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          * Create a new cache object of the specified type.
  26          */
  27         static function newFromId( $id ) {
  28                 global $wgObjectCaches;
  29
  30                 if ( !isset( $wgObjectCaches[$id] ) ) {
  31                         throw new MWException( "Invalid object cache type \"$id\" requested. " .
  32                                 "It is not present in \$wgObjectCaches." );
  33                 }
  34
  35                 return self::newFromParams( $wgObjectCaches[$id] );
  36         }
  37
  38         /**
  39          * Create a new cache object from parameters
  40          */
  41         static function newFromParams( $params ) {
  42                 if ( isset( $params['factory'] ) ) {
  43                         return call_user_func( $params['factory'], $params );
  44                 } elseif ( isset( $params['class'] ) ) {
  45                         $class = $params['class'];
  46                         return new $class( $params );
  47                 } else {
  48                         throw new MWException( "The definition of cache type \"$id\" lacks both " .
  49                                 "factory and class parameters." );
  50                 }
  51         }
  52
  53         /**
  54          * Factory function referenced from DefaultSettings.php for CACHE_ANYTHING
  55          */
  56         static function newAnything( $params ) {
  57                 global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
  58                 $candidates = array( $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType );
  59                 foreach ( $candidates as $candidate ) {
  60                         if ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
  61                                 return self::getInstance( $candidate );
  62                         }
  63                 }
  64                 return self::getInstance( CACHE_DB );
  65         }
  66
  67         /**
  68          * Factory function referenced from DefaultSettings.php for CACHE_ACCEL.
  69          */
  70         static function newAccelerator( $params ) {
  71                 if ( function_exists( 'eaccelerator_get' ) ) {
  72                         $id = 'eaccelerator';
  73                 } elseif ( function_exists( 'apc_fetch') ) {
  74                         $id = 'apc';
  75                 } elseif( function_exists( 'xcache_get' ) ) {
  76                         $id = 'xcache';
  77                 } elseif( function_exists( 'wincache_ucache_get' ) ) {
  78                         $id = 'wincache';
  79                 } else {
  80                         throw new MWException( "CACHE_ACCEL requested but no suitable object " .
  81                                 "cache is present. You may want to install APC." );
  82                 }
  83                 return self::newFromId( $id );
  84         }
  85
  86         /**
  87          * Factory function that creates a memcached client object.
  88          * The idea of this is that it might eventually detect and automatically
  89          * support the PECL extension, assuming someone can get it to compile.
  90          */
  91         static function newMemcached( $params ) {
  92                 return new MemcachedPhpBagOStuff( $params );
  93         }
  94 }