From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 19 Apr 2020 04:28:29 -0400
Subject: [PATCH] Load Chunks for Login Asynchronously


diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index 73dc7394a7209a8cd1eec40115cb6e7828f1dbd6..30f8f4a8314c849a66143a545c1af3440965c6aa 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -178,6 +178,7 @@ public class ServerPlayer extends Player {
     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_XZ = 32;
     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_Y = 10;
     public ServerGamePacketListenerImpl connection;
+    public net.minecraft.network.Connection networkManager; // Paper
     public final MinecraftServer server;
     public final ServerPlayerGameMode gameMode;
     private final PlayerAdvancements advancements;
@@ -244,6 +245,7 @@ public class ServerPlayer extends Player {
     public boolean joining = true;
     public boolean sentListPacket = false;
     public boolean supressTrackerForLogin = false; // Paper
+    public boolean didPlayerJoinEvent = false; // Paper
     public Integer clientViewDistance;
     // CraftBukkit end
     public PlayerNaturallySpawnCreaturesEvent playerNaturallySpawnedEvent; // Paper
diff --git a/src/main/java/net/minecraft/server/level/TicketType.java b/src/main/java/net/minecraft/server/level/TicketType.java
index be677d437d17b74c6188ce1bd5fc6fdc228fd92f..78fbb4c3e52e900956ae0811aaf934c81ee5ea48 100644
--- a/src/main/java/net/minecraft/server/level/TicketType.java
+++ b/src/main/java/net/minecraft/server/level/TicketType.java
@@ -23,6 +23,7 @@ public class TicketType<T> {
     public static final TicketType<ChunkPos> FORCED = TicketType.create("forced", Comparator.comparingLong(ChunkPos::toLong));
     public static final TicketType<ChunkPos> LIGHT = TicketType.create("light", Comparator.comparingLong(ChunkPos::toLong));
     public static final TicketType<BlockPos> PORTAL = TicketType.create("portal", Vec3i::compareTo, 300);
+    public static final TicketType<Long> LOGIN = create("login", Long::compareTo, 100); // Paper
     public static final TicketType<Integer> POST_TELEPORT = TicketType.create("post_teleport", Integer::compareTo, 5);
     public static final TicketType<ChunkPos> UNKNOWN = TicketType.create("unknown", Comparator.comparingLong(ChunkPos::toLong), 1);
     public static final TicketType<Unit> PLUGIN = TicketType.create("plugin", (a, b) -> 0); // CraftBukkit
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 67ede93bed3fafcb548c394397bcc2ca7a86c39f..36815e17d521e420fb04db108a12c2b9d1a9dce8 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -220,6 +220,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
     private static final int LATENCY_CHECK_INTERVAL = 15000;
     public final Connection connection;
     private final MinecraftServer server;
+    public Runnable playerJoinReady; // Paper
     public ServerPlayer player;
     private int tickCount;
     private long keepAliveTime = Util.getMillis();
@@ -294,6 +295,15 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
     // CraftBukkit end
 
     public void tick() {
+        // Paper start - login async
+        Runnable playerJoinReady = this.playerJoinReady;
+        if (playerJoinReady != null) {
+            this.playerJoinReady = null;
+            playerJoinReady.run();
+        }
+        // Don't tick if not valid (dead), otherwise we load chunks below
+        if (this.player.valid) {
+        // Paper end
         this.resetPosition();
         this.player.xo = this.player.getX();
         this.player.yo = this.player.getY();
@@ -335,7 +345,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
             this.lastVehicle = null;
             this.clientVehicleIsFloating = false;
             this.aboveGroundVehicleTickCount = 0;
-        }
+        }} // Paper - end if (valid)
 
         this.server.getProfiler().push("keepAlive");
         // Paper Start - give clients a longer time to respond to pings as per pre 1.12.2 timings
diff --git a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
index b5d8987d2903086d69bbd6ba8092e568c94be63f..bd1203a5b58bac7cccf1f81337fa2967a0e9eb40 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -88,7 +88,7 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener
             }
             // Paper end
         } else if (this.state == ServerLoginPacketListenerImpl.State.DELAY_ACCEPT) {
-            ServerPlayer entityplayer = this.server.getPlayerList().getPlayer(this.gameProfile.getId());
+            ServerPlayer entityplayer = this.server.getPlayerList().getActivePlayer(this.gameProfile.getId()); // Paper
 
             if (entityplayer == null) {
                 this.state = ServerLoginPacketListenerImpl.State.READY_TO_ACCEPT;
@@ -194,7 +194,7 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener
             }
 
