lib/pkp/classes/cache/CacheManager.inc.php

   1 <?php
   2
   3 /**
   4  * @file classes/cache/CacheManager.inc.php
   5  *
   6  * Copyright (c) 2000-2009 John Willinsky
   7  * Distributed under the GNU GPL v2. For full terms see the file docs/COPYING.
   8  *
   9  * @ingroup cache
  10  * @see GenericCache
  11  *
  12  * @brief Provides cache management functions.
  13  *
  14  */
  15
  16 // $Id: CacheManager.inc.php,v 1.7 2009/09/22 18:36:21 asmecher Exp $
  17
  18
  19 class CacheManager {
  20         /**
  21          * Get the static instance of the cache manager.
  22          * @return object CacheManager
  23          */
  24         function &getManager() {
  25                 $manager =& Registry::get('cacheManager', true, null);
  26                 if ($manager === null) {
  27                         $manager = new CacheManager();
  28                 }
  29                 return $manager;
  30         }
  31
  32         /**
  33          * Get a file cache.
  34          * @param $context string
  35          * @param $cacheId string
  36          * @param $fallback callback
  37          * @return object FileCache
  38          */
  39         function &getFileCache($context, $cacheId, $fallback) {
  40                 import('cache.FileCache');
  41                 $returner = new FileCache(
  42                         $context, $cacheId, $fallback,
  43                         $this->getFileCachePath()
  44                 );
  45                 return $returner;
  46         }
  47
  48         /**
  49          * Get a cache.
  50          * @param $context string
  51          * @param $cacheId string
  52          * @param $fallback callback
  53          * @return object Cache
  54          */
  55         function &getCache($context, $cacheId, $fallback) {
  56                 $cacheType = Config::getVar('cache','cache');
  57                 switch ($cacheType) {
  58                         case 'memcache':
  59                                 import('cache.MemcacheCache');
  60                                 $cache = new MemcacheCache(
  61                                         $context, $cacheId, $fallback,
  62                                         Config::getVar('cache','memcache_hostname'),
  63                                         Config::getVar('cache','memcache_port')
  64                                 );
  65                                 break;
  66                         case '': // Provide a default if not specified
  67                         case 'file':
  68                                 $cache =& $this->getFileCache($context, $cacheId, $fallback);
  69                                 break;
  70                         case 'none':
  71                                 import('cache.GenericCache');
  72                                 $cache = new GenericCache(
  73                                         $context, $cacheId, $fallback
  74                                 );
  75                                 break;
  76                         default:
  77                                 die ("Unknown cache type \"$cacheType\"!\n");
  78                                 break;
  79                 }
  80                 return $cache;
  81         }
  82
  83         /**
  84          * Get the path in which file caches will be stored.
  85          * @return string The full path to the file cache directory
  86          */
  87         function getFileCachePath() {
  88                 return Core::getBaseDir() . DIRECTORY_SEPARATOR . 'cache';
  89         }
  90
  91         /**
  92          * Flush an entire context, if specified, or
  93          * the whole cache.
  94          * @param $context string The context to flush, if only one is to be flushed
  95          */
  96         function flush($context = null) {
  97                 $cacheType = Config::getVar('cache','cache');
  98                 switch ($cacheType) {
  99                         case 'memcache':
 100                                 // There is no(t yet) selective flushing in memcache;
 101                                 // invalidate the whole thing.
 102                                 $junkCache =& $this->getCache(null, null, null);
 103                                 $junkCache->flush();
 104                                 break;
 105                         case 'file':
 106                                 $filePath = $this->getFileCachePath();
 107                                 $files = glob($filePath . DIRECTORY_SEPARATOR . 'fc-' . (isset($context)?$context . '-':'') . '*.php');
 108                                 foreach ($files as $file) {
 109                                         unlink ($file);
 110                                 }
 111                                 break;
 112                         case 'none':
 113                                 // Nothing necessary.
 114                                 break;
 115                         default:
 116                                 die ("Unknown cache type \"$cacheType\"!\n");
 117                 }
 118         }
 119 }
 120
 121 ?>