Version bump

* Cancel swap item, fix #364

* Remove canceling drop item

README.md

@@ -1,4 +1,4 @@
-# ViaVersion 0.7.5
+# ViaVersion 0.7.8
 [![Build Status](https://travis-ci.org/MylesIsCool/ViaVersion.svg?branch=master)](https://travis-ci.org/MylesIsCool/ViaVersion)
 [![Gitter](https://badges.gitter.im/MylesIsCool/ViaVersion.svg)](https://gitter.im/MylesIsCool/ViaVersion)
 

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>us.myles</groupId>
     <artifactId>viaversion</artifactId>
-    <version>0.7.6-SNAPSHOT</version>
+    <version>0.7.9-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>ViaVersion</name>

src/main/java/us/myles/ViaVersion/ViaIdleThread.java

@@ -1,47 +0,0 @@
-package us.myles.ViaVersion;
-
-import io.netty.channel.ChannelHandlerContext;
-import org.bukkit.scheduler.BukkitRunnable;
-import us.myles.ViaVersion.api.data.UserConnection;
-import us.myles.ViaVersion.protocols.base.ProtocolInfo;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9TO1_8;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.MovementTracker;
-import us.myles.ViaVersion.util.PipelineUtil;
-import us.myles.ViaVersion.util.ReflectionUtil;
-
-import java.util.Map;
-import java.util.UUID;
-
-public class ViaIdleThread extends BukkitRunnable {
-    private final Map<UUID, UserConnection> portedPlayers;
-    private final Object idlePacket;
-
-    public ViaIdleThread(Map<UUID, UserConnection> portedPlayers) {
-        this.portedPlayers = portedPlayers;
-        try {
-            Class<?> idlePacketClass = ReflectionUtil.nms("PacketPlayInFlying");
-            idlePacket = idlePacketClass.newInstance();
-        } catch (InstantiationException | IllegalArgumentException | IllegalAccessException | ClassNotFoundException e) {
-            throw new RuntimeException("Couldn't find/make player idle packet, help!", e);
-        }
-    }
-
-    @Override
-    public void run() {
-        for (UserConnection info : portedPlayers.values()) {
-            if (info.get(ProtocolInfo.class).getPipeline().contains(Protocol1_9TO1_8.class)) {
-                long nextIdleUpdate = info.get(MovementTracker.class).getNextIdlePacket();
-                if (nextIdleUpdate <= System.currentTimeMillis()) {
-                    ChannelHandlerContext context = PipelineUtil.getContextBefore("decoder", info.getChannel().pipeline());
-                    if (info.getChannel().isOpen()) {
-                        if (context != null) {
-                            context.fireChannelRead(idlePacket);
-
-                            info.get(MovementTracker.class).incrementIdlePacket();
-                        }
-                    }
-                }
-            }
-        }
-    }
-}

src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -397,6 +397,36 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI, ViaVe
         return getConfig().getBoolean("block-break-patch", true);
     }
 
+    @Override
+    public int getMaxPPS() {
+        return getConfig().getInt("max-pps", 140);
+    }
+
+    @Override
+    public String getMaxPPSKickMessage() {
+        return getConfig().getString("max-pps-kick-msg", "Sending packets too fast? lag?");
+    }
+
+    @Override
+    public int getTrackingPeriod() {
+        return getConfig().getInt("tracking-period", 6);
+    }
+
+    @Override
+    public int getWarningPPS() {
+        return getConfig().getInt("tracking-warning-pps", 120);
+    }
+
+    @Override
+    public int getMaxWarnings() {
+        return getConfig().getInt("tracking-max-warnings", 3);
+    }
+
+    @Override
+    public String getMaxWarningsKickMessage() {
+        return getConfig().getString("tracking-max-kick-msg", "You are sending too many packets, :(");
+    }
+
     public boolean isAutoTeam() {
         // Collision has to be enabled first
         return isPreventCollision() && getConfig().getBoolean("auto-team", true);
@@ -432,4 +462,34 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI, ViaVe
     public Map<UUID, UserConnection> getPortedPlayers() {
         return portedPlayers;
     }
+
+    public boolean handlePPS(UserConnection info) {
+        // Max PPS Checker
+        if (getMaxPPS() > 0) {
+            if (info.getPacketsPerSecond() >= getMaxPPS()) {
+                info.disconnect(getMaxPPSKickMessage());
+                return true; // don't send current packet
+            }
+        }
+
+        // Tracking PPS Checker
+        if (getMaxWarnings() > 0 && getTrackingPeriod() > 0) {
+            if (info.getSecondsObserved() > getTrackingPeriod()) {
+                // Reset
+                info.setWarnings(0);
+                info.setSecondsObserved(1);
+            } else {
+                info.setSecondsObserved(info.getSecondsObserved() + 1);
+                if (info.getPacketsPerSecond() >= getWarningPPS()) {
+                    info.setWarnings(info.getWarnings() + 1);
+                }
+
+                if (info.getWarnings() >= getMaxWarnings()) {
+                    info.disconnect(getMaxWarningsKickMessage());
+                    return true; // don't send current packet
+                }
+            }
+        }
+        return false;
+    }
 }

