includes/cache/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 for the emergency abort/fallback to cache.
  11  *
  12  * Global options that affect this module:
  13  * - $wgCachePages
  14  * - $wgCacheEpoch
  15  * - $wgUseFileCache
  16  * - $wgCacheDirectory
  17  * - $wgFileCacheDirectory
  18  * - $wgUseGzip
  19  *
  20  * @ingroup Cache
  21  */
  22 class HTMLFileCache {
  23
  24         /**
  25          * @var Title
  26          */
  27         var $mTitle;
  28         var $mFileCache, $mType;
  29
  30         public function __construct( $title, $type = 'view' ) {
  31                 $this->mTitle = $title;
  32                 $this->mType = ( $type == 'view' ) ? $type : false;
  33                 $this->fileCacheName(); // init name
  34         }
  35
  36         public function fileCacheName() {
  37                 if( !$this->mFileCache ) {
  38                         global $wgCacheDirectory, $wgFileCacheDirectory, $wgFileCacheDepth;
  39
  40                         if ( $wgFileCacheDirectory ) {
  41                                 $dir = $wgFileCacheDirectory;
  42                         } elseif ( $wgCacheDirectory ) {
  43                                 $dir = "$wgCacheDirectory/html";
  44                         } else {
  45                                 throw new MWException( 'Please set $wgCacheDirectory in LocalSettings.php if you wish to use the HTML file cache' );
  46                         }
  47
  48                         # Store other views of aspects of pages elsewhere
  49                         $subdir = ($this->mType === 'view') ? '' : "{$this->mType}/";
  50
  51                         $key = $this->mTitle->getPrefixedDbkey();
  52                         if ( $wgFileCacheDepth > 0 ) {
  53                                 $hash = md5( $key );
  54                                 for ( $i = 1; $i <= $wgFileCacheDepth; $i++ ) {
  55                                         $subdir .= substr( $hash, 0, $i ) . '/';
  56                                 }
  57                         }
  58                         # Avoid extension confusion
  59                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  60                         $this->mFileCache = "{$dir}/{$subdir}{$key}.html";
  61
  62                         if( $this->useGzip() ) {
  63                                 $this->mFileCache .= '.gz';
  64                         }
  65
  66                         wfDebug( __METHOD__ . ": {$this->mFileCache}\n" );
  67                 }
  68                 return $this->mFileCache;
  69         }
  70
  71         public function isFileCached() {
  72                 if( $this->mType === false ) {
  73                         return false;
  74                 }
  75                 return file_exists( $this->fileCacheName() );
  76         }
  77
  78         public function fileCacheTime() {
  79                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  80         }
  81
  82         /**
  83          * Check if pages can be cached for this request/user
  84          * @return bool
  85          */
  86         public static function useFileCache() {
  87                 global $wgUser, $wgUseFileCache, $wgShowIPinHeader, $wgRequest, $wgLang, $wgContLang;
  88                 if( !$wgUseFileCache ) {
  89                         return false;
  90                 }
  91                 // Get all query values
  92                 $queryVals = $wgRequest->getValues();
  93                 foreach( $queryVals as $query => $val ) {
  94                         if( $query == 'title' || $query == 'curid' ) {
  95                                 continue; // note: curid sets title
  96                         // Normal page view in query form can have action=view.
  97                         // Raw hits for pages also stored, like .css pages for example.
  98                         } elseif( $query == 'action' && $val == 'view' ) {
  99                                 continue;
 100                         // Below are header setting params
 101                         } elseif( $query == 'maxage' || $query == 'smaxage' ) {
 102                                 continue;
 103                         } else {
 104                                 return false;
 105                         }
 106                 }
 107                 // Check for non-standard user language; this covers uselang,
 108                 // and extensions for auto-detecting user language.
