Small code cleanups and switch more stuff to adventure

proxy/src/main/java/com/velocitypowered/proxy/Metrics.java

@@ -43,7 +43,7 @@ public class Metrics {
   private static boolean logFailedRequests = false;
 
   // The logger for the failed requests
-  private static Logger logger = LogManager.getLogger(Metrics.class);
+  private static final Logger logger = LogManager.getLogger(Metrics.class);
 
   // The name of the server software
   private final String name;

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

@@ -568,7 +568,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
 
           if (event.getResult() instanceof DisconnectPlayer) {
             DisconnectPlayer res = (DisconnectPlayer) event.getResult();
-            disconnect(res.getReason());
+            disconnect(res.getReasonComponent());
           } else if (event.getResult() instanceof RedirectPlayer) {
             RedirectPlayer res = (RedirectPlayer) event.getResult();
             createConnectionRequest(res.getServer())
@@ -587,9 +587,9 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
           } else if (event.getResult() instanceof Notify) {
             Notify res = (Notify) event.getResult();
             if (event.kickedDuringServerConnect()) {
-              sendMessage(res.getMessage());
+              sendMessage(res.getMessageComponent());
             } else {
-              disconnect(res.getMessage());
+              disconnect(res.getMessageComponent());
             }
           } else {
             // In case someone gets creative, assume we want to disconnect the player.

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

@@ -43,7 +43,7 @@ import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ThreadLocalRandom;
-import net.kyori.text.Component;
+import net.kyori.adventure.text.Component;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.asynchttpclient.ListenableFuture;
@@ -167,10 +167,11 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
           }
 
           PreLoginComponentResult result = event.getResult();
-          Optional<Component> disconnectReason = result.getReason();
+          Optional<Component> disconnectReason = result.getReasonComponent();
           if (disconnectReason.isPresent()) {
             // The component is guaranteed to be provided if the connection was denied.
-            mcConnection.closeWith(Disconnect.create(disconnectReason.get()));
+            mcConnection.closeWith(Disconnect.create(disconnectReason.get(),
+                inbound.getProtocolVersion()));
             return;
           }
 
@@ -260,7 +261,7 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
             return;
           }
 
-          Optional<Component> reason = event.getResult().getReason();
+          Optional<Component> reason = event.getResult().getReasonComponent();
           if (reason.isPresent()) {
             player.disconnect0(reason.get(), true);
           } else {

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

@@ -16,8 +16,6 @@ import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.WriteBufferWaterMark;
 import io.netty.channel.epoll.EpollChannelOption;
-import io.netty.resolver.dns.DnsAddressResolverGroup;
-import io.netty.resolver.dns.DnsNameResolverBuilder;
 import io.netty.util.concurrent.GlobalEventExecutor;
 import java.net.InetSocketAddress;
 import java.util.HashMap;

proxy/src/main/java/com/velocitypowered/proxy/network/netty/SeparatePoolInetNameResolver.java

@@ -1,5 +1,7 @@
 package com.velocitypowered.proxy.network.netty;
 
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import io.netty.resolver.AddressResolver;
 import io.netty.resolver.AddressResolverGroup;
@@ -14,11 +16,13 @@ import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.TimeUnit;
 
 public final class SeparatePoolInetNameResolver extends InetNameResolver {
 
   private final ExecutorService resolveExecutor;
   private final InetNameResolver delegate;
+  private final Cache<String, List<InetAddress>> cache;
   private AddressResolverGroup<InetSocketAddress> resolverGroup;
 
   /**
@@ -35,12 +39,28 @@ public final class SeparatePoolInetNameResolver extends InetNameResolver {
             .setDaemon(true)
             .build());
     this.delegate = new DefaultNameResolver(executor);
+    this.cache = CacheBuilder.newBuilder()
+        .expireAfterWrite(30, TimeUnit.SECONDS)
+        .build();
   }
 
