includes/CacheManager.php

   1 <?php
   2 /**
   3  * Contain the CacheManager class
   4  * @package MediaWiki
   5  * @subpackage Cache
   6  */
   7
   8 /**
   9  * We need the title class
  10  */
  11 require_once( 'Title.php' );
  12
  13 /**
  14  * Handles talking to the file cache, putting stuff in and taking it back out.
  15  * Mostly called from Article.php, also from DatabaseFunctions.php for the
  16  * emergency abort/fallback to cache.
  17  *
  18  * Global options that affect this module:
  19  * $wgCachePages
  20  * $wgCacheEpoch
  21  * $wgUseFileCache
  22  * $wgFileCacheDirectory
  23  * $wgUseGzip
  24  * @package MediaWiki
  25  */
  26 class CacheManager {
  27         private
  28                 $mTitle,
  29                 $mFileCache;
  30
  31         function CacheManager( &$title ) {
  32                 $this->mTitle =& $title;
  33                 $this->mFileCache = '';
  34         }
  35
  36         function fileCacheName() {
  37                 global $wgFileCacheDirectory;
  38                 if( !$this->mFileCache ) {
  39                         $key = $this->mTitle->getPrefixedDbkey();
  40                         $hash = md5( $key );
  41                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  42
  43                         $hash1 = substr( $hash, 0, 1 );
  44                         $hash2 = substr( $hash, 0, 2 );
  45                         $this->mFileCache = "{$wgFileCacheDirectory}/{$hash1}/{$hash2}/{$key}.html";
  46
  47                         if($this->useGzip())
  48                                 $this->mFileCache .= '.gz';
  49
  50                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  51                 }
  52                 return $this->mFileCache;
  53         }
  54
  55         function isFileCached() {
  56                 return file_exists( $this->fileCacheName() );
  57         }
  58
  59         function fileCacheTime() {
  60                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  61         }
  62
  63         function isFileCacheGood( $timestamp ) {
  64                 global $wgCacheEpoch;
  65
  66                 if( !$this->isFileCached() ) return false;
  67
  68                 $cachetime = $this->fileCacheTime();
  69                 $good = (( $timestamp <= $cachetime ) &&
  70                          ( $wgCacheEpoch <= $cachetime ));
  71
  72                 wfDebug(" isFileCacheGood() - cachetime $cachetime, touched {$timestamp} epoch {$wgCacheEpoch}, good $good\n");
  73                 return $good;
  74         }
  75
  76         function useGzip() {
  77                 global $wgUseGzip;
  78                 return $wgUseGzip;
  79         }
  80
  81         /* In handy string packages */
  82         function fetchRawText() {
  83                 return file_get_contents( $this->fileCacheName() );
  84         }
  85
  86         function fetchPageText() {
  87                 if( $this->useGzip() ) {
  88                         /* Why is there no gzfile_get_contents() or gzdecode()? */
  89                         return implode( '', gzfile( $this->fileCacheName() ) );
  90                 } else {
  91                         return $this->fetchRawText();
  92                 }
  93         }
  94
  95         /* Working directory to/from output */
  96         function loadFromFileCache() {
  97                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgContLanguageCode;
  98                 wfDebug(" loadFromFileCache()\n");
  99
 100                 $filename=$this->fileCacheName();
 101                 $wgOut->sendCacheControl();
 102
 103                 header( "Content-type: $wgMimeType; charset={$wgOutputEncoding}" );
 104                 header( "Content-language: $wgContLanguageCode" );
 105
 106                 if( $this->useGzip() ) {
 107                         if( wfClientAcceptsGzip() ) {
 108                                 header( 'Content-Encoding: gzip' );
 109                         } else {
 110                                 /* Send uncompressed */
 111                                 readgzfile( $filename );
 112                                 return;
 113                         }
 114                 }
 115                 readfile( $filename );
 116         }
 117
 118         function checkCacheDirs() {
 119                 $filename = $this->fileCacheName();
 120                 $mydir2=substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 121                 $mydir1=substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 122
 123                 if(!file_exists($mydir1)) { mkdir($mydir1,0775); } # create if necessary
 124                 if(!file_exists($mydir2)) { mkdir($mydir2,0775); }
 125         }
 126
 127         function saveToFileCache( $origtext ) {
 128                 $text = $origtext;
 129                 if(strcmp($text,'') == 0) return '';
 130
 131                 wfDebug(" saveToFileCache()\n", false);
 132
 133                 $this->checkCacheDirs();
 134
 135                 $f = fopen( $this->fileCacheName(), 'w' );
 136                 if($f) {
 137                         $now = wfTimestampNow();
 138                         if( $this->useGzip() ) {
 139                                 $rawtext = str_replace( '</html>',
 140                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 141                                         $text );
 142                                 $text = gzencode( $rawtext );
 143                         } else {
 144                                 $text = str_replace( '</html>',
 145                                         '<!-- Cached '.$now." -->\n</html>",
 146                                         $text );
 147                         }
 148                         fwrite( $f, $text );
 149                         fclose( $f );
 150                         if( $this->useGzip() ) {
 151                                 if( wfClientAcceptsGzip() ) {
 152                                         header( 'Content-Encoding: gzip' );
 153                                         return $text;
 154                                 } else {
 155                                         return $rawtext;
 156                                 }
 157                         } else {
 158                                 return $text;
 159                         }
 160                 }
 161                 return $text;
 162         }
 163
 164 }
 165
 166 ?>