includes/CacheManager.php

   1 <?
   2
   3 # Handles talking to the file cache, putting stuff in and taking it back out.
   4 # Mostly called from Article.php, also from DatabaseFunctions.php for the
   5 # emergency abort/fallback to cache.
   6
   7 # Global options that affect this module:
   8 # $wgCachePages
   9 # $wgCacheEpoch
  10 # $wgUseFileCache
  11 # $wgFileCacheDirectory
  12 # $wgUseGzip
  13
  14 include_once( "Title.php" );
  15
  16 class CacheManager {
  17         var $mTitle, $mFileCache;
  18
  19         function CacheManager( &$title ) {
  20                 $this->mTitle =& $title;
  21                 $this->mFileCache = "";
  22         }
  23
  24         function fileCacheName() {
  25                 global $wgFileCacheDirectory, $wgLang;
  26                 if( !$this->mFileCache ) {
  27                         $hash = md5( $key = $this->mTitle->getDbkey() );
  28                         if( $this->mTitle->getNamespace() )
  29                                 $key = $wgLang->getNsText( $this->mTitle->getNamespace() ) . ":" . $key;
  30                         $key = str_replace( ".", "%2E", urlencode( $key ) );
  31
  32                         $hash1 = substr( $hash, 0, 1 );
  33                         $hash2 = substr( $hash, 0, 2 );
  34                         $this->mFileCache = "{$wgFileCacheDirectory}/{$hash1}/{$hash2}/{$key}.html";
  35
  36                         if($this->useGzip())
  37                                 $this->mFileCache .= ".gz";
  38
  39                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  40                 }
  41                 return $this->mFileCache;
  42         }
  43
  44         function isFileCached() {
  45                 return file_exists( $this->fileCacheName() );
  46         }
  47
  48         function fileCacheTime() {
  49                 return wfUnix2Timestamp( filemtime( $this->fileCacheName() ) );
  50         }
  51
  52         function isFileCacheGood( $timestamp ) {
  53                 global $wgCacheEpoch;
  54
  55                 if( !$this->isFileCached() ) return false;
  56
  57                 $cachetime = $this->fileCacheTime();
  58                 $good = (( $timestamp <= $cachetime ) &&
  59                          ( $wgCacheEpoch <= $cachetime ));
  60
  61                 wfDebug(" isFileCacheGood() - cachetime $cachetime, touched {$timestamp} epoch {$wgCacheEpoch}, good $good\n");
  62                 return $good;
  63         }
  64
  65         function useGzip() {
  66                 global $wgUseGzip;
  67                 return $wgUseGzip;
  68         }
  69
  70         /* In handy string packages */
  71         function fetchRawText() {
  72                 return file_get_contents( $this->fileCacheName() );
  73         }
  74
  75         function fetchPageText() {
  76                 if( $this->useGzip() ) {
  77                         /* Why is there no gzfile_get_contents() or gzdecode()? */
  78                         return implode( "", gzfile( $this->fileCacheName() ) );
  79                 } else {
  80                         return $this->fetchRawText();
  81                 }
  82         }
  83
  84         /* Working directory to/from output */
  85         function loadFromFileCache() {
  86                 global $wgOut;
  87                 wfDebug(" loadFromFileCache()\n");
  88
  89                 $filename=$this->fileCacheName();
  90                 $wgOut->sendCacheControl();
  91
  92                 if( $this->useGzip() ) {
  93                         if( wfClientAcceptsGzip() ) {
  94                                 header( "Content-Encoding: gzip" );
  95                         } else {
  96                                 /* Send uncompressed */
  97                                 readgzfile( $filename );
  98                                 return;
  99                         }
 100                 }
 101                 readfile( $filename );
 102         }
 103
 104         function checkCacheDirs() {
 105                 $filename = $this->fileCacheName();
 106                 $mydir2=substr($filename,0,strrpos($filename,"/")); # subdirectory level 2
 107                 $mydir1=substr($mydir2,0,strrpos($mydir2,"/")); # subdirectory level 1
 108
 109                 if(!file_exists($mydir1)) { mkdir($mydir1,0775); } # create if necessary
 110                 if(!file_exists($mydir2)) { mkdir($mydir2,0775); }
 111         }
 112
 113         function saveToFileCache( $text ) {
 114                 if(strcmp($text,"") == 0) return "";
 115
 116                 wfDebug(" saveToFileCache()\n", false);
 117
 118                 $this->checkCacheDirs();
 119
 120                 $f = fopen( $this->fileCacheName(), "w" );
 121                 if($f) {
 122                         $now = wfTimestampNow();
 123                         if( $this->useGzip() ) {
 124                                 $rawtext = str_replace( "</html>",
 125                                         "<!-- Cached/compressed $now -->\n</html>",
 126                                         $text );
 127                                 $text = gzencode( $rawtext );
 128                         } else {
 129                                 $text = str_replace( "</html>",
 130                                         "<!-- Cached $now -->\n</html>",
 131                                         $text );
 132                         }
 133                         fwrite( $f, $text );
 134                         fclose( $f );
 135                         if( $this->useGzip() ) {
 136                                 if( wfClientAcceptsGzip() ) {
 137                                         header( "Content-Encoding: gzip" );
 138                                         return $text;
 139                                 } else {
 140                                         return $rawtext;
 141                                 }
 142                         } else {
 143                                 return $text;
 144                         }
 145                 }
 146                 return $text;
 147         }
 148
 149 }
 150
 151 ?>