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

Co-authored-by: Aikar <aikar@aikar.co>

paper-server/patches/sources/net/minecraft/server/network/ServerGamePacketListenerImpl.java.patch

@@ -48,7 +48,7 @@
  import net.minecraft.world.level.GameRules;
  import net.minecraft.world.level.GameType;
  import net.minecraft.world.level.Level;
-@@ -192,12 +196,72 @@
+@@ -192,11 +196,71 @@
  import net.minecraft.world.level.block.state.BlockState;
  import net.minecraft.world.phys.AABB;
  import net.minecraft.world.phys.BlockHitResult;
@@ -58,7 +58,7 @@
  import net.minecraft.world.phys.shapes.Shapes;
  import net.minecraft.world.phys.shapes.VoxelShape;
  import org.slf4j.Logger;
- 
++
 +// CraftBukkit start
 +import io.papermc.paper.adventure.ChatProcessor; // Paper
 +import io.papermc.paper.adventure.PaperAdventure; // Paper
@@ -117,10 +117,9 @@
 +import org.bukkit.inventory.InventoryView;
 +import org.bukkit.inventory.SmithingInventory;
 +// CraftBukkit end
-+
+ 
  public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl implements ServerGamePacketListener, ServerPlayerConnection, TickablePacketListener {
  
-     static final Logger LOGGER = LogUtils.getLogger();
 @@ -247,7 +311,7 @@
      private boolean waitingForSwitchToConfig;
  
@@ -130,14 +129,14 @@
          this.chunkSender = new PlayerChunkSender(connection.isMemoryConnection());
          this.player = player;
          player.connection = this;
-@@ -256,9 +320,25 @@
+@@ -256,8 +320,24 @@
  
          Objects.requireNonNull(server);
          this.signedMessageDecoder = SignedMessageChain.Decoder.unsigned(uuid, server::enforceSecureProfile);
 -        this.chatMessageChain = new FutureChain(server);
 +        this.chatMessageChain = new FutureChain(server.chatExecutor); // CraftBukkit - async chat
      }
- 
++
 +    // CraftBukkit start - add fields and methods
 +    private int lastTick = MinecraftServer.currentTick;
 +    private int allowedPlayerTicks = 1;
@@ -153,10 +152,9 @@
 +    private float lastYaw = Float.MAX_VALUE;
 +    private boolean justTeleported = false;
 +    // CraftBukkit end
-+
+ 
      @Override
      public void tick() {
-         if (this.ackBlockChangesUpTo > -1) {
 @@ -277,7 +357,7 @@
          if (this.clientIsFloating && !this.player.isSleeping() && !this.player.isPassenger() && !this.player.isDeadOrDying()) {
              if (++this.aboveGroundTickCount > this.getMaximumFlyingTicks(this.player)) {
@@ -336,20 +334,63 @@
          this.player.getRecipeBook().setBookSetting(packet.getBookType(), packet.isOpen(), packet.isFiltering());
      }
  
-@@ -548,6 +723,12 @@
+@@ -545,18 +720,62 @@
+ 
+     }
+ 
++    // Paper start - AsyncTabCompleteEvent
++    private static final java.util.concurrent.ExecutorService TAB_COMPLETE_EXECUTOR = java.util.concurrent.Executors.newFixedThreadPool(4,
++        new com.google.common.util.concurrent.ThreadFactoryBuilder().setDaemon(true).setNameFormat("Async Tab Complete Thread - #%d").setUncaughtExceptionHandler(new net.minecraft.DefaultUncaughtExceptionHandlerWithName(net.minecraft.server.MinecraftServer.LOGGER)).build());
++    // Paper end - AsyncTabCompleteEvent
      @Override
      public void handleCustomCommandSuggestions(ServerboundCommandSuggestionPacket packet) {
-         PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
+-        PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
++        // PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel()); // Paper - AsyncTabCompleteEvent; run this async
 +        // CraftBukkit start
 +        if (!this.chatSpamThrottler.isIncrementAndUnderThreshold(1, 500) && !this.server.getPlayerList().isOp(this.player.getGameProfile()) && !this.server.isSingleplayerOwner(this.player.getGameProfile())) {
 +            this.disconnect(Component.translatable("disconnect.spam"));
 +            return;
 +        }
 +        // CraftBukkit end
++        // Paper start - AsyncTabCompleteEvent
++        TAB_COMPLETE_EXECUTOR.execute(() -> this.handleCustomCommandSuggestions0(packet));
++    }
++
++    private void handleCustomCommandSuggestions0(final ServerboundCommandSuggestionPacket packet) {
          StringReader stringreader = new StringReader(packet.getCommand());
  
