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  * - $wgCacheDirectory
  18  * - $wgFileCacheDirectory
  19  * - $wgUseGzip
  20  *
  21  * @ingroup Cache
  22  */
  23 class HTMLFileCache {
  24         var $mTitle, $mFileCache, $mType;
  25
  26         public function __construct( &$title, $type = 'view' ) {
  27                 $this->mTitle = $title;
  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 $wgCacheDirectory, $wgFileCacheDirectory, $wgRequest;
  35
  36                         if ( $wgFileCacheDirectory ) {
  37                                 $dir = $wgFileCacheDirectory;
  38                         } elseif ( $wgCacheDirectory ) {
  39                                 $dir = "$wgCacheDirectory/html";
  40                         } else {
  41                                 throw new MWException( 'Please set $wgCacheDirectory in LocalSettings.php if you wish to use the HTML file cache' );
  42                         }
  43
  44                         # Store raw pages (like CSS hits) elsewhere
  45                         $subdir = ($this->mType === 'raw') ? 'raw/' : '';
  46                         $key = $this->mTitle->getPrefixedDbkey();
  47                         $hash = md5( $key );
  48                         # Avoid extension confusion
  49                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  50
  51                         $hash1 = substr( $hash, 0, 1 );
  52                         $hash2 = substr( $hash, 0, 2 );
  53                         $this->mFileCache = "{$wgFileCacheDirectory}/{$subdir}{$hash1}/{$hash2}/{$key}.html";
  54
  55                         if( $this->useGzip() )
  56                                 $this->mFileCache .= '.gz';
  57
  58                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  59                 }
  60                 return $this->mFileCache;
  61         }
  62
  63         public function isFileCached() {
  64                 if( $this->mType === false ) return false;
  65                 return file_exists( $this->fileCacheName() );
  66         }
  67
  68         public function fileCacheTime() {
  69                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  70         }
  71
  72         /**
  73          * Check if pages can be cached for this request/user
  74          * @return bool
  75          */
  76         public static function useFileCache() {
  77                 global $wgUser, $wgUseFileCache, $wgShowIPinHeader, $wgRequest, $wgLang, $wgContLang;
  78                 if( !$wgUseFileCache ) return false;
  79                 // Get all query values
  80                 $queryVals = $wgRequest->getValues();
  81                 foreach( $queryVals as $query => $val ) {
  82                         if( $query == 'title' || $query == 'curid' ) continue;
  83                         // Normal page view in query form can have action=view.
  84                         // Raw hits for pages also stored, like .css pages for example.
  85                         else if( $query == 'action' && ($val == 'view' || $val == 'raw') ) continue;
  86                         else if( $query == 'usemsgcache' && $val == 'yes' ) continue;
  87                         // Below are header setting params
  88                         else if( $query == 'maxage' || $query == 'smaxage' || $query == 'ctype' || $query == 'gen' )
  89                                 continue;
  90                         else
  91                                 return false;
  92                 }
  93                 // Check for non-standard user language; this covers uselang,
  94                 // and extensions for auto-detecting user language.
