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 use MediaWiki\MediaWikiServices;
  25
  26 /**
  27  * Page view caching in the file system.
  28  * The only cacheable actions are "view" and "history". Also special pages
  29  * will not be cached.
  30  *
  31  * @ingroup Cache
  32  */
  33 class HTMLFileCache extends FileCacheBase {
  34         const MODE_NORMAL = 0; // normal cache mode
  35         const MODE_OUTAGE = 1; // fallback cache for DB outages
  36         const MODE_REBUILD = 2; // background cache rebuild mode
  37
  38         /**
  39          * @param Title|string $title Title object or prefixed DB key string
  40          * @param string $action
  41          * @throws MWException
  42          */
  43         public function __construct( $title, $action ) {
  44                 parent::__construct();
  45
  46                 $allowedTypes = self::cacheablePageActions();
  47                 if ( !in_array( $action, $allowedTypes ) ) {
  48                         throw new MWException( 'Invalid file cache type given.' );
  49                 }
  50                 $this->mKey = ( $title instanceof Title )
  51                         ? $title->getPrefixedDBkey()
  52                         : (string)$title;
  53                 $this->mType = (string)$action;
  54                 $this->mExt = 'html';
  55         }
  56
  57         /**
  58          * Cacheable actions
  59          * @return array
  60          */
  61         protected static function cacheablePageActions() {
  62                 return [ 'view', 'history' ];
  63         }
  64
  65         /**
  66          * Get the base file cache directory
  67          * @return string
  68          */
  69         protected function cacheDirectory() {
  70                 return $this->baseCacheDirectory(); // no subdir for b/c with old cache files
  71         }
  72
  73         /**
  74          * Get the cache type subdirectory (with the trailing slash) or the empty string
  75          * Alter the type -> directory mapping to put action=view cache at the root.
  76          *
  77          * @return string
  78          */
  79         protected function typeSubdirectory() {
  80                 if ( $this->mType === 'view' ) {
  81                         return ''; //  b/c to not skip existing cache
  82                 } else {
  83                         return $this->mType . '/';
  84                 }
  85         }
  86
  87         /**
  88          * Check if pages can be cached for this request/user
  89          * @param IContextSource $context
  90          * @param int $mode One of the HTMLFileCache::MODE_* constants (since 1.28)
  91          * @return bool
  92          */
  93         public static function useFileCache( IContextSource $context, $mode = self::MODE_NORMAL ) {
  94                 global $wgContLang;
  95                 $config = MediaWikiServices::getInstance()->getMainConfig();
  96
  97                 if ( !$config->get( 'UseFileCache' ) && $mode !== self::MODE_REBUILD ) {
  98                         return false;
  99                 } elseif ( $config->get( 'DebugToolbar' ) ) {
 100                         wfDebug( "HTML file cache skipped. \$wgDebugToolbar on\n" );
 101
 102                         return false;
 103                 }
 104
 105                 // Get all query values
 106                 $queryVals = $context->getRequest()->getValues();
 107                 foreach ( $queryVals as $query => $val ) {
 108                         if ( $query === 'title' || $query === 'curid' ) {
 109                                 continue; // note: curid sets title
 110                         // Normal page view in query form can have action=view.
 111                         } elseif ( $query === 'action' && in_array( $val, self::cacheablePageActions() ) ) {
 112                                 continue;
 113                         // Below are header setting params
 114                         } elseif ( $query === 'maxage' || $query === 'smaxage' ) {
 115                                 continue;
 116                         }
 117
 118                         return false;
 119                 }
 120
 121                 $user = $context->getUser();
 122                 // Check for non-standard user language; this covers uselang,
 123                 // and extensions for auto-detecting user language.