   @Override
   protected void doResolve(String inetHost, Promise<InetAddress> promise) throws Exception {
+    List<InetAddress> addresses = cache.getIfPresent(inetHost);
+    if (addresses != null) {
+      promise.trySuccess(addresses.get(0));
+      return;
+    }
+
     try {
-      resolveExecutor.execute(() -> this.delegate.resolve(inetHost, promise));
+      resolveExecutor.execute(() -> {
+        promise.addListener(future -> {
+          if (future.isSuccess()) {
+            cache.put(inetHost, (List<InetAddress>) future.getNow());
+          }
+        });
+        this.delegate.resolve(inetHost, promise);
+      });
     } catch (RejectedExecutionException e) {
       promise.setFailure(e);
     }
@@ -49,7 +69,18 @@ public final class SeparatePoolInetNameResolver extends InetNameResolver {
   @Override
   protected void doResolveAll(String inetHost, Promise<List<InetAddress>> promise)
       throws Exception {
+    List<InetAddress> addresses = cache.getIfPresent(inetHost);
+    if (addresses != null) {
+      promise.trySuccess(addresses);
+      return;
+    }
+
     try {
+      promise.addListener(future -> {
+        if (future.isSuccess()) {
+          cache.put(inetHost, (List<InetAddress>) future.getNow());
+        }
+      });
       resolveExecutor.execute(() -> this.delegate.resolveAll(inetHost, promise));
     } catch (RejectedExecutionException e) {
       promise.setFailure(e);

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

@@ -340,7 +340,7 @@ public enum ProtocolUtils {
     // No vanilla packet should give a 3 byte packet
     int len = readExtendedForgeShort(buf);
 
-    Preconditions.checkArgument(len <= (FORGE_MAX_ARRAY_LENGTH),
+    checkArgument(len <= FORGE_MAX_ARRAY_LENGTH,
         "Cannot receive array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH, len);
 
     byte[] ret = new byte[len];
@@ -360,7 +360,7 @@ public enum ProtocolUtils {
     // No vanilla packet should give a 3 byte packet
     int len = readExtendedForgeShort(buf);
 
-    checkFrame(len <= (FORGE_MAX_ARRAY_LENGTH),
+    checkFrame(len <= FORGE_MAX_ARRAY_LENGTH,
         "Cannot receive array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH, len);
 
     return buf.readRetainedSlice(len);
@@ -375,7 +375,7 @@ public enum ProtocolUtils {
    */
   public static void writeByteArray17(byte[] b, ByteBuf buf, boolean allowExtended) {
     if (allowExtended) {
-      checkFrame(b.length <= (FORGE_MAX_ARRAY_LENGTH),
+      checkFrame(b.length <= FORGE_MAX_ARRAY_LENGTH,
           "Cannot send array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH,
           b.length);
     } else {
@@ -399,7 +399,7 @@ public enum ProtocolUtils {
    */
   public static void writeByteBuf17(ByteBuf b, ByteBuf buf, boolean allowExtended) {
     if (allowExtended) {
-      checkFrame(b.readableBytes() <= (FORGE_MAX_ARRAY_LENGTH),
+      checkFrame(b.readableBytes() <= FORGE_MAX_ARRAY_LENGTH,
           "Cannot send array longer than %s (got %s bytes)", FORGE_MAX_ARRAY_LENGTH,
           b.readableBytes());
     } else {

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

@@ -11,7 +11,7 @@ import java.util.Queue;
  * A variation on {@link io.netty.handler.flow.FlowControlHandler} that explicitly holds messages
  * on {@code channelRead} and only releases them on an explicit read operation.
  */
-public class AutoReadHolderHandler extends ChannelDuplexHandler implements ChannelInboundHandler {
+public class AutoReadHolderHandler extends ChannelDuplexHandler {
 
   private final Queue<Object> queuedMessages;
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/ByteBufDataInput.java

@@ -10,7 +10,7 @@ import java.io.IOException;
  * A wrapper around {@link io.netty.buffer.ByteBuf} that implements the exception-free
  * {@link ByteArrayDataInput} interface from Guava.
  */
-public class ByteBufDataInput implements ByteArrayDataInput, DataInput {
+public class ByteBufDataInput implements ByteArrayDataInput {
 
   private final ByteBuf in;
 

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/ByteBufDataOutput.java

@@ -12,7 +12,7 @@ import java.nio.charset.StandardCharsets;
 /**
  * A {@link DataOutput} equivalent to {@link ByteBufDataInput}.
  */
-public class ByteBufDataOutput extends OutputStream implements DataOutput, ByteArrayDataOutput {
+public class ByteBufDataOutput extends OutputStream implements ByteArrayDataOutput {
 
   private final ByteBuf buf;
   private final DataOutputStream utf8out;