src/main/java/us/myles/ViaVersion/api/PacketWrapper.java

@@ -56,6 +56,26 @@ public class PacketWrapper {
         throw new InformativeException(e).set("Type", type.getTypeName()).set("Index", index).set("Packet ID", getId()).set("Data", packetValues);
     }
 
+    /**
+     * Check if a type is at an index
+     *
+     * @param type  The type of the part you wish to get.
+     * @param index The index of the part (relative to the type)
+     * @return True if the type is at the index
+     */
+    public boolean is(Type type, int index) {
+        int currentIndex = 0;
+        for (Pair<Type, Object> packetValue : packetValues) {
+            if (packetValue.getKey() == type) { // Ref check
+                if (currentIndex == index) {
+                    return true;
+                }
+                currentIndex++;
+            }
+        }
+        return false;
+    }
+
     /**
      * Set a currently existing part in the output
      *

src/main/java/us/myles/ViaVersion/api/ViaVersionConfig.java

@@ -100,4 +100,46 @@ public interface ViaVersionConfig {
      * @return true if it is enabled.
      */
     boolean isBlockBreakPatch();
+
+    /**
+     * Get the maximum number of packets a client can send per second.
+     *
+     * @return The number of packets a client can send per second.
+     */
+    int getMaxPPS();
+
+    /**
+     * Get the kick message sent if the user hits the max packets per second.
+     *
+     * @return Kick message, with colour codes using '&'
+     */
+    String getMaxPPSKickMessage();
+
+    /**
+     * The time in seconds that should be tracked for warnings
+     *
+     * @return Time in seconds that should be tracked for warnings
+     */
+    int getTrackingPeriod();
+
+    /**
+     * The number of packets per second to count as a warning
+     *
+     * @return The number of packets per second to count as a warning.
+     */
+    int getWarningPPS();
+
+    /**
+     * Get the maximum number of warnings the client can have in the interval
+     *
+     * @return The number of packets a client can send per second.
+     */
+    int getMaxWarnings();
+
+    /**
+     * Get the kick message sent if the user goes over the warnings in the interval
+     *
+     * @return Kick message, with colour codes using '&'
+     */
+    String getMaxWarningsKickMessage();
 }

src/main/java/us/myles/ViaVersion/api/data/UserConnection.java

@@ -1,28 +1,37 @@
 package us.myles.ViaVersion.api.data;
 
+import com.google.gson.Gson;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.socket.SocketChannel;
+import lombok.Data;
 import lombok.Getter;
 import lombok.Setter;
+import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
+import org.bukkit.entity.Player;
+import us.myles.ViaVersion.protocols.base.ProtocolInfo;
 
 import java.util.Map;
+import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 
+@Data
 public class UserConnection {
-    @Getter
     private final SocketChannel channel;
     Map<Class, StoredObject> storedObjects = new ConcurrentHashMap<>();
-    @Getter
-    @Setter
     private boolean active = true;
-    @Getter
-    @Setter
+    private boolean pendingDisconnect = false;
     private Object lastPacket;
-    @Getter
     private long sentPackets = 0L;
-    @Getter
     private long receivedPackets = 0L;
+    // Used for tracking pps
+    private long startTime = 0L;
+    private long intervalPackets = 0L;
+    private long packetsPerSecond = -1L;
+    // Used for handling warnings (over time)
+    private int secondsObserved = 0;
+    private int warnings = 0;
 