 124                 $ulang = $context->getLanguage();
 125
 126                 // Check that there are no other sources of variation
 127                 if ( $user->getId() || !$ulang->equals( $wgContLang ) ) {
 128                         return false;
 129                 }
 130
 131                 if ( $mode === self::MODE_NORMAL ) {
 132                         if ( $user->getNewtalk() ) {
 133                                 return false;
 134                         }
 135                 }
 136
 137                 // Allow extensions to disable caching
 138                 return Hooks::run( 'HTMLFileCache::useFileCache', [ $context ] );
 139         }
 140
 141         /**
 142          * Read from cache to context output
 143          * @param IContextSource $context
 144          * @param int $mode One of the HTMLFileCache::MODE_* constants
 145          * @return void
 146          */
 147         public function loadFromFileCache( IContextSource $context, $mode = self::MODE_NORMAL ) {
 148                 global $wgContLang;
 149                 $config = MediaWikiServices::getInstance()->getMainConfig();
 150
 151                 wfDebug( __METHOD__ . "()\n" );
 152                 $filename = $this->cachePath();
 153
 154                 if ( $mode === self::MODE_OUTAGE ) {
 155                         // Avoid DB errors for queries in sendCacheControl()
 156                         $context->getTitle()->resetArticleID( 0 );
 157                 }
 158
 159                 $context->getOutput()->sendCacheControl();
 160                 header( "Content-Type: {$config->get( 'MimeType' )}; charset=UTF-8" );
 161                 header( "Content-Language: {$wgContLang->getHtmlCode()}" );
 162                 if ( $this->useGzip() ) {
 163                         if ( wfClientAcceptsGzip() ) {
 164                                 header( 'Content-Encoding: gzip' );
 165                                 readfile( $filename );
 166                         } else {
 167                                 /* Send uncompressed */
 168                                 wfDebug( __METHOD__ . " uncompressing cache file and sending it\n" );
 169                                 readgzfile( $filename );
 170                         }
 171                 } else {
 172                         readfile( $filename );
 173                 }
 174
 175                 $context->getOutput()->disable(); // tell $wgOut that output is taken care of
 176         }
 177
 178         /**
 179          * Save this cache object with the given text.
 180          * Use this as an ob_start() handler.
 181          *
 182          * Normally this is only registed as a handler if $wgUseFileCache is on.
 183          * If can be explicitly called by rebuildFileCache.php when it takes over
 184          * handling file caching itself, disabling any automatic handling the the
 185          * process.
 186          *
 187          * @param string $text
 188          * @return string|bool The annotated $text or false on error
 189          */
 190         public function saveToFileCache( $text ) {
 191                 if ( strlen( $text ) < 512 ) {
 192                         // Disabled or empty/broken output (OOM and PHP errors)
 193                         return $text;
 194                 }
 195
 196                 wfDebug( __METHOD__ . "()\n", 'private' );
 197
 198                 $now = wfTimestampNow();
 199                 if ( $this->useGzip() ) {
 200                         $text = str_replace(
 201                                 '</html>', '<!-- Cached/compressed ' . $now . " -->\n</html>", $text );
 202                 } else {
 203                         $text = str_replace(
 204                                 '</html>', '<!-- Cached ' . $now . " -->\n</html>", $text );
 205                 }
 206
 207                 // Store text to FS...
 208                 $compressed = $this->saveText( $text );
 209                 if ( $compressed === false ) {
 210                         return $text; // error
 211                 }
 212
 213                 // gzip output to buffer as needed and set headers...
 214                 if ( $this->useGzip() ) {
 215                         // @todo Ugly wfClientAcceptsGzip() function - use context!
 216                         if ( wfClientAcceptsGzip() ) {
 217                                 header( 'Content-Encoding: gzip' );
 218
 219                                 return $compressed;
 220                         } else {
 221                                 return $text;
 222                         }
 223                 } else {
 224                         return $text;
 225                 }
 226         }
 227
 228         /**
 229          * Clear the file caches for a page for all actions
 230          * @param Title $title
 231          * @return bool Whether $wgUseFileCache is enabled
 232          */
 233         public static function clearFileCache( Title $title ) {
 234                 $config = MediaWikiServices::getInstance()->getMainConfig();
 235
 236                 if ( !$config->get( 'UseFileCache' ) ) {
 237                         return false;
 238                 }
 239
 240                 foreach ( self::cacheablePageActions() as $type ) {
 241                         $fc = new self( $title, $type );
 242                         $fc->clearCache();
 243                 }
 244
 245                 return true;
 246         }
 247 }