Merge branch 'decode-multiple' into dev/1.1.0

.gitignore

@@ -89,3 +89,5 @@ plugins/
 ### Natives stuff ###
 native/mbedtls
 native/zlib-ng
+native/zlib-cf
+native/libdeflate

native/compile-linux.sh

@@ -1,21 +1,22 @@
 #!/bin/bash
 
-if [ ! -d zlib-ng ]; then
+if [ ! -d libdeflate ]; then
-  echo "Cloning zlib-ng..."
+  echo "Cloning libdeflate..."
-  git clone https://github.com/zlib-ng/zlib-ng.git
+  git clone https://github.com/ebiggers/libdeflate.git
 fi
 
-echo "Compiling zlib-ng..."
+echo "Compiling libdeflate..."
-cd zlib-ng
+cd libdeflate || exit
-CFLAGS="-fPIC -O3" ./configure --zlib-compat --static
+make
-make clean && make
 cd ..
 
 # Modify as you need.
 MBEDTLS_ROOT=mbedtls
-CFLAGS="-O3 -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/ -fPIC -shared"
+CFLAGS="-O3 -I$JAVA_HOME/include/ -I$JAVA_HOME/include/linux/ -fPIC -shared -Wl,-z,noexecstack"
-gcc $CFLAGS -Izlib-ng src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
+ARCH=$(uname -m)
-    src/main/c/jni_zlib_common.c zlib-ng/libz.a  -o src/main/resources/linux_x64/velocity-compress.so
+mkdir -p src/main/resources/linux_$ARCH
-gcc $CFLAGS  -I $MBEDTLS_ROOT/include -shared $MBEDTLS_ROOT/library/aes.c $MBEDTLS_ROOT/library/aesni.c \
+gcc $CFLAGS -Ilibdeflate src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
+    libdeflate/libdeflate.a -o src/main/resources/linux_$ARCH/velocity-compress.so
+gcc $CFLAGS -I $MBEDTLS_ROOT/include -shared $MBEDTLS_ROOT/library/aes.c $MBEDTLS_ROOT/library/aesni.c \
     $MBEDTLS_ROOT/library/platform.c $MBEDTLS_ROOT/library/platform_util.c src/main/c/jni_util.c src/main/c/jni_cipher.c \
-    -o src/main/resources/linux_x64/velocity-cipher.so
+    -o src/main/resources/linux_$ARCH/velocity-cipher.so

native/compile-osx.sh

@@ -1,23 +0,0 @@
-#!/bin/bash
-
-if [ ! -d zlib-ng ]; then
-  echo "Cloning zlib-ng..."
-  git clone https://github.com/zlib-ng/zlib-ng.git
-fi
-
-echo "Compiling zlib-ng..."
-cd zlib-ng
-CFLAGS="-fPIC -O3" ./configure --zlib-compat --static
-make clean && make
-cd ..
-
-# Modify as you need.
-MBEDTLS_ROOT=mbedtls
-export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home
-CFLAGS="-O3 -I$JAVA_HOME/include/ -I$JAVA_HOME/include/darwin/ -fPIC -shared"
-
-clang $CFLAGS -Izlib-ng src/main/c/jni_util.c src/main/c/jni_zlib_deflate.c src/main/c/jni_zlib_inflate.c \
-    src/main/c/jni_zlib_common.c zlib-ng/libz.a -o src/main/resources/macosx/velocity-compress.dylib
-clang $CFLAGS -I $MBEDTLS_ROOT/include -shared $MBEDTLS_ROOT/library/aes.c $MBEDTLS_ROOT/library/aesni.c \
-    $MBEDTLS_ROOT/library/platform.c $MBEDTLS_ROOT/library/platform_util.c src/main/c/jni_util.c src/main/c/jni_cipher.c \
-    -o src/main/resources/macosx/velocity-cipher.dylib

native/src/main/c/jni_zlib_common.c

@@ -1,29 +0,0 @@
-#include <jni.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <zlib.h>
-#include "jni_util.h"
-
-void JNICALL
-check_zlib_free(JNIEnv *env, z_stream *stream, bool deflate)
-{
-    int ret = deflate ? deflateEnd(stream) : inflateEnd(stream);
-    const char *msg = stream->msg;
-    free((void*) stream);
-
-    switch (ret) {
-        case Z_OK:
-            break;
-        case Z_STREAM_ERROR:
-            if (msg == NULL) {
-                msg = "stream state inconsistent";
-            }
-            // fall-through
-        case Z_DATA_ERROR:
-            if (msg == NULL) {
-                msg = "data was discarded";
-            }
-            throwException(env, "java/lang/IllegalArgumentException", msg);
-            break;
-    }
-}