          if (stringreader.canRead() && stringreader.peek() == '/') {
-@@ -557,6 +738,7 @@
+             stringreader.skip();
++        }
++
++        final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(this.getCraftPlayer(), packet.getCommand(), true, null);
++        event.callEvent();
++        final List<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.completions();
++        // 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()) {
++                return;
++            }
++
++            // This needs to be on main
++            this.server.scheduleOnMain(() -> this.sendServerSuggestions(packet, stringreader));
++        } else if (!completions.isEmpty()) {
++            final com.mojang.brigadier.suggestion.SuggestionsBuilder builder0 = new com.mojang.brigadier.suggestion.SuggestionsBuilder(packet.getCommand(), stringreader.getTotalLength());
++            final com.mojang.brigadier.suggestion.SuggestionsBuilder builder = builder0.createOffset(builder0.getInput().lastIndexOf(' ') + 1);
++            for (final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion completion : completions) {
++                final Integer intSuggestion = com.google.common.primitives.Ints.tryParse(completion.suggestion());
++                if (intSuggestion != null) {
++                    builder.suggest(intSuggestion, PaperAdventure.asVanilla(completion.tooltip()));
++                } else {
++                    builder.suggest(completion.suggestion(), PaperAdventure.asVanilla(completion.tooltip()));
++                }
++            }
++            this.connection.send(new ClientboundCommandSuggestionsPacket(packet.getId(), builder.buildFuture().join()));
+         }
++    }
+ 
++    private void sendServerSuggestions(final ServerboundCommandSuggestionPacket packet, final StringReader stringreader) {
++        // Paper end - AsyncTabCompleteEvent
          ParseResults<CommandSourceStack> parseresults = this.server.getCommands().getDispatcher().parse(stringreader, this.player.createCommandSourceStack());
  
          this.server.getCommands().getDispatcher().getCompletionSuggestions(parseresults).thenAccept((suggestions) -> {
@@ -357,7 +398,7 @@
              Suggestions suggestions1 = suggestions.getList().size() <= 1000 ? suggestions : new Suggestions(suggestions.getRange(), suggestions.getList().subList(0, 1000));
  
              this.send(new ClientboundCommandSuggestionsPacket(packet.getId(), suggestions1));
-@@ -668,7 +850,7 @@
+@@ -668,7 +887,7 @@
                  ItemStack itemstack = iblockdata.getCloneItemStack(worldserver, blockposition, flag);
  
                  if (!itemstack.isEmpty()) {
@@ -366,7 +407,7 @@
                          ServerGamePacketListenerImpl.addBlockDataToItem(iblockdata, worldserver, blockposition, itemstack);
                      }
  
-@@ -866,6 +1048,13 @@
+@@ -866,6 +1085,13 @@
          AbstractContainerMenu container = this.player.containerMenu;
  
          if (container instanceof MerchantMenu containermerchant) {
@@ -380,7 +421,7 @@
              if (!containermerchant.stillValid(this.player)) {
                  ServerGamePacketListenerImpl.LOGGER.debug("Player {} interacted with invalid menu {}", this.player, containermerchant);
                  return;
-@@ -879,6 +1068,13 @@
+@@ -879,6 +1105,13 @@
  
