Keep alive

src/main/java/mc/core/embedded/InMemoryPlayerManager.java

@@ -4,6 +4,7 @@
  */
 package mc.core.embedded;
 
+import lombok.extern.slf4j.Slf4j;
 import mc.core.Config;
 import mc.core.Player;
 import mc.core.PlayerManager;
@@ -14,18 +15,24 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
-public class InMemoryPlayerManager implements PlayerManager {
+@Slf4j
+public class InMemoryPlayerManager implements PlayerManager, Runnable {
     private List<Player> players;
+    private final Object lock = new Object();
 
     @Autowired
     public InMemoryPlayerManager(Config config) {
         final int c = config.getMaxPlayers() > 50 ? 50 : config.getMaxPlayers();
         players = Collections.synchronizedList(new ArrayList<>(c));
+        (new Thread(this, "KeepAlive")).start();
     }
 
     @Override
     public void addPlayer(Player player) {
-        players.add(player);
+        synchronized (lock) {
+            players.add(player);
+            lock.notify();
+        }
     }
 
     @Override
@@ -53,4 +60,29 @@ public class InMemoryPlayerManager implements PlayerManager {
     public void bloadcastWrite(final CSPacket packet) {
         players.forEach(player -> player.getChannel().writeAndFlush(packet));
     }
+
+    @Override
+    public void run() {
+        while (!Thread.currentThread().isInterrupted()) {
+            synchronized (lock) {
+                while (players.size() == 0) {
+                    try {
+                        lock.wait();
+                    } catch (InterruptedException e) {
+                        return;
+                    }
+                }
+            }
+
+            players.stream()
+                   .parallel()
+                   .forEach(player -> player.getChannel().sendKeepAlive());
+
+            try {
+                Thread.sleep(1);
+            } catch (InterruptedException e) {
+                return;
+            }
+        }
+    }
 }

src/main/java/mc/core/network/NetChannel.java

@@ -5,8 +5,7 @@
 package mc.core.network;
 
 public interface NetChannel {
-    void write(Object obj);
-    void flush();
-    void writeAndFlush(Object obj);
+    void sendKeepAlive();
 
+    void writeAndFlush(SCPacket pkt);
 }

src/main/java/mc/core/network/proto_125/netty/PacketHandler.java

@@ -8,8 +8,10 @@ package mc.core.network.proto_125.netty;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.util.AttributeKey;
 import lombok.extern.slf4j.Slf4j;
 import mc.core.Location;
+import mc.core.Player;
 import mc.core.PlayerManager;
 import mc.core.network.CSPacket;
 import mc.core.Config;
@@ -25,11 +27,18 @@ import java.util.Random;
 @Slf4j
 public class PacketHandler extends SimpleChannelInboundHandler<CSPacket> {
     private static final Random random = new Random();
+    private static final AttributeKey<Player> ATTR_PLAYER = AttributeKey.newInstance("ATTR_PLAYER");
     @Autowired
     private Config config;
     @Autowired
     private PlayerManager playerManager;
 
+    @Override
+    public void channelInactive(ChannelHandlerContext context) throws Exception {
+        super.channelInactive(context);
+        playerManager.removePlayer(context.channel().attr(ATTR_PLAYER).get());
+    }
+
     @Override
     protected void channelRead0(ChannelHandlerContext ctx, CSPacket packet) throws Exception {
         Optional<Method> optionalMethod = Arrays.stream(this.getClass().getDeclaredMethods())
@@ -145,6 +154,7 @@ public class PacketHandler extends SimpleChannelInboundHandler<CSPacket> {
         channel.write(posLookPkt);
 
         playerManager.addPlayer(player);
+        channel.attr(ATTR_PLAYER).set(player);
         channel.flush();
     }
 }

src/main/java/mc/core/network/proto_125/netty/wrappers/WrapperNetChannel.java

@@ -7,23 +7,21 @@ package mc.core.network.proto_125.netty.wrappers;
 import io.netty.channel.Channel;
 import lombok.RequiredArgsConstructor;
 import mc.core.network.NetChannel;
+import mc.core.network.SCPacket;
+import mc.core.network.proto_125.packets.KeepAlivePacket;
+import mc.core.network.proto_125.packets.PingPacket;
 
 @RequiredArgsConstructor
 public class WrapperNetChannel implements NetChannel {
     private final Channel channel;
 
     @Override
-    public void write(Object obj) {
-        channel.write(obj);
+    public void sendKeepAlive() {
+        channel.writeAndFlush(new KeepAlivePacket());
     }
 
     @Override
-    public void flush() {
-        channel.flush();
-    }
-
-    @Override
-    public void writeAndFlush(Object obj) {
-        channel.writeAndFlush(obj);
+    public void writeAndFlush(SCPacket pkt) {
+        channel.writeAndFlush(pkt);
     }
 }

src/main/java/mc/core/network/proto_125/packets/KeepAlivePacket.java

@@ -0,0 +1,21 @@
+/*
+ * DmitriyMX <dimon550@gmail.com>
+ * 2018-04-21
+ */
+package mc.core.network.proto_125.packets;
+
+import mc.core.network.SCPacket;
+import mc.core.network.proto_125.ByteArrayOutputNetStream;
+
+import java.util.Random;
+
+public class KeepAlivePacket implements SCPacket {
+    private static final Random rand = new Random();
+
+    @Override
+    public byte[] toByteArray() {
+        ByteArrayOutputNetStream netStream = new ByteArrayOutputNetStream();
+        netStream.writeInt(rand.nextInt(Integer.MAX_VALUE));
+        return netStream.toByteArray();
+    }
+}

src/main/java/mc/core/network/proto_125/packets/PacketManager.java

@@ -12,6 +12,7 @@ import mc.core.network.proto_125.packets.*;
 
 public class PacketManager {
     private static final BiMap<Integer, Class<?>> packetMap = ImmutableBiMap.<Integer, Class<?>>builder()
+            .put(0x00, KeepAlivePacket.class)
             .put(0x01, LoginPacket.class)
             .put(0x02, HandshakePacket.class)
             .put(0x06, SpawnPositionPacket.class)