includes/cache/HTMLFileCache.php

   1 <?php
   2 /**
   3  * Page view caching in the file system.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Cache
  22  */
  23
  24 /**
  25  * Page view caching in the file system.
  26  * The only cacheable actions are "view" and "history". Also special pages
  27  * will not be cached.
  28  *
  29  * @ingroup Cache
  30  */
  31 class HTMLFileCache extends FileCacheBase {
  32         /**
  33          * Construct an ObjectFileCache from a Title and an action
  34          * @param $title Title|string Title object or prefixed DB key string
  35          * @param $action string
  36          * @throws MWException
  37          * @return HTMLFileCache
  38          */
  39         public static function newFromTitle( $title, $action ) {
  40                 $cache = new self();
  41
  42                 $allowedTypes = self::cacheablePageActions();
  43                 if ( !in_array( $action, $allowedTypes ) ) {
  44                         throw new MWException( "Invalid filecache type given." );
  45                 }
  46                 $cache->mKey = ( $title instanceof Title )
  47                         ? $title->getPrefixedDBkey()
  48                         : (string)$title;
  49                 $cache->mType = (string)$action;
  50                 $cache->mExt = 'html';
  51
  52                 return $cache;
  53         }
  54
  55         /**
  56          * Cacheable actions
  57          * @return array
  58          */
  59         protected static function cacheablePageActions() {
  60                 return array( 'view', 'history' );
  61         }
  62
  63         /**
  64          * Get the base file cache directory
  65          * @return string
  66          */
  67         protected function cacheDirectory() {
  68                 return $this->baseCacheDirectory(); // no subdir for b/c with old cache files
  69         }
  70
  71         /**
  72          * Get the cache type subdirectory (with the trailing slash) or the empty string
  73          * Alter the type -> directory mapping to put action=view cache at the root.
  74          *
  75          * @return string
  76          */
  77         protected function typeSubdirectory() {
  78                 if ( $this->mType === 'view' ) {
  79                         return ''; //  b/c to not skip existing cache
  80                 } else {
  81                         return $this->mType . '/';
  82                 }
  83         }
  84
  85         /**
  86          * Check if pages can be cached for this request/user
  87          * @param $context IContextSource
  88          * @return bool
  89          */
  90         public static function useFileCache( IContextSource $context ) {
  91                 global $wgUseFileCache, $wgShowIPinHeader, $wgDebugToolbar, $wgContLang;
  92                 if ( !$wgUseFileCache ) {
  93                         return false;
  94                 }
  95                 if ( $wgShowIPinHeader || $wgDebugToolbar ) {
  96                         wfDebug( "HTML file cache skipped. Either \$wgShowIPinHeader and/or \$wgDebugToolbar on\n" );
  97                         return false;
  98                 }
  99
 100                 // Get all query values
 101                 $queryVals = $context->getRequest()->getValues();
 102                 foreach ( $queryVals as $query => $val ) {
 103                         if ( $query === 'title' || $query === 'curid' ) {
 104                                 continue; // note: curid sets title
 105                         // Normal page view in query form can have action=view.
 106                         } elseif ( $query === 'action' && in_array( $val, self::cacheablePageActions() ) ) {
 107                                 continue;
 108                         // Below are header setting params
 109                         } elseif ( $query === 'maxage' || $query === 'smaxage' ) {
 110                                 continue;
 111                         }
 112                         return false;
 113                 }
 114                 $user = $context->getUser();
 115                 // Check for non-standard user language; this covers uselang,
 116                 // and extensions for auto-detecting user language.
 117                 $ulang = $context->getLanguage()->getCode();
 118                 $clang = $wgContLang->getCode();
 119                 // Check that there are no other sources of variation
 120                 return !$user->getId() && !$user->getNewtalk() && $ulang == $clang;
 121         }
 122
 123         /**
 124          * Read from cache to context output
 125          * @param $context IContextSource
 126          * @return void
 127          */
 128         public function loadFromFileCache( IContextSource $context ) {
 129                 global $wgMimeType, $wgLanguageCode;
 130
 131                 wfDebug( __METHOD__ . "()\n" );
 132                 $filename = $this->cachePath();
 133
 134                 $context->getOutput()->sendCacheControl();
 135                 header( "Content-Type: $wgMimeType; charset=UTF-8" );
 136                 header( "Content-Language: $wgLanguageCode" );
 137                 if ( $this->useGzip() ) {
 138                         if ( wfClientAcceptsGzip() ) {
 139                                 header( 'Content-Encoding: gzip' );
 140                                 readfile( $filename );
 141                         } else {
 142                                 /* Send uncompressed */
 143                                 wfDebug( __METHOD__ . " uncompressing cache file and sending it\n" );
 144                                 readgzfile( $filename );
 145                         }
 146                 } else {
 147                         readfile( $filename );
 148                 }
 149                 $context->getOutput()->disable(); // tell $wgOut that output is taken care of
 150         }
 151
 152         /**
 153          * Save this cache object with the given text.
 154          * Use this as an ob_start() handler.
 155          * @param $text string
 156          * @return bool Whether $wgUseFileCache is enabled
 157          */
 158         public function saveToFileCache( $text ) {
 159                 global $wgUseFileCache;
 160
 161                 if ( !$wgUseFileCache || strlen( $text ) < 512 ) {
 162                         // Disabled or empty/broken output (OOM and PHP errors)
 163                         return $text;
 164                 }
 165
 166                 wfDebug( __METHOD__ . "()\n", false );
 167
 168                 $now = wfTimestampNow();
 169                 if ( $this->useGzip() ) {
 170                         $text = str_replace(
 171                                 '</html>', '<!-- Cached/compressed ' . $now . " -->\n</html>", $text );
 172                 } else {
 173                         $text = str_replace(
 174                                 '</html>', '<!-- Cached ' . $now . " -->\n</html>", $text );
 175                 }
 176
 177                 // Store text to FS...
 178                 $compressed = $this->saveText( $text );
 179                 if ( $compressed === false ) {
 180                         return $text; // error
 181                 }
 182
 183                 // gzip output to buffer as needed and set headers...
 184                 if ( $this->useGzip() ) {
 185                         // @TODO: ugly wfClientAcceptsGzip() function - use context!
 186                         if ( wfClientAcceptsGzip() ) {
 187                                 header( 'Content-Encoding: gzip' );
 188                                 return $compressed;
 189                         } else {
 190                                 return $text;
 191                         }
 192                 } else {
 193                         return $text;
 194                 }
 195         }
 196
 197         /**
 198          * Clear the file caches for a page for all actions
 199          * @param $title Title
 200          * @return bool Whether $wgUseFileCache is enabled
 201          */
 202         public static function clearFileCache( Title $title ) {
 203                 global $wgUseFileCache;
 204
 205                 if ( !$wgUseFileCache ) {
 206                         return false;
 207                 }
 208
 209                 foreach ( self::cacheablePageActions() as $type ) {
 210                         $fc = self::newFromTitle( $title, $type );
 211                         $fc->clearCache();
 212                 }
 213
 214                 return true;
 215         }
 216 }