Minor cleanup.

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

@@ -74,6 +74,8 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
   public boolean handle(ServerLogin packet) {
     this.login = packet;
     if (mcConnection.getProtocolVersion().compareTo(MINECRAFT_1_13) >= 0) {
+      // To make sure the connecting client isn't Velocity, send a plugin message that Velocity will
+      // recognize and respond to.
       playerInfoId = ThreadLocalRandom.current().nextInt();
       mcConnection.write(new LoginPluginMessage(playerInfoId, VELOCITY_IP_FORWARDING_CHANNEL,
           Unpooled.EMPTY_BUFFER));

proxy/src/main/java/com/velocitypowered/proxy/network/ConnectionManager.java

@@ -13,12 +13,9 @@ import io.netty.channel.EventLoopGroup;
 import io.netty.channel.WriteBufferWaterMark;
 import io.netty.resolver.dns.DefaultDnsServerAddressStreamProvider;
 import io.netty.resolver.dns.DnsAddressResolverGroup;
-import io.netty.resolver.dns.MultiDnsServerAddressStreamProvider;
 import java.net.InetSocketAddress;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Map;
-import java.util.Set;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -32,6 +29,9 @@ public final class ConnectionManager {
   private final EventLoopGroup bossGroup;
   private final EventLoopGroup workerGroup;
   private final VelocityServer server;
+  // This is intentionally made public for plugins like ViaVersion, which inject their own
+  // protocol logic into the proxy.
+  @SuppressWarnings("WeakerAccess")
   public final ServerChannelInitializerHolder serverChannelInitializer;
 
   private final DnsAddressResolverGroup resolverGroup;

proxy/src/main/java/com/velocitypowered/proxy/network/ServerChannelInitializer.java

@@ -52,7 +52,7 @@ public class ServerChannelInitializer extends ChannelInitializer<Channel> {
     connection.setSessionHandler(new HandshakeSessionHandler(connection, this.server));
     ch.pipeline().addLast(Connections.HANDLER, connection);
 
-    if (ServerChannelInitializer.this.server.getConfiguration().isProxyProtocol()) {
+    if (this.server.getConfiguration().isProxyProtocol()) {
       ch.pipeline().addFirst(new HAProxyMessageDecoder());
     }
   }

proxy/src/main/java/com/velocitypowered/proxy/network/ServerChannelInitializerHolder.java

@@ -11,7 +11,7 @@ public class ServerChannelInitializerHolder implements Supplier<ChannelInitializ
   private static final Logger LOGGER = LogManager.getLogger(ConnectionManager.class);
   private ChannelInitializer<Channel> initializer;
 
-  public ServerChannelInitializerHolder(final ChannelInitializer<Channel> initializer) {
+  ServerChannelInitializerHolder(final ChannelInitializer<Channel> initializer) {
     this.initializer = initializer;
   }
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCompressDecoder.java

@@ -25,25 +25,24 @@ public class MinecraftCompressDecoder extends MessageToMessageDecoder<ByteBuf> {
 
   @Override
   protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
-    int expectedUncompressedSize = ProtocolUtils.readVarInt(in);
+    int expectedSize = ProtocolUtils.readVarInt(in);
-    if (expectedUncompressedSize == 0) {
+    if (expectedSize == 0) {
       // Strip the now-useless uncompressed size, this message is already uncompressed.
       out.add(in.retainedSlice());
       in.skipBytes(in.readableBytes());
       return;
     }
 
-    checkFrame(expectedUncompressedSize >= threshold,
+    checkFrame(expectedSize >= threshold, "Uncompressed size %s is greater than threshold %s",
-        "Uncompressed size %s is greater than threshold %s",
+        expectedSize, threshold);
-        expectedUncompressedSize, threshold);
     ByteBuf compatibleIn = ensureCompatible(ctx.alloc(), compressor, in);
-    int initialCapacity = Math.min(expectedUncompressedSize, MAXIMUM_INITIAL_BUFFER_SIZE);
+    int initialCapacity = Math.min(expectedSize, MAXIMUM_INITIAL_BUFFER_SIZE);
     ByteBuf uncompressed = preferredBuffer(ctx.alloc(), compressor, initialCapacity);
     try {
       compressor.inflate(compatibleIn, uncompressed);
-      checkFrame(expectedUncompressedSize == uncompressed.readableBytes(),
+      checkFrame(expectedSize == uncompressed.readableBytes(),
           "Mismatched compression sizes (got %s, expected %s)",
-          uncompressed.readableBytes(), expectedUncompressedSize);
+          uncompressed.readableBytes(), expectedSize);
       out.add(uncompressed);
     } catch (Exception e) {
       uncompressed.release();

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/brigadier/VoidArgumentPropertySerializer.java

@@ -10,7 +10,7 @@ class VoidArgumentPropertySerializer<T extends ArgumentType<?>>
 
   private final Supplier<T> argumentSupplier;
 
-  public VoidArgumentPropertySerializer(Supplier<T> argumentSupplier) {
+  private VoidArgumentPropertySerializer(Supplier<T> argumentSupplier) {
     this.argumentSupplier = argumentSupplier;
   }