 
     public UserConnection(SocketChannel socketChannel) {
@@ -97,7 +106,45 @@ public class UserConnection {
     /**
      * Used for incrementing the number of packets received from the client
      */
-    public void incrementReceived() {
+    public boolean incrementReceived() {
+        // handle stats
+        Long diff = System.currentTimeMillis() - startTime;
+        if (diff >= 1000) {
+            packetsPerSecond = intervalPackets;
+            startTime = System.currentTimeMillis();
+            intervalPackets = 1;
+            return true;
+        } else {
+            intervalPackets++;
+        }
+        // increase total
         this.receivedPackets++;
+        return false;
+    }
+
+    /**
+     * Disconnect a connection
+     *
+     * @param reason The reason to use, not used if player is not active.
+     */
+    public void disconnect(final String reason) {
+        if(!getChannel().isOpen()) return;
+        if(pendingDisconnect) return;
+        pendingDisconnect = true;
+        if (get(ProtocolInfo.class).getUuid() != null) {
+            final UUID uuid = get(ProtocolInfo.class).getUuid();
+            if (Bukkit.getPlayer(uuid) != null) {
+                Bukkit.getScheduler().runTask(Bukkit.getPluginManager().getPlugin("ViaVersion"), new Runnable() {
+                    @Override
+                    public void run() {
+                        Player player = Bukkit.getPlayer(uuid);
+                        if (player != null)
+                            player.kickPlayer(ChatColor.translateAlternateColorCodes('&', reason));
+                    }
+                });
+                return;
+            }
+        }
+        getChannel().close(); // =)
     }
 }

src/main/java/us/myles/ViaVersion/boss/ViaBossBar.java

@@ -153,14 +153,16 @@ public class ViaBossBar implements BossBar {
     }
 
     private void sendPacket(UpdateAction action) {
-        ByteBuf buf = getPacket(action);
-        for (UUID uuid : new ArrayList<>(players))
+        for (UUID uuid : new ArrayList<>(players)) {
+            ByteBuf buf = getPacket(action);
             sendPacket(uuid, buf);
+        }
     }
 
     private void sendPacket(UUID uuid, ByteBuf buf) {
         if (!ViaVersion.getInstance().isPorted(uuid) || !(ViaVersion.getInstance().getPlayerVersion(uuid) >= ProtocolVersion.v1_9.getId())) {
             players.remove(uuid);
+            buf.release();
             return;
         }
         ViaVersion.getInstance().sendRawPacket(uuid, buf);

src/main/java/us/myles/ViaVersion/commands/ViaCommandHandler.java

@@ -130,6 +130,7 @@ public class ViaCommandHandler implements ViaVersionCommand, CommandExecutor, Ta
 
     private void registerDefaults() throws Exception {
         registerSubCommand(new ListSubCmd());
+        registerSubCommand(new PPSSubCmd());
         registerSubCommand(new DebugSubCmd());
         registerSubCommand(new DisplayLeaksSubCmd());
         registerSubCommand(new DontBugMeSubCmd());

src/main/java/us/myles/ViaVersion/commands/defaultsubs/PPSSubCmd.java

@@ -0,0 +1,62 @@
+package us.myles.ViaVersion.commands.defaultsubs;
+
+import org.bukkit.Bukkit;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.api.command.ViaSubCommand;
+import us.myles.ViaVersion.api.data.UserConnection;
+import us.myles.ViaVersion.api.protocol.ProtocolVersion;
+
+import java.util.*;
+
+public class PPSSubCmd extends ViaSubCommand {
+    @Override
+    public String name() {
+        return "pps";
+    }
+
+    @Override
+    public String description() {
+        return "Shows the packets per second of online players";
+    }
+
+    @Override
+    public String usage() {
+        return "pps";
+    }
+
+    @Override
+    public boolean execute(CommandSender sender, String[] args) {
+        Map<Integer, Set<String>> playerVersions = new HashMap<>();
+        int totalPackets = 0;
+        int clients = 0;
+        long max = 0;
+
+        for (Player p : Bukkit.getOnlinePlayers()) {
+            int playerVersion = ViaVersion.getInstance().getPlayerVersion(p);
+            if (!playerVersions.containsKey(playerVersion))
+                playerVersions.put(playerVersion, new HashSet<String>());
+            UserConnection uc = ((ViaVersionPlugin) ViaVersion.getInstance()).getConnection(p);
+            if (uc.getPacketsPerSecond() > -1) {
+                playerVersions.get(playerVersion).add(p.getName() + " (" + uc.getPacketsPerSecond() + " PPS)");
+                totalPackets += uc.getPacketsPerSecond();
+                if (uc.getPacketsPerSecond() > max) {
+                    max = uc.getPacketsPerSecond();
+                }
+                clients++;
+            }
+        }
+        Map<Integer, Set<String>> sorted = new TreeMap<>(playerVersions);
+        sendMessage(sender, "&4Live Packets Per Second");
+        if (clients > 1) {
+            sendMessage(sender, "&cAverage: &f" + (totalPackets / clients));
+            sendMessage(sender, "&cHighest: &f" + max);
+        }
+        for (Map.Entry<Integer, Set<String>> entry : sorted.entrySet())
+            sendMessage(sender, "&8[&6%s&8]: &b%s", ProtocolVersion.getProtocol(entry.getKey()).getName(), entry.getValue());
+        sorted.clear();
+        return true;
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaDecodeHandler.java

