PaperMC/Spigot-Server-Patches/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 23c07ca5c..b04eae4bb 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -0,0 +0,0 @@ import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.GenericFutureListener;
 import java.util.Collections;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Set;
 import java.util.function.Consumer;
 import javax.annotation.Nullable;
@@ -0,0 +0,0 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
     }
 
     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.postToMainThread(() -> this.disconnect(new ChatMessage("disconnect.spam", new Object[0]))); // Paper
             return;
         }
         // CraftBukkit end
@@ -0,0 +0,0 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
             stringreader.skip();
         }
 
-        ParseResults parseresults = this.minecraftServer.getCommandDispatcher().a().parse(stringreader, this.player.getCommandListener());
+        // Paper start
+        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() && org.bukkit.event.server.TabCompleteEvent.getHandlerList().getRegisteredListeners().length > 0) {
+                java.util.List<String> finalCompletions = completions;
+                Waitable<java.util.List<String>> syncCompletions = new Waitable<java.util.List<String>>() {
+                    @Override
+                    protected java.util.List<String> evaluate() {
+                        org.bukkit.event.server.TabCompleteEvent syncEvent = new org.bukkit.event.server.TabCompleteEvent(PlayerConnection.this.getPlayer(), buffer, finalCompletions, true, null);
+                        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();
+                }
+            }
+            java.util.List<String> otherSuggestions = completions;
+            minecraftServer.postToMainThread(() -> sendSuggestions(packetplayintabcomplete, stringreader, otherSuggestions));
+            return;
+        } else if (!completions.isEmpty()) {
+            com.mojang.brigadier.suggestion.SuggestionsBuilder suggestionsBuilder = new com.mojang.brigadier.suggestion.SuggestionsBuilder(packetplayintabcomplete.c(), stringreader.getTotalLength());
+            completions.forEach(suggestionsBuilder::suggest);
+
+            player.playerConnection.sendPacket(new PacketPlayOutTabComplete(packetplayintabcomplete.b(), suggestionsBuilder.build()));
+        }
 
-        this.minecraftServer.getCommandDispatcher().a().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
-            if (((Suggestions) 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) suggestions)); // CraftBukkit - decompile error
+    }
+    public void sendSuggestions(PacketPlayInTabComplete packetplayintabcomplete, StringReader reader, List<String> otherSuggestions) {
+
+        ParseResults parseresults = this.minecraftServer.getCommandDispatcher().a().parse(reader, this.player.getCommandListener());
+        //noinspection unchecked
+        java.util.concurrent.CompletableFuture<Suggestions> completionSuggestions = this.minecraftServer.getCommandDispatcher().a().getCompletionSuggestions(parseresults);
+        completionSuggestions.thenAccept((Suggestions suggestions) -> {
+            if (otherSuggestions != null && !otherSuggestions.isEmpty()) {
+                com.mojang.brigadier.suggestion.SuggestionsBuilder builder = new com.mojang.brigadier.suggestion.SuggestionsBuilder(packetplayintabcomplete.c(), reader.getTotalLength());
+                otherSuggestions.forEach(builder::suggest);
+                suggestions.getList().addAll(builder.build().getList());
+            }
+            // Paper end
+            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)); // CraftBukkit - decompile error
         });
     }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index c79e673fb..015a8db94 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -0,0 +0,0 @@ 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 ? 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 1e3aae3b8..95d13c146 100644
--- a/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
+++ b/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java
@@ -0,0 +0,0 @@ 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
--