  95                 $ulang = $wgLang->getCode();
  96                 $clang = $wgContLang->getCode();
  97                 // Check that there are no other sources of variation
  98                 return !$wgShowIPinHeader && !$wgUser->getId() && !$wgUser->getNewtalk() && $ulang == $clang;
  99         }
 100
 101         /*
 102         * Check if up to date cache file exists
 103         * @param $timestamp string
 104         */
 105         public function isFileCacheGood( $timestamp = '' ) {
 106                 global $wgCacheEpoch;
 107
 108                 if( !$this->isFileCached() ) return false;
 109                 if( !$timestamp ) return true; // should be invalidated on change
 110
 111                 $cachetime = $this->fileCacheTime();
 112                 $good = $timestamp <= $cachetime && $wgCacheEpoch <= $cachetime;
 113
 114                 wfDebug(" isFileCacheGood() - cachetime $cachetime, touched '{$timestamp}' epoch {$wgCacheEpoch}, good $good\n");
 115                 return $good;
 116         }
 117
 118         public function useGzip() {
 119                 global $wgUseGzip;
 120                 return $wgUseGzip;
 121         }
 122
 123         /* In handy string packages */
 124         public function fetchRawText() {
 125                 return file_get_contents( $this->fileCacheName() );
 126         }
 127
 128         public function fetchPageText() {
 129                 if( $this->useGzip() ) {
 130                         /* Why is there no gzfile_get_contents() or gzdecode()? */
 131                         return implode( '', gzfile( $this->fileCacheName() ) );
 132                 } else {
 133                         return $this->fetchRawText();
 134                 }
 135         }
 136
 137         /* Working directory to/from output */
 138         public function loadFromFileCache() {
 139                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgContLanguageCode;
 140                 wfDebug(" loadFromFileCache()\n");
 141                 $filename = $this->fileCacheName();
 142                 // Raw pages should handle cache control on their own,
 143                 // even when using file cache. This reduces hits from clients.
 144                 if( $this->mType !== 'raw' ) {
 145                         $wgOut->sendCacheControl();
 146                         header( "Content-Type: $wgMimeType; charset={$wgOutputEncoding}" );
 147                         header( "Content-Language: $wgContLanguageCode" );
 148                 }
 149
 150                 if( $this->useGzip() ) {
 151                         if( wfClientAcceptsGzip() ) {
 152                                 header( 'Content-Encoding: gzip' );
 153                         } else {
 154                                 /* Send uncompressed */
 155                                 readgzfile( $filename );
 156                                 return;
 157                         }
 158                 }
 159                 readfile( $filename );
 160                 $wgOut->disable(); // tell $wgOut that output is taken care of
 161         }
 162
 163         protected function checkCacheDirs() {
 164                 $filename = $this->fileCacheName();
 165                 $mydir2 = substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 166                 $mydir1 = substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 167
 168                 wfMkdirParents( $mydir1 );
 169                 wfMkdirParents( $mydir2 );
 170         }
 171
 172         public function saveToFileCache( $text ) {
 173                 global $wgUseFileCache;
 174                 if( !$wgUseFileCache || strlen( $text ) < 512 ) {
 175                         // Disabled or empty/broken output (OOM and PHP errors)
 176                         return $text;
 177                 }
 178
 179                 wfDebug(" saveToFileCache()\n", false);
 180
 181                 $this->checkCacheDirs();
 182
 183                 $f = fopen( $this->fileCacheName(), 'w' );
 184                 if($f) {
 185                         $now = wfTimestampNow();
 186                         if( $this->useGzip() ) {
 187                                 $rawtext = str_replace( '</html>',
 188                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 189                                         $text );
 190                                 $text = gzencode( $rawtext );
 191                         } else {
 192                                 $text = str_replace( '</html>',
 193                                         '<!-- Cached '.$now." -->\n</html>",
 194                                         $text );
 195                         }
 196                         fwrite( $f, $text );
 197                         fclose( $f );
 198                         if( $this->useGzip() ) {
 199                                 if( wfClientAcceptsGzip() ) {
 200                                         header( 'Content-Encoding: gzip' );
 201                                         return $text;
 202                                 } else {
 203                                         return $rawtext;
 204                                 }
 205                         } else {
 206                                 return $text;
 207                         }
 208                 }
 209                 return $text;
 210         }
 211
 212         public static function clearFileCache( $title ) {
 213                 global $wgUseFileCache;
 214                 if( !$wgUseFileCache ) return false;
 215                 $fc = new self( $title, 'view' );
 216                 @unlink( $fc->fileCacheName() );
 217                 $fc = new self( $title, 'raw' );
 218                 @unlink( $fc->fileCacheName() );
 219                 return true;
 220         }
 221 }