@@ -3,7 +3,9 @@ package us.myles.ViaVersion.handlers;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
+import us.myles.ViaVersion.ViaVersionPlugin;
 import us.myles.ViaVersion.api.PacketWrapper;
+import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.exception.CancelException;
@@ -29,9 +31,19 @@ public class ViaDecodeHandler extends ByteToMessageDecoder {
     protected void decode(ChannelHandlerContext ctx, ByteBuf bytebuf, List<Object> list) throws Exception {
         // use transformers
         if (bytebuf.readableBytes() > 0) {
+            // Ignore if pending disconnect
+            if (info.isPendingDisconnect()) {
+                return;
+            }
+            // Increment received
+            boolean second = info.incrementReceived();
+            // Check PPS
+            if(second) {
+                if (((ViaVersionPlugin) ViaVersion.getConfig()).handlePPS(info))
+                    return;
+            }
+
             if (info.isActive()) {
-                // Increment received
-                info.incrementReceived();
                 // Handle ID
                 int id = Type.VAR_INT.read(bytebuf);
                 // Transform

src/main/java/us/myles/ViaVersion/handlers/ViaEncodeHandler.java

@@ -39,9 +39,9 @@ public class ViaEncodeHandler extends MessageToByteEncoder {
         if (bytebuf.readableBytes() == 0) {
             throw new CancelException();
         }
+        // Increment sent
+        info.incrementSent();
         if (info.isActive()) {
-            // Increment sent
-            info.incrementSent();
             // Handle ID
             int id = Type.VAR_INT.read(bytebuf);
             // Transform

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/PlayerMovementMapper.java

@@ -2,17 +2,17 @@ package us.myles.ViaVersion.protocols.protocol1_9to1_8;
 
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.remapper.PacketHandler;
-import us.myles.ViaVersion.api.remapper.PacketRemapper;
+import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.MovementTracker;
 
-public class PlayerMovementMapper extends PacketRemapper {
+public class PlayerMovementMapper extends PacketHandler {
     @Override
-    public void registerMap() {
-        handler(new PacketHandler() {
-            @Override
-            public void handle(PacketWrapper wrapper) throws Exception {
-                wrapper.user().get(MovementTracker.class).incrementIdlePacket();
-            }
-        });
+    public void handle(PacketWrapper wrapper) throws Exception {
+        MovementTracker tracker = wrapper.user().get(MovementTracker.class);
+        tracker.incrementIdlePacket();
+        // If packet has the ground data
+        if (wrapper.is(Type.BOOLEAN, 0)) {
+            tracker.setGround(wrapper.get(Type.BOOLEAN, 0));
+        }
     }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/Protocol1_9TO1_8.java

@@ -4,12 +4,11 @@ import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonObject;
 import org.bukkit.Bukkit;
-import org.bukkit.inventory.ItemStack;
-import us.myles.ViaVersion.ViaIdleThread;
 import us.myles.ViaVersion.ViaVersionPlugin;
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.data.UserConnection;
+import us.myles.ViaVersion.api.minecraft.item.Item;
 import us.myles.ViaVersion.api.minecraft.metadata.Metadata;
 import us.myles.ViaVersion.api.protocol.Protocol;
 import us.myles.ViaVersion.api.remapper.ValueTransformer;
@@ -62,23 +61,27 @@ public class Protocol1_9TO1_8 extends Protocol {
         return line;
     }
 
