Add Via channel handlers instead of wrapping Vanilla handlers on Bukkit (#3132)

api/src/main/java/com/viaversion/viaversion/util/PipelineUtil.java

@@ -34,29 +34,21 @@ import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 
-public class PipelineUtil {
+public final class PipelineUtil {
-    private static Method DECODE_METHOD;
+    private static final Method DECODE_METHOD;
-    private static Method ENCODE_METHOD;
+    private static final Method ENCODE_METHOD;
-    private static Method MTM_DECODE;
+    private static final Method MTM_DECODE;
 
     static {
         try {
             DECODE_METHOD = ByteToMessageDecoder.class.getDeclaredMethod("decode", ChannelHandlerContext.class, ByteBuf.class, List.class);
             DECODE_METHOD.setAccessible(true);
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        }
-        try {
             ENCODE_METHOD = MessageToByteEncoder.class.getDeclaredMethod("encode", ChannelHandlerContext.class, Object.class, ByteBuf.class);
             ENCODE_METHOD.setAccessible(true);
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        }
-        try {
             MTM_DECODE = MessageToMessageDecoder.class.getDeclaredMethod("decode", ChannelHandlerContext.class, Object.class, List.class);
             MTM_DECODE.setAccessible(true);
         } catch (NoSuchMethodException e) {
-            e.printStackTrace();
+            throw new RuntimeException(e);
         }
     }
 

bukkit/src/main/java/com/viaversion/viaversion/ViaVersionPlugin.java

@@ -29,7 +29,6 @@ import com.viaversion.viaversion.api.platform.ViaPlatform;
 import com.viaversion.viaversion.bukkit.classgenerator.ClassGenerator;
 import com.viaversion.viaversion.bukkit.commands.BukkitCommandHandler;
 import com.viaversion.viaversion.bukkit.commands.BukkitCommandSender;
-import com.viaversion.viaversion.bukkit.listeners.ProtocolLibEnableListener;
 import com.viaversion.viaversion.bukkit.platform.BukkitViaAPI;
 import com.viaversion.viaversion.bukkit.platform.BukkitViaConfig;
 import com.viaversion.viaversion.bukkit.platform.BukkitViaInjector;
@@ -89,10 +88,6 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform<Player>
 
     @Override
     public void onLoad() {
-        // Via should load before PL, so we can't check for it in the constructor
-        Plugin protocolLib = Bukkit.getPluginManager().getPlugin("ProtocolLib");
-        ProtocolLibEnableListener.checkCompat(protocolLib);
-
         // Spigot detector
         try {
             Class.forName("org.spigotmc.SpigotConfig");
@@ -134,8 +129,6 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform<Player>
         getCommand("viaversion").setExecutor(commandHandler);
         getCommand("viaversion").setTabCompleter(commandHandler);
 
-        getServer().getPluginManager().registerEvents(new ProtocolLibEnableListener(), this);
-
         // Warn them if they have anti-xray on and they aren't using spigot
         if (conf.isAntiXRay() && !spigot) {
             getLogger().info("You have anti-xray on in your config, since you're not using spigot it won't fix xray!");

bukkit/src/main/java/com/viaversion/viaversion/bukkit/classgenerator/ClassGenerator.java

@@ -21,8 +21,7 @@ import com.viaversion.viaversion.ViaVersionPlugin;
 import com.viaversion.viaversion.bukkit.handlers.BukkitDecodeHandler;
 import com.viaversion.viaversion.bukkit.handlers.BukkitEncodeHandler;
 import com.viaversion.viaversion.bukkit.util.NMSUtil;
-import com.viaversion.viaversion.classgenerator.generated.BasicHandlerConstructor;
+import com.viaversion.viaversion.classgenerator.generated.HandlerSupplier;
-import com.viaversion.viaversion.classgenerator.generated.HandlerConstructor;
 import javassist.CannotCompileException;
 import javassist.ClassPool;
 import javassist.CtClass;
@@ -48,11 +47,11 @@ import java.lang.reflect.Method;
 //TODO maybe clean this up a bit 👀
 public final class ClassGenerator {
     private static final boolean useModules = hasModuleMethod();
-    private static HandlerConstructor constructor = new BasicHandlerConstructor();
+    private static HandlerSupplier constructor = new HandlerSupplier.DefaultHandlerSupplier();
     private static String psPackage;
     private static Class psConnectListener;
 