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/FaviconSerializer.java

@@ -9,7 +9,7 @@ import com.google.gson.JsonSerializer;
 import com.velocitypowered.api.util.Favicon;
 import java.lang.reflect.Type;
 
-public class FaviconSerializer implements JsonSerializer<Favicon>, JsonDeserializer<Favicon> {
+public final class FaviconSerializer implements JsonSerializer<Favicon>, JsonDeserializer<Favicon> {
 
   @Override
   public Favicon deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) {

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/GameProfileSerializer.java

@@ -13,7 +13,7 @@ import com.velocitypowered.api.util.GameProfile.Property;
 import java.lang.reflect.Type;
 import java.util.List;
 
-public class GameProfileSerializer implements JsonSerializer<GameProfile>,
+public final class GameProfileSerializer implements JsonSerializer<GameProfile>,
     JsonDeserializer<GameProfile> {
 
   private static final Type propertyList = new TypeToken<List<Property>>() {}.getType();

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/NettyPreconditions.java

@@ -8,7 +8,7 @@ import io.netty.handler.codec.CorruptedFrameException;
 /**
  * Extends {@link com.google.common.base.Preconditions} for Netty's {@link CorruptedFrameException}.
  */
-public class NettyPreconditions {
+public final class NettyPreconditions {
   private static final QuietDecoderException BAD = new QuietDecoderException(
       "Invalid packet received. Launch Velocity with -Dvelocity.packet-decode-logging=true "
           + "to see more.");

proxy/src/main/java/com/velocitypowered/proxy/protocol/util/PluginMessageUtil.java

@@ -17,7 +17,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.regex.Pattern;
 
-public class PluginMessageUtil {
+public final class PluginMessageUtil {
 
   private static final String BRAND_CHANNEL_LEGACY = "MC|Brand";
   private static final String BRAND_CHANNEL = "minecraft:brand";
@@ -110,8 +110,8 @@ public class PluginMessageUtil {
    */
   public static PluginMessage constructChannelsPacket(ProtocolVersion protocolVersion,
                                                       Collection<String> channels) {
-    Preconditions.checkNotNull(channels, "channels");
-    Preconditions.checkArgument(channels.size() > 0, "no channels specified");
+    checkNotNull(channels, "channels");
+    checkArgument(!channels.isEmpty(), "no channels specified");
     String channelName = protocolVersion.compareTo(ProtocolVersion.MINECRAFT_1_13) >= 0
         ? REGISTER_CHANNEL : REGISTER_CHANNEL_LEGACY;
     ByteBuf contents = Unpooled.buffer();
@@ -131,14 +131,14 @@ public class PluginMessageUtil {
     checkNotNull(version, "version");
     checkArgument(isMcBrand(message), "message is not a brand plugin message");
 
-    String toAppend = " (" + version.getName() + ")";
     String currentBrand = readBrandMessage(message.content());
+    String rewrittenBrand = String.format("%s (%s)", currentBrand, version.getName());
 
     ByteBuf rewrittenBuf = Unpooled.buffer();
     if (protocolVersion.compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0) {
-      ProtocolUtils.writeString(rewrittenBuf, currentBrand + toAppend);
+      ProtocolUtils.writeString(rewrittenBuf, rewrittenBrand);
     } else {
-      rewrittenBuf.writeBytes((currentBrand + toAppend).getBytes());
+      rewrittenBuf.writeCharSequence(rewrittenBrand, StandardCharsets.UTF_8);
     }
 
     return new PluginMessage(message.getChannel(), rewrittenBuf);

proxy/src/main/java/com/velocitypowered/proxy/util/AddressUtil.java

@@ -6,13 +6,13 @@ import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.URI;
 
-public class AddressUtil {
+public final class AddressUtil {
   private AddressUtil() {
     throw new AssertionError();
   }
 
   /**
-   * Attempts to parse an IP address of the form <code>127.0.0.1:25565</code>. The returned
+   * Attempts to parse an IP address of the form {@code 127.0.0.1:25565}. The returned
    * {@link InetSocketAddress} is not resolved.
    *
    * @param ip the IP to parse
@@ -30,7 +30,7 @@ public class AddressUtil {
   }
 
