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         var $mTitle, $mFileCache;
  28
  29         function CacheManager( &$title ) {
  30                 $this->mTitle =& $title;
  31                 $this->mFileCache = '';
  32         }
  33
  34         function fileCacheName() {
  35                 global $wgFileCacheDirectory, $wgContLang;
  36                 if( !$this->mFileCache ) {
  37                         $key = $this->mTitle->getPrefixedDbkey();
  38                         $hash = md5( $key );
  39                         $key = str_replace( '.', '%2E', urlencode( $key ) );
  40
  41                         $hash1 = substr( $hash, 0, 1 );
  42                         $hash2 = substr( $hash, 0, 2 );
  43                         $this->mFileCache = "{$wgFileCacheDirectory}/{$hash1}/{$hash2}/{$key}.html";
  44
  45                         if($this->useGzip())
  46                                 $this->mFileCache .= '.gz';
  47
  48                         wfDebug( " fileCacheName() - {$this->mFileCache}\n" );
  49                 }
  50                 return $this->mFileCache;
  51         }
  52
  53         function isFileCached() {
  54                 return file_exists( $this->fileCacheName() );
  55         }
  56
  57         function fileCacheTime() {
  58                 return wfTimestamp( TS_MW, filemtime( $this->fileCacheName() ) );
  59         }
  60
  61         function isFileCacheGood( $timestamp ) {
  62                 global $wgCacheEpoch;
  63
  64                 if( !$this->isFileCached() ) return false;
  65
  66                 $cachetime = $this->fileCacheTime();
  67                 $good = (( $timestamp <= $cachetime ) &&
  68                          ( $wgCacheEpoch <= $cachetime ));
  69
  70                 wfDebug(" isFileCacheGood() - cachetime $cachetime, touched {$timestamp} epoch {$wgCacheEpoch}, good $good\n");
  71                 return $good;
  72         }
  73
  74         function useGzip() {
  75                 global $wgUseGzip;
  76                 return $wgUseGzip;
  77         }
  78
  79         /* In handy string packages */
  80         function fetchRawText() {
  81                 return file_get_contents( $this->fileCacheName() );
  82         }
  83
  84         function fetchPageText() {
  85                 if( $this->useGzip() ) {
  86                         /* Why is there no gzfile_get_contents() or gzdecode()? */
  87                         return implode( '', gzfile( $this->fileCacheName() ) );
  88                 } else {
  89                         return $this->fetchRawText();
  90                 }
  91         }
  92
  93         /* Working directory to/from output */
  94         function loadFromFileCache() {
  95                 global $wgOut, $wgMimeType, $wgOutputEncoding, $wgContLanguageCode;
  96                 wfDebug(" loadFromFileCache()\n");
  97
  98                 $filename=$this->fileCacheName();
  99                 $wgOut->sendCacheControl();
 100
 101                 header( "Content-type: $wgMimeType; charset={$wgOutputEncoding}" );
 102                 header( "Content-language: $wgContLanguageCode" );
 103
 104                 if( $this->useGzip() ) {
 105                         if( wfClientAcceptsGzip() ) {
 106                                 header( 'Content-Encoding: gzip' );
 107                         } else {
 108                                 /* Send uncompressed */
 109                                 readgzfile( $filename );
 110                                 return;
 111                         }
 112                 }
 113                 readfile( $filename );
 114         }
 115
 116         function checkCacheDirs() {
 117                 $filename = $this->fileCacheName();
 118                 $mydir2=substr($filename,0,strrpos($filename,'/')); # subdirectory level 2
 119                 $mydir1=substr($mydir2,0,strrpos($mydir2,'/')); # subdirectory level 1
 120
 121                 if(!file_exists($mydir1)) { mkdir($mydir1,0775); } # create if necessary
 122                 if(!file_exists($mydir2)) { mkdir($mydir2,0775); }
 123         }
 124
 125         function saveToFileCache( $origtext ) {
 126                 $text = $origtext;
 127                 if(strcmp($text,'') == 0) return '';
 128
 129                 wfDebug(" saveToFileCache()\n", false);
 130
 131                 $this->checkCacheDirs();
 132
 133                 $f = fopen( $this->fileCacheName(), 'w' );
 134                 if($f) {
 135                         $now = wfTimestampNow();
 136                         if( $this->useGzip() ) {
 137                                 $rawtext = str_replace( '</html>',
 138                                         '<!-- Cached/compressed '.$now." -->\n</html>",
 139                                         $text );
 140                                 $text = gzencode( $rawtext );
 141                         } else {
 142                                 $text = str_replace( '</html>',
 143                                         '<!-- Cached '.$now." -->\n</html>",
 144                                         $text );
 145                         }
 146                         fwrite( $f, $text );
 147                         fclose( $f );
 148                         if( $this->useGzip() ) {
 149                                 if( wfClientAcceptsGzip() ) {
 150                                         header( 'Content-Encoding: gzip' );
 151                                         return $text;
 152                                 } else {
 153                                         return $rawtext;
 154                                 }
 155                         } else {
 156                                 return $text;
 157                         }
 158                 }
 159                 return $text;
 160         }
 161
 162 }
 163
 164 ?>