-    public static HandlerConstructor getConstructor() {
+    public static HandlerSupplier handlerSupplier() {
         return constructor;
     }
 
@@ -91,7 +90,7 @@ public final class ClassGenerator {
 
                 // Implement Constructor
                 CtClass generated = pool.makeClass("com.viaversion.viaversion.classgenerator.generated.GeneratedConstructor");
-                CtClass handlerInterface = pool.get(HandlerConstructor.class.getName());
+                CtClass handlerInterface = pool.get(HandlerSupplier.class.getName());
 
                 generated.setInterfaces(new CtClass[]{handlerInterface});
                 // Import required classes
@@ -107,7 +106,7 @@ public final class ClassGenerator {
                         "        return new BukkitDecodeHandler(info, minecraftDecoder);\n" +
                         "    }", generated));
 
-                constructor = (HandlerConstructor) toClass(generated).getConstructor().newInstance();
+                constructor = (HandlerSupplier) toClass(generated).getConstructor().newInstance();
             } catch (ReflectiveOperationException | CannotCompileException | NotFoundException e) {
                 e.printStackTrace();
             }
@@ -332,7 +331,7 @@ public final class ClassGenerator {
 
     @SuppressWarnings("deprecation")
     private static Class<?> toClass(CtClass ctClass) throws CannotCompileException {
-        return useModules ? ctClass.toClass(HandlerConstructor.class) : ctClass.toClass(HandlerConstructor.class.getClassLoader());
+        return useModules ? ctClass.toClass(HandlerSupplier.class) : ctClass.toClass(HandlerSupplier.class.getClassLoader());
     }
 
     private static boolean hasModuleMethod() {

bukkit/src/main/java/com/viaversion/viaversion/bukkit/handlers/BukkitChannelInitializer.java

@@ -20,31 +20,47 @@ package com.viaversion.viaversion.bukkit.handlers;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.bukkit.classgenerator.ClassGenerator;
 import com.viaversion.viaversion.bukkit.platform.PaperViaInjector;
-import com.viaversion.viaversion.classgenerator.generated.HandlerConstructor;
 import com.viaversion.viaversion.connection.UserConnectionImpl;
 import com.viaversion.viaversion.platform.WrappedChannelInitializer;
 import com.viaversion.viaversion.protocol.ProtocolPipelineImpl;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
-import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.channel.ChannelPipeline;
-import io.netty.handler.codec.MessageToByteEncoder;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.lang.reflect.Method;
 
-public class BukkitChannelInitializer extends ChannelInitializer<Channel> implements WrappedChannelInitializer {
+public final class BukkitChannelInitializer extends ChannelInitializer<Channel> implements WrappedChannelInitializer {
 
+    public static final String VIA_ENCODER = "via-encoder";
+    public static final String VIA_DECODER = "via-decoder";
+    public static final String MINECRAFT_ENCODER = "encoder";
+    public static final String MINECRAFT_DECODER = "decoder";
+    public static final String MINECRAFT_COMPRESSOR = "compress";
+    public static final String MINECRAFT_DECOMPRESSOR = "decompress";
+    public static final Object COMPRESSION_ENABLED_EVENT = paperCompressionEnabledEvent();
     private static final Method INIT_CHANNEL_METHOD;
     private final ChannelInitializer<Channel> original;
 
+
     static {
         try {
             INIT_CHANNEL_METHOD = ChannelInitializer.class.getDeclaredMethod("initChannel", Channel.class);
             INIT_CHANNEL_METHOD.setAccessible(true);
-        } catch (NoSuchMethodException e) {
+        } catch (final ReflectiveOperationException e) {
             throw new RuntimeException(e);
         }
     }
 