   /**
-   * Attempts to parse an IP address of the form <code>127.0.0.1:25565</code>. The returned
+   * Attempts to parse an IP address of the form {@code 127.0.0.1:25565}. The returned
    * {@link InetSocketAddress} is resolved.
    *
    * @param ip the IP to parse

proxy/src/main/java/com/velocitypowered/proxy/util/DurationUtils.java

@@ -5,7 +5,7 @@ import java.time.Duration;
 /**
  * Provides utility functions for working with durations.
  */
-public class DurationUtils {
+public final class DurationUtils {
   private static final long ONE_TICK_IN_MILLISECONDS = 50;
 
   private DurationUtils() {

proxy/src/main/java/com/velocitypowered/proxy/util/VelocityMessages.java

@@ -4,7 +4,7 @@ import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.TextComponent;
 import net.kyori.adventure.text.format.NamedTextColor;
 
-public class VelocityMessages {
+public final class VelocityMessages {
 
   public static final Component ONLINE_MODE_ONLY = TextComponent
       .builder("This server only accepts connections from online-mode clients.")

proxy/src/main/java/com/velocitypowered/proxy/util/bossbar/BossBarManager.java

@@ -57,7 +57,7 @@ public class BossBarManager implements BossBar.Listener {
   }
 
   private BossBarHolder getOrCreateHandler(BossBar bar) {
-    BossBarHolder holder = this.bars.computeIfAbsent(bar, (k) -> new BossBarHolder(bar));
+    BossBarHolder holder = this.bars.computeIfAbsent(bar, k -> new BossBarHolder(bar));
     holder.register();
     return holder;
   }

proxy/src/main/java/com/velocitypowered/proxy/util/concurrent/Once.java

@@ -1,17 +1,12 @@
 package com.velocitypowered.proxy.util.concurrent;
 
-import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
-
 /**
- * A class that guarantees that a given initialization shall only happen once. The implementation
+ * A class that guarantees that a given initialization shall only occur once. The implementation
  * is (almost) a direct Java port of the Go {@code sync.Once} type (see the
  * <a href="https://golang.org/pkg/sync/#Once">Go documentation</a>) and thus has similar
  * semantics.
  */
 public final class Once {
-  private static final AtomicIntegerFieldUpdater<Once> COMPLETED_UPDATER =
-      AtomicIntegerFieldUpdater.newUpdater(Once.class, "completed");
-
   private static final int NOT_STARTED = 0;
   private static final int COMPLETED = 1;
 
@@ -20,25 +15,25 @@ public final class Once {
 
   /**
    * Calls {@code runnable.run()} exactly once if this instance is being called for the first time,
-   * otherwise the invocation shall wait until {@code runnable.run()} completes. Future calls to
-   * this method once {@code runnable.run()} completes are no-ops - a new instance should be used
-   * instead.
+   * otherwise the invocation shall wait until {@code runnable.run()} completes. The first runnable
+   * used when this function is called is run. Future calls to this method once the initial
+   * runnable completes are no-ops - a new instance should be used instead.
    *
    * @param runnable the runnable to run
    */
   public void run(Runnable runnable) {
-    if (COMPLETED_UPDATER.get(this) == NOT_STARTED) {
+    if (completed == NOT_STARTED) {
       slowRun(runnable);
     }
   }
 
   private void slowRun(Runnable runnable) {
     synchronized (lock) {
-      if (this.completed == NOT_STARTED) {
+      if (completed == NOT_STARTED) {
         try {
           runnable.run();
         } finally {
-          COMPLETED_UPDATER.set(this, COMPLETED);
+          completed = COMPLETED;
         }
       }
     }

proxy/src/test/java/com/velocitypowered/proxy/util/concurrent/OnceTest.java

@@ -21,11 +21,13 @@ public class OnceTest {
 
   @Test
   void contendedOnce() throws Exception {
-    ExecutorService service = Executors.newFixedThreadPool(10);
+    int threadsForTest = 25;
+
+    ExecutorService service = Executors.newFixedThreadPool(threadsForTest);
     AtomicInteger i = new AtomicInteger();
     Once once = new Once();
-    CountDownLatch latch = new CountDownLatch(10);
-    for (int i1 = 0; i1 < 10; i1++) {
+    CountDownLatch latch = new CountDownLatch(threadsForTest);
+    for (int i1 = 0; i1 < threadsForTest; i1++) {
       service.execute(() -> {
         once.run(i::incrementAndGet);
         latch.countDown();