From: Aaron Schulz <aschulz@wikimedia.org>
Date: Fri, 22 Apr 2016 19:52:06 +0000 (-0700)
Subject: Make WAN cache config use $wgEventRelayerConfig
X-Git-Tag: 1.31.0-rc.0~7188^2
X-Git-Url: https://git.cyclocoop.org/%7B%24www_url%7Dadmin/compta/comptes/ajouter.php?a=commitdiff_plain;h=09a0a5e4f6b6ee2117e32e15e67d166c426a727f;p=lhc%2Fweb%2Fwiklou.git

Make WAN cache config use $wgEventRelayerConfig

This makes the channels more explicit and defined in a less
ad-hoc way. Systems like Kafka would prefer explicit channel
definitions anyway, so the channel prefix just obscures things.

Change-Id: I5631eb1b1382083396a0f08904d9273cc92601e8
---

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 2a30352124..7d771c1ea7 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -2223,27 +2223,24 @@ $wgMainWANCache = false;
  *
  * The format is an associative array where the key is a cache identifier, and
  * the value is an associative array of parameters. The "cacheId" parameter is
- * a cache identifier from $wgObjectCaches. The "relayerConfig" parameter is an
- * array used to construct an EventRelayer object. The "pool" parameter is a
- * string that is used as a PubSub channel prefix. The "loggroup" parameter
- * controls where log events are sent.
+ * a cache identifier from $wgObjectCaches. The "channels" parameter is a map of
+ * actions ('purge') to PubSub channels defined in $wgEventRelayerConfig.
+ * The "loggroup" parameter controls where log events are sent.
  *
  * @since 1.26
  */
 $wgWANObjectCaches = [
 	CACHE_NONE => [
-		'class'         => 'WANObjectCache',
-		'cacheId'       => CACHE_NONE,
-		'pool'          => 'mediawiki-main-none',
-		'relayerConfig' => [ 'class' => 'EventRelayerNull' ]
+		'class'    => 'WANObjectCache',
+		'cacheId'  => CACHE_NONE,
+		'channels' => []
 	]
 	/* Example of a simple single data-center cache:
-	'memcached-php' => array(
-		'class'         => 'WANObjectCache',
-		'cacheId'       => 'memcached-php',
-		'pool'          => 'mediawiki-main-memcached',
-		'relayerConfig' => array( 'class' => 'EventRelayerNull' )
-	)
+	'memcached-php' => [
+		'class'    => 'WANObjectCache',
+		'cacheId'  => 'memcached-php',
+		'channels' => [ 'purge' => 'wancache-main-memcached-purge' ]
+	]
 	*/
 ];
 
diff --git a/includes/Setup.php b/includes/Setup.php
index cddb4369f9..9898b84313 100644
--- a/includes/Setup.php
+++ b/includes/Setup.php
@@ -618,10 +618,9 @@ if ( $wgMainWANCache === false ) {
 	// Sites using multiple datacenters can configure a relayer.
 	$wgMainWANCache = 'mediawiki-main-default';
 	$wgWANObjectCaches[$wgMainWANCache] = [
-		'class'         => 'WANObjectCache',
-		'cacheId'       => $wgMainCacheType,
-		'pool'          => 'mediawiki-main-default',
-		'relayerConfig' => [ 'class' => 'EventRelayerNull' ]
+		'class'    => 'WANObjectCache',
+		'cacheId'  => $wgMainCacheType,
+		'channels' => [ 'purge' => 'wancache-main-default-purge' ]
 	];
 }
 
diff --git a/includes/libs/eventrelayer/EventRelayer.php b/includes/libs/eventrelayer/EventRelayer.php
index f28a4c0c26..b0cd413699 100644
--- a/includes/libs/eventrelayer/EventRelayer.php
+++ b/includes/libs/eventrelayer/EventRelayer.php
@@ -54,10 +54,6 @@ abstract class EventRelayer implements LoggerAwareInterface {
 		return $this->doNotify( $channel, $events );
 	}
 