+    private static @Nullable Object paperCompressionEnabledEvent() {
+        try {
+            final Class<?> eventClass = Class.forName("io.papermc.paper.network.ConnectionEvent");
+            return eventClass.getDeclaredField("COMPRESSION_THRESHOLD_SET").get(null);
+        } catch (final ReflectiveOperationException e) {
+            return null;
+        }
+    }
+
     public BukkitChannelInitializer(ChannelInitializer<Channel> oldInit) {
         this.original = oldInit;
     }
@@ -62,7 +78,7 @@ public class BukkitChannelInitializer extends ChannelInitializer<Channel> implem
     }
 
     public static void afterChannelInitialize(Channel channel) {
-        UserConnection connection = new UserConnectionImpl(channel);
+        final UserConnection connection = new UserConnectionImpl(channel);
         new ProtocolPipelineImpl(connection);
 
         if (PaperViaInjector.PAPER_PACKET_LIMITER) {
@@ -70,12 +86,9 @@ public class BukkitChannelInitializer extends ChannelInitializer<Channel> implem
         }
 
         // Add our transformers
-        HandlerConstructor constructor = ClassGenerator.getConstructor();
+        final ChannelPipeline pipeline = channel.pipeline();
-        MessageToByteEncoder encoder = constructor.newEncodeHandler(connection, (MessageToByteEncoder) channel.pipeline().get("encoder"));
+        pipeline.addBefore(MINECRAFT_ENCODER, VIA_ENCODER, ClassGenerator.handlerSupplier().newEncodeHandler(connection));
-        ByteToMessageDecoder decoder = constructor.newDecodeHandler(connection, (ByteToMessageDecoder) channel.pipeline().get("decoder"));
+        pipeline.addBefore(MINECRAFT_DECODER, VIA_DECODER, ClassGenerator.handlerSupplier().newDecodeHandler(connection));
-
-        channel.pipeline().replace("encoder", "encoder", encoder);
-        channel.pipeline().replace("decoder", "decoder", decoder);
     }
 
     @Override

bukkit/src/main/java/com/viaversion/viaversion/bukkit/handlers/BukkitDecodeHandler.java

@@ -26,59 +26,64 @@ import com.viaversion.viaversion.exception.CancelDecoderException;
 import com.viaversion.viaversion.exception.InformativeException;
 import com.viaversion.viaversion.util.PipelineUtil;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.channel.ChannelPipeline;
+import io.netty.handler.codec.MessageToMessageDecoder;
 
-import java.lang.reflect.InvocationTargetException;
 import java.util.List;
 
-public class BukkitDecodeHandler extends ByteToMessageDecoder {
+@ChannelHandler.Sharable
-    private final ByteToMessageDecoder minecraftDecoder;
+public final class BukkitDecodeHandler extends MessageToMessageDecoder<ByteBuf> {
-    private final UserConnection info;
+    private final UserConnection connection;
 
-    public BukkitDecodeHandler(UserConnection info, ByteToMessageDecoder minecraftDecoder) {
+    public BukkitDecodeHandler(final UserConnection connection) {
-        this.info = info;
+        this.connection = connection;
-        this.minecraftDecoder = minecraftDecoder;
     }
 
     @Override
-    protected void decode(ChannelHandlerContext ctx, ByteBuf bytebuf, List<Object> list) throws Exception {
+    protected void decode(final ChannelHandlerContext ctx, final ByteBuf bytebuf, final List<Object> out) throws Exception {
-        if (!info.checkServerboundPacket()) {
+        if (!connection.checkServerboundPacket()) {
-            bytebuf.clear(); // Don't accumulate
             throw CancelDecoderException.generate(null);
         }
+        if (!connection.shouldTransformPacket()) {
+            out.add(bytebuf.retain());
+            return;
+        }
 
-        ByteBuf transformedBuf = null;
+        final ByteBuf transformedBuf = ctx.alloc().buffer().writeBytes(bytebuf);
         try {
-            if (info.shouldTransformPacket()) {
+            connection.transformIncoming(transformedBuf, CancelDecoderException::generate);
-                transformedBuf = ctx.alloc().buffer().writeBytes(bytebuf);
+            out.add(transformedBuf.retain());
-                info.transformServerbound(transformedBuf, CancelDecoderException::generate);
-            }
-
-            try {
-                list.addAll(PipelineUtil.callDecode(this.minecraftDecoder, ctx, transformedBuf == null ? bytebuf : transformedBuf));
-            } catch (InvocationTargetException e) {
-                if (e.getCause() instanceof Exception) {
-                    throw (Exception) e.getCause();
-                } else if (e.getCause() instanceof Error) {
-                    throw (Error) e.getCause();
-                }
-            }
         } finally {
-            if (transformedBuf != null) {
+            transformedBuf.release();
-                transformedBuf.release();
-            }
         }
     }
 