 109                 $ulang = $wgLang->getCode();
 110                 $clang = $wgContLang->getCode();
 111                 // Check that there are no other sources of variation
 112                 return !$wgShowIPinHeader && !$wgUser->getId() && !$wgUser->getNewtalk() && $ulang == $clang;
 113         }
 114
 115         /**
 116          * Check if up to date cache file exists
 117          * @param $timestamp string
 118          *
 119          * @return bool
 120          */
 121         public function isFileCacheGood( $timestamp = '' ) {
 122                 global $wgCacheEpoch;
 123
 124                 if( !$this->isFileCached() ) {
 125                         return false;
 126                 }
 127
 128                 $cachetime = $this->fileCacheTime();
 129                 $good = $timestamp <= $cachetime && $wgCacheEpoch <= $cachetime;
 130
 131                 wfDebug( __METHOD__ . ": cachetime $cachetime, touched '{$timestamp}' epoch {$wgCacheEpoch}, good $good\n");
 132                 return $good;
 133         }
 134
 135         public function useGzip() {
 136                 global $wgUseGzip;
 137                 return $wgUseGzip;
 138         }
 139
 140         /* In handy string packages */
 141         public function fetchRawText() {
 142                 return file_get_contents( $this->fileCacheName() );
 143         }
 144
 145         public function fetchPageText() {
 146                 if( $this->useGzip() ) {
 147                         /* Why is there no gzfile_get_contents() or gzdecode()? */
 148                         return implode( '', gzfile( $this->fileCacheName() ) );
 149                 } else {
 150                         return $this->fetchRawText();
 151                 }
 152         }
 153
 154         /* Working directory to/from output */
 155         public function loadFromFileCache() {
 156                 global $wgOut, $wgMimeType, $wgLanguageCode;
 157                 wfDebug( __METHOD__ . "()\n");
 158                 $filename = $this->fileCacheName();
 159                 $wgOut->sendCacheControl();
 160                 header( "Content-Type: $wgMimeType; charset=UTF-8" );
 161                 header( "Content-Language: $wgLanguageCode" );
 162                 if( $this->useGzip() ) {
 163                         if( wfClientAcceptsGzip() ) {
 164                                 header( 'Content-Encoding: gzip' );
 165                         } else {
 166                                 /* Send uncompressed */
 167                                 readgzfile( $filename );
 168                                 return;
 169                         }
 170                 }
 171                 readfile( $filename );
 172                 $wgOut->disable(); // tell $wgOut that output is taken care of
 173         }
 174
 175         protected function checkCacheDirs() {
 176                 $filename = $this->fileCacheName();
 177                 $mydir2 = substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 178                 $mydir1 = substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 179
 180                 wfMkdirParents( $mydir1, null, __METHOD__ );
 181                 wfMkdirParents( $mydir2, null, __METHOD__ );
 182         }
 183
 184         public function saveToFileCache( $text ) {
 185                 global $wgUseFileCache;
 186                 if( !$wgUseFileCache || strlen( $text ) < 512 ) {
 187                         // Disabled or empty/broken output (OOM and PHP errors)
 188                         return $text;
 189                 }
 190
 191                 wfDebug( __METHOD__ . "()\n", false);
 192
 193                 $this->checkCacheDirs();
 194
 195                 $f = fopen( $this->fileCacheName(), 'w' );
 196                 if($f) {
 197                         $now = wfTimestampNow();
 198                         if( $this->useGzip() ) {
 199                                 $rawtext = str_replace( '</html>',
 200                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 201                                         $text );
 202                                 $text = gzencode( $rawtext );
 203                         } else {
 204                                 $text = str_replace( '</html>',
 205                                         '<!-- Cached '.$now." -->\n</html>",
 206                                         $text );
 207                         }
 208                         fwrite( $f, $text );
 209                         fclose( $f );
 210                         if( $this->useGzip() ) {
 211                                 if( wfClientAcceptsGzip() ) {
 212                                         header( 'Content-Encoding: gzip' );
 213                                         return $text;
 214                                 } else {
 215                                         return $rawtext;
 216                                 }
 217                         } else {
 218                                 return $text;
 219                         }
 220                 }
 221                 return $text;
 222         }
 223
 224         public static function clearFileCache( $title ) {
 225                 global $wgUseFileCache;
 226
 227                 if ( !$wgUseFileCache ) {
 228                         return false;
 229                 }
 230
 231                 wfSuppressWarnings();
 232
 233                 $fc = new self( $title, 'view' );
 234                 unlink( $fc->fileCacheName() );
 235
 236                 wfRestoreWarnings();
 237
 238                 return true;
 239         }
 240 }