             this.connection.send(new ClientboundGameProfilePacket(this.gameProfile));
-            ServerPlayer entityplayer = this.server.getPlayerList().getPlayer(this.gameProfile.getId());
+            ServerPlayer entityplayer = this.server.getPlayerList().getActivePlayer(this.gameProfile.getId()); // Paper
 
             try {
                 ServerPlayer entityplayer1 = this.server.getPlayerList().processLogin(this.gameProfile, s); // CraftBukkit - add player reference
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 9609579e6d61c3975740d07a394680aeef952516..6b23b9389ff92ae8016d4adb289ac2a097670be5 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -40,6 +40,7 @@ import net.minecraft.network.protocol.Packet;
 import net.minecraft.network.protocol.game.ClientboundChangeDifficultyPacket;
 import net.minecraft.network.protocol.game.ClientboundChatPacket;
 import net.minecraft.network.protocol.game.ClientboundCustomPayloadPacket;
+import net.minecraft.network.protocol.game.ClientboundDisconnectPacket;
 import net.minecraft.network.protocol.game.ClientboundEntityEventPacket;
 import net.minecraft.network.protocol.game.ClientboundGameEventPacket;
 import net.minecraft.network.protocol.game.ClientboundInitializeBorderPacket;
@@ -135,6 +136,7 @@ public abstract class PlayerList {
     private final IpBanList ipBans;
     private final ServerOpList ops;
     private final UserWhiteList whitelist;
+    private final Map<UUID, ServerPlayer> pendingPlayers = Maps.newHashMap(); // Paper
     // CraftBukkit start
     // private final Map<UUID, ServerStatisticManager> stats;
     // private final Map<UUID, AdvancementDataPlayer> advancements;
@@ -173,6 +175,11 @@ public abstract class PlayerList {
     }
 
     public void placeNewPlayer(Connection connection, ServerPlayer player) {
+        ServerPlayer prev = pendingPlayers.put(player.getUUID(), player);// Paper
+        if (prev != null) {
+            disconnectPendingPlayer(prev);
+        }
+        player.networkManager = connection; // Paper
         player.loginTime = System.currentTimeMillis(); // Paper
         GameProfile gameprofile = player.getGameProfile();
         GameProfileCache usercache = this.server.getProfileCache();
@@ -186,7 +193,7 @@ public abstract class PlayerList {
         if (nbttagcompound != null && nbttagcompound.contains("bukkit")) {
             CompoundTag bukkit = nbttagcompound.getCompound("bukkit");
             s = bukkit.contains("lastKnownName", 8) ? bukkit.getString("lastKnownName") : s;
-        }
+        }String lastKnownName = s; // Paper
         // CraftBukkit end
 
         if (nbttagcompound != null) {
@@ -260,6 +267,52 @@ public abstract class PlayerList {
         player.getRecipeBook().sendInitialRecipeBook(player);
         this.updateEntireScoreboard(worldserver1.getScoreboard(), player);
         this.server.invalidateStatus();
+        // Paper start - async load spawn in chunk
+        ServerLevel finalWorldserver = worldserver1;
+        int chunkX = loc.getBlockX() >> 4;
+        int chunkZ = loc.getBlockZ() >> 4;
+        final net.minecraft.world.level.ChunkPos pos = new net.minecraft.world.level.ChunkPos(chunkX, chunkZ);
+        net.minecraft.server.level.ChunkMap playerChunkMap = worldserver1.getChunkSource().chunkMap;
+        net.minecraft.server.level.DistanceManager distanceManager = playerChunkMap.distanceManager;
+        distanceManager.addTicketAtLevel(net.minecraft.server.level.TicketType.LOGIN, pos, 31, pos.toLong());
+        worldserver1.getChunkSource().runDistanceManagerUpdates();
+        worldserver1.getChunkSource().getChunkAtAsynchronously(chunkX, chunkZ, true, true).thenApply(chunk -> {
+            net.minecraft.server.level.ChunkHolder updatingChunk = playerChunkMap.getUpdatingChunkIfPresent(pos.toLong());
+            if (updatingChunk != null) {
+                return updatingChunk.getEntityTickingChunkFuture();
+            } else {
+                return java.util.concurrent.CompletableFuture.completedFuture(chunk);
+            }
+        }).thenAccept(chunk -> {
+            playerconnection.playerJoinReady = () -> {
+                postChunkLoadJoin(
+                    player, finalWorldserver, connection, playerconnection,
+                    nbttagcompound, connection.getRemoteAddress().toString(), lastKnownName
+                );
+            };
+        });
+    }
+
+    public ServerPlayer getActivePlayer(UUID uuid) {
+        ServerPlayer player = this.playersByUUID.get(uuid);
+        return player != null ? player : pendingPlayers.get(uuid);
+    }
+
+    void disconnectPendingPlayer(ServerPlayer entityplayer) {
+        TranslatableComponent msg = new TranslatableComponent("multiplayer.disconnect.duplicate_login", new Object[0]);
+        entityplayer.networkManager.send(new ClientboundDisconnectPacket(msg), (future) -> {
+            entityplayer.networkManager.disconnect(msg);
+            entityplayer.networkManager = null;
+        });
+    }
+
+    private void postChunkLoadJoin(ServerPlayer player, ServerLevel worldserver1, Connection networkmanager, ServerGamePacketListenerImpl playerconnection, CompoundTag nbttagcompound, String s1, String s) {
+        pendingPlayers.remove(player.getUUID(), player);
+        if (!networkmanager.isConnected()) {
+            return;
+        }
+        player.didPlayerJoinEvent = true;
+        // Paper end
         TranslatableComponent chatmessage;
 
