Mostly brought 2.0.0 up to update with Velocity 1.1.5-SNAPSHOT changes.

I have not verified that this actually works.

api/src/main/java/com/velocitypowered/api/event/player/PlayerChannelRegisterEvent.java

@@ -1,7 +1,7 @@
 package com.velocitypowered.api.event.player;
 
 import com.google.common.base.Preconditions;
-import com.velocitypowered.api.proxy.Player;
+import com.velocitypowered.api.proxy.connection.Player;
 import com.velocitypowered.api.proxy.messages.ChannelIdentifier;
 
 import java.util.List;

proxy/src/main/java/com/velocitypowered/proxy/connection/backend/BackendPlaySessionHandler.java

@@ -71,8 +71,8 @@ public class BackendPlaySessionHandler implements MinecraftSessionHandler {
     if (server.getConfiguration().isBungeePluginChannelEnabled()) {
       MinecraftConnection serverMc = serverConn.ensureConnected();
       serverMc.write(PluginMessageUtil.constructChannelsPacket(serverMc.getProtocolVersion(),
-          ImmutableList.of(getBungeeCordChannel(serverMc.getProtocolVersion()))
-      ));
+          ImmutableList.of(getBungeeCordChannel(serverMc.getProtocolVersion())),
+          ServerboundPluginMessagePacket.FACTORY));
     }
   }
 
@@ -88,7 +88,7 @@ public class BackendPlaySessionHandler implements MinecraftSessionHandler {
 
   @Override
   public boolean handle(ClientboundKeepAlivePacket packet) {
-    serverConn.setLastPingId(packet.getRandomId());
+    serverConn.getPendingPings().put(packet.getRandomId(), System.currentTimeMillis());
     return false; // forwards on
   }
 

proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java

@@ -113,7 +113,7 @@ public class VelocityServerConnection implements MinecraftConnectionAssociation,
       return getHandshakeRemoteAddress();
     }
     StringBuilder data = new StringBuilder()
-        .append(registeredServer.getServerInfo().getAddress().getHostString())
+        .append(getHandshakeRemoteAddress())
         .append('\0')
         .append(((InetSocketAddress) proxyPlayer.getRemoteAddress()).getHostString())
         .append('\0')

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -42,6 +42,7 @@ import com.velocitypowered.proxy.network.StateRegistry;
 import com.velocitypowered.proxy.network.packet.AbstractPluginMessagePacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundChatPacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundDisconnectPacket;
+import com.velocitypowered.proxy.network.packet.clientbound.ClientboundHeaderAndFooterPacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundKeepAlivePacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundPluginMessagePacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundResourcePackRequestPacket;
@@ -268,16 +269,6 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     }
   }
 
-  @Override
-  public Component getPlayerListHeader() {
-    return this.playerListHeader;
-  }
-
-  @Override
-  public Component getPlayerListFooter() {
-    return this.playerListFooter;
-  }
-
   @Override
   public void sendPlayerListHeader(@NonNull final Component header) {
     this.sendPlayerListHeaderAndFooter(header, this.playerListFooter);
@@ -292,9 +283,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
   public void sendPlayerListHeaderAndFooter(final Component header, final Component footer) {
     this.playerListHeader = Objects.requireNonNull(header, "header");
     this.playerListFooter = Objects.requireNonNull(footer, "footer");
-    if (this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
-      this.connection.write(HeaderAndFooter.create(header, footer, this.getProtocolVersion()));
-    }
+    this.tabList.setHeaderAndFooter(header, footer);
   }
 
   @Override
@@ -360,11 +349,6 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     this.profile = profile.withProperties(properties);
   }
 
-  @Override
-  public void clearHeaderAndFooter() {
-    tabList.clearHeaderAndFooter();
-  }
-
   @Override
   public VelocityTabList getTabList() {
     return tabList;

proxy/src/main/java/com/velocitypowered/proxy/network/packet/Packet.java

@@ -15,4 +15,12 @@ public interface Packet {
 
   boolean handle(PacketHandler handler);
 
+  // TODO: Move this into decoder
+  default int expectedMinLength(ByteBuf buf, PacketDirection direction, ProtocolVersion version) {
+    return 0;
+  }
+
+  default int expectedMaxLength(ByteBuf buf, PacketDirection direction, ProtocolVersion version) {
+    return -1;
+  }
 }

proxy/src/main/java/com/velocitypowered/proxy/network/packet/clientbound/ClientboundAvailableCommandsPacket.java

@@ -24,6 +24,7 @@ import com.velocitypowered.proxy.network.packet.PacketDirection;
 import com.velocitypowered.proxy.network.packet.PacketHandler;
 import com.velocitypowered.proxy.network.packet.PacketReader;
 import com.velocitypowered.proxy.network.serialization.brigadier.ArgumentPropertyRegistry;
+import com.velocitypowered.proxy.util.collect.IdentityHashStrategy;
 import io.netty.buffer.ByteBuf;
 import it.unimi.dsi.fastutil.objects.Object2IntLinkedOpenCustomHashMap;
 import it.unimi.dsi.fastutil.objects.Object2IntLinkedOpenHashMap;

proxy/src/main/java/com/velocitypowered/proxy/network/packet/clientbound/ClientboundJoinGamePacket.java

