Paper/patches/server/0400-Load-Chunks-for-Login-Asynchronously.patch

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/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index f5a9edf47230a1552a36ee5de4cb7560ea9ba7c4..a778b4b5b2413c25c2f0f0efc72ba1d362d89acf 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -170,6 +170,7 @@ import org.bukkit.event.world.GenericGameEvent;
 import org.bukkit.event.world.TimeSkipEvent;
 // CraftBukkit end
 import it.unimi.dsi.fastutil.ints.IntArrayList; // Paper
+import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet; // Paper
 
 public class ServerLevel extends Level implements WorldGenLevel {
 
@@ -406,6 +407,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
         return this.getServer().getPlayerList().getPlayer(uuid);
     }
     // Paper end
+    public final ReferenceOpenHashSet<ServerPlayer> pendingLogin = new ReferenceOpenHashSet<>(); // Paper
 
     // Add env and gen to constructor, IWorldDataServer -> WorldDataServer
     public ServerLevel(MinecraftServer minecraftserver, Executor executor, LevelStorageSource.LevelStorageAccess convertable_conversionsession, PrimaryLevelData iworlddataserver, ResourceKey<Level> resourcekey, LevelStem worlddimension, ChunkProgressListener worldloadlistener, boolean flag, long i, List<CustomSpawner> list, boolean flag1, org.bukkit.World.Environment env, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider) {
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index 53dcb40f5217d560ee42da3d73d1e66e2620067a..971f72c1dd713077c128279a78ed37f15aedeff6 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;
@@ -256,6 +257,7 @@ 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 478109526cff7ceb0565cea3b5e97b9a07fbf8d1..3c1698ba0d3bc412ab957777d9b5211dbc555208 100644
--- a/src/main/java/net/minecraft/server/level/TicketType.java
+++ b/src/main/java/net/minecraft/server/level/TicketType.java
@@ -25,6 +25,7 @@ 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 0df93b204ddf55a2a3b8af33d6a3273697eea91e..88d4c2a9c628d32f1633a376eff37c3e6ae33a72 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -346,6 +346,10 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Tic
 
     @Override
     public void tick() {
+        // Paper start - login async
+        // 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;
@@ -392,7 +396,7 @@ 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 c83395364edb4f2ba8515326b19c4f1a436a0502..c99266d4782c5d58339e63f7564c28b4b5b7ac1d 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -90,7 +90,7 @@ 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;
@@ -199,7 +199,7 @@ 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 a7bc7e83b9355ef920d94fff8572528965352fb6..32ab0cd6cb42b0ab8a14f790dfcf4b155c945d6d 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;
@@ -180,6 +181,13 @@ public abstract class PlayerList {
     public void placeNewPlayer(Connection connection, ServerPlayer player) {
         player.isRealPlayer = true; // Paper - Chunk priority
         player.loginTime = System.currentTimeMillis(); // Paper
+        // Paper start
+        ServerPlayer prev = pendingPlayers.put(player.getUUID(), player);
+        if (prev != null) {
+            disconnectPendingPlayer(prev);
+        }
+        player.networkManager = connection;
+        // Paper end
         GameProfile gameprofile = player.getGameProfile();
         GameProfileCache usercache = this.server.getProfileCache();
         Optional<GameProfile> optional = usercache.get(gameprofile.getId());
@@ -192,7 +200,7 @@ 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) {
@@ -219,11 +227,15 @@ 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();
@@ -265,6 +277,56 @@ 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;
+        finalWorldserver.pendingLogin.add(player);
+        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;
+        net.minecraft.server.ChunkSystem.scheduleTickingState(
+            worldserver1, chunkX, chunkZ, net.minecraft.server.level.ChunkHolder.FullChunkStatus.ENTITY_TICKING, true,
+            ca.spottedleaf.concurrentutil.executor.standard.PrioritisedExecutor.Priority.HIGHEST,
+            (chunk) -> {
+                MinecraftServer.getServer().scheduleOnMain(() -> {
+                    try {
+                        if (!playerconnection.connection.isConnected()) {
+                            return;
+                        }
+                        PlayerList.this.postChunkLoadJoin(
+                            player, finalWorldserver, connection, playerconnection,
+                            nbttagcompound, s1, lastKnownName
+                        );
+                        distanceManager.addTicket(net.minecraft.server.level.TicketType.LOGIN, pos, 31, pos.toLong());
+                    } finally {
+                        finalWorldserver.pendingLogin.remove(player);
+                    }
+                });
+            }
+        );
+    }
+
+    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)) {
@@ -506,6 +568,7 @@ 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
 
@@ -533,7 +596,7 @@ 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)
@@ -578,6 +641,13 @@ 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}));
@@ -595,7 +665,7 @@ 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
@@ -614,6 +684,13 @@ 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();
 
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 4016b31bd020e00c0e79328646f9b5411b312e88..c8c11ec3c5c4c4d1ed09163aa6d3a4275e497e11 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1219,7 +1219,7 @@ public final class CraftServer implements Server {
             return false;
         }
 
-        if (handle.players().size() > 0) {
+        if (handle.players().size() > 0 || handle.pendingLogin.size() > 0) { // Paper
             return false;
         }