         if (player.getGameProfile().getName().equalsIgnoreCase(s)) {
@@ -503,6 +556,7 @@ public abstract class PlayerList {
 
     protected void save(ServerPlayer player) {
         if (!player.getBukkitEntity().isPersistent()) return; // CraftBukkit
+        if (!player.didPlayerJoinEvent) return; // Paper - If we never fired PJE, we disconnected during login. Data has not changed, and additionally, our saved vehicle is not loaded! If we save now, we will lose our vehicle (CraftBukkit bug)
         this.playerIo.save(player);
         ServerStatsCounter serverstatisticmanager = (ServerStatsCounter) player.getStats(); // CraftBukkit
 
@@ -530,7 +584,7 @@ public abstract class PlayerList {
         }
 
         PlayerQuitEvent playerQuitEvent = new PlayerQuitEvent(entityplayer.getBukkitEntity(), net.kyori.adventure.text.Component.translatable("multiplayer.player.left", net.kyori.adventure.text.format.NamedTextColor.YELLOW, com.destroystokyo.paper.PaperConfig.useDisplayNameInQuit ? entityplayer.getBukkitEntity().displayName() : net.kyori.adventure.text.Component.text(entityplayer.getScoreboardName())));
-        this.cserver.getPluginManager().callEvent(playerQuitEvent);
+        if (entityplayer.didPlayerJoinEvent) this.cserver.getPluginManager().callEvent(playerQuitEvent); // Paper - if we disconnected before join ever fired, don't fire quit
         entityplayer.getBukkitEntity().disconnect(playerQuitEvent.getQuitMessage());
 
         if (server.isSameThread()) entityplayer.doTick(); // SPIGOT-924 // Paper - don't tick during emergency shutdowns (Watchdog)
@@ -575,6 +629,13 @@ public abstract class PlayerList {
             // this.advancements.remove(uuid);
             // CraftBukkit end
         }
+        // Paper start
+        entityplayer1 = pendingPlayers.get(uuid);
+        if (entityplayer1 == entityplayer) {
+            pendingPlayers.remove(uuid);
+        }
+        entityplayer.networkManager = null;
+        // Paper end
 
         // CraftBukkit start
         // this.sendAll(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.REMOVE_PLAYER, new EntityPlayer[]{entityplayer}));
@@ -592,7 +653,7 @@ public abstract class PlayerList {
         this.cserver.getScoreboardManager().removePlayer(entityplayer.getBukkitEntity());
         // CraftBukkit end
 
-        return playerQuitEvent.quitMessage(); // Paper - Adventure
+        return entityplayer.didPlayerJoinEvent ? playerQuitEvent.quitMessage() : null; // CraftBukkit // Paper - Adventure // Paper - don't print quit if we never printed join
     }
 
     // CraftBukkit start - Whole method, SocketAddress to LoginListener, added hostname to signature, return EntityPlayer
@@ -611,6 +672,13 @@ public abstract class PlayerList {
                 list.add(entityplayer);
             }
         }
+        // Paper start - check pending players too
+        entityplayer = pendingPlayers.get(uuid);
+        if (entityplayer != null) {
+            this.pendingPlayers.remove(uuid);
+            disconnectPendingPlayer(entityplayer);
+        }
+        // Paper end
 
         Iterator iterator = list.iterator();
 
