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