     @Override
-    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+    public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) throws Exception {
-        if (PipelineUtil.containsCause(cause, CancelCodecException.class)) return; // ProtocolLib compat
+        if (PipelineUtil.containsCause(cause, CancelCodecException.class)) {
+            return;
+        }
 
         super.exceptionCaught(ctx, cause);
         if (!NMSUtil.isDebugPropertySet() && PipelineUtil.containsCause(cause, InformativeException.class)
-                && (info.getProtocolInfo().getState() != State.HANDSHAKE || Via.getManager().isDebug())) {
+                && (connection.getProtocolInfo().getState() != State.HANDSHAKE || Via.getManager().isDebug())) {
             cause.printStackTrace(); // Print if CB doesn't already do it
         }
     }
+
+    @Override
+    public void userEventTriggered(final ChannelHandlerContext ctx, final Object event) throws Exception {
+        if (BukkitChannelInitializer.COMPRESSION_ENABLED_EVENT == null || event != BukkitChannelInitializer.COMPRESSION_ENABLED_EVENT) {
+            super.userEventTriggered(ctx, event);
+            return;
+        }
+
+        // When compression handlers are added, the order becomes Minecraft Encoder -> Compressor -> Via Encoder; fix the order again
+        final ChannelPipeline pipeline = ctx.pipeline();
+        pipeline.addAfter(BukkitChannelInitializer.MINECRAFT_COMPRESSOR, BukkitChannelInitializer.VIA_ENCODER, pipeline.remove(BukkitChannelInitializer.VIA_ENCODER));
+        pipeline.addAfter(BukkitChannelInitializer.MINECRAFT_DECOMPRESSOR, BukkitChannelInitializer.VIA_DECODER, pipeline.remove(BukkitChannelInitializer.VIA_DECODER));
+        super.userEventTriggered(ctx, event);
+    }
 }

bukkit/src/main/java/com/viaversion/viaversion/bukkit/handlers/BukkitEncodeHandler.java

@@ -24,84 +24,99 @@ import com.viaversion.viaversion.bukkit.util.NMSUtil;
 import com.viaversion.viaversion.exception.CancelCodecException;
 import com.viaversion.viaversion.exception.CancelEncoderException;
 import com.viaversion.viaversion.exception.InformativeException;
-import com.viaversion.viaversion.handlers.ChannelHandlerContextWrapper;
-import com.viaversion.viaversion.handlers.ViaCodecHandler;
 import com.viaversion.viaversion.util.PipelineUtil;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPipeline;
+import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.MessageToByteEncoder;
+import io.netty.handler.codec.MessageToMessageEncoder;
 
-import java.lang.reflect.Field;
+import java.util.List;
-import java.lang.reflect.InvocationTargetException;
 
-public class BukkitEncodeHandler extends MessageToByteEncoder implements ViaCodecHandler {
+@ChannelHandler.Sharable
-    private static Field versionField;
+public final class BukkitEncodeHandler extends MessageToMessageEncoder<ByteBuf> {
+    private final UserConnection connection;
+    private boolean handledCompression = BukkitChannelInitializer.COMPRESSION_ENABLED_EVENT != null;
 
-    static {
+    public BukkitEncodeHandler(final UserConnection connection) {
-        try {
+        this.connection = connection;
-            // Attempt to get any version info from the handler
-            versionField = NMSUtil.nms(
-                    "PacketEncoder",
-                    "net.minecraft.network.PacketEncoder"
-            ).getDeclaredField("version");
-
-            versionField.setAccessible(true);
-        } catch (Exception e) {
-            // Not compat version
-        }
-    }
-
-    private final UserConnection info;
-    private final MessageToByteEncoder minecraftEncoder;
-
-    public BukkitEncodeHandler(UserConnection info, MessageToByteEncoder minecraftEncoder) {
-        this.info = info;
-        this.minecraftEncoder = minecraftEncoder;
     }
 
