includes/CacheManager.php

   1 <?php
   2 /**
   3  * Contain the CacheManager class
   4  * @package MediaWiki
   5  * @subpackage 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  * @package MediaWiki
  20  */
  21 class CacheManager {
  22         var $mTitle, $mFileCache;
  23
  24         function CacheManager( &$title ) {
  25                 $this->mTitle =& $title;
  26                 $this->mFileCache = '';
  27         }
  28
  29         function fileCacheName() {
  30                 global $wgFileCacheDirectory;
  31                 if( !$this->mFileCache ) {
  32                         $key = $this->mTitle->getPrefixedDbkey();
  33                         $hash = md5( $key );
  34                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  35
  36                         $hash1 = substr( $hash, 0, 1 );
  37                         $hash2 = substr( $hash, 0, 2 );
  38                         $this->mFileCache = "{$wgFileCacheDirectory}/{$hash1}/{$hash2}/{$key}.html";
  39
  40                         if($this->useGzip())
  41                                 $this->mFileCache .= '.gz';
  42
  43                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  44                 }
  45                 return $this->mFileCache;
  46         }
  47
  48         function isFileCached() {
  49                 return file_exists( $this->fileCacheName() );
  50         }
  51
  52         function fileCacheTime() {
  53                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  54         }
  55
  56         function isFileCacheGood( $timestamp ) {
  57                 global $wgCacheEpoch;
  58
  59                 if( !$this->isFileCached() ) return false;
  60
  61                 $cachetime = $this->fileCacheTime();
  62                 $good = (( $timestamp <= $cachetime ) &&
  63                          ( $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($mydir2,'/')); # subdirectory level 1
 115
 116                 if(!file_exists($mydir1)) { mkdir($mydir1,0775); } # create if necessary
 117                 if(!file_exists($mydir2)) { mkdir($mydir2,0775); }
 118         }
 119
 120         function saveToFileCache( $origtext ) {
 121                 $text = $origtext;
 122                 if(strcmp($text,'') == 0) return '';
 123
 124                 wfDebug(" saveToFileCache()\n", false);
 125
 126                 $this->checkCacheDirs();
 127
 128                 $f = fopen( $this->fileCacheName(), 'w' );
 129                 if($f) {
 130                         $now = wfTimestampNow();
 131                         if( $this->useGzip() ) {
 132                                 $rawtext = str_replace( '</html>',
 133                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 134                                         $text );
 135                                 $text = gzencode( $rawtext );
 136                         } else {
 137                                 $text = str_replace( '</html>',
 138                                         '<!-- Cached '.$now." -->\n</html>",
 139                                         $text );
 140                         }
 141                         fwrite( $f, $text );
 142                         fclose( $f );
 143                         if( $this->useGzip() ) {
 144                                 if( wfClientAcceptsGzip() ) {
 145                                         header( 'Content-Encoding: gzip' );
 146                                         return $text;
 147                                 } else {
 148                                         return $rawtext;
 149                                 }
 150                         } else {
 151                                 return $text;
 152                         }
 153                 }
 154                 return $text;
 155         }
 156
 157 }
 158
 159 ?>