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 3a40d6fe9edbd997dc9a6b8ac009c3f621ecfe51..8dc31f65126db6b2527d4106a885cb9b6dbc7a75 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -182,6 +182,7 @@ 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;
@@ -255,6 +256,7 @@ 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;
     public String kickLeaveMessage = null; // SPIGOT-3034: Forward leave message to PlayerQuitEvent
     // CraftBukkit end
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 e1e35bd6fb827149b23da4d19876a9a6989dde7e..4408c30532119277abb1027cd5a08e4cb9ebe587 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -251,6 +251,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
     private static final int PENDING_MESSAGE_DISCONNECT_THRESHOLD = 4096;
     public final Connection connection;
     private final MinecraftServer server;
+    public Runnable playerJoinReady; // Paper
     public ServerPlayer player;
     private int tickCount;
     private int ackBlockChangesUpTo = -1;
@@ -343,6 +344,15 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
 
     @Override
     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
         if (this.ackBlockChangesUpTo > -1) {
             this.send(new ClientboundBlockChangedAckPacket(this.ackBlockChangesUpTo));
             this.ackBlockChangesUpTo = -1;
@@ -389,7 +399,7 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
             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 63abdc84bbd8d3ef78e18ffe792f2f1e5035e2ff..11a7b79b25f3ad83687f6f9076231e227ebea165 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -95,7 +95,7 @@ public class ServerLoginPacketListenerImpl implements TickablePacketListener, Se
             }
             // 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;
@@ -204,7 +204,7 @@ public class ServerLoginPacketListenerImpl implements TickablePacketListener, Se
             }
 
             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().getPlayerForLogin(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 1f32ba033eedcb69b02c29da8594be9edf958f43..4173c9c364be3a266a8ba43b384ee230e6f98f62 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -139,6 +139,7 @@ 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;
@@ -178,6 +179,11 @@ 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();
@@ -191,7 +197,7 @@ 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) {
@@ -218,11 +224,15 @@ public abstract class PlayerList {
         if (nbttagcompound == null) player.fudgeSpawnLocation(worldserver1); // Paper - only move to spawn on first login, otherwise, stay where you are....
 
         player.setLevel(worldserver1);
-        String s1 = "local";
+        // Paper start - make s1 final
+        final String s1;
 
         if (connection.getRemoteAddress() != null) {
             s1 = connection.getRemoteAddress().toString();
+        } else {
+            s1 = "local";
         }
+        // Paper end
 
         // Spigot start - spawn location event
         Player spawnPlayer = player.getBukkitEntity();
@@ -264,6 +274,52 @@ 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.addTicket(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, s1, lastKnownName
+                );
+            };
+        });
+    }
+
+    public ServerPlayer getActivePlayer(UUID uuid) {
+        ServerPlayer player = this.playersByUUID.get(uuid);
+        return player != null ? player : pendingPlayers.get(uuid);
+    }
+
+    void disconnectPendingPlayer(ServerPlayer entityplayer) {
+        Component msg = Component.translatable("multiplayer.disconnect.duplicate_login");
+        entityplayer.networkManager.send(new net.minecraft.network.protocol.game.ClientboundDisconnectPacket(msg), net.minecraft.network.PacketSendListener.thenRun(() -> {
+            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
         MutableComponent ichatmutablecomponent;
 
         if (player.getGameProfile().getName().equalsIgnoreCase(s)) {
@@ -505,6 +561,7 @@ 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
 
@@ -532,7 +589,7 @@ 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, io.papermc.paper.configuration.GlobalConfiguration.get().messages.useDisplayNameInQuitMessage ? 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)
@@ -577,6 +634,13 @@ 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.broadcastAll(new PacketPlayOutPlayerInfo(PacketPlayOutPlayerInfo.EnumPlayerInfoAction.REMOVE_PLAYER, new EntityPlayer[]{entityplayer}));
@@ -594,7 +658,7 @@ 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
@@ -613,6 +677,13 @@ 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();
 