     @Override
-    protected void encode(final ChannelHandlerContext ctx, Object o, final ByteBuf bytebuf) throws Exception {
+    protected void encode(final ChannelHandlerContext ctx, final ByteBuf bytebuf, final List<Object> out) throws Exception {
-        if (versionField != null) {
+        if (!connection.checkClientboundPacket()) {
-            versionField.set(minecraftEncoder, versionField.get(this));
+            throw CancelEncoderException.generate(null);
         }
-        // handle the packet type
+        if (!connection.shouldTransformPacket()) {
-        if (!(o instanceof ByteBuf)) {
+            out.add(bytebuf.retain());
-            // call minecraft encoder
+            return;
-            try {
+        }
-                PipelineUtil.callEncode(this.minecraftEncoder, new ChannelHandlerContextWrapper(ctx, this), o, bytebuf);
+
-            } catch (InvocationTargetException e) {
+        final ByteBuf transformedBuf = ctx.alloc().buffer().writeBytes(bytebuf);
-                if (e.getCause() instanceof Exception) {
+        try {
-                    throw (Exception) e.getCause();
+            final boolean needsCompression = !handledCompression && handleCompressionOrder(ctx, transformedBuf);
-                } else if (e.getCause() instanceof Error) {
+            connection.transformClientbound(transformedBuf, CancelEncoderException::generate);
-                    throw (Error) e.getCause();
+            if (needsCompression) {
-                }
+                recompress(ctx, transformedBuf);
             }
 
-        } else {
+            out.add(transformedBuf.retain());
-            bytebuf.writeBytes((ByteBuf) o);
+        } finally {
+            transformedBuf.release();
+        }
+    }
+
+    private boolean handleCompressionOrder(final ChannelHandlerContext ctx, final ByteBuf buf) throws Exception {
+        final ChannelPipeline pipeline = ctx.pipeline();
+        final List<String> names = pipeline.names();
+        final int compressorIndex = names.indexOf(BukkitChannelInitializer.MINECRAFT_COMPRESSOR);
+        if (compressorIndex == -1) {
+            return false;
+        }
+
+        handledCompression = true;
+        if (compressorIndex > names.indexOf(BukkitChannelInitializer.VIA_ENCODER)) {
+            // Need to decompress this packet due to bad order
+            final ByteBuf decompressed = (ByteBuf) PipelineUtil.callDecode((ByteToMessageDecoder) pipeline.get(BukkitChannelInitializer.MINECRAFT_DECOMPRESSOR), ctx, buf).get(0);
+            try {
+                buf.clear().writeBytes(decompressed);
+            } finally {
+                decompressed.release();
+            }
+
+            pipeline.addAfter(BukkitChannelInitializer.MINECRAFT_COMPRESSOR, BukkitChannelInitializer.VIA_ENCODER, pipeline.remove(BukkitChannelInitializer.VIA_ENCODER));
+            pipeline.addAfter(BukkitChannelInitializer.MINECRAFT_DECOMPRESSOR, BukkitChannelInitializer.VIA_DECODER, pipeline.remove(BukkitChannelInitializer.VIA_DECODER));
+            return true;
+        }
+        return true;
+    }
+
+    private void recompress(final ChannelHandlerContext ctx, final ByteBuf buf) throws Exception {
+        final ByteBuf compressed = ctx.alloc().buffer();
+        try {
+            PipelineUtil.callEncode((MessageToByteEncoder<ByteBuf>) ctx.pipeline().get(BukkitChannelInitializer.MINECRAFT_COMPRESSOR), ctx, buf, compressed);
+            buf.clear().writeBytes(compressed);
+        } finally {
+            compressed.release();
         }
-        transform(bytebuf);
     }
 
     @Override
-    public void transform(ByteBuf bytebuf) throws Exception {
+    public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) throws Exception {
-        if (!info.checkClientboundPacket()) throw CancelEncoderException.generate(null);
+        if (PipelineUtil.containsCause(cause, CancelCodecException.class)) {
-        if (!info.shouldTransformPacket()) return;
+            return;
-        info.transformClientbound(bytebuf, CancelEncoderException::generate);
+        }
-    }
-
-    @Override
-    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-        if (PipelineUtil.containsCause(cause, CancelCodecException.class)) return; // ProtocolLib compat
 
         super.exceptionCaught(ctx, cause);
         if (!NMSUtil.isDebugPropertySet() && PipelineUtil.containsCause(cause, InformativeException.class)
-                && (info.getProtocolInfo().getState() != State.HANDSHAKE || Via.getManager().isDebug())) {
+                && (connection.getProtocolInfo().getState() != State.HANDSHAKE || Via.getManager().isDebug())) {
             cause.printStackTrace(); // Print if CB doesn't already do it
         }
     }
 
