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 2eb2ddcb4456437bb449a86c18fb24c8629870a7..4452a6e7f550f362145ce6533e6cc77c367793eb 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -521,10 +521,10 @@ 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
@@ -534,12 +534,35 @@ 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 6f9efe4e5d286fc73a1ecf82e39865715ff03a33..2cc7c1038dae2c521fee5cf471c22221db0a22fc 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1790,7 +1790,7 @@ 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