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