      @Override
      public void handleEditBook(ServerboundEditBookPacket packet) {
@@ -394,7 +435,7 @@
          int i = packet.slot();
  
          if (Inventory.isHotbarSlot(i) || i == 40) {
-@@ -899,12 +1095,16 @@
+@@ -899,12 +1132,16 @@
      }
  
      private void updateBookContents(List<FilteredText> pages, int slotId) {
@@ -412,7 +453,7 @@
          }
      }
  
-@@ -915,12 +1115,13 @@
+@@ -915,12 +1152,13 @@
              ItemStack itemstack1 = itemstack.transmuteCopy(Items.WRITTEN_BOOK);
  
              itemstack1.remove(DataComponents.WRITABLE_BOOK_CONTENT);
@@ -428,7 +469,7 @@
          }
      }
  
-@@ -982,7 +1183,7 @@
+@@ -982,7 +1220,7 @@
          } else {
              ServerLevel worldserver = this.player.serverLevel();
  
@@ -437,7 +478,7 @@
                  if (this.tickCount == 0) {
                      this.resetPosition();
                  }
-@@ -997,7 +1198,15 @@
+@@ -997,7 +1235,15 @@
                      if (this.player.isPassenger()) {
                          this.player.absMoveTo(this.player.getX(), this.player.getY(), this.player.getZ(), f, f1);
                          this.player.serverLevel().getChunkSource().move(this.player);
@@ -453,7 +494,7 @@
                          double d3 = this.player.getX();
                          double d4 = this.player.getY();
                          double d5 = this.player.getZ();
-@@ -1019,15 +1228,33 @@
+@@ -1019,15 +1265,33 @@
                                  ++this.receivedMovePacketCount;
                                  int i = this.receivedMovePacketCount - this.knownMovePacketCount;
  
@@ -489,7 +530,7 @@
                                          ServerGamePacketListenerImpl.LOGGER.warn("{} moved too quickly! {},{},{}", new Object[]{this.player.getName().getString(), d6, d7, d8});
                                          this.teleport(this.player.getX(), this.player.getY(), this.player.getZ(), this.player.getYRot(), this.player.getXRot());
                                          return;
-@@ -1043,12 +1270,40 @@
+@@ -1043,12 +1307,40 @@
                              boolean flag1 = d7 > 0.0D;
  
                              if (this.player.onGround() && !packet.isOnGround() && flag1) {
@@ -531,7 +572,7 @@
                              double d11 = d7;
  
                              d6 = d0 - this.player.getX();
-@@ -1061,15 +1316,81 @@
+@@ -1061,15 +1353,81 @@
                              d10 = d6 * d6 + d7 * d7 + d8 * d8;
                              boolean flag3 = false;
  
@@ -615,7 +656,7 @@
                                  this.player.absMoveTo(d0, d1, d2, f, f1);
                                  boolean flag4 = this.player.isAutoSpinAttack();
  
-@@ -1119,6 +1440,7 @@
+@@ -1119,6 +1477,7 @@
                  this.awaitingTeleportTime = this.tickCount;
                  this.teleport(this.awaitingPositionFromClient.x, this.awaitingPositionFromClient.y, this.awaitingPositionFromClient.z, this.player.getYRot(), this.player.getXRot());
              }
@@ -623,7 +664,7 @@
  
              return true;
          } else {
-@@ -1147,23 +1469,83 @@
+@@ -1147,23 +1506,83 @@
      }
  
      public void teleport(double x, double y, double z, float yaw, float pitch) {
@@ -710,7 +751,7 @@
          if (this.player.hasClientLoaded()) {
              BlockPos blockposition = packet.getPos();
  
-@@ -1175,14 +1557,46 @@
+@@ -1175,14 +1594,46 @@
                      if (!this.player.isSpectator()) {
                          ItemStack itemstack = this.player.getItemInHand(InteractionHand.OFF_HAND);
  
