Reuse timings handlers for event handlers of the same events

due to direct repeated usage of registerEvent() with closures, we've seen some libraries like muqsit/SimplePacketHandler generate very large timings reports, because a new timings handler gets created every time a plugin registers or unregisters a new packet handler callback.

This change fixes the problem by ensuring that any handlers derived from the same function, handling the same event class, will share the same timer.

src/plugin/PluginManager.php

@@ -37,7 +37,7 @@
 use pocketmine\permission\PermissionManager;
 use pocketmine\permission\PermissionParser;
 use pocketmine\Server;
-use pocketmine\timings\TimingsHandler;
+use pocketmine\timings\Timings;
 use pocketmine\utils\AssumptionFailedError;
 use pocketmine\utils\Utils;
 use Symfony\Component\Filesystem\Path;
@@ -651,7 +651,7 @@ public function registerEvent(string $event, \Closure $handler, int $priority, P
 			throw new PluginException("Plugin attempted to register event handler " . $handlerName . "() to event " . $event . " while not enabled");
 		}
 
-		$timings = new TimingsHandler($handlerName . "(" . (new \ReflectionClass($event))->getShortName() . ")", group: $plugin->getDescription()->getFullName());
+		$timings = Timings::getEventHandlerTimings($event, $handlerName, $plugin->getDescription()->getFullName());
 
 		$registeredListener = new RegisteredListener($handler, $priority, $plugin, $handleCancelled, $timings);
 		HandlerListManager::global()->getListFor($event)->register($registeredListener);

src/timings/Timings.php

@@ -166,6 +166,8 @@ abstract class Timings{
 
 	/** @var TimingsHandler[] */
 	private static array $events = [];
+	/** @var TimingsHandler[][] */
+	private static array $eventHandlers = [];
 
 	public static function init() : void{
 		if(self::$initialized){
@@ -336,4 +338,16 @@ public static function getEventTimings(Event $event) : TimingsHandler{
 
 		return self::$events[$eventClass];
 	}
+
+	/**
+	 * @phpstan-template TEvent of Event
+	 * @phpstan-param class-string<TEvent> $event
+	 */
+	public static function getEventHandlerTimings(string $event, string $handlerName, string $group) : TimingsHandler{
+		if(!isset(self::$eventHandlers[$event][$handlerName])){
+			self::$eventHandlers[$event][$handlerName] = new TimingsHandler($handlerName . "(" . self::shortenCoreClassName($event, "pocketmine\\event\\") . ")", group: $group);
+		}
+
+		return self::$eventHandlers[$event][$handlerName];
+	}
 }