $this->getGadgetIdsKey();
  33
  34                 return $this->wanCache->getWithSetCallback(
  35                         $key,
  36                         self::CACHE_TTL,
  37                         function ( $oldValue, &$ttl, array &$setOpts ) {
  38                                 $dbr = wfGetDB( DB_SLAVE );
  39                                 $setOpts += Database::getCacheSetOptions( $dbr );
  40
  41                                 return $dbr->selectFieldValues(
  42                                         'page',
  43                                         'page_title',
  44                                         [ 'page_namespace' => NS_GADGET_DEFINITION ],
  45                                         __METHOD__
  46                                 );
  47                         },
  48                         [
  49                                 'checkKeys' => [ $key ],
  50                                 'pcTTL' => WANObjectCache::TTL_PROC_SHORT,
  51                                 'lockTSE' => 30
  52                         ]
  53                 );
  54         }
  55
  56         /**
  57          * Purge the list of gadget ids when a page is deleted or if a new page is created
  58          */
  59         public function purgeGadgetIdsList() {
  60                 $this->wanCache->touchCheckKey( $this->getGadgetIdsKey() );
  61         }
  62
  63         /**
  64          * @param string $id
  65          * @throws InvalidArgumentException
  66          * @return Gadget
  67          */
  68         public function getGadget( $id ) {
  69                 $key = $this->getGadgetCacheKey( $id );
  70                 $gadget = $this->wanCache->getWithSetCallback(
  71                         $key,
  72                         self::CACHE_TTL,
  73                         function ( $old, &$ttl, array &$setOpts ) use ( $id ) {
  74                                 $setOpts += Database::getCacheSetOptions( wfGetDB( DB_SLAVE ) );
  75                                 $title = Title::makeTitleSafe( NS_GADGET_DEFINITION, $id );
  76                                 if ( !$title ) {
  77                                         $ttl = WANObjectCache::TTL_UNCACHEABLE;
  78                                         return null;
  79                                 }
  80
  81                                 $rev = Revision::newFromTitle( $title );
  82                                 if ( !$rev ) {
  83                                         $ttl = WANObjectCache::TTL_UNCACHEABLE;
  84                                         return null;
  85                                 }
  86
  87                                 $content = $rev->getContent();
  88                                 if ( !$content instanceof GadgetDefinitionContent ) {
  89                                         // Uhm...
  90                                         $ttl = WANObjectCache::TTL_UNCACHEABLE;
  91                                         return null;
  92                                 }
  93
  94                                 return Gadget::newFromDefinitionContent( $id, $content );
  95                         },
  96                         [
  97                                 'checkKeys' => [ $key ],
  98                                 'pcTTL' => WANObjectCache::TTL_PROC_SHORT,
  99                                 'lockTSE' => 30
 100                         ]
 101                 );
 102
 103                 if ( $gadget === null ) {
 104                         throw new InvalidArgumentException( "No gadget registered for '$id'" );
 105                 }
 106
 107                 return $gadget;
 108         }
 109
 110         /**
 111          * Update the cache for a specific Gadget whenever it is updated
 112          *
 113          * @param string $id
 114          */
 115         public function purgeGadgetEntry( $id ) {
 116                 $this->wanCache->touchCheckKey( $this->getGadgetCacheKey( $id ) );
 117         }
 118
 119         /**
 120          * @return string
 121          */
 122         private function getGadgetIdsKey() {
 123                 return $this->wanCache->makeKey( 'gadgets', 'namespace', 'ids' );
 124         }
 125
 126         /**
 127          * @param strng $id
 128          * @return string
 129          */
 130         private function getGadgetCacheKey( $id ) {
 131                 return $this->wanCache->makeKey(
 132                         'gadgets', 'object', md5( $id ), Gadget::GADGET_CLASS_VERSION );
 133         }
 134 }