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|string $title Title object or prefixed DB key string
  35          * @param string $action
  36          * @throws MWException
  37          * @return HTMLFileCache
  38          *
  39          * @deprecated Since 1.24, instantiate this class directly
  40          */
  41         public static function newFromTitle( $title, $action ) {
  42                 return new self( $title, $action );
  43         }
  44
  45         /**
  46          * @param Title|string $title Title object or prefixed DB key string
  47          * @param string $action
  48          * @throws MWException
  49          */
  50         public function __construct( $title, $action ) {
  51                 parent::__construct();
  52                 $allowedTypes = self::cacheablePageActions();
  53                 if ( !in_array( $action, $allowedTypes ) ) {
  54                         throw new MWException( 'Invalid file cache type given.' );
  55                 }
  56                 $this->mKey = ( $title instanceof Title )
  57                         ? $title->getPrefixedDBkey()
  58                         : (string)$title;
  59                 $this->mType = (string)$action;
  60                 $this->mExt = 'html';
  61         }
  62
  63         /**
  64          * Cacheable actions
  65          * @return array
  66          */
  67         protected static function cacheablePageActions() {
  68                 return array( 'view', 'history' );
  69         }
  70
  71         /**
  72          * Get the base file cache directory
  73          * @return string
  74          */
  75         protected function cacheDirectory() {
  76                 return $this->baseCacheDirectory(); // no subdir for b/c with old cache files
  77         }
  78
  79         /**
  80          * Get the cache type subdirectory (with the trailing slash) or the empty string
  81          * Alter the type -> directory mapping to put action=view cache at the root.
  82          *
  83          * @return string
  84          */
  85         protected function typeSubdirectory() {
  86                 if ( $this->mType === 'view' ) {
  87                         return ''; //  b/c to not skip existing cache
  88                 } else {
  89                         return $this->mType . '/';
  90                 }
  91         }
  92
  93         /**
  94          * Check if pages can be cached for this request/user
  95          * @param IContextSource $context
  96          * @return bool
  97          */
  98         public static function useFileCache( IContextSource $context ) {
  99                 global $wgUseFileCache, $wgDebugToolbar, $wgContLang;
 100                 if ( !$wgUseFileCache ) {
 101                         return false;
 102                 }
 103                 if ( $wgDebugToolbar ) {
 104                         wfDebug( "HTML file cache skipped. \$wgDebugToolbar on\n" );
 105
 106                         return false;
 107                 }
 108
 109                 // Get all query values
 110                 $queryVals = $context->getRequest()->getValues();
 111                 foreach ( $queryVals as $query => $val ) {
 112                         if ( $query === 'title' || $query === 'curid' ) {
 113                                 continue; // note: curid sets title
 114                         // Normal page view in query form can have action=view.
 115                         } elseif ( $query === 'action' && in_array( $val, self::cacheablePageActions() ) ) {
 116                                 continue;
 117                         // Below are header setting params
 118                         } elseif ( $query === 'maxage' || $query === 'smaxage' ) {
 119                                 continue;
 120                         }
 121
 122                         return false;
 123                 }
 124                 $user = $context->getUser();
 125                 // Check for non-standard user language; this covers uselang,
 126                 // and extensions for auto-detecting user language.
 127                 $ulang = $context->getLanguage()->getCode();
 128                 $clang = $wgContLang->getCode();
 129
 130                 // Check that there are no other sources of variation
 131                 if ( $user->getId() || $user->getNewtalk() || $ulang != $clang ) {
 132                         return false;
 133                 }
 134                 // Allow extensions to disable caching
 135                 return Hooks::run( 'HTMLFileCache::useFileCache', array( $context ) );
 136         }
 137
 138         /**
 139          * Read from cache to context output
 140          * @param IContextSource $context
 141          * @return void
 142          */
 143         public function loadFromFileCache( IContextSource $context ) {
 144                 global $wgMimeType, $wgLanguageCode;
 145
 146                 wfDebug( __METHOD__ . "()\n" );
 147                 $filename = $this->cachePath();
 148
 149                 $context->getOutput()->sendCacheControl();
 150                 header( "Content-Type: $wgMimeType; charset=UTF-8" );
 151                 header( "Content-Language: $wgLanguageCode" );
 152                 if ( $this->useGzip() ) {
 153                         if ( wfClientAcceptsGzip() ) {
 154                                 header( 'Content-Encoding: gzip' );
 155                                 readfile( $filename );
 156                         } else {
 157                                 /* Send uncompressed */
 158                                 wfDebug( __METHOD__ . " uncompressing cache file and sending it\n" );
 159                                 readgzfile( $filename );
 160                         }
 161                 } else {
 162                         readfile( $filename );
 163                 }
 164                 $context->getOutput()->disable(); // tell $wgOut that output is taken care of
 165         }
 166
 167         /**
 168          * Save this cache object with the given text.
 169          * Use this as an ob_start() handler.
 170          * @param string $text
 171          * @return bool Whether $wgUseFileCache is enabled
 172          */
 173         public function saveToFileCache( $text ) {
 174                 global $wgUseFileCache;
 175
 176                 if ( !$wgUseFileCache || strlen( $text ) < 512 ) {
 177                         // Disabled or empty/broken output (OOM and PHP errors)
 178                         return $text;
 179                 }
 180
 181                 wfDebug( __METHOD__ . "()\n", 'private' );
 182
 183                 $now = wfTimestampNow();
 184                 if ( $this->useGzip() ) {
 185                         $text = str_replace(
 186                                 '</html>', '<!-- Cached/compressed ' . $now . " -->\n</html>", $text );
 187                 } else {
 188                         $text = str_replace(
 189                                 '</html>', '<!-- Cached ' . $now . " -->\n</html>", $text );
 190                 }
 191
 192                 // Store text to FS...
 193                 $compressed = $this->saveText( $text );
 194                 if ( $compressed === false ) {
 195                         return $text; // error
 196                 }
 197
 198                 // gzip output to buffer as needed and set headers...
 199                 if ( $this->useGzip() ) {
 200                         // @todo Ugly wfClientAcceptsGzip() function - use context!
 201                         if ( wfClientAcceptsGzip() ) {
 202                                 header( 'Content-Encoding: gzip' );
 203
 204                                 return $compressed;
 205                         } else {
 206                                 return $text;
 207                         }
 208                 } else {
 209                         return $text;
 210                 }
 211         }
 212
 213         /**
 214          * Clear the file caches for a page for all actions
 215          * @param Title $title
 216          * @return bool Whether $wgUseFileCache is enabled
 217          */
 218         public static function clearFileCache( Title $title ) {
 219                 global $wgUseFileCache;
 220
 221                 if ( !$wgUseFileCache ) {
 222                         return false;
 223                 }
 224
 225                 foreach ( self::cacheablePageActions() as $type ) {
 226                         $fc = new self( $title, $type );
 227                         $fc->clearCache();
 228                 }
 229
 230                 return true;
 231         }
 232 }