Optimize NonFlush Packet Sending

leaf-server/minecraft-patches/features/0155-Optimize-NonFlush-PacketSending.patch

@@ -0,0 +1,55 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Taiyou06 <kaandindar21@gmail.com>
+Date: Wed, 26 Mar 2025 17:33:30 +0100
+Subject: [PATCH] Optimize NonFlush PacketSending
+
+Places like entity tracking make heavy use of packet sending,
+and internally netty will use some very expensive thread wakeup
+calls when scheduling.
+
+Thanks to various hacks in ProtocolLib as well as other
+plugins, we cannot simply use a queue of packets to group
+send on execute. We have to call execute for each packet.
+
+Tux's suggestion here is exactly what was needed - tag
+the Runnable indicating it should not make a wakeup call.
+
+Big thanks to Tux for making this possible as I had given
+up on this optimisation before he came along.
+
+Locally this patch drops the entity tracker tick by a full 1.5x.
+
+Co-authored-by: Quang Tran <3d7777456@gmail.com>
+
+diff --git a/net/minecraft/network/Connection.java b/net/minecraft/network/Connection.java
+index 5b46036868b6c9d082e35591e58735e16adaae62..208674673169b7258d9411d818870a640df08b24 100644
+--- a/net/minecraft/network/Connection.java
++++ b/net/minecraft/network/Connection.java
+@@ -147,6 +147,7 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     @Nullable public SocketAddress haProxyAddress; // Paper - Add API to get player's proxy address
+     // Paper start - Optimize network
+     public boolean isPending = true;
++    private io.netty.channel.SingleThreadEventLoop eventLoop; // Leaf - optimise packets that are not flushed
+     public boolean queueImmunity;
+     // Paper end - Optimize network
+ 
+@@ -158,6 +159,7 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     public void channelActive(ChannelHandlerContext context) throws Exception {
+         super.channelActive(context);
+         this.channel = context.channel();
++        this.eventLoop = (io.netty.channel.SingleThreadEventLoop) this.channel.eventLoop(); // Leaf - optimise packets that are not flushed
+         this.address = this.channel.remoteAddress();
+         this.preparing = false; // Spigot
+         if (this.delayedDisconnect != null) {
+@@ -477,6 +479,11 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+         if (this.channel.eventLoop().inEventLoop()) {
+             this.doSendPacket(packet, sendListener, flush);
+         } else {
++            // Leaf start - optimise packets that are not flushed
++            if (!flush && org.dreeam.leaf.config.modules.network.OptimizeNonFlushPacketSending.enabled) {
++                this.eventLoop.lazyExecute(() -> this.doSendPacket(packet, sendListener, flush));
++            } else
++            // Leaf end - optimise packets that are not flushed
+             this.channel.eventLoop().execute(() -> this.doSendPacket(packet, sendListener, flush));
+         }
+     }

leaf-server/src/main/java/org/dreeam/leaf/config/modules/network/ConnectionFlushQueueRewrite.java

@@ -1,30 +0,0 @@
-package org.dreeam.leaf.config.modules.network;
-
-import org.dreeam.leaf.config.ConfigModules;
-import org.dreeam.leaf.config.EnumConfigCategory;
-
-public class ConnectionFlushQueueRewrite extends ConfigModules {
-
-    public String getBasePath() {
-        return EnumConfigCategory.NETWORK.getBaseKeyName();
-    }
-
-    public static boolean enabled = false;
-
-    @Override
-    public void onLoaded() {
-        enabled = config.getBoolean(getBasePath() + ".connection-flush-queue-rewrite", enabled, config.pickStringRegionBased("""
-                This replaces ConcurrentLinkedQueue with ArrayDeque for better performance
-                and uses the Netty event loop to ensure thread safety.
-
-                May increase the Netty thread usage and requires server restart to take effect
-                Default: false
-                """,
-            """
-                此选项将 ConcurrentLinkedQueue 替换为 ArrayDeque 以提高性能，
-                并使用 Netty 事件循环以确保线程安全。
-
-                默认值: false
-                """));
-    }
-}

leaf-server/src/main/java/org/dreeam/leaf/config/modules/network/OptimizeNonFlushPacketSending.java

@@ -0,0 +1,35 @@
+package org.dreeam.leaf.config.modules.network;
+
+import org.dreeam.leaf.config.ConfigModules;
+import org.dreeam.leaf.config.EnumConfigCategory;
+
+public class OptimizeNonFlushPacketSending extends ConfigModules {
+
+    public String getBasePath() {
+        return EnumConfigCategory.NETWORK.getBaseKeyName();
+    }
+
+    public static boolean enabled = false;
+
+    @Override
+    public void onLoaded() {
+        enabled = config.getBoolean(getBasePath() + ".OptimizeNonFlushPacketSending", enabled, config.pickStringRegionBased("""
+                WARNING: This option is NOT compatible with ProtocolLib and may cause 
+                issues with other plugins that modify packet handling.
+                
+                Optimizes non-flush packet sending by using Netty's lazyExecute method to avoid 
+                expensive thread wakeup calls when scheduling packet operations.
+                
+                Requires server restart to take effect.
+                """,
+            """           
+                警告：此选项与 ProtocolLib 不兼容，并可能导致与其他修改数据包
+                处理的插件出现问题。
+                
+                通过使用 Netty 的 lazyExecute 方法来优化非刷新数据包的发送，
+                避免在调度数据包操作时进行昂贵的线程唤醒调用。
+                
+                需要重启服务器才能生效。
+                """));
+    }
+}