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