includes/objectcache/ObjectCache.php

   1 <?php
   2 /**
   3  * Functions to get cache objects
   4  *
   5  * @file
   6  * @ingroup Cache
   7  */
   8 class ObjectCache {
   9         static $instances = array();
  10
  11         /**
  12          * Get a cached instance of the specified type of cache object.
  13          */
  14         static function getInstance( $id ) {
  15                 if ( isset( self::$instances[$id] ) ) {
  16                         return self::$instances[$id];
  17                 }
  18
  19                 $object = self::newFromId( $id );
  20                 self::$instances[$id] = $object;
  21                 return $object;
  22         }
  23
  24         /**
  25          * Clear all the cached instances.
  26          */
  27         static function clear() {
  28                 self::$instances = array();
  29         }
  30
  31         /**
  32          * Create a new cache object of the specified type.
  33          */
  34         static function newFromId( $id ) {
  35                 global $wgObjectCaches;
  36
  37                 if ( !isset( $wgObjectCaches[$id] ) ) {
  38                         throw new MWException( "Invalid object cache type \"$id\" requested. " .
  39                                 "It is not present in \$wgObjectCaches." );
  40                 }
  41
  42                 return self::newFromParams( $wgObjectCaches[$id] );
  43         }
  44
  45         /**
  46          * Create a new cache object from parameters
  47          */
  48         static function newFromParams( $params ) {
  49                 if ( isset( $params['factory'] ) ) {
  50                         return call_user_func( $params['factory'], $params );
  51                 } elseif ( isset( $params['class'] ) ) {
  52                         $class = $params['class'];
  53                         return new $class( $params );
  54                 } else {
  55                         throw new MWException( "The definition of cache type \"$id\" lacks both " .
  56                                 "factory and class parameters." );
  57                 }
  58         }
  59
  60         /**
  61          * Factory function referenced from DefaultSettings.php for CACHE_ANYTHING
  62          */
  63         static function newAnything( $params ) {
  64                 global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
  65                 $candidates = array( $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType );
  66                 foreach ( $candidates as $candidate ) {
  67                         if ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
  68                                 return self::getInstance( $candidate );
  69                         }
  70                 }
  71                 return self::getInstance( CACHE_DB );
  72         }
  73
  74         /**
  75          * Factory function referenced from DefaultSettings.php for CACHE_ACCEL.
  76          */
  77         static function newAccelerator( $params ) {
  78                 if ( function_exists( 'eaccelerator_get' ) ) {
  79                         $id = 'eaccelerator';
  80                 } elseif ( function_exists( 'apc_fetch') ) {
  81                         $id = 'apc';
  82                 } elseif( function_exists( 'xcache_get' ) ) {
  83                         $id = 'xcache';
  84                 } elseif( function_exists( 'wincache_ucache_get' ) ) {
  85                         $id = 'wincache';
  86                 } else {
  87                         throw new MWException( "CACHE_ACCEL requested but no suitable object " .
  88                                 "cache is present. You may want to install APC." );
  89                 }
  90                 return self::newFromId( $id );
  91         }
  92
  93         /**
  94          * Factory function that creates a memcached client object.
  95          * The idea of this is that it might eventually detect and automatically
  96          * support the PECL extension, assuming someone can get it to compile.
  97          */
  98         static function newMemcached( $params ) {
  99                 return new MemcachedPhpBagOStuff( $params );
 100         }
 101 }