@@ -759,7 +800,7 @@
                          this.player.drop(false);
                      }
  
-@@ -1218,9 +1632,31 @@
+@@ -1218,9 +1669,31 @@
          }
      }
  
@@ -791,7 +832,7 @@
          if (this.player.hasClientLoaded()) {
              this.player.connection.ackBlockChangesUpTo(packet.getSequence());
              ServerLevel worldserver = this.player.serverLevel();
-@@ -1244,6 +1680,7 @@
+@@ -1244,6 +1717,7 @@
  
                          if (blockposition.getY() <= i) {
                              if (this.awaitingPositionFromClient == null && worldserver.mayInteract(this.player, blockposition)) {
@@ -799,7 +840,7 @@
                                  InteractionResult enuminteractionresult = this.player.gameMode.useItemOn(this.player, worldserver, itemstack, enumhand, movingobjectpositionblock);
  
                                  if (enuminteractionresult.consumesAction()) {
-@@ -1281,6 +1718,8 @@
+@@ -1281,6 +1755,8 @@
      @Override
      public void handleUseItem(ServerboundUseItemPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -808,7 +849,7 @@
          if (this.player.hasClientLoaded()) {
              this.ackBlockChangesUpTo(packet.getSequence());
              ServerLevel worldserver = this.player.serverLevel();
-@@ -1296,6 +1735,47 @@
+@@ -1296,6 +1772,47 @@
                      this.player.absRotateTo(f, f1);
                  }
  
@@ -856,7 +897,7 @@
                  InteractionResult enuminteractionresult = this.player.gameMode.useItem(this.player, worldserver, itemstack, enumhand);
  
                  if (enuminteractionresult instanceof InteractionResult.Success) {
-@@ -1321,7 +1801,7 @@
+@@ -1321,7 +1838,7 @@
                  Entity entity = packet.getEntity(worldserver);
  
                  if (entity != null) {
@@ -865,7 +906,7 @@
                      return;
                  }
              }
-@@ -1342,6 +1822,13 @@
+@@ -1342,6 +1859,13 @@
  
      @Override
      public void onDisconnect(DisconnectionDetails info) {
@@ -879,7 +920,7 @@
          ServerGamePacketListenerImpl.LOGGER.info("{} lost connection: {}", this.player.getName().getString(), info.reason().getString());
          this.removePlayerFromWorld();
          super.onDisconnect(info);
-@@ -1349,10 +1836,20 @@
+@@ -1349,10 +1873,20 @@
  
      private void removePlayerFromWorld() {
          this.chatMessageChain.close();
@@ -902,7 +943,7 @@
          this.player.getTextFilter().leave();
      }
  
-@@ -1367,7 +1864,16 @@
+@@ -1367,7 +1901,16 @@
      @Override
      public void handleSetCarriedItem(ServerboundSetCarriedItemPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -919,7 +960,7 @@
              if (this.player.getInventory().selected != packet.getSlot() && this.player.getUsedItemHand() == InteractionHand.MAIN_HAND) {
                  this.player.stopUsingItem();
              }
-@@ -1376,11 +1882,18 @@
+@@ -1376,11 +1919,18 @@
              this.player.resetLastActionTime();
          } else {
              ServerGamePacketListenerImpl.LOGGER.warn("{} tried to set an invalid carried item", this.player.getName().getString());
@@ -938,7 +979,7 @@
          Optional<LastSeenMessages> optional = this.unpackAndApplyLastSeen(packet.lastSeenMessages());
  
          if (!optional.isEmpty()) {
-@@ -1394,27 +1907,44 @@
+@@ -1394,27 +1944,44 @@
                      return;
                  }
  
