From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: jmp <jasonpenilla2@me.com>
Date: Sat, 31 Oct 2020 11:49:01 -0700
Subject: [PATCH] Fix client lag on advancement loading

When new advancements are added via the UnsafeValues#loadAdvancement
API, it triggers a full datapack reload when this is not necessary. The
advancement is already loaded directly into the advancement registry,
and the point of saving the advancement to the Bukkit datapack seems to
be for persistence. By removing the call to reload datapacks when an
advancement is loaded, the client no longer completely freezes up when
adding a new advancement.
To ensure the client still receives the updated advancement data, we
manually reload the advancement data for all players, which
normally takes place as a part of the datapack reloading.

diff --git a/src/main/java/net/minecraft/server/PlayerAdvancements.java b/src/main/java/net/minecraft/server/PlayerAdvancements.java
index acb41cc3965154c5b515cd8e808bf2cf5dc850e4..b8d3f2c59199e245e2035d6205dd1a042aa93f77 100644
--- a/src/main/java/net/minecraft/server/PlayerAdvancements.java
+++ b/src/main/java/net/minecraft/server/PlayerAdvancements.java
@@ -97,6 +97,7 @@ public class PlayerAdvancements {
 
     }
 
+    public final void reload(ServerAdvancementManager advancementDataWorld) { this.reload(advancementDataWorld); } // Paper - OBFHELPER
     public void reload(ServerAdvancementManager advancementLoader) {
         this.stopListening();
         this.advancements.clear();
@@ -393,6 +394,7 @@ public class PlayerAdvancements {
 
     }
 
+    public final void sendUpdateIfNeeded(ServerPlayer entityPlayer) { this.flushDirty(entityPlayer); } // Paper - OBFHELPER
     public void flushDirty(ServerPlayer player) {
         if (this.isFirstPacket || !this.visibilityChanged.isEmpty() || !this.progressChanged.isEmpty()) {
             Map<ResourceLocation, AdvancementProgress> map = Maps.newHashMap();
diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index 9a16882deee21faf78ea46e08b2f2ad3fbb6021b..ac94fd569bd4c79e30adef148e09e395ba8c1812 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -307,7 +307,13 @@ public final class CraftMagicNumbers implements UnsafeValues {
                     Bukkit.getLogger().log(Level.SEVERE, "Error saving advancement " + key, ex);
                 }
 
-                MinecraftServer.getServer().getPlayerList().reloadResources();
+                // Paper start
+                //MinecraftServer.getServer().getPlayerList().reload();
+                MinecraftServer.getServer().getPlayerList().getPlayers().forEach(player -> {
+                    player.getAdvancements().reload(MinecraftServer.getServer().getAdvancements());
+                    player.getAdvancements().sendUpdateIfNeeded(player);
+                });
+                // Paper end
 
                 return bukkit;
             }