<?php
/**
- * Functions to get cache objects
+ * Functions to get cache objects.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Cache
*/
+
+/**
+ * Functions to get cache objects
+ *
+ * @ingroup Cache
+ */
class ObjectCache {
static $instances = array();
/**
* Get a cached instance of the specified type of cache object.
+ *
+ * @param $id
+ *
+ * @return object
*/
static function getInstance( $id ) {
if ( isset( self::$instances[$id] ) ) {
return $object;
}
+ /**
+ * Clear all the cached instances.
+ */
+ static function clear() {
+ self::$instances = array();
+ }
+
/**
* Create a new cache object of the specified type.
+ *
+ * @param $id
+ *
+ * @return ObjectCache
*/
static function newFromId( $id ) {
global $wgObjectCaches;
if ( !isset( $wgObjectCaches[$id] ) ) {
- throw new MWException( "Invalid object cache type \"$id\" requested. " .
+ throw new MWException( "Invalid object cache type \"$id\" requested. " .
"It is not present in \$wgObjectCaches." );
}
/**
* Create a new cache object from parameters
+ *
+ * @param $params array
+ *
+ * @return ObjectCache
*/
static function newFromParams( $params ) {
if ( isset( $params['factory'] ) ) {
$class = $params['class'];
return new $class( $params );
} else {
- throw new MWException( "The definition of cache type \"$id\" lacks both " .
+ throw new MWException( "The definition of cache type \"" . print_r( $params, true ) . "\" lacks both " .
"factory and class parameters." );
}
}
/**
* Factory function referenced from DefaultSettings.php for CACHE_ANYTHING
+ *
+ * CACHE_ANYTHING means that stuff has to be cached, not caching is not an option.
+ * If a caching method is configured for any of the main caches ($wgMainCacheType,
+ * $wgMessageCacheType, $wgParserCacheType), then CACHE_ANYTHING will effectively
+ * be an alias to the configured cache choice for that.
+ * If no cache choice is configured (by default $wgMainCacheType is CACHE_NONE),
+ * then CACHE_ANYTHING will forward to CACHE_DB.
*/
static function newAnything( $params ) {
global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
$candidates = array( $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType );
foreach ( $candidates as $candidate ) {
if ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
- return self::newFromId( $candidate );
+ return self::getInstance( $candidate );
}
}
- return self::newFromId( CACHE_DB );
+ return self::getInstance( CACHE_DB );
}
/**
* Factory function referenced from DefaultSettings.php for CACHE_ACCEL.
+ *
+ * @return ObjectCache
*/
static function newAccelerator( $params ) {
- if ( function_exists( 'eaccelerator_get' ) ) {
- $id = 'eaccelerator';
- } elseif ( function_exists( 'apc_fetch') ) {
+ if ( function_exists( 'apc_fetch') ) {
$id = 'apc';
- } elseif( function_exists( 'xcache_get' ) ) {
+ } elseif( function_exists( 'xcache_get' ) && wfIniGetBool( 'xcache.var_size' ) ) {
$id = 'xcache';
} elseif( function_exists( 'wincache_ucache_get' ) ) {
$id = 'wincache';
/**
* Factory function that creates a memcached client object.
- * The idea of this is that it might eventually detect and automatically
- * support the PECL extension, assuming someone can get it to compile.
+ *
+ * This always uses the PHP client, since the PECL client has a different
+ * hashing scheme and a different interpretation of the flags bitfield, so
+ * switching between the two clients randomly would be disasterous.
+ *
+ * @param $params array
+ *
+ * @return MemcachedPhpBagOStuff
*/
static function newMemcached( $params ) {
return new MemcachedPhpBagOStuff( $params );