@@ -990,7 +1031,7 @@
          ParseResults<CommandSourceStack> parseresults = this.parseCommand(command);
  
          if (this.server.enforceSecureProfile() && SignableCommand.hasSignableArguments(parseresults)) {
-@@ -1431,19 +1961,37 @@
+@@ -1431,19 +1998,37 @@
  
          if (!optional.isEmpty()) {
              this.tryHandleChat(packet.command(), () -> {
@@ -1032,7 +1073,7 @@
          } catch (SignedMessageChain.DecodeException signedmessagechain_a) {
              this.handleMessageDecodeFailure(signedmessagechain_a);
              return;
-@@ -1451,10 +1999,10 @@
+@@ -1451,10 +2036,10 @@
  
          CommandSigningContext.SignedArguments commandsigningcontext_a = new CommandSigningContext.SignedArguments(map);
  
@@ -1045,7 +1086,7 @@
      }
  
      private void handleMessageDecodeFailure(SignedMessageChain.DecodeException exception) {
-@@ -1530,14 +2078,20 @@
+@@ -1530,14 +2115,20 @@
          return com_mojang_brigadier_commanddispatcher.parse(command, this.player.createCommandSourceStack());
      }
  
@@ -1070,10 +1111,12 @@
          }
      }
  
-@@ -1566,6 +2120,127 @@
+@@ -1564,8 +2155,129 @@
-         return false;
+         }
-     }
  
+         return false;
++    }
++
 +    // CraftBukkit start - add method
 +    public void chat(String s, PlayerChatMessage original, boolean async) {
 +        if (s.isEmpty() || this.player.getChatVisibility() == ChatVisiblity.HIDDEN) {
@@ -1166,8 +1209,8 @@
 +                this.server.console.sendMessage(s);
 +            }
 +        }
-+    }
+     }
-+
+ 
 +    private void handleCommand(String s) {
 +        org.spigotmc.AsyncCatcher.catchOp("Command Dispatched Async: " + s); // Paper - Add async catcher
 +        if ( org.spigotmc.SpigotConfig.logCommands ) // Spigot
@@ -1198,7 +1241,7 @@
      private PlayerChatMessage getSignedMessage(ServerboundChatPacket packet, LastSeenMessages lastSeenMessages) throws SignedMessageChain.DecodeException {
          SignedMessageBody signedmessagebody = new SignedMessageBody(packet.message(), packet.timeStamp(), packet.salt(), lastSeenMessages);
  
-@@ -1573,13 +2248,42 @@
+@@ -1573,13 +2285,42 @@
      }
  
      private void broadcastChatMessage(PlayerChatMessage message) {
@@ -1246,7 +1289,7 @@
              this.disconnect((Component) Component.translatable("disconnect.spam"));
          }
  
-@@ -1601,7 +2305,33 @@
+@@ -1601,7 +2342,33 @@
      @Override
      public void handleAnimate(ServerboundSwingPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -1280,7 +1323,7 @@
          this.player.swing(packet.getHand());
      }
  
-@@ -1609,6 +2339,29 @@
+@@ -1609,6 +2376,29 @@
      public void handlePlayerCommand(ServerboundPlayerCommandPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
          if (this.player.hasClientLoaded()) {
@@ -1310,7 +1353,7 @@
              this.player.resetLastActionTime();
              Entity entity;
              PlayerRideableJumping ijumpable;
-@@ -1616,6 +2369,11 @@
+@@ -1616,6 +2406,11 @@
              switch (packet.getAction()) {
                  case PRESS_SHIFT_KEY:
                      this.player.setShiftKeyDown(true);
@@ -1322,7 +1365,7 @@
                      break;
                  case RELEASE_SHIFT_KEY:
                      this.player.setShiftKeyDown(false);
-@@ -1691,6 +2449,12 @@
+@@ -1691,6 +2486,12 @@
      }
  
      public void sendPlayerChatMessage(PlayerChatMessage message, ChatType.Bound params) {
@@ -1335,7 +1378,7 @@
          this.send(new ClientboundPlayerChatPacket(message.link().sender(), message.link().index(), message.signature(), message.signedBody().pack(this.messageSignatureCache), message.unsignedContent(), message.filterMask(), params));
          this.addPendingMessage(message);
      }
-@@ -1703,6 +2467,13 @@
+@@ -1703,6 +2504,13 @@
          return this.connection.getRemoteAddress();
      }
  