-    public static ItemStack getHandItem(final UserConnection info) {
-        try {
-            return Bukkit.getScheduler().callSyncMethod(Bukkit.getPluginManager().getPlugin("ViaVersion"), new Callable<ItemStack>() {
-                @Override
-                public ItemStack call() throws Exception {
-                    UUID playerUUID = info.get(ProtocolInfo.class).getUuid();
-                    if (Bukkit.getPlayer(playerUUID) != null) {
-                        return Bukkit.getPlayer(playerUUID).getItemInHand();
+    public static Item getHandItem(final UserConnection info) {
+        if(HandItemCache.CACHE){
+            return HandItemCache.getHandItem(info.get(ProtocolInfo.class).getUuid());
+        }else {
+            try {
+                return Bukkit.getScheduler().callSyncMethod(Bukkit.getPluginManager().getPlugin("ViaVersion"), new Callable<Item>() {
+                    @Override
+                    public Item call() throws Exception {
+                        UUID playerUUID = info.get(ProtocolInfo.class).getUuid();
+                        if (Bukkit.getPlayer(playerUUID) != null) {
+                            return Item.getItem(Bukkit.getPlayer(playerUUID).getItemInHand());
+                        }
+                        return null;
                     }
-                    return null;
-                }
-            }).get(10, TimeUnit.SECONDS);
-        } catch (Exception e) {
-            System.out.println("Error fetching hand item: " + e.getClass().getName());
-            if (ViaVersion.getInstance().isDebug())
-                e.printStackTrace();
-            return null;
+                }).get(10, TimeUnit.SECONDS);
+            } catch (Exception e) {
+                System.out.println("Error fetching hand item: " + e.getClass().getName());
+                if (ViaVersion.getInstance().isDebug())
+                    e.printStackTrace();
+                return null;
+            }
         }
     }
 
@@ -103,7 +106,11 @@ public class Protocol1_9TO1_8 extends Protocol {
             Bukkit.getPluginManager().registerEvents(new PaperPatch(), plugin);
         }
         if (plugin.getConfig().getBoolean("simulate-pt", true))
-            new ViaIdleThread(plugin.getPortedPlayers()).runTaskTimerAsynchronously(plugin, 1L, 1L); // Updates player's idle status
+            new ViaIdleThread(plugin.getPortedPlayers()).runTaskTimer(plugin, 1L, 1L); // Updates player's idle status
+        if (plugin.getConfig().getBoolean("item-cache", true)) {
+            new HandItemCache().runTaskTimerAsynchronously(plugin, 2L, 2L); // Updates player's items :)
+            HandItemCache.CACHE = true;
+        }
     }
 
     @Override

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/ViaIdleThread.java

@@ -0,0 +1,109 @@
+package us.myles.ViaVersion.protocols.protocol1_9to1_8;
+
+import io.netty.channel.ChannelHandlerContext;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.scheduler.BukkitRunnable;
+import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.api.data.UserConnection;
+import us.myles.ViaVersion.protocols.base.ProtocolInfo;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.MovementTracker;
+import us.myles.ViaVersion.util.PipelineUtil;
+import us.myles.ViaVersion.util.ReflectionUtil;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.UUID;
+
+public class ViaIdleThread extends BukkitRunnable {
+    private static boolean USE_NMS = true;
+    private final Map<UUID, UserConnection> portedPlayers;
+    // Used for packet mode
+    private Object idlePacket;
+    private Object idlePacket2;
+    // Use for nms
+    private Method getHandle;
+    private Field connection;
+    private Method handleFlying;
+
+    public ViaIdleThread(Map<UUID, UserConnection> portedPlayers) {
+        USE_NMS = ((ViaVersionPlugin) ViaVersion.getInstance()).getConfig().getBoolean("nms-player-ticking", true);
+
+        this.portedPlayers = portedPlayers;
+        Class<?> idlePacketClass;
+        try {
+            idlePacketClass = ReflectionUtil.nms("PacketPlayInFlying");
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException("Couldn't find idle packet, help!", e);
+        }
+        try {
+            idlePacket = idlePacketClass.newInstance();
+            idlePacket2 = idlePacketClass.newInstance();
+
+            Field flying = idlePacketClass.getDeclaredField("f");
+            flying.setAccessible(true);
+
+            flying.set(idlePacket2, true);
+        } catch (NoSuchFieldException | InstantiationException | IllegalArgumentException | IllegalAccessException e) {
+            throw new RuntimeException("Couldn't make player idle packet, help!", e);
+        }
+        if(USE_NMS) {
+            try {
+                getHandle = ReflectionUtil.obc("entity.CraftPlayer").getDeclaredMethod("getHandle");
+            } catch (NoSuchMethodException | ClassNotFoundException e) {
+                throw new RuntimeException("Couldn't find CraftPlayer", e);
+            }
+
+            try {
+                connection = ReflectionUtil.nms("EntityPlayer").getDeclaredField("playerConnection");
+            } catch (NoSuchFieldException | ClassNotFoundException e) {
+                throw new RuntimeException("Couldn't find Player Connection", e);
+            }
+
+            try {
+                handleFlying = ReflectionUtil.nms("PlayerConnection").getDeclaredMethod("a", idlePacketClass);
+            } catch (NoSuchMethodException | ClassNotFoundException e) {
+                throw new RuntimeException("Couldn't find CraftPlayer", e);
+            }
+        }
+    }
+    @Override
+    public void run() {
+        for (UserConnection info : portedPlayers.values()) {
+            if (info.get(ProtocolInfo.class).getPipeline().contains(Protocol1_9TO1_8.class)) {
+                long nextIdleUpdate = info.get(MovementTracker.class).getNextIdlePacket();
+                if (nextIdleUpdate <= System.currentTimeMillis()) {
+                    if (info.getChannel().isOpen()) {
+                        if (USE_NMS) {
+                            Player player = Bukkit.getPlayer(info.get(ProtocolInfo.class).getUuid());
+                            try {
+                                // Tick player
+                                Object entityPlayer = getHandle.invoke(player);
+                                Object pc = connection.get(entityPlayer);
+                                handleFlying.invoke(pc, (info.get(MovementTracker.class).isGround() ? idlePacket2 : idlePacket));
+                                // Tick world
+                                info.get(MovementTracker.class).incrementIdlePacket();
+                            } catch (IllegalAccessException | InvocationTargetException e) {
+                                e.printStackTrace();
+                            }
+                        } else {
+                            // Old method using packets.
+                            ChannelHandlerContext context = PipelineUtil.getContextBefore("decoder", info.getChannel().pipeline());
+                            if (context != null) {
+                                if (info.get(MovementTracker.class).isGround()) {
+                                    context.fireChannelRead(idlePacket2);
+                                } else {
+                                    context.fireChannelRead(idlePacket);
+                                }
+                                info.get(MovementTracker.class).incrementIdlePacket();
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/listeners/CommandBlockListener.java

