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, also from DatabaseFunctions.php for the
  11  * emergency abort/fallback to cache.
  12  *
  13  * Global options that affect this module:
  14  * - $wgCachePages
  15  * - $wgCacheEpoch
  16  * - $wgUseFileCache
  17  * - $wgFileCacheDirectory
  18  * - $wgUseGzip
  19  *
  20  * @ingroup Cache
  21  */
  22 class HTMLFileCache {
  23         var $mTitle, $mFileCache;
  24
  25         public function __construct( &$title ) {
  26                 $this->mTitle = $title;
  27                 $this->mFileCache = $this->fileCacheName();
  28         }
  29
  30         public function fileCacheName() {
  31                 if( !$this->mFileCache ) {
  32                         global $wgFileCacheDirectory, $wgRequest;
  33                         $key = $this->mTitle->getPrefixedDbkey();
  34                         $hash = md5( $key );
  35                         # Avoid extension confusion
  36                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  37                         # Store raw pages (like CSS hits) elsewhere
  38                         $subdir = $wgRequest->getVal('action') == 'raw' ? 'raw/' : '';
  39
  40                         $hash1 = substr( $hash, 0, 1 );
  41                         $hash2 = substr( $hash, 0, 2 );
  42                         $this->mFileCache = "{$wgFileCacheDirectory}/{$subdir}{$hash1}/{$hash2}/{$key}.html";
  43
  44                         if( $this->useGzip() )
  45                                 $this->mFileCache .= '.gz';
  46
  47                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  48                 }
  49                 return $this->mFileCache;
  50         }
  51
  52         public function isFileCached() {
  53                 return file_exists( $this->fileCacheName() );
  54         }
  55
  56         public function fileCacheTime() {
  57                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  58         }
  59
  60         /**
  61          * Check if pages can be cached for this request/user
  62          * @return bool
  63          */
  64         public static function useFileCache() {
  65                 global $wgUser, $wgUseFileCache, $wgShowIPinHeader, $wgRequest, $wgLang, $wgContLang;
  66                 if( !$wgUseFileCache ) return false;
  67                 // Get all query values
  68                 $queryVals = $wgRequest->getValues();
  69                 foreach( $queryVals as $query => $val ) {
  70                         if( $query == 'title' || $query == 'curid' ) continue;
  71                         // Normal page view in query form can have action=view.
  72                         // Raw hits for pages also stored, like .css pages for example.
  73                         if( $query == 'action' && ($val == 'view' || $val == 'raw') ) continue;
  74                         if( $query == 'usemsgcache' && $val == 'yes' ) continue;
  75                         // Below are header setting params
  76                         if( $query == 'maxage' || $query == 'smaxage' || $query == 'ctype' || $query == 'gen' )
  77                                 continue;
  78                 }
  79                 // Check for non-standard user language; this covers uselang,
  80                 // and extensions for auto-detecting user language.
  81                 $ulang = $wgLang->getCode();
  82                 $clang = $wgContLang->getCode();
  83                 // Check that there are no other sources of variation
  84                 return !$wgShowIPinHeader && !$wgUser->getId() && !$wgUser->getNewtalk() && $ulang == $clang;
  85         }
  86
  87         /*
  88         * Check if up to date cache file exists
  89         * @param $timestamp string
  90         */
  91         public function isFileCacheGood( $timestamp = '' ) {
  92                 global $wgCacheEpoch;
  93
  94                 if( !$this->isFileCached() ) return false;
  95                 if( !$timestamp ) return true; // should be invalidated on change
  96
  97                 $cachetime = $this->fileCacheTime();
  98                 $good = $timestamp <= $cachetime && $wgCacheEpoch <= $cachetime;
  99
 100                 wfDebug(" isFileCacheGood() - cachetime $cachetime, touched '{$timestamp}' epoch {$wgCacheEpoch}, good $good\n");
 101                 return $good;
 102         }
 103
 104         public function useGzip() {
 105                 global $wgUseGzip;
 106                 return $wgUseGzip;
 107         }
 108
 109         /* In handy string packages */
 110         public function fetchRawText() {
 111                 return file_get_contents( $this->fileCacheName() );
 112         }
 113
 114         public function fetchPageText() {
 115                 if( $this->useGzip() ) {
 116                         /* Why is there no gzfile_get_contents() or gzdecode()? */
 117                         return implode( '', gzfile( $this->fileCacheName() ) );
 118                 } else {
 119                         return $this->fetchRawText();
 120                 }
 121         }
 122
 123         /* Working directory to/from output */
 124         public function loadFromFileCache() {
 125                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgContLanguageCode;
 126                 wfDebug(" loadFromFileCache()\n");
 127
 128                 $filename = $this->fileCacheName();
 129                 $wgOut->sendCacheControl();
 130
 131                 header( "Content-type: $wgMimeType; charset={$wgOutputEncoding}" );
 132                 header( "Content-language: $wgContLanguageCode" );
 133
 134                 if( $this->useGzip() ) {
 135                         if( wfClientAcceptsGzip() ) {
 136                                 header( 'Content-Encoding: gzip' );
 137                         } else {
 138                                 /* Send uncompressed */
 139                                 readgzfile( $filename );
 140                                 return;
 141                         }
 142                 }
 143                 readfile( $filename );
 144         }
 145
 146         protected function checkCacheDirs() {
 147                 $filename = $this->fileCacheName();
 148                 $mydir2 = substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 149                 $mydir1 = substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 150
 151                 wfMkdirParents( $mydir1 );
 152                 wfMkdirParents( $mydir2 );
 153         }
 154
 155         public function saveToFileCache( $origtext ) {
 156                 global $wgUseFileCache;
 157                 if( !$wgUseFileCache ) {
 158                         return $origtext; // return to output
 159                 }
 160                 $text = $origtext;
 161                 if( strcmp($text,'') == 0 ) return '';
 162
 163                 wfDebug(" saveToFileCache()\n", false);
 164
 165                 $this->checkCacheDirs();
 166
 167                 $f = fopen( $this->fileCacheName(), 'w' );
 168                 if($f) {
 169                         $now = wfTimestampNow();
 170                         if( $this->useGzip() ) {
 171                                 $rawtext = str_replace( '</html>',
 172                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 173                                         $text );
 174                                 $text = gzencode( $rawtext );
 175                         } else {
 176                                 $text = str_replace( '</html>',
 177                                         '<!-- Cached '.$now." -->\n</html>",
 178                                         $text );
 179                         }
 180                         fwrite( $f, $text );
 181                         fclose( $f );
 182                         if( $this->useGzip() ) {
 183                                 if( wfClientAcceptsGzip() ) {
 184                                         header( 'Content-Encoding: gzip' );
 185                                         return $text;
 186                                 } else {
 187                                         return $rawtext;
 188                                 }
 189                         } else {
 190                                 return $text;
 191                         }
 192                 }
 193                 return $text;
 194         }
 195
 196 }