@@ -1349,7 +1392,7 @@
      public void switchToConfig() {
          this.waitingForSwitchToConfig = true;
          this.removePlayerFromWorld();
-@@ -1718,9 +2489,17 @@
+@@ -1718,9 +2526,17 @@
      @Override
      public void handleInteract(ServerboundInteractPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -1367,7 +1410,7 @@
  
              this.player.resetLastActionTime();
              this.player.setShiftKeyDown(packet.isUsingSecondaryAction());
-@@ -1733,20 +2512,58 @@
+@@ -1733,20 +2549,58 @@
  
                  if (this.player.canInteractWithEntity(axisalignedbb, 3.0D)) {
                      packet.dispatch(new ServerboundInteractPacket.Handler() {
@@ -1383,7 +1426,7 @@
 +                                ItemStack itemInHand = ServerGamePacketListenerImpl.this.player.getItemInHand(enumhand);
 +                                boolean triggerLeashUpdate = itemInHand != null && itemInHand.getItem() == Items.LEAD && entity instanceof Mob;
 +                                Item origItem = ServerGamePacketListenerImpl.this.player.getInventory().getSelected() == null ? null : ServerGamePacketListenerImpl.this.player.getInventory().getSelected().getItem();
-+
+ 
 +                                ServerGamePacketListenerImpl.this.cserver.getPluginManager().callEvent(event);
 +
 +                                // Entity in bucket - SPIGOT-4048 and SPIGOT-6859a
@@ -1412,7 +1455,7 @@
 +                                }
 +                                // CraftBukkit end
 +                                InteractionResult enuminteractionresult = playerconnection_a.run(ServerGamePacketListenerImpl.this.player, entity, enumhand);
- 
++
 +                                // CraftBukkit start
 +                                if (!itemInHand.isEmpty() && itemInHand.getCount() <= -1) {
 +                                    ServerGamePacketListenerImpl.this.player.containerMenu.sendAllDataToRemote();
@@ -1430,7 +1473,7 @@
                                      }
                                  }
  
-@@ -1755,19 +2572,20 @@
+@@ -1755,19 +2609,20 @@
  
                          @Override
                          public void onInteraction(InteractionHand hand) {
@@ -1454,7 +1497,7 @@
                                  label23:
                                  {
                                      if (entity instanceof AbstractArrow) {
-@@ -1785,6 +2603,11 @@
+@@ -1785,6 +2640,11 @@
                                      }
  
                                      ServerGamePacketListenerImpl.this.player.attack(entity);
@@ -1466,7 +1509,7 @@
                                      return;
                                  }
                              }
-@@ -1795,7 +2618,26 @@
+@@ -1795,7 +2655,26 @@
                      });
                  }
              }
@@ -1493,7 +1536,7 @@
          }
      }
  
-@@ -1809,7 +2651,7 @@
+@@ -1809,7 +2688,7 @@
              case PERFORM_RESPAWN:
                  if (this.player.wonGame) {
                      this.player.wonGame = false;
@@ -1502,7 +1545,7 @@
                      this.resetPosition();
                      CriteriaTriggers.CHANGED_DIMENSION.trigger(this.player, Level.END, Level.OVERWORLD);
                  } else {
-@@ -1817,11 +2659,11 @@
+@@ -1817,11 +2696,11 @@
                          return;
                      }
  