@@ -314,26 +314,4 @@ public class ClientboundJoinGamePacket implements Packet {
   public boolean handle(PacketHandler handler) {
     return handler.handle(this);
   }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-      .add("entityId", this.entityId)
-      .add("gamemode", this.gamemode)
-      .add("dimension", this.dimension)
-      .add("partialHashedSeed", this.partialHashedSeed)
-      .add("difficulty", this.difficulty)
-      .add("isHardcore", this.isHardcore)
-      .add("maxPlayers", this.maxPlayers)
-      .add("levelType", this.levelType)
-      .add("viewDistance", this.viewDistance)
-      .add("reducedDebugInfo", this.reducedDebugInfo)
-      .add("showRespawnScreen", this.showRespawnScreen)
-      .add("dimensionRegistry", this.dimensionRegistry)
-      .add("dimensionInfo", this.dimensionInfo)
-      .add("currentDimensionData", this.currentDimensionData)
-      .add("previousGamemode", this.previousGamemode)
-      .add("biomeRegistry", this.biomeRegistry)
-      .toString();
-  }
 }

proxy/src/main/java/com/velocitypowered/proxy/network/pipeline/MinecraftDecoder.java

@@ -7,6 +7,7 @@ import com.velocitypowered.proxy.network.StateRegistry;
 import com.velocitypowered.proxy.network.packet.Packet;
 import com.velocitypowered.proxy.network.packet.PacketDirection;
 import com.velocitypowered.proxy.util.except.QuietDecoderException;
+import com.velocitypowered.proxy.util.except.QuietRuntimeException;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;

proxy/src/main/java/com/velocitypowered/proxy/protocol/MinecraftPacket.java

@@ -1,24 +0,0 @@
-package com.velocitypowered.proxy.protocol;
-
-import com.velocitypowered.api.network.ProtocolVersion;
-import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
-import io.netty.buffer.ByteBuf;
-
-public interface MinecraftPacket {
-
-  void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion protocolVersion);
-
-  void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion protocolVersion);
-
-  boolean handle(MinecraftSessionHandler handler);
-
-  default int expectedMaxLength(ByteBuf buf, ProtocolUtils.Direction direction,
-      ProtocolVersion version) {
-    return -1;
-  }
-
-  default int expectedMinLength(ByteBuf buf, ProtocolUtils.Direction direction,
-      ProtocolVersion version) {
-    return 0;
-  }
-}

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/PluginMessage.java

@@ -1,129 +0,0 @@
-package com.velocitypowered.proxy.protocol.packet;
-
-import static com.velocitypowered.proxy.protocol.util.PluginMessageUtil.transformLegacyToModernChannel;
-
-import com.velocitypowered.api.network.ProtocolVersion;
-import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
-import com.velocitypowered.proxy.protocol.MinecraftPacket;
-import com.velocitypowered.proxy.protocol.ProtocolUtils;
-import com.velocitypowered.proxy.protocol.util.DeferredByteBufHolder;
-import io.netty.buffer.ByteBuf;
-import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
-import org.checkerframework.checker.nullness.qual.Nullable;
-
-public class PluginMessage extends DeferredByteBufHolder implements MinecraftPacket {
-
-  private @Nullable String channel;
-
-  public PluginMessage() {
-    super(null);
-  }
-
-  public PluginMessage(String channel,
-      @MonotonicNonNull ByteBuf backing) {
-    super(backing);
-    this.channel = channel;
-  }
-
-  public String getChannel() {
-    if (channel == null) {
-      throw new IllegalStateException("Channel is not specified.");
-    }
-    return channel;
-  }
-
-  public void setChannel(String channel) {
-    this.channel = channel;
-  }
-
-  @Override
-  public String toString() {
-    return "PluginMessage{"
-        + "channel='" + channel + '\''
-        + ", data=" + super.toString()
-        + '}';
-  }
-
-  @Override
-  public void decode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
-    this.channel = ProtocolUtils.readString(buf);
-    if (version.compareTo(ProtocolVersion.MINECRAFT_1_13) >= 0) {
-      this.channel = transformLegacyToModernChannel(this.channel);
-    }
-    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
-      this.replace(buf.readRetainedSlice(buf.readableBytes()));
-    } else {
-      this.replace(ProtocolUtils.readRetainedByteBufSlice17(buf));
-    }
-
-  }
-
-  @Override
-  public void encode(ByteBuf buf, ProtocolUtils.Direction direction, ProtocolVersion version) {
-    if (channel == null) {
-      throw new IllegalStateException("Channel is not specified.");
-    }
-
-    if (refCnt() == 0) {
-      throw new IllegalStateException("Plugin message contents for " + this.channel
-          + " freed too many times.");
-    }
-
-    if (version.compareTo(ProtocolVersion.MINECRAFT_1_13) >= 0) {
-      ProtocolUtils.writeString(buf, transformLegacyToModernChannel(this.channel));
-    } else {
-      ProtocolUtils.writeString(buf, this.channel);
-    }
-    if (version.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
-      buf.writeBytes(content());
-    } else {
-      ProtocolUtils.writeByteBuf17(content(), buf, true); // True for Forge support
-    }
-
-  }
-
-  @Override
-  public boolean handle(MinecraftSessionHandler handler) {
-    return handler.handle(this);
-  }
-
-  @Override
-  public PluginMessage copy() {
-    return (PluginMessage) super.copy();
-  }
-
-  @Override
-  public PluginMessage duplicate() {
-    return (PluginMessage) super.duplicate();
-  }
-
-  @Override
-  public PluginMessage retainedDuplicate() {
-    return (PluginMessage) super.retainedDuplicate();
-  }
-
-  @Override
-  public PluginMessage replace(ByteBuf content) {
-    return (PluginMessage) super.replace(content);
-  }
-
-  @Override
-  public PluginMessage retain() {
-    return (PluginMessage) super.retain();
-  }
-
-  @Override
-  public PluginMessage retain(int increment) {
-    return (PluginMessage) super.retain(increment);
-  }
-
-  @Override
-  public PluginMessage touch() {
-    return (PluginMessage) super.touch();
-  }
-
-  @Override
-  public PluginMessage touch(Object hint) {
-    return (PluginMessage) super.touch(hint);
-  }
-}

proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabList.java

@@ -5,6 +5,7 @@ import com.velocitypowered.api.proxy.player.TabList;
 import com.velocitypowered.api.proxy.player.TabListEntry;
 import com.velocitypowered.api.util.GameProfile;
 import com.velocitypowered.proxy.connection.MinecraftConnection;
+import com.velocitypowered.proxy.connection.client.ConnectedPlayer;
 import com.velocitypowered.proxy.network.ProtocolUtils;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundHeaderAndFooterPacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundPlayerListItemPacket;
@@ -16,6 +17,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
+import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
 import org.checkerframework.checker.nullness.qual.Nullable;
 

proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabListLegacy.java

@@ -3,7 +3,7 @@ package com.velocitypowered.proxy.tablist;
 import com.google.common.collect.ImmutableList;
 import com.velocitypowered.api.proxy.player.TabListEntry;
 import com.velocitypowered.api.util.GameProfile;
-import com.velocitypowered.proxy.connection.MinecraftConnection;
+import com.velocitypowered.proxy.connection.client.ConnectedPlayer;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundPlayerListItemPacket;
 import com.velocitypowered.proxy.network.packet.clientbound.ClientboundPlayerListItemPacket.Item;
 import java.util.Collections;
@@ -18,8 +18,8 @@ public class VelocityTabListLegacy extends VelocityTabList {
 
   private final Map<String, UUID> nameMapping = new ConcurrentHashMap<>();
 
-  public VelocityTabListLegacy(MinecraftConnection connection) {
-    super(connection);
+  public VelocityTabListLegacy(ConnectedPlayer player) {
+    super(player);
   }
 
   @Override

proxy/src/test/java/com/velocitypowered/proxy/command/CommandManagerTests.java

@@ -27,6 +27,7 @@ import java.util.List;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.junit.jupiter.api.Test;
 
 public class CommandManagerTests {
@@ -444,29 +445,29 @@ public class CommandManagerTests {
       }
     };
 
-    manager.register(rawCommand, "foo");
+    manager.register("foo", rawCommand);
 
     assertTrue(manager.offerSuggestions(MockCommandSource.INSTANCE, "foo").get().isEmpty());
     assertFalse(manager.offerSuggestions(MockCommandSource.INSTANCE, "foo bar").get().isEmpty());
 
-    Command oldCommand = new Command() {
+    SimpleCommand oldCommand = new SimpleCommand() {
       @Override
-      public void execute(CommandSource source, String @NonNull [] args) {
+      public void execute(Invocation invocation) {
         fail("The Command should not be executed while testing suggestions");
       }
 
       @Override
-      public boolean hasPermission(CommandSource source, String @NonNull [] args) {
-        return args.length > 0;
+      public boolean hasPermission(Invocation invocation) {
+        return invocation.arguments().length > 0;
       }
 
       @Override
-      public List<String> suggest(CommandSource source, String @NonNull [] currentArgs) {
+      public List<String> suggest(Invocation invocation) {
         return ImmutableList.of("suggestion");
       }
     };
 
-    manager.register(oldCommand, "bar");
+    manager.register("bar", oldCommand);
 
     assertTrue(manager.offerSuggestions(MockCommandSource.INSTANCE, "bar").get().isEmpty());
     assertFalse(manager.offerSuggestions(MockCommandSource.INSTANCE, "bar foo").get().isEmpty());