Paper/patches/server/0302-Async-command-map-building.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Callahan <mr.callahhh@gmail.com>
Date: Wed, 8 Apr 2020 02:42:14 -0500
Subject: [PATCH] Async command map building


diff --git a/src/main/java/net/minecraft/commands/Commands.java b/src/main/java/net/minecraft/commands/Commands.java
index 7d6b416f0889221d63233f8650c530467ea8fbd7..f3bbe012541a71ab75c1863990d0c056c62d8c6e 100644
--- a/src/main/java/net/minecraft/commands/Commands.java
+++ b/src/main/java/net/minecraft/commands/Commands.java
@@ -31,6 +31,7 @@ import net.minecraft.network.chat.MutableComponent;
 import net.minecraft.network.chat.TextComponent;
 import net.minecraft.network.chat.TranslatableComponent;
 import net.minecraft.network.protocol.game.ClientboundCommandsPacket;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.commands.AdvancementCommands;
 import net.minecraft.server.commands.AttributeCommand;
 import net.minecraft.server.commands.BanIpCommands;
@@ -346,6 +347,12 @@ public class Commands {
         if ( org.spigotmc.SpigotConfig.tabComplete < 0 ) return; // Spigot
         // CraftBukkit start
         // Register Vanilla commands into builtRoot as before
+        // Paper start - Async command map building
+        net.minecraft.server.MCUtil.scheduleAsyncTask(() -> this.sendAsync(player));
+    }
+
+    private void sendAsync(ServerPlayer player) {
+        // Paper end - Async command map building
         Map<CommandNode<CommandSourceStack>, CommandNode<SharedSuggestionProvider>> map = Maps.newIdentityHashMap(); // Use identity to prevent aliasing issues
         RootCommandNode vanillaRoot = new RootCommandNode();
 
@@ -363,7 +370,14 @@ public class Commands {
         for (CommandNode node : rootcommandnode.getChildren()) {
             bukkit.add(node.getName());
         }
+        // Paper start - Async command map building
+        MinecraftServer.getServer().execute(() -> {
+           runSync(player, bukkit, rootcommandnode);
+        });
+    }
 
+    private void runSync(ServerPlayer player, Collection<String> bukkit, RootCommandNode<SharedSuggestionProvider> rootcommandnode) {
+        // Paper end - Async command map building
         PlayerCommandSendEvent event = new PlayerCommandSendEvent(player.getBukkitEntity(), new LinkedHashSet<>(bukkit));
         event.getPlayer().getServer().getPluginManager().callEvent(event);