includes/HTMLFileCache.php

   1 <?php
   2 /**
   3  * Contain the HTMLFileCache class
   4  * @file
   5  * @ingroup Cache
   6  */
   7
   8 /**
   9  * Handles talking to the file cache, putting stuff in and taking it back out.
  10  * Mostly called from Article.php for the emergency abort/fallback to cache.
  11  *
  12  * Global options that affect this module:
  13  * - $wgCachePages
  14  * - $wgCacheEpoch
  15  * - $wgUseFileCache
  16  * - $wgCacheDirectory
  17  * - $wgFileCacheDirectory
  18  * - $wgUseGzip
  19  *
  20  * @ingroup Cache
  21  */
  22 class HTMLFileCache {
  23
  24         /**
  25          * @var Title
  26          */
  27         var $mTitle;
  28         var $mFileCache, $mType;
  29
  30         public function __construct( &$title, $type = 'view' ) {
  31                 $this->mTitle = $title;
  32                 $this->mType = ($type == 'raw' || $type == 'view' ) ? $type : false;
  33                 $this->fileCacheName(); // init name
  34         }
  35
  36         public function fileCacheName() {
  37                 if( !$this->mFileCache ) {
  38                         global $wgCacheDirectory, $wgFileCacheDirectory, $wgFileCacheDepth;
  39
  40                         if ( $wgFileCacheDirectory ) {
  41                                 $dir = $wgFileCacheDirectory;
  42                         } elseif ( $wgCacheDirectory ) {
  43                                 $dir = "$wgCacheDirectory/html";
  44                         } else {
  45                                 throw new MWException( 'Please set $wgCacheDirectory in LocalSettings.php if you wish to use the HTML file cache' );
  46                         }
  47
  48                         # Store raw pages (like CSS hits) elsewhere
  49                         $subdir = ($this->mType === 'raw') ? 'raw/' : '';
  50
  51                         $key = $this->mTitle->getPrefixedDbkey();
  52                         if ( $wgFileCacheDepth > 0 ) {
  53                                 $hash = md5( $key );
  54                                 for ( $i = 1; $i <= $wgFileCacheDepth; $i++ ) {
  55                                         $subdir .= substr( $hash, 0, $i ) . '/';
  56                                 }
  57                         }
  58                         # Avoid extension confusion
  59                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  60                         $this->mFileCache = "{$dir}/{$subdir}{$key}.html";
  61
  62                         if( $this->useGzip() ) {
  63                                 $this->mFileCache .= '.gz';
  64                         }
  65
  66                         wfDebug( __METHOD__ . ": {$this->mFileCache}\n" );
  67                 }
  68                 return $this->mFileCache;
  69         }
  70
  71         public function isFileCached() {
  72                 if( $this->mType === false ) return false;
  73                 return file_exists( $this->fileCacheName() );
  74         }
  75
  76         public function fileCacheTime() {
  77                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  78         }
  79
  80         /**
  81          * Check if pages can be cached for this request/user
  82          * @return bool
  83          */
  84         public static function useFileCache() {
  85                 global $wgUser, $wgUseFileCache, $wgShowIPinHeader, $wgRequest, $wgLang, $wgContLang;
  86                 if( !$wgUseFileCache ) return false;
  87                 // Get all query values
  88                 $queryVals = $wgRequest->getValues();
  89                 foreach( $queryVals as $query => $val ) {
  90                         if( $query == 'title' || $query == 'curid' ) continue;
  91                         // Normal page view in query form can have action=view.
  92                         // Raw hits for pages also stored, like .css pages for example.
  93                         else if( $query == 'action' && ($val == 'view' || $val == 'raw') ) continue;
  94                         else if( $query == 'usemsgcache' && $val == 'yes' ) continue;
  95                         // Below are header setting params
  96                         else if( $query == 'maxage' || $query == 'smaxage' || $query == 'ctype' || $query == 'gen' )
  97                                 continue;
  98                         else
  99                                 return false;
 100                 }
 101                 // Check for non-standard user language; this covers uselang,
 102                 // and extensions for auto-detecting user language.
