* Primary entry points:
*
* - ObjectCache::newAccelerator( $fallbackType )
- * Purpose: Cache.
+ * Purpose: Cache for very hot keys.
* Stored only on the individual web server.
* Not associated with other servers.
*
- * - ObjectCache::getMainClusterInstance()
- * Purpose: Cache.
- * Stored centrally within the local data-center.
- * Not replicated to other DCs.
- * Also known as $wgMemc. Configured by $wgMainCacheType.
- *
* - ObjectCache::getMainWANInstance()
* Purpose: Cache.
* Stored in the local data-center's main cache (uses different cache keys).
*
* - ObjectCache::getMainStashInstance()
* Purpose: Ephemeral storage.
- * Stored centrally within the local data-center.
- * Changes are replicated to other DCs (eventually consistent).
+ * Stored centrally within the primary data-center.
+ * Changes are applied there first and replicated to other DCs (best-effort).
* To retrieve the latest value (e.g. not from a slave), use BagOStuff:READ_LATEST.
* This store may be subject to LRU style evictions.
*
+ * - ObjectCache::getLocalClusterInstance()
+ * Purpose: Memory storage for per-cluster coordination and tracking.
+ * A typical use case would be a rate limit counter or cache regeneration mutex.
+ * Stored centrally within the local data-center. Not replicated to other DCs.
+ * Also known as $wgMemc. Configured by $wgMainCacheType.
+ *
* - wfGetCache( $cacheType )
* Get a specific cache type by key in $wgObjectCaches.
*
+ * All the above cache instances (BagOStuff and WANObjectCache) have their makeKey()
+ * method scoped to the *current* wiki ID. Use makeGlobalKey() to avoid this scoping
+ * when using keys that need to be shared amongst wikis.
+ *
* @ingroup Cache
*/
class ObjectCache {
- /** @var Array Map of (id => BagOStuff) */
+ /** @var BagOStuff[] Map of (id => BagOStuff) */
public static $instances = array();
-
- /** @var Array Map of (id => WANObjectCache) */
+ /** @var WANObjectCache[] Map of (id => WANObjectCache) */
public static $wanInstances = array();
/**
return self::newFromParams( $wgObjectCaches[$id] );
}
+ /**
+ * Get the default keyspace for this wiki.
+ *
+ * This is either the value of the `CachePrefix` configuration variable,
+ * or (if the former is unset) the `DBname` configuration variable, with
+ * `DBprefix` (if defined).
+ *
+ * @return string
+ */
+ public static function getDefaultKeyspace() {
+ global $wgCachePrefix;
+
+ $keyspace = $wgCachePrefix;
+ if ( is_string( $keyspace ) && $keyspace !== '' ) {
+ return $keyspace;
+ }
+
+ return wfWikiID();
+ }
+
/**
* Create a new cache object from parameters.
*
if ( isset( $params['loggroup'] ) ) {
$params['logger'] = LoggerFactory::getInstance( $params['loggroup'] );
} else {
- // For backwards-compatability with custom parameters, lets not
- // have all logging suddenly disappear
$params['logger'] = LoggerFactory::getInstance( 'objectcache' );
}
+ if ( !isset( $params['keyspace'] ) ) {
+ $params['keyspace'] = self::getDefaultKeyspace();
+ }
if ( isset( $params['factory'] ) ) {
return call_user_func( $params['factory'], $params );
} elseif ( isset( $params['class'] ) ) {
$class = $params['class'];
+ // Automatically set the 'async' update handler
+ if ( $class === 'MultiWriteBagOStuff' ) {
+ $params['asyncHandler'] = isset( $params['asyncHandler'] )
+ ? $params['asyncHandler']
+ : 'DeferredUpdates::addCallableUpdate';
+ }
+ // Do b/c logic for MemcachedBagOStuff
+ if ( is_subclass_of( $class, 'MemcachedBagOStuff' ) ) {
+ if ( !isset( $params['servers'] ) ) {
+ $params['servers'] = $GLOBALS['wgMemCachedServers'];
+ }
+ if ( !isset( $params['debug'] ) ) {
+ $params['debug'] = $GLOBALS['wgMemCachedDebug'];
+ }
+ if ( !isset( $params['persistent'] ) ) {
+ $params['persistent'] = $GLOBALS['wgMemCachedPersistent'];
+ }
+ if ( !isset( $params['timeout'] ) ) {
+ $params['timeout'] = $GLOBALS['wgMemCachedTimeout'];
+ }
+ }
return new $class( $params );
} else {
throw new MWException( "The definition of cache type \""
}
$id = $fallback;
}
- return self::newFromId( $id );
- }
-
- /**
- * Factory function that creates a memcached client object.
- *
- * 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 disastrous.
- *
- * @param array $params
- * @return MemcachedPhpBagOStuff
- */
- public static function newMemcached( $params ) {
- return new MemcachedPhpBagOStuff( $params );
+ return self::getInstance( $id );
}
/**
$class = $params['relayerConfig']['class'];
$params['relayer'] = new $class( $params['relayerConfig'] );
$params['cache'] = self::newFromId( $params['cacheId'] );
+ if ( isset( $params['loggroup'] ) ) {
+ $params['logger'] = LoggerFactory::getInstance( $params['loggroup'] );
+ } else {
+ $params['logger'] = LoggerFactory::getInstance( 'objectcache' );
+ }
$class = $params['class'];
return new $class( $params );
* @since 1.27
* @return BagOStuff
*/
- public static function getMainClusterInstance() {
- $config = RequestContext::getMain()->getConfig();
- $id = $config->get( 'MainCacheType' );
- return self::getInstance( $id );
+ public static function getLocalClusterInstance() {
+ global $wgMainCacheType;
+
+ return self::getInstance( $wgMainCacheType );
}
/**
dépôts / lhc / web / wiklou.git / blobdiff