@@ -1516,7 +1559,7 @@
                      }
                  }
                  break;
-@@ -1834,15 +2676,21 @@
+@@ -1834,15 +2713,21 @@
      @Override
      public void handleContainerClose(ServerboundContainerClosePacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -1540,7 +1583,7 @@
                  this.player.containerMenu.sendAllDataToRemote();
              } else if (!this.player.containerMenu.stillValid(this.player)) {
                  ServerGamePacketListenerImpl.LOGGER.debug("Player {} interacted with invalid menu {}", this.player, this.player.containerMenu);
-@@ -1855,7 +2703,284 @@
+@@ -1855,7 +2740,284 @@
                      boolean flag = packet.getStateId() != this.player.containerMenu.getStateId();
  
                      this.player.containerMenu.suppressRemoteUpdates();
@@ -1826,7 +1869,7 @@
                      ObjectIterator objectiterator = Int2ObjectMaps.fastIterable(packet.getChangedSlots()).iterator();
  
                      while (objectiterator.hasNext()) {
-@@ -1901,8 +3026,22 @@
+@@ -1901,8 +3063,22 @@
                                  return;
                              }
  
@@ -1850,7 +1893,7 @@
                              if (containerrecipebook_a == RecipeBookMenu.PostPlaceAction.PLACE_GHOST_RECIPE) {
                                  this.player.connection.send(new ClientboundPlaceGhostRecipePacket(this.player.containerMenu.containerId, craftingmanager_d.display().display()));
                              }
-@@ -1917,6 +3056,7 @@
+@@ -1917,6 +3093,7 @@
      @Override
      public void handleContainerButtonClick(ServerboundContainerButtonClickPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -1858,7 +1901,7 @@
          this.player.resetLastActionTime();
          if (this.player.containerMenu.containerId == packet.containerId() && !this.player.isSpectator()) {
              if (!this.player.containerMenu.stillValid(this.player)) {
-@@ -1945,7 +3085,44 @@
+@@ -1945,7 +3122,44 @@
  
              boolean flag1 = packet.slotNum() >= 1 && packet.slotNum() <= 45;
              boolean flag2 = itemstack.isEmpty() || itemstack.getCount() <= itemstack.getMaxStackSize();
@@ -1866,7 +1909,7 @@
 +                // CraftBukkit start - Call click event
 +                InventoryView inventory = this.player.inventoryMenu.getBukkitView();
 +                org.bukkit.inventory.ItemStack item = CraftItemStack.asBukkitCopy(packet.itemStack());
- 
++
 +                SlotType type = SlotType.QUICKBAR;
 +                if (flag) {
 +                    type = SlotType.OUTSIDE;
@@ -1881,7 +1924,7 @@
 +                this.cserver.getPluginManager().callEvent(event);
 +
 +                itemstack = CraftItemStack.asNMSCopy(event.getCursor());
-+
+ 
 +                switch (event.getResult()) {
 +                case ALLOW:
 +                    // Plugin cleared the id / stacksize checks
@@ -1903,7 +1946,7 @@
              if (flag1 && flag2) {
                  this.player.inventoryMenu.getSlot(packet.slotNum()).setByPlayer(itemstack);
                  this.player.inventoryMenu.setRemoteSlot(packet.slotNum(), itemstack);
-@@ -1972,6 +3149,7 @@
+@@ -1972,6 +3186,7 @@
      }
  
      private void updateSignText(ServerboundSignUpdatePacket packet, List<FilteredText> signText) {
@@ -1911,7 +1954,7 @@
          this.player.resetLastActionTime();
          ServerLevel worldserver = this.player.serverLevel();
          BlockPos blockposition = packet.getPos();
-@@ -1993,7 +3171,17 @@
+@@ -1993,7 +3208,17 @@
      @Override
      public void handlePlayerAbilities(ServerboundPlayerAbilitiesPacket packet) {
          PacketUtils.ensureRunningOnSameThread(packet, this, this.player.serverLevel());
@@ -1930,7 +1973,7 @@
      }
  
