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          * @return HTMLFileCache
  37          */
  38         public static function newFromTitle( $title, $action ) {
  39                 $cache = new self();
  40
  41                 $allowedTypes = self::cacheablePageActions();
  42                 if ( !in_array( $action, $allowedTypes ) ) {
  43                         throw new MWException( "Invalid filecache type given." );
  44                 }
  45                 $cache->mKey = ( $title instanceof Title )
  46                         ? $title->getPrefixedDBkey()
  47                         : (string)$title;
  48                 $cache->mType = (string)$action;
  49                 $cache->mExt = 'html';
  50
  51                 return $cache;
  52         }
  53
  54         /**
  55          * Cacheable actions
  56          * @return array
  57          */
  58         protected static function cacheablePageActions() {
  59                 return array( 'view', 'history' );
  60         }
  61
  62         /**
  63          * Get the base file cache directory
  64          * @return string
  65          */
  66         protected function cacheDirectory() {
  67                 return $this->baseCacheDirectory(); // no subdir for b/c with old cache files
  68         }
  69
  70         /**
  71          * Get the cache type subdirectory (with the trailing slash) or the empty string
  72          * Alter the type -> directory mapping to put action=view cache at the root.
  73          *
  74          * @return string
  75          */
  76         protected function typeSubdirectory() {
  77                 if ( $this->mType === 'view' ) {
  78                         return ''; //  b/c to not skip existing cache
  79                 } else {
  80                         return $this->mType . '/';
  81                 }
  82         }
  83
  84         /**
  85          * Check if pages can be cached for this request/user
  86          * @param $context IContextSource
  87          * @return bool
  88          */
  89         public static function useFileCache( IContextSource $context ) {
  90                 global $wgUseFileCache, $wgShowIPinHeader, $wgDebugToolbar, $wgContLang;
  91                 if ( !$wgUseFileCache ) {
  92                         return false;
  93                 }
  94                 if ( $wgShowIPinHeader || $wgDebugToolbar ) {
  95                         wfDebug( "HTML file cache skipped. Either \$wgShowIPinHeader and/or \$wgDebugToolbar on\n" );
  96                         return false;
  97                 }
  98
  99                 // Get all query values
 100                 $queryVals = $context->getRequest()->getValues();
 101                 foreach ( $queryVals as $query => $val ) {
 102                         if ( $query === 'title' || $query === 'curid' ) {
 103                                 continue; // note: curid sets title
 104                         // Normal page view in query form can have action=view.
 105                         } elseif ( $query === 'action' && in_array( $val, self::cacheablePageActions() ) ) {
 106                                 continue;
 107                         // Below are header setting params
 108                         } elseif ( $query === 'maxage' || $query === 'smaxage' ) {
 109                                 continue;
 110                         }
 111                         return false;
 112                 }
 113                 $user = $context->getUser();
 114                 // Check for non-standard user language; this covers uselang,
 115                 // and extensions for auto-detecting user language.
 116                 $ulang = $context->getLanguage()->getCode();
 117                 $clang = $wgContLang->getCode();
 118                 // Check that there are no other sources of variation
 119                 return !$user->getId() && !$user->getNewtalk() && $ulang == $clang;
 120         }
 121
 122         /**
 123          * Read from cache to context output
 124          * @param $context IContextSource
 125          * @return void
 126          */
 127         public function loadFromFileCache( IContextSource $context ) {
 128                 global $wgMimeType, $wgLanguageCode;
 129
 130                 wfDebug( __METHOD__ . "()\n");
 131                 $filename = $this->cachePath();
 132
 133                 $context->getOutput()->sendCacheControl();
 134                 header( "Content-Type: $wgMimeType; charset=UTF-8" );
 135                 header( "Content-Language: $wgLanguageCode" );
 136                 if ( $this->useGzip() ) {
 137                         if ( wfClientAcceptsGzip() ) {
 138                                 header( 'Content-Encoding: gzip' );
 139                                 readfile( $filename );
 140                         } else {
 141                                 /* Send uncompressed */
 142                                 wfDebug( __METHOD__ . " uncompressing cache file and sending it\n" );
 143                                 readgzfile( $filename );
 144                         }
 145                 } else {
 146                         readfile( $filename );
 147                 }
 148                 $context->getOutput()->disable(); // tell $wgOut that output is taken care of
 149         }
 150
 151         /**
 152          * Save this cache object with the given text.
 153          * Use this as an ob_start() handler.
 154          * @param $text string
 155          * @return bool Whether $wgUseFileCache is enabled
 156          */
 157         public function saveToFileCache( $text ) {
 158                 global $wgUseFileCache;
 159
 160                 if ( !$wgUseFileCache || strlen( $text ) < 512 ) {
 161                         // Disabled or empty/broken output (OOM and PHP errors)
 162                         return $text;
 163                 }
 164
 165                 wfDebug( __METHOD__ . "()\n", false);
 166
 167                 $now = wfTimestampNow();
 168                 if ( $this->useGzip() ) {
 169                         $text = str_replace(
 170                                 '</html>', '<!-- Cached/compressed '.$now." -->\n</html>", $text );
 171                 } else {
 172                         $text = str_replace(
 173                                 '</html>', '<!-- Cached '.$now." -->\n</html>", $text );
 174                 }
 175
 176                 // Store text to FS...
 177                 $compressed = $this->saveText( $text );
 178                 if ( $compressed === false ) {
 179                         return $text; // error
 180                 }
 181
 182                 // gzip output to buffer as needed and set headers...
 183                 if ( $this->useGzip() ) {
 184                         // @TODO: ugly wfClientAcceptsGzip() function - use context!
 185                         if ( wfClientAcceptsGzip() ) {
 186                                 header( 'Content-Encoding: gzip' );
 187                                 return $compressed;
 188                         } else {
 189                                 return $text;
 190                         }
 191                 } else {
 192                         return $text;
 193                 }
 194         }
 195
 196         /**
 197          * Clear the file caches for a page for all actions
 198          * @param $title Title
 199          * @return bool Whether $wgUseFileCache is enabled
 200          */
 201         public static function clearFileCache( Title $title ) {
 202                 global $wgUseFileCache;
 203
 204                 if ( !$wgUseFileCache ) {
 205                         return false;
 206                 }
 207
 208                 foreach ( self::cacheablePageActions() as $type ) {
 209                         $fc = self::newFromTitle( $title, $type );
 210                         $fc->clearCache();
 211                 }
 212
 213                 return true;
 214         }
 215 }