Skip events without listeners

patches/server/0040-Skip-event-if-no-listeners.patch

@@ -0,0 +1,34 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: foss-mc <69294560+foss-mc@users.noreply.github.com>
+Date: Sat, 8 Jul 2023 01:31:10 +0300
+Subject: [PATCH] Skip event if no listeners
+
+
+diff --git a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
+index 7ce9ebba8ce304d1f3f21d4f15ee5f3560d7700b..d0f6d4e6ab3a7a4bd6cb8e27c90c7c7300f204a5 100644
+--- a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
++++ b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
+@@ -36,14 +36,21 @@ class PaperEventManager {
+ 
+     // SimplePluginManager
+     public void callEvent(@NotNull Event event) {
++        // Kaiiju start - Skip event of no listeners
++        HandlerList handlers = event.getHandlers();
++        RegisteredListener[] listeners = handlers.getRegisteredListeners();
++        if (listeners.length == 0) return;
++        // Kaiiju end
+         if (event.isAsynchronous() && this.server.isPrimaryThread()) {
+             throw new IllegalStateException(event.getEventName() + " may only be triggered asynchronously.");
+         } else if (!event.isAsynchronous() && !this.server.isPrimaryThread() && !this.server.isStopping()) {
+             throw new IllegalStateException(event.getEventName() + " may only be triggered synchronously.");
+         }
+ 
+-        HandlerList handlers = event.getHandlers();
+-        RegisteredListener[] listeners = handlers.getRegisteredListeners();
++        // Kaiiju start - Moved up
++        //HandlerList handlers = event.getHandlers();
++        //RegisteredListener[] listeners = handlers.getRegisteredListeners();
++        // Kaiiju end
+ 
+         for (RegisteredListener registration : listeners) {
+             if (!registration.getPlugin().isEnabled()) {