 103                 $ulang = $wgLang->getCode();
 104                 $clang = $wgContLang->getCode();
 105                 // Check that there are no other sources of variation
 106                 return !$wgShowIPinHeader && !$wgUser->getId() && !$wgUser->getNewtalk() && $ulang == $clang;
 107         }
 108
 109         /*
 110         * Check if up to date cache file exists
 111         * @param $timestamp string
 112         */
 113         public function isFileCacheGood( $timestamp = '' ) {
 114                 global $wgCacheEpoch;
 115
 116                 if( !$this->isFileCached() ) return false;
 117
 118                 $cachetime = $this->fileCacheTime();
 119                 $good = $timestamp <= $cachetime && $wgCacheEpoch <= $cachetime;
 120
 121                 wfDebug( __METHOD__ . ": cachetime $cachetime, touched '{$timestamp}' epoch {$wgCacheEpoch}, good $good\n");
 122                 return $good;
 123         }
 124
 125         public function useGzip() {
 126                 global $wgUseGzip;
 127                 return $wgUseGzip;
 128         }
 129
 130         /* In handy string packages */
 131         public function fetchRawText() {
 132                 return file_get_contents( $this->fileCacheName() );
 133         }
 134
 135         public function fetchPageText() {
 136                 if( $this->useGzip() ) {
 137                         /* Why is there no gzfile_get_contents() or gzdecode()? */
 138                         return implode( '', gzfile( $this->fileCacheName() ) );
 139                 } else {
 140                         return $this->fetchRawText();
 141                 }
 142         }
 143
 144         /* Working directory to/from output */
 145         public function loadFromFileCache() {
 146                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgLanguageCode;
 147                 wfDebug( __METHOD__ . "()\n");
 148                 $filename = $this->fileCacheName();
 149                 // Raw pages should handle cache control on their own,
 150                 // even when using file cache. This reduces hits from clients.
 151                 if( $this->mType !== 'raw' ) {
 152                         $wgOut->sendCacheControl();
 153                         header( "Content-Type: $wgMimeType; charset={$wgOutputEncoding}" );
 154                         header( "Content-Language: $wgLanguageCode" );
 155                 }
 156
 157                 if( $this->useGzip() ) {
 158                         if( wfClientAcceptsGzip() ) {
 159                                 header( 'Content-Encoding: gzip' );
 160                         } else {
 161                                 /* Send uncompressed */
 162                                 readgzfile( $filename );
 163                                 return;
 164                         }
 165                 }
 166                 readfile( $filename );
 167                 $wgOut->disable(); // tell $wgOut that output is taken care of
 168         }
 169
 170         protected function checkCacheDirs() {
 171                 $filename = $this->fileCacheName();
 172                 $mydir2 = substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 173                 $mydir1 = substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 174
 175                 wfMkdirParents( $mydir1 );
 176                 wfMkdirParents( $mydir2 );
 177         }
 178
 179         public function saveToFileCache( $text ) {
 180                 global $wgUseFileCache;
 181                 if( !$wgUseFileCache || strlen( $text ) < 512 ) {
 182                         // Disabled or empty/broken output (OOM and PHP errors)
 183                         return $text;
 184                 }
 185
 186                 wfDebug( __METHOD__ . "()\n", false);
 187
 188                 $this->checkCacheDirs();
 189
 190                 $f = fopen( $this->fileCacheName(), 'w' );
 191                 if($f) {
 192                         $now = wfTimestampNow();
 193                         if( $this->useGzip() ) {
 194                                 $rawtext = str_replace( '</html>',
 195                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 196                                         $text );
 197                                 $text = gzencode( $rawtext );
 198                         } else {
 199                                 $text = str_replace( '</html>',
 200                                         '<!-- Cached '.$now." -->\n</html>",
 201                                         $text );
 202                         }
 203                         fwrite( $f, $text );
 204                         fclose( $f );
 205                         if( $this->useGzip() ) {
 206                                 if( wfClientAcceptsGzip() ) {
 207                                         header( 'Content-Encoding: gzip' );
 208                                         return $text;
 209                                 } else {
 210                                         return $rawtext;
 211                                 }
 212                         } else {
 213                                 return $text;
 214                         }
 215                 }
 216                 return $text;
 217         }
 218
 219         public static function clearFileCache( $title ) {
 220                 global $wgUseFileCache;
 221
 222                 if ( !$wgUseFileCache ) {
 223                         return false;
 224                 }
 225
 226                 wfSuppressWarnings();
 227
 228                 $fc = new self( $title, 'view' );
 229                 unlink( $fc->fileCacheName() );
 230
 231                 $fc = new self( $title, 'raw' );
 232                 unlink( $fc->fileCacheName() );
 233
 234                 wfRestoreWarnings();
 235
 236                 return true;
 237         }
 238 }