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         var $mTitle, $mFileCache, $mType;
  24
  25         public function __construct( &$title, $type = 'view' ) {
  26                 $this->mTitle = $title;
  27                 $this->mType = ($type == 'raw' || $type == 'view' ) ? $type : false;
  28                 $this->fileCacheName(); // init name
  29         }
  30
  31         public function fileCacheName() {
  32                 if( !$this->mFileCache ) {
  33                         global $wgCacheDirectory, $wgFileCacheDirectory;
  34
  35                         if ( $wgFileCacheDirectory ) {
  36                                 $dir = $wgFileCacheDirectory;
  37                         } elseif ( $wgCacheDirectory ) {
  38                                 $dir = "$wgCacheDirectory/html";
  39                         } else {
  40                                 throw new MWException( 'Please set $wgCacheDirectory in LocalSettings.php if you wish to use the HTML file cache' );
  41                         }
  42
  43                         # Store raw pages (like CSS hits) elsewhere
  44                         $subdir = ($this->mType === 'raw') ? 'raw/' : '';
  45                         $key = $this->mTitle->getPrefixedDbkey();
  46                         $hash = md5( $key );
  47                         # Avoid extension confusion
  48                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  49
  50                         $hash1 = substr( $hash, 0, 1 );
  51                         $hash2 = substr( $hash, 0, 2 );
  52                         $this->mFileCache = "{$wgFileCacheDirectory}/{$subdir}{$hash1}/{$hash2}/{$key}.html";
  53
  54                         if( $this->useGzip() )
  55                                 $this->mFileCache .= '.gz';
  56
  57                         wfDebug( __METHOD__ . ": {$this->mFileCache}\n" );
  58                 }
  59                 return $this->mFileCache;
  60         }
  61
  62         public function isFileCached() {
  63                 if( $this->mType === false ) return false;
  64                 return file_exists( $this->fileCacheName() );
  65         }
  66
  67         public function fileCacheTime() {
  68                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  69         }
  70
  71         /**
  72          * Check if pages can be cached for this request/user
  73          * @return bool
  74          */
  75         public static function useFileCache() {
  76                 global $wgUser, $wgUseFileCache, $wgShowIPinHeader, $wgRequest, $wgLang, $wgContLang;
  77                 if( !$wgUseFileCache ) return false;
  78                 // Get all query values
  79                 $queryVals = $wgRequest->getValues();
  80                 foreach( $queryVals as $query => $val ) {
  81                         if( $query == 'title' || $query == 'curid' ) continue;
  82                         // Normal page view in query form can have action=view.
  83                         // Raw hits for pages also stored, like .css pages for example.
  84                         else if( $query == 'action' && ($val == 'view' || $val == 'raw') ) continue;
  85                         else if( $query == 'usemsgcache' && $val == 'yes' ) continue;
  86                         // Below are header setting params
  87                         else if( $query == 'maxage' || $query == 'smaxage' || $query == 'ctype' || $query == 'gen' )
  88                                 continue;
  89                         else
  90                                 return false;
  91                 }
  92                 // Check for non-standard user language; this covers uselang,
  93                 // and extensions for auto-detecting user language.