      @Override
-@@ -2002,6 +3190,7 @@
+@@ -2002,6 +3227,7 @@
          boolean flag = this.player.isModelPartShown(PlayerModelPart.HAT);
  
          this.player.updateOptions(packet.information());
@@ -1938,7 +1981,7 @@
          if (this.player.isModelPartShown(PlayerModelPart.HAT) != flag) {
              this.server.getPlayerList().broadcastAll(new ClientboundPlayerInfoUpdatePacket(ClientboundPlayerInfoUpdatePacket.Action.UPDATE_HAT, this.player));
          }
-@@ -2058,7 +3247,7 @@
+@@ -2058,7 +3284,7 @@
          if (!this.waitingForSwitchToConfig) {
              throw new IllegalStateException("Client acknowledged config, but none was requested");
          } else {
@@ -1947,7 +1990,7 @@
          }
      }
  
-@@ -2083,8 +3272,10 @@
+@@ -2083,8 +3309,10 @@
          });
      }
  

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java

@@ -2297,7 +2297,7 @@ public final class CraftServer implements Server {
             offers = this.tabCompleteChat(player, message);
         }
 
-        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers);
+        TabCompleteEvent tabEvent = new TabCompleteEvent(player, message, offers, message.startsWith("/") || forceCommand, pos != null ? io.papermc.paper.util.MCUtil.toLocation(((CraftWorld) player.getWorld()).getHandle(), BlockPos.containing(pos)) : null); // Paper - AsyncTabCompleteEvent
         this.getPluginManager().callEvent(tabEvent);
 
         return tabEvent.isCancelled() ? Collections.EMPTY_LIST : tabEvent.getCompletions();

paper-server/src/main/java/org/bukkit/craftbukkit/command/ConsoleCommandCompleter.java

@@ -28,6 +28,61 @@ 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
+        final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent event =
+            new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(server.getConsoleSender(), buffer, true, null);
+        event.callEvent();
+        final List<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> completions = event.isCancelled() ? com.google.common.collect.ImmutableList.of() : event.completions();
+
+        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<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> finalCompletions = new java.util.ArrayList<>(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.stream()
+                                .map(com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion::suggestion)
+                                .collect(java.util.stream.Collectors.toList()));
+                        return syncEvent.callEvent() ? syncEvent.getCompletions() : com.google.common.collect.ImmutableList.of();
+                    }
+                };
+                server.getServer().processQueue.add(syncCompletions);
+                try {
+                    final List<String> legacyCompletions = syncCompletions.get();
+                    completions.removeIf(it -> !legacyCompletions.contains(it.suggestion())); // remove any suggestions that were removed
+                    // add any new suggestions
+                    for (final String completion : legacyCompletions) {
+                        if (notNewSuggestion(completions, completion)) {
+                            continue;
+                        }
+                        completions.add(com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion.completion(completion));
+                    }
+                } catch (InterruptedException | ExecutionException e1) {
+                    e1.printStackTrace();
+                }
+            }
+
+            if (!completions.isEmpty()) {
+                for (final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion completion : completions) {
+                    if (completion.suggestion().isEmpty()) {
+                        continue;
+                    }
+                    candidates.add(new Candidate(
+                        completion.suggestion(),
+                        completion.suggestion(),
+                        null,
+                        io.papermc.paper.adventure.PaperAdventure.PLAIN.serializeOr(completion.tooltip(), null),
+                        null,
+                        null,
+                        false
+                    ));
+                }
+            }
+            return;
+        }
+
         // Paper end
         Waitable<List<String>> waitable = new Waitable<List<String>>() {
             @Override
@@ -73,4 +128,15 @@ public class ConsoleCommandCompleter implements Completer {
             Thread.currentThread().interrupt();
         }
     }
+
+    // Paper start
+    private boolean notNewSuggestion(final List<com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion> completions, final String completion) {
+        for (final com.destroystokyo.paper.event.server.AsyncTabCompleteEvent.Completion it : completions) {
+            if (it.suggestion().equals(completion)) {
+                return true;
+            }
+        }
+        return false;
+    }
+    // Paper end
 }