@@ -122,11 +122,15 @@ public class CommandBlockListener implements Listener {
     private long[] getPosition(Object obj) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
         return new long[]{
                 (long) ReflectionUtil.getSuper(obj, "a", int.class), //X
-                (long) ReflectionUtil.getSuper(obj, "c", int.class), //Y
-                (long) ReflectionUtil.getSuper(obj, "d", int.class)  //Z
+                (long) ReflectionUtil.getSuper(obj, isR1() ? "b" : "c", int.class), //Y
+                (long) ReflectionUtil.getSuper(obj, isR1() ? "c" : "d", int.class)  //Z
         };
     }
 
+    private boolean isR1() {
+        return ReflectionUtil.getVersion().equals("v1_8_R1");
+    }
+
     private CompoundTag getNBT(Object obj) throws Exception {
         ByteBuf buf = Unpooled.buffer();
         Method m = ReflectionUtil.nms("NBTCompressedStreamTools").getMethod("a", ReflectionUtil.nms("NBTTagCompound"), DataOutput.class);

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/listeners/HandItemCache.java

@@ -0,0 +1,36 @@
+package us.myles.ViaVersion.protocols.protocol1_9to1_8.listeners;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.scheduler.BukkitRunnable;
+import us.myles.ViaVersion.api.minecraft.item.Item;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class HandItemCache extends BukkitRunnable {
+    public static boolean CACHE = false;
+    private static ConcurrentHashMap<UUID, Item> handCache = new ConcurrentHashMap<>();
+
+    public static Item getHandItem(UUID player) {
+        if (!handCache.containsKey(player))
+            return null;
+        return handCache.get(player);
+    }
+
+    @Override
+    public void run() {
+        List<UUID> players = new ArrayList<>(handCache.keySet());
+
+        for (Player p : Bukkit.getOnlinePlayers()) {
+            handCache.put(p.getUniqueId(), Item.getItem(p.getItemInHand()));
+            players.remove(p.getUniqueId());
+        }
+        // Remove offline players
+        for (UUID uuid : players) {
+            handCache.remove(uuid);
+        }
+    }
+}

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/InventoryPackets.java

@@ -146,10 +146,10 @@ public class InventoryPackets {
                                 Item[] oldStack = wrapper.get(Type.ITEM_ARRAY, 0);
                                 Item[] newStack = new Item[oldStack.length + 1];
                                 for (int i = 0; i < newStack.length; i++) {
-                                    if (i > 3) {
+                                    if (i > 4) {
                                         newStack[i] = oldStack[i - 1];
                                     } else {
-                                        if (i != 3) { // Leave index 3 blank
+                                        if (i != 4) { // Leave index 3 blank
                                             newStack[i] = oldStack[i];
                                         }
                                     }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/PlayerPackets.java