-    public UserConnection getInfo() {
+    public UserConnection connection() {
-        return info;
+        return connection;
     }
 }

bukkit/src/main/java/com/viaversion/viaversion/bukkit/listeners/JoinListener.java

@@ -103,7 +103,7 @@ public class JoinListener implements Listener {
 
     private @Nullable UserConnection getUserConnection(Channel channel) {
         BukkitEncodeHandler encoder = channel.pipeline().get(BukkitEncodeHandler.class);
-        return encoder != null ? encoder.getInfo() : null;
+        return encoder != null ? encoder.connection() : null;
     }
 
     private Channel getChannel(Player player) throws Exception {

bukkit/src/main/java/com/viaversion/viaversion/bukkit/listeners/ProtocolLibEnableListener.java

@@ -1,62 +0,0 @@
-/*
- * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
- * Copyright (C) 2016-2022 ViaVersion and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package com.viaversion.viaversion.bukkit.listeners;
-
-import com.viaversion.viaversion.api.Via;
-import com.viaversion.viaversion.bukkit.platform.BukkitViaInjector;
-import org.bukkit.event.EventHandler;
-import org.bukkit.event.Listener;
-import org.bukkit.event.server.PluginDisableEvent;
-import org.bukkit.event.server.PluginEnableEvent;
-import org.bukkit.plugin.Plugin;
-import org.jetbrains.annotations.Nullable;
-
-public class ProtocolLibEnableListener implements Listener {
-
-    @EventHandler
-    public void onPluginEnable(PluginEnableEvent e) {
-        // Will likely never happen, but try to account for hacky plugin loading systems anyways
-        if (e.getPlugin().getName().equals("ProtocolLib")) {
-            checkCompat(e.getPlugin());
-        }
-    }
-
-    @EventHandler
-    public void onPluginDisable(PluginDisableEvent e) {
-        if (e.getPlugin().getName().equals("ProtocolLib")) {
-            ((BukkitViaInjector) Via.getManager().getInjector()).setProtocolLib(false);
-        }
-    }
-
-    public static void checkCompat(@Nullable Plugin protocolLib) {
-        if (protocolLib != null) {
-            String version = protocolLib.getDescription().getVersion();
-            String majorVersion = version.split("\\.", 2)[0];
-            try {
-                // Only need the compat check for version < 5
-                if (Integer.parseInt(majorVersion) < 5) {
-                    ((BukkitViaInjector) Via.getManager().getInjector()).setProtocolLib(true);
-                    return;
-                }
-            } catch (NumberFormatException ignored) {
-                Via.getPlatform().getLogger().warning("ProtocolLib version check failed for version " + version);
-            }
-        }
-        ((BukkitViaInjector) Via.getManager().getInjector()).setProtocolLib(false);
-    }
-}

bukkit/src/main/java/com/viaversion/viaversion/bukkit/platform/BukkitViaInjector.java

@@ -35,7 +35,6 @@ import java.lang.reflect.Method;
 import java.util.List;
 
 public class BukkitViaInjector extends LegacyViaInjector {
-    private boolean protocolLib;
 
     @Override
     public void inject() throws ReflectiveOperationException {
@@ -112,11 +111,6 @@ public class BukkitViaInjector extends LegacyViaInjector {
         throw new RuntimeException("Failed to get server");
     }
 
-    @Override
-    public String getDecoderName() {
-        return protocolLib ? "protocol_lib_decoder" : "decoder";
-    }
-
     @Override
     protected @Nullable Object getServerConnection() throws ReflectiveOperationException {
         Class<?> serverClass = NMSUtil.nms(
@@ -189,8 +183,4 @@ public class BukkitViaInjector extends LegacyViaInjector {
         }
         return false;
     }
-
-    public void setProtocolLib(boolean protocolLib) {
-        this.protocolLib = protocolLib;
-    }
 }

bukkit/src/main/java/com/viaversion/viaversion/classgenerator/generated/HandlerConstructor.java

