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