@@ -443,6 +443,52 @@ public class PlayerPackets {
             }
         });
 
+        // Player Position Packet
+        protocol.registerIncoming(State.PLAY, 0x04, 0x0C, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.DOUBLE); // 0 - X
+                map(Type.DOUBLE); // 1 - Y
+                map(Type.DOUBLE); // 2 - Z
+                map(Type.BOOLEAN); // 3 - Ground
+                handler(new PlayerMovementMapper());
+            }
+        });
+
+        // Player Move & Look Packet
+        protocol.registerIncoming(State.PLAY, 0x06, 0x0D, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.DOUBLE); // 0 - X
+                map(Type.DOUBLE); // 1 - Y
+                map(Type.DOUBLE); // 2 - Z
+                map(Type.FLOAT); // 3 - Yaw
+                map(Type.FLOAT); // 4 - Pitch
+                map(Type.BOOLEAN); // 5 - Ground
+                handler(new PlayerMovementMapper());
+            }
+        });
+
+        // Player Look Packet
+        protocol.registerIncoming(State.PLAY, 0x05, 0x0E, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.FLOAT); // 0 - Yaw
+                map(Type.FLOAT); // 1 - Pitch
+                map(Type.BOOLEAN); // 2 - Ground
+                handler(new PlayerMovementMapper());
+            }
+        });
+
+        // Player Packet
+        protocol.registerIncoming(State.PLAY, 0x03, 0x0F, new PacketRemapper() {
+            @Override
+            public void registerMap() {
+                map(Type.BOOLEAN); // 0 - Ground
+                handler(new PlayerMovementMapper());
+            }
+        });
+
         /* Packets which do not have any field remapping or handlers */
 
         protocol.registerIncoming(State.PLAY, 0x01, 0x02); // Chat Message Packet
@@ -451,9 +497,6 @@ public class PlayerPackets {
 
         protocol.registerIncoming(State.PLAY, 0x00, 0x0B); // Keep Alive Request Packet
 
-        protocol.registerIncoming(State.PLAY, 0x04, 0x0C, new PlayerMovementMapper()); // Player Position Packet
-        protocol.registerIncoming(State.PLAY, 0x06, 0x0D, new PlayerMovementMapper()); // Player Move & Look Packet
-        protocol.registerIncoming(State.PLAY, 0x05, 0x0E, new PlayerMovementMapper()); // Player Look Packet
-        protocol.registerIncoming(State.PLAY, 0x03, 0x0F, new PlayerMovementMapper()); // Player Packet
+
     }
 }

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/SpawnPackets.java

@@ -294,7 +294,7 @@ public class SpawnPackets {
                         if (item != 0) {
                             PacketWrapper packet = new PacketWrapper(0x3C, null, wrapper.user());
                             packet.write(Type.VAR_INT, wrapper.get(Type.VAR_INT, 0));
-                            packet.write(Type.VAR_INT, 1);
+                            packet.write(Type.VAR_INT, 0);
                             packet.write(Type.ITEM, new Item(item, (byte) 1, (short) 0, null));
                             try {
                                 packet.send();

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/WorldPackets.java

@@ -180,21 +180,6 @@ public class WorldPackets {
             public void registerMap() {
                 map(Type.POSITION);
                 map(Type.VAR_INT);
-                handler(new PacketHandler() {
-                    @Override
-                    public void handle(PacketWrapper wrapper) throws Exception {
-                        Position pos = wrapper.user().get(EntityTracker.class).getCurrentlyDigging();
-                        if (pos != null) {
-                            if (wrapper.get(Type.POSITION, 0).equals(pos)) {
-                                // cancel this one
-                                if (wrapper.get(Type.VAR_INT, 0) != 0) {
-                                    wrapper.cancel();
-                                    wrapper.user().get(EntityTracker.class).setCurrentlyDigging(null);
-                                }
-                            }
-                        }
-                    }
-                });
             }
         });
         /* Packets which do not have any field remapping or handlers */
@@ -241,7 +226,7 @@ public class WorldPackets {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
                         int status = wrapper.get(Type.UNSIGNED_BYTE, 0);
-                        if (status == 5) {
+                        if (status == 4) {
                             EntityTracker entityTracker = wrapper.user().get(EntityTracker.class);
                             if (entityTracker.isBlocking()) {
                                 entityTracker.setBlocking(false);
@@ -250,26 +235,6 @@ public class WorldPackets {
                         }
                     }
                 });
-                // Digging patch (prevents it glitching)
-                handler(new PacketHandler() {
-                    @Override
-                    public void handle(PacketWrapper wrapper) throws Exception {
-                        if(!ViaVersion.getConfig().isBlockBreakPatch()) return;
-
-                        EntityTracker entityTracker = wrapper.user().get(EntityTracker.class);
-                        final Position block = wrapper.get(Type.POSITION, 0);
-                        int status = wrapper.get(Type.UNSIGNED_BYTE, 0);
-                        if (status == 0) {
-                            entityTracker.setCurrentlyDigging(null);
-                        }
-                        if (status == 1) {
-                            entityTracker.setCurrentlyDigging(null);
-                        }
-                        if (status == 2) {
-                            entityTracker.setCurrentlyDigging(block);
-                        }
-                    }
-                });
             }
         });
 