@@ -1,28 +0,0 @@
-/*
- * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
- * Copyright (C) 2016-2022 ViaVersion and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-package com.viaversion.viaversion.classgenerator.generated;
-
-import com.viaversion.viaversion.api.connection.UserConnection;
-import io.netty.handler.codec.ByteToMessageDecoder;
-import io.netty.handler.codec.MessageToByteEncoder;
-
-public interface HandlerConstructor {
-    public MessageToByteEncoder newEncodeHandler(UserConnection info, MessageToByteEncoder minecraftEncoder);
-
-    public ByteToMessageDecoder newDecodeHandler(UserConnection info, ByteToMessageDecoder minecraftDecoder);
-}

bukkit/src/main/java/com/viaversion/viaversion/classgenerator/generated/HandlerSupplier.java

@@ -20,17 +20,25 @@ package com.viaversion.viaversion.classgenerator.generated;
 import com.viaversion.viaversion.api.connection.UserConnection;
 import com.viaversion.viaversion.bukkit.handlers.BukkitDecodeHandler;
 import com.viaversion.viaversion.bukkit.handlers.BukkitEncodeHandler;
-import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.buffer.ByteBuf;
-import io.netty.handler.codec.MessageToByteEncoder;
+import io.netty.handler.codec.MessageToMessageDecoder;
+import io.netty.handler.codec.MessageToMessageEncoder;
 
-public class BasicHandlerConstructor implements HandlerConstructor {
+public interface HandlerSupplier {
-    @Override
-    public BukkitEncodeHandler newEncodeHandler(UserConnection info, MessageToByteEncoder minecraftEncoder) {
-        return new BukkitEncodeHandler(info, minecraftEncoder);
-    }
 
-    @Override
+    MessageToMessageEncoder<ByteBuf> newEncodeHandler(UserConnection connection);
-    public BukkitDecodeHandler newDecodeHandler(UserConnection info, ByteToMessageDecoder minecraftDecoder) {
+
-        return new BukkitDecodeHandler(info, minecraftDecoder);
+    MessageToMessageDecoder<ByteBuf> newDecodeHandler(UserConnection connection);
+
+    final class DefaultHandlerSupplier implements HandlerSupplier {
+        @Override
+        public MessageToMessageEncoder<ByteBuf> newEncodeHandler(final UserConnection connection) {
+            return new BukkitEncodeHandler(connection);
+        }
+
+        @Override
+        public MessageToMessageDecoder<ByteBuf> newDecodeHandler(final UserConnection connection) {
+            return new BukkitDecodeHandler(connection);
+        }
     }
 }

common/src/main/java/com/viaversion/viaversion/platform/LegacyViaInjector.java

@@ -235,16 +235,6 @@ public abstract class LegacyViaInjector implements ViaInjector {
         return data;
     }
 
-    @Override
-    public String getEncoderName() {
-        return "encoder";
-    }
-
-    @Override
-    public String getDecoderName() {
-        return "decoder";
-    }
-
     /**
      * Returns the Vanilla server connection object the channels to be injected should be searched in.
      *

gradle.properties

@@ -1,5 +1,5 @@
 # Project properties - we put these here so they can be modified without causing a recompile of the build scripts
-projectVersion=4.4.3-SNAPSHOT
+projectVersion=4.5.0-SNAPSHOT
 
 # Gradle properties
 org.gradle.daemon=true

sponge/src/main/java/com/viaversion/viaversion/sponge/platform/SpongeViaInjector.java

@@ -50,4 +50,14 @@ public class SpongeViaInjector extends LegacyViaInjector {
     protected void blame(ChannelHandler bootstrapAcceptor) {
         throw new RuntimeException("Unable to find core component 'childHandler', please check your plugins. Issue: " + bootstrapAcceptor.getClass().getName());
     }
+
+    @Override
+    public String getEncoderName() {
+        return "encoder";
+    }
+
+    @Override
+    public String getDecoderName() {
+        return "decoder";
+    }
 }