-	/**
-	 * Set logger instance.
-	 * @param LoggerInterface $logger
-	 */
 	public function setLogger( LoggerInterface $logger ) {
 		$this->logger = $logger;
 	}
diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index dd2e0d5d4b..57cecd0e78 100644
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -69,10 +69,10 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	protected $cache;
 	/** @var HashBagOStuff Script instance PHP cache */
 	protected $procCache;
-	/** @var string Cache pool name */
-	protected $pool;
+	/** @var string Purge channel name */
+	protected $purgeChannel;
 	/** @var EventRelayer Bus that handles purge broadcasts */
-	protected $relayer;
+	protected $purgeRelayer;
 	/** @var LoggerInterface */
 	protected $logger;
 
@@ -134,25 +134,27 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 
 	const MAX_PC_KEYS = 1000; // max keys to keep in process cache
 
+	const DEFAULT_PURGE_CHANNEL = 'wancache-purge';
+
 	/**
 	 * @param array $params
-	 *   - cache   : BagOStuff object
-	 *   - pool    : pool name
-	 *   - relayer : EventRelayer object
-	 *   - logger  : LoggerInterface object
+	 *   - cache    : BagOStuff object for a persistent cache
+	 *   - channels : Map of (action => channel string). Actions include "purge".
+	 *   - relayers : Map of (action => EventRelayer object). Actions include "purge".
+	 *   - logger   : LoggerInterface object
 	 */
 	public function __construct( array $params ) {
 		$this->cache = $params['cache'];
-		$this->pool = $params['pool'];
-		$this->relayer = $params['relayer'];
 		$this->procCache = new HashBagOStuff( [ 'maxKeys' => self::MAX_PC_KEYS ] );
+		$this->purgeChannel = isset( $params['channels']['purge'] )
+			? $params['channels']['purge']
+			: self::DEFAULT_PURGE_CHANNEL;
+		$this->purgeRelayer = isset( $params['relayers']['purge'] )
+			? $params['relayers']['purge']
+			: new EventRelayerNull( [] );
 		$this->setLogger( isset( $params['logger'] ) ? $params['logger'] : new NullLogger() );
 	}
 
-	/**
-	 * Set logger instance.
-	 * @param LoggerInterface $logger
-	 */
 	public function setLogger( LoggerInterface $logger ) {
 		$this->logger = $logger;
 	}
@@ -950,7 +952,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 			'sbt' => true, // substitute $UNIXTIME$ with actual microtime
 		] );
 
-		$ok = $this->relayer->notify( "{$this->pool}:purge", $event );
+		$ok = $this->purgeRelayer->notify( $this->purgeChannel, $event );
 		if ( !$ok ) {
 			$this->lastRelayError = self::ERR_RELAY;
 		}
@@ -970,7 +972,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 			'key' => $key,
 		] );
 
-		$ok = $this->relayer->notify( "{$this->pool}:purge", $event );
+		$ok = $this->purgeRelayer->notify( $this->purgeChannel, $event );
 		if ( !$ok ) {
 			$this->lastRelayError = self::ERR_RELAY;
 		}
diff --git a/includes/objectcache/ObjectCache.php b/includes/objectcache/ObjectCache.php
index bf152b6ec6..e9f2211aaf 100644
--- a/includes/objectcache/ObjectCache.php
+++ b/includes/objectcache/ObjectCache.php
@@ -298,8 +298,10 @@ class ObjectCache {
 		}
 
 		$params = $wgWANObjectCaches[$id];
-		$class = $params['relayerConfig']['class'];
-		$params['relayer'] = new $class( $params['relayerConfig'] );
+		foreach ( $params['channels'] as $action => $channel ) {
+			$params['relayers'][$action] = EventRelayerGroup::singleton()->getRelayer( $channel );
+			$params['channels'][$action] = $channel;
+		}
 		$params['cache'] = self::newFromId( $params['cacheId'] );
 		if ( isset( $params['loggroup'] ) ) {
 			$params['logger'] = LoggerFactory::getInstance( $params['loggroup'] );