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