includes/cache/ResourceFileCache.php

   1 <?php
   2 /**
   3  * Contain the ResourceFileCache class
   4  * @file
   5  * @ingroup Cache
   6  */
   7 class ResourceFileCache extends FileCacheBase {
   8         protected $mCacheWorthy;
   9
  10         /* @TODO: configurable? */
  11         const MISS_THRESHOLD = 360; // 6/min * 60 min
  12
  13         /**
  14          * Construct an ResourceFileCache from a context
  15          * @param $context ResourceLoaderContext
  16          * @return ResourceFileCache
  17          */
  18         public static function newFromContext( ResourceLoaderContext $context ) {
  19                 $cache = new self();
  20
  21                 if ( $context->getOnly() === 'styles' ) {
  22                         $cache->mType = 'css';
  23                 } else {
  24                         $cache->mType = 'js';
  25                 }
  26                 $modules = array_unique( $context->getModules() ); // remove duplicates
  27                 sort( $modules ); // normalize the order (permutation => combination)
  28                 $cache->mKey = sha1( $context->getHash() . implode( '|', $modules ) );
  29                 if ( count( $modules ) == 1 ) {
  30                         $cache->mCacheWorthy = true; // won't take up much space
  31                 }
  32
  33                 return $cache;
  34         }
  35
  36         /**
  37          * Check if an RL request can be cached.
  38          * Caller is responsible for checking if any modules are private.
  39          * @param $context ResourceLoaderContext
  40          * @return bool
  41          */
  42         public static function useFileCache( ResourceLoaderContext $context ) {
  43                 global $wgUseFileCache, $wgDefaultSkin, $wgLanguageCode;
  44                 if ( !$wgUseFileCache ) {
  45                         return false;
  46                 }
  47                 // Get all query values
  48                 $queryVals = $context->getRequest()->getValues();
  49                 foreach ( $queryVals as $query => $val ) {
  50                         if ( $query === 'modules' || $query === 'version' || $query === '*' ) {
  51                                 continue; // note: &* added as IE fix
  52                         } elseif ( $query === 'skin' && $val === $wgDefaultSkin ) {
  53                                 continue;
  54                         } elseif ( $query === 'lang' && $val === $wgLanguageCode ) {
  55                                 continue;
  56                         } elseif ( $query === 'only' && in_array( $val, array( 'styles', 'scripts' ) ) ) {
  57                                 continue;
  58                         } elseif ( $query === 'debug' && $val === 'false' ) {
  59                                 continue;
  60                         }
  61                         return false;
  62                 }
  63                 return true; // cacheable
  64         }
  65
  66         /**
  67          * Get the base file cache directory
  68          * @return string
  69          */
  70         protected function cacheDirectory() {
  71                 return $this->baseCacheDirectory() . '/resources';
  72         }
  73
  74         /**
  75          * Item has many recent cache misses
  76          * @return bool
  77          */
  78         public function isCacheWorthy() {
  79                 if ( $this->mCacheWorthy === null ) {
  80                         $this->mCacheWorthy = (
  81                                 $this->isCached() || // even stale cache indicates it was cache worthy
  82                                 $this->getMissesRecent() >= self::MISS_THRESHOLD // many misses
  83                         );
  84                 }
  85                 return $this->mCacheWorthy;
  86         }
  87 }