  94                 $ulang = $wgLang->getCode();
  95                 $clang = $wgContLang->getCode();
  96                 // Check that there are no other sources of variation
  97                 return !$wgShowIPinHeader && !$wgUser->getId() && !$wgUser->getNewtalk() && $ulang == $clang;
  98         }
  99
 100         /*
 101         * Check if up to date cache file exists
 102         * @param $timestamp string
 103         */
 104         public function isFileCacheGood( $timestamp = '' ) {
 105                 global $wgCacheEpoch;
 106
 107                 if( !$this->isFileCached() ) return false;
 108
 109                 $cachetime = $this->fileCacheTime();
 110                 $good = $timestamp <= $cachetime && $wgCacheEpoch <= $cachetime;
 111
 112                 wfDebug( __METHOD__ . ": cachetime $cachetime, touched '{$timestamp}' epoch {$wgCacheEpoch}, good $good\n");
 113                 return $good;
 114         }
 115
 116         public function useGzip() {
 117                 global $wgUseGzip;
 118                 return $wgUseGzip;
 119         }
 120
 121         /* In handy string packages */
 122         public function fetchRawText() {
 123                 return file_get_contents( $this->fileCacheName() );
 124         }
 125
 126         public function fetchPageText() {
 127                 if( $this->useGzip() ) {
 128                         /* Why is there no gzfile_get_contents() or gzdecode()? */
 129                         return implode( '', gzfile( $this->fileCacheName() ) );
 130                 } else {
 131                         return $this->fetchRawText();
 132                 }
 133         }
 134
 135         /* Working directory to/from output */
 136         public function loadFromFileCache() {
 137                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgContLanguageCode;
 138                 wfDebug( __METHOD__ . "()\n");
 139                 $filename = $this->fileCacheName();
 140                 // Raw pages should handle cache control on their own,
 141                 // even when using file cache. This reduces hits from clients.
 142                 if( $this->mType !== 'raw' ) {
 143                         $wgOut->sendCacheControl();
 144                         header( "Content-Type: $wgMimeType; charset={$wgOutputEncoding}" );
 145                         header( "Content-Language: $wgContLanguageCode" );
 146                 }
 147
 148                 if( $this->useGzip() ) {
 149                         if( wfClientAcceptsGzip() ) {
 150                                 header( 'Content-Encoding: gzip' );
 151                         } else {
 152                                 /* Send uncompressed */
 153                                 readgzfile( $filename );
 154                                 return;
 155                         }
 156                 }
 157                 readfile( $filename );
 158                 $wgOut->disable(); // tell $wgOut that output is taken care of
 159         }
 160
 161         protected function checkCacheDirs() {
 162                 $filename = $this->fileCacheName();
 163                 $mydir2 = substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 164                 $mydir1 = substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 165
 166                 wfMkdirParents( $mydir1 );
 167                 wfMkdirParents( $mydir2 );
 168         }
 169
 170         public function saveToFileCache( $text ) {
 171                 global $wgUseFileCache;
 172                 if( !$wgUseFileCache || strlen( $text ) < 512 ) {
 173                         // Disabled or empty/broken output (OOM and PHP errors)
 174                         return $text;
 175                 }
 176
 177                 wfDebug( __METHOD__ . "()\n", false);
 178
 179                 $this->checkCacheDirs();
 180
 181                 $f = fopen( $this->fileCacheName(), 'w' );
 182                 if($f) {
 183                         $now = wfTimestampNow();
 184                         if( $this->useGzip() ) {
 185                                 $rawtext = str_replace( '</html>',
 186                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 187                                         $text );
 188                                 $text = gzencode( $rawtext );
 189                         } else {
 190                                 $text = str_replace( '</html>',
 191                                         '<!-- Cached '.$now." -->\n</html>",
 192                                         $text );
 193                         }
 194                         fwrite( $f, $text );
 195                         fclose( $f );
 196                         if( $this->useGzip() ) {
 197                                 if( wfClientAcceptsGzip() ) {
 198                                         header( 'Content-Encoding: gzip' );
 199                                         return $text;
 200                                 } else {
 201                                         return $rawtext;
 202                                 }
 203                         } else {
 204                                 return $text;
 205                         }
 206                 }
 207                 return $text;
 208         }
 209
 210         public static function clearFileCache( $title ) {
 211                 global $wgUseFileCache;
 212
 213                 if ( !$wgUseFileCache ) {
 214                         return false;
 215                 }
 216
 217                 wfSuppressWarnings();
 218
 219                 $fc = new self( $title, 'view' );
 220                 unlink( $fc->fileCacheName() );
 221
 222                 $fc = new self( $title, 'raw' );
 223                 unlink( $fc->fileCacheName() );
 224
 225                 wfRestoreWarnings();
 226
 227                 return true;
 228         }
 229 }