From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrHua269 <novau233@163.com>
Date: Wed, 7 Feb 2024 08:35:11 +0000
Subject: [PATCH] Purpur use alternative keep alive


diff --git a/src/main/java/me/earthme/luminol/config/modules/optimizations/PurpurAlternativeKeepaliveConfig.java b/src/main/java/me/earthme/luminol/config/modules/optimizations/PurpurAlternativeKeepaliveConfig.java
new file mode 100644
index 0000000000000000000000000000000000000000..43bbc2c30bdd3872a0179e0070403c3e257c320e
--- /dev/null
+++ b/src/main/java/me/earthme/luminol/config/modules/optimizations/PurpurAlternativeKeepaliveConfig.java
@@ -0,0 +1,20 @@
+package me.earthme.luminol.config.modules.optimizations;
+
+import me.earthme.luminol.config.ConfigInfo;
+import me.earthme.luminol.config.EnumConfigCategory;
+import me.earthme.luminol.config.IConfigModule;
+
+public class PurpurAlternativeKeepaliveConfig implements IConfigModule {
+    @ConfigInfo(baseName = "enabled")
+    public static boolean useAlternateKeepAlive = false;
+
+    @Override
+    public EnumConfigCategory getCategory() {
+        return EnumConfigCategory.OPTIMIZATIONS;
+    }
+
+    @Override
+    public String getBaseName() {
+        return "alternative_keepalive_handling";
+    }
+}
diff --git a/src/main/java/net/minecraft/server/network/ServerCommonPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerCommonPacketListenerImpl.java
index 22f0d91df0a81040d72c499fbff32b3a9d41598f..c68910b2a2eb703406fb406a86783cf6ab48651e 100644
--- a/src/main/java/net/minecraft/server/network/ServerCommonPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerCommonPacketListenerImpl.java
@@ -51,6 +51,7 @@ public abstract class ServerCommonPacketListenerImpl implements ServerCommonPack
     private long keepAliveTime = Util.getMillis(); // Paper
     private boolean keepAlivePending;
     private long keepAliveChallenge;
+    private it.unimi.dsi.fastutil.longs.LongList keepAlives = new it.unimi.dsi.fastutil.longs.LongArrayList(); // Purpur
     private int latency;
     private volatile boolean suspendFlushingOnServerThread = false;
     public final java.util.Map<java.util.UUID, net.kyori.adventure.resource.ResourcePackCallback> packCallbacks = new java.util.concurrent.ConcurrentHashMap<>(); // Paper - adventure resource pack callbacks
@@ -103,6 +104,16 @@ public abstract class ServerCommonPacketListenerImpl implements ServerCommonPack
 
     @Override
     public void handleKeepAlive(ServerboundKeepAlivePacket packet) {
+        // Purpur start
+        if (me.earthme.luminol.config.modules.optimizations.PurpurAlternativeKeepaliveConfig.useAlternateKeepAlive) {
+            long id = packet.getId();
+            if (keepAlives.size() > 0 && keepAlives.contains(id)) {
+                int ping = (int) (Util.getMillis() - id);
+                this.latency = (this.latency * 3 + ping) / 4;
+                keepAlives.clear(); // we got a valid response, lets roll with it and forget the rest
+            }
+        } else
+            // Purpur end
         //PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel()); // CraftBukkit // Paper - handle ServerboundKeepAlivePacket async
         if (this.keepAlivePending && packet.getId() == this.keepAliveChallenge) {
             int i = (int) (Util.getMillis() - this.keepAliveTime);
@@ -221,6 +232,21 @@ public abstract class ServerCommonPacketListenerImpl implements ServerCommonPack
         long currentTime = Util.getMillis();
         long elapsedTime = currentTime - this.keepAliveTime;
 
+        // Purpur start
+        if (me.earthme.luminol.config.modules.optimizations.PurpurAlternativeKeepaliveConfig.useAlternateKeepAlive) {
+            if (elapsedTime >= 1000L) { // 1 second
+                if (!processedDisconnect && keepAlives.size() * 1000L >= KEEPALIVE_LIMIT) {
+                    LOGGER.warn("{} was kicked due to keepalive timeout!", this.player.getScoreboardName());
+                    disconnect(ServerCommonPacketListenerImpl.TIMEOUT_DISCONNECTION_MESSAGE, org.bukkit.event.player.PlayerKickEvent.Cause.TIMEOUT);
+                } else {
+                    keepAliveTime = currentTime; // hijack this field for 1 second intervals
+                    keepAlives.add(currentTime); // currentTime is ID
+                    send(new ClientboundKeepAlivePacket(currentTime));
+                }
+            }
+        } else
+        // Purpur end
+
         if (this.keepAlivePending) {
             if (!this.processedDisconnect && elapsedTime >= KEEPALIVE_LIMIT) { // check keepalive limit, don't fire if already disconnected
                 ServerGamePacketListenerImpl.LOGGER.warn("{} was kicked due to keepalive timeout!", this.player.getScoreboardName()); // more info