Paper/Spigot-Server-Patches/0181-AsyncTabCompleteEvent.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 26 Nov 2017 13:19:58 -0500
Subject: [PATCH] AsyncTabCompleteEvent

Let plugins be able to control tab completion of commands and chat async.

This will be useful for frameworks like ACF so we can define async safe completion handlers,
and avoid going to main for tab completions.

Especially useful if you need to query a database in order to obtain the results for tab
completion, such as offline players.

Also adds isCommand and getLocation to the sync TabCompleteEvent

diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 76cd3ea9512f4355a055d9c683d939680dc5a1b7..ccf083fbfa97b2a24338a3c1fe18e9a8c850feaf 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -527,10 +527,10 @@ public class PlayerConnection implements PacketListenerPlayIn {
 
     @Override
     public void a(PacketPlayInTabComplete packetplayintabcomplete) {
-        PlayerConnectionUtils.ensureMainThread(packetplayintabcomplete, this, this.player.getWorldServer());
+        // PlayerConnectionUtils.ensureMainThread(packetplayintabcomplete, this, this.player.getWorldServer()); // Paper - run this async
         // CraftBukkit start
         if (chatSpamField.addAndGet(this, 1) > 500 && !this.minecraftServer.getPlayerList().isOp(this.player.getProfile())) {
-            this.disconnect(new ChatMessage("disconnect.spam", new Object[0]));
+            minecraftServer.scheduleOnMain(() -> this.disconnect(new ChatMessage("disconnect.spam", new Object[0]))); // Paper
             return;
         }
         // CraftBukkit end
@@ -540,12 +540,35 @@ public class PlayerConnection implements PacketListenerPlayIn {
             stringreader.skip();
         }
 
-        ParseResults<CommandListenerWrapper> parseresults = this.minecraftServer.getCommandDispatcher().a().parse(stringreader, this.player.getCommandListener());
+        // Paper start - async tab completion
+        com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event;
+        java.util.List<String> completions = new java.util.ArrayList<>();
+        String buffer = packetplayintabcomplete.c();
+        event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(this.getPlayer(), completions,
+                buffer, true, null);
+        event.callEvent();
+        completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.getCompletions();
+        // If the event isn't handled, we can assume that we have no completions, and so we'll ask the server
+        if (!event.isHandled()) {
+            if (!event.isCancelled()) {
 
-        this.minecraftServer.getCommandDispatcher().a().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
-            if (suggestions.isEmpty()) return; // CraftBukkit - don't send through empty suggestions - prevents [<args>] from showing for plugins with nothing more to offer
-            this.networkManager.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), suggestions));
-        });
+                this.minecraftServer.scheduleOnMain(() -> { // Paper - This needs to be on main
+                    ParseResults<CommandListenerWrapper> parseresults = this.minecraftServer.getCommandDispatcher().a().parse(stringreader, this.player.getCommandListener());
+
+                    this.minecraftServer.getCommandDispatcher().a().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
+                        if (suggestions.isEmpty()) return; // CraftBukkit - don't send through empty suggestions - prevents [<args>] from showing for plugins with nothing more to offer
+                        this.networkManager.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), suggestions));
+                    });
+                });
+            }
+        } else if (!completions.isEmpty()) {
+            com.mojang.brigadier.suggestion.SuggestionsBuilder builder = new com.mojang.brigadier.suggestion.SuggestionsBuilder(packetplayintabcomplete.c(), stringreader.getTotalLength());
+
+            builder = builder.createOffset(builder.getInput().lastIndexOf(' ') + 1);
+            completions.forEach(builder::suggest);
+            player.playerConnection.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), builder.buildFuture().join()));
+        }
+        // Paper end - async tab completion
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 73b69d4acda27995961306831c39696604559ad6..bfe812fdb3aca643634281a57c4f94509dbe70b1 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1789,7 +1789,7 @@ public final class CraftServer implements Server {
             offers = tabCompleteChat(player, message);
         }
 
-        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers);
+        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers, message.startsWith("/") || forceCommand, pos != null ? net.minecraft.server.MCUtil.toLocation(((CraftWorld) player.getWorld()).getHandle(), new BlockPosition(pos)) : null); // Paper
         getPluginManager().callEvent(tabEvent);
 
         return tabEvent.isCancelled() ? Collections.EMPTY_LIST : tabEvent.getCompletions();
diff --git a/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java b/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
index 5510266fb114954322823b72e3199f33c4d7a9a7..a51202ed53d8ba99b364e8797fe32fa8aeb4fc87 100644
--- a/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
+++ b/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
@@ -28,6 +28,39 @@ public class ConsoleCommandCompleter implements Completer {
     public void complete(LineReader reader, ParsedLine line, List<Candidate> candidates) {
         final CraftServer server = this.server.server;
         final String buffer = line.line();
+        // Async Tab Complete
+        com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event;
+        java.util.List<String> completions = new java.util.ArrayList<>();
+        event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(server.getConsoleSender(), completions,
+            buffer, true, null);
+        event.callEvent();
+        completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.getCompletions();
+
+        if (event.isCancelled() || event.isHandled()) {
+            // Still fire sync event with the provided completions, if someone is listening
+            if (!event.isCancelled() && TabCompleteEvent.getHandlerList().getRegisteredListeners().length > 0) {
+                List<String> finalCompletions = completions;
+                Waitable<List<String>> syncCompletions = new Waitable<List<String>>() {
+                    @Override
+                    protected List<String> evaluate() {
+                        org.bukkit.event.server.TabCompleteEvent syncEvent = new org.bukkit.event.server.TabCompleteEvent(server.getConsoleSender(), buffer, finalCompletions);
+                        return syncEvent.callEvent() ? syncEvent.getCompletions() : com.google.common.collect.ImmutableList.of();
+                    }
+                };
+                server.getServer().processQueue.add(syncCompletions);
+                try {
+                    completions = syncCompletions.get();
+                } catch (InterruptedException | ExecutionException e1) {
+                    e1.printStackTrace();
+                }
+            }
+
+            if (!completions.isEmpty()) {
+                candidates.addAll(completions.stream().map(Candidate::new).collect(java.util.stream.Collectors.toList()));
+            }
+            return;
+        }
+
         // Paper end
         Waitable<List<String>> waitable = new Waitable<List<String>>() {
             @Override