@@ -288,7 +253,7 @@ public class WorldPackets {
                         wrapper.write(Type.LONG, -1L);
                         wrapper.write(Type.BYTE, (byte) 255);
                         // Write item in hand
-                        Item item = Item.getItem(Protocol1_9TO1_8.getHandItem(wrapper.user()));
+                        Item item = Protocol1_9TO1_8.getHandItem(wrapper.user());
                         // Blocking patch
                         if (ViaVersion.getConfig().isShieldBlocking()) {
                             if (item != null) {
@@ -368,7 +333,7 @@ public class WorldPackets {
                 create(new ValueCreator() {
                     @Override
                     public void write(PacketWrapper wrapper) throws Exception {
-                        Item item = Item.getItem(Protocol1_9TO1_8.getHandItem(wrapper.user()));
+                        Item item = Protocol1_9TO1_8.getHandItem(wrapper.user());
                         wrapper.write(Type.ITEM, item); // 3 - Item
                     }
                 });

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/MovementTracker.java

@@ -1,6 +1,7 @@
 package us.myles.ViaVersion.protocols.protocol1_9to1_8.storage;
 
 import lombok.Getter;
+import lombok.Setter;
 import us.myles.ViaVersion.api.data.StoredObject;
 import us.myles.ViaVersion.api.data.UserConnection;
 
@@ -9,6 +10,9 @@ public class MovementTracker extends StoredObject {
     private static final long IDLE_PACKET_LIMIT = 20; // Max 20 ticks behind
     @Getter
     private long nextIdlePacket = 0L;
+    @Getter
+    @Setter
+    private boolean ground = true;
 
     public MovementTracker(UserConnection user) {
         super(user);

src/main/java/us/myles/ViaVersion/util/ReflectionUtil.java

@@ -22,6 +22,10 @@ public class ReflectionUtil {
         return Class.forName(BASE + "." + className);
     }
 
+    public static String getVersion() {
+        return BASE.substring(BASE.lastIndexOf('.') + 1);
+    }
+
     public static Object invokeStatic(Class<?> clazz, String method) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
         Method m = clazz.getDeclaredMethod(method);
         return m.invoke(null);

src/main/resources/config.yml

@@ -16,6 +16,8 @@ hologram-patch: false
 hologram-y: -1
 # Enable player tick simulation, this fixes eating, drinking, nether portals.
 simulate-pt: true
+# Should we use nms player to simulate packets, (may fix anti-cheat issues)
+nms-player-ticking: true
 # Should we patch boss bars so they work? (Default: true, disable if you're having issues)
 bossbar-patch: true
 # If your boss bar flickers on 1.9, set this to 'true'. It will keep all boss bars on 100% (not recommended)
@@ -28,4 +30,25 @@ use-new-deathmessages: false
 # This error message means one of you plugins is sending bad packets!
 suppress-entityid-errors: false
 # Our patch for block breaking issue, if you have issues with block updates then disable this.
-block-break-patch: true
+block-break-patch: true
+# Should we cache our items, this will prevent server from being lagged out, however the cost is a constant task caching items
+item-cache: true
+# Anti-Cheat, Packets Per Second (PPS) limiter
+# Clients by default send around 20-90 packets per second.
+
+# What is the maximum per second a client can send
+# Use -1 to disable.
+max-pps: 400
+max-pps-kick-msg: "You are sending too many packets!"
+
+# We can also kick them if over a period they send over a threshold a certain amount of times.
+
+# Period to track (in seconds)
+# Use -1 to disable.
+tracking-period: 6
+# How many packets per second counts as a warning
+tracking-warning-pps: 120
+# How many warnings over the interval can we have
+# This can never be higher than "tracking-interval"
+tracking-max-warnings: 4
+tracking-max-kick-msg: "You are sending too many packets, :("