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, $mFileCache;
  24
  25         function HTMLFileCache( &$title ) {
  26                 $this->mTitle = $title;
  27                 $this->mFileCache = $this->fileCacheName();
  28         }
  29
  30         function fileCacheName() {
  31                 global $wgFileCacheDirectory;
  32                 if( !$this->mFileCache ) {
  33                         $key = $this->mTitle->getPrefixedDbkey();
  34                         $hash = md5( $key );
  35                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  36
  37                         $hash1 = substr( $hash, 0, 1 );
  38                         $hash2 = substr( $hash, 0, 2 );
  39                         $this->mFileCache = "{$wgFileCacheDirectory}/{$hash1}/{$hash2}/{$key}.html";
  40
  41                         if( $this->useGzip() )
  42                                 $this->mFileCache .= '.gz';
  43
  44                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  45                 }
  46                 return $this->mFileCache;
  47         }
  48
  49         function isFileCached() {
  50                 return file_exists( $this->fileCacheName() );
  51         }
  52
  53         function fileCacheTime() {
  54                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  55         }
  56
  57         function isFileCacheGood( $timestamp ) {
  58                 global $wgCacheEpoch;
  59
  60                 if( !$this->isFileCached() ) return false;
  61
  62                 $cachetime = $this->fileCacheTime();
  63                 $good = $timestamp <= $cachetime && $wgCacheEpoch <= $cachetime;
  64
  65                 wfDebug(" isFileCacheGood() - cachetime $cachetime, touched {$timestamp} epoch {$wgCacheEpoch}, good $good\n");
  66                 return $good;
  67         }
  68
  69         function useGzip() {
  70                 global $wgUseGzip;
  71                 return $wgUseGzip;
  72         }
  73
  74         /* In handy string packages */
  75         function fetchRawText() {
  76                 return file_get_contents( $this->fileCacheName() );
  77         }
  78
  79         function fetchPageText() {
  80                 if( $this->useGzip() ) {
  81                         /* Why is there no gzfile_get_contents() or gzdecode()? */
  82                         return implode( '', gzfile( $this->fileCacheName() ) );
  83                 } else {
  84                         return $this->fetchRawText();
  85                 }
  86         }
  87
  88         /* Working directory to/from output */
  89         function loadFromFileCache() {
  90                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgContLanguageCode;
  91                 wfDebug(" loadFromFileCache()\n");
  92
  93                 $filename = $this->fileCacheName();
  94                 $wgOut->sendCacheControl();
  95
  96                 header( "Content-type: $wgMimeType; charset={$wgOutputEncoding}" );
  97                 header( "Content-language: $wgContLanguageCode" );
  98
  99                 if( $this->useGzip() ) {
 100                         if( wfClientAcceptsGzip() ) {
 101                                 header( 'Content-Encoding: gzip' );
 102                         } else {
 103                                 /* Send uncompressed */
 104                                 readgzfile( $filename );
 105                                 return;
 106                         }
 107                 }
 108                 readfile( $filename );
 109         }
 110
 111         function checkCacheDirs() {
 112                 $filename = $this->fileCacheName();
 113                 $mydir2 = substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 114                 $mydir1 = substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 115
 116                 wfMkdirParents( $mydir1 );
 117                 wfMkdirParents( $mydir2 );
 118         }
 119
 120         function saveToFileCache( $origtext ) {
 121                 global $wgUseFileCache;
 122                 if( !$wgUseFileCache ) {
 123                         return $origtext; // return to output
 124                 }
 125                 $text = $origtext;
 126                 if( strcmp($text,'') == 0 ) return '';
 127
 128                 wfDebug(" saveToFileCache()\n", false);
 129
 130                 $this->checkCacheDirs();
 131
 132                 $f = fopen( $this->fileCacheName(), 'w' );
 133                 if($f) {
 134                         $now = wfTimestampNow();
 135                         if( $this->useGzip() ) {
 136                                 $rawtext = str_replace( '</html>',
 137                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 138                                         $text );
 139                                 $text = gzencode( $rawtext );
 140                         } else {
 141                                 $text = str_replace( '</html>',
 142                                         '<!-- Cached '.$now." -->\n</html>",
 143                                         $text );
 144                         }
 145                         fwrite( $f, $text );
 146                         fclose( $f );
 147                         if( $this->useGzip() ) {
 148                                 if( wfClientAcceptsGzip() ) {
 149                                         header( 'Content-Encoding: gzip' );
 150                                         return $text;
 151                                 } else {
 152                                         return $rawtext;
 153                                 }
 154                         } else {
 155                                 return $text;
 156                         }
 157                 }
 158                 return $text;
 159         }
 160
 161 }