native/src/main/c/jni_zlib_common.h

@@ -1,6 +0,0 @@
-#include <jni.h>
-#include <stdbool.h>
-#include <zlib.h>
-
-void JNICALL
-check_zlib_free(JNIEnv *env, z_stream *stream, bool deflate);

native/src/main/c/jni_zlib_deflate.c

@@ -2,56 +2,21 @@
 #include <jni.h>
 #include <stdbool.h>
 #include <stdlib.h>
-#include <zlib.h>
+#include <libdeflate.h>
 #include "jni_util.h"
-#include "jni_zlib_common.h"
-
-static jfieldID finishedID;
-static jfieldID consumedID;
-
-JNIEXPORT void JNICALL
-Java_com_velocitypowered_natives_compression_NativeZlibDeflate_initIDs(JNIEnv *env, jclass cls)
-{
-    finishedID = (*env)->GetFieldID(env, cls, "finished", "Z");
-    consumedID = (*env)->GetFieldID(env, cls, "consumed", "I");
-}
 
 JNIEXPORT jlong JNICALL
 Java_com_velocitypowered_natives_compression_NativeZlibDeflate_init(JNIEnv *env,
     jobject obj,
     jint level)
 {
-    z_stream* stream = calloc(1, sizeof(z_stream));
+    struct libdeflate_compressor *compressor = libdeflate_alloc_compressor(level);
-
+    if (compressor == NULL) {
-    if (stream == 0) {
         // Out of memory!
-        throwException(env, "java/lang/OutOfMemoryError", "zlib allocate stream");
+        throwException(env, "java/lang/OutOfMemoryError", "libdeflate allocate compressor");
-        return 0;
-    }
-
-    int ret = deflateInit(stream, level);
-    if (ret == Z_OK) {
-        return (jlong) stream;
-    } else {
-        const char *zlib_msg = stream->msg;
-        free(stream);
-        switch (ret) {
-            case Z_MEM_ERROR:
-                throwException(env, "java/lang/OutOfMemoryError", "zlib init");
-                break;
-            case Z_STREAM_ERROR: {
-                // Thanks Ken and Ritchie!
-                char message[32];
-                snprintf(message, 32, "invalid level %d", level);
-                throwException(env, "java/lang/IllegalArgumentException", message);
-                break;
-            }
-            default:
-                throwException(env, "java/util/zip/DataFormatException", zlib_msg);
-                break;
-        }
         return 0;
     }
+    return (jlong) compressor;
 }
 
 JNIEXPORT void JNICALL
@@ -59,11 +24,10 @@ Java_com_velocitypowered_natives_compression_NativeZlibDeflate_free(JNIEnv *env,
     jobject obj,
     jlong ctx)
 {
-    z_stream* stream = (z_stream*) ctx;
+    libdeflate_free_compressor((struct libdeflate_compressor *) ctx);
-    check_zlib_free(env, stream, true);
 }
 
-JNIEXPORT int JNICALL
+JNIEXPORT jboolean JNICALL
 Java_com_velocitypowered_natives_compression_NativeZlibDeflate_process(JNIEnv *env,
     jobject obj,
     jlong ctx,
@@ -73,38 +37,8 @@ Java_com_velocitypowered_natives_compression_NativeZlibDeflate_process(JNIEnv *e
     jint destinationLength,
     jboolean finish)
 {
-    z_stream* stream = (z_stream*) ctx;
+    struct libdeflate_compressor *compressor = (struct libdeflate_compressor *) ctx;
-    stream->next_in = (Bytef *) sourceAddress;
+    size_t produced = libdeflate_zlib_compress(compressor, (void *) sourceAddress, sourceLength,
-    stream->next_out = (Bytef *) destinationAddress;
+        (void *) destinationAddress, destinationLength);
-    stream->avail_in = sourceLength;
+    return (jlong) produced;
-    stream->avail_out = destinationLength;
-
-    int res = deflate(stream, finish ? Z_FINISH : Z_NO_FLUSH);
-    switch (res) {
-        case Z_STREAM_END:
-            // The stream has ended.
-            (*env)->SetBooleanField(env, obj, finishedID, JNI_TRUE);
-            // fall-through
-        case Z_OK:
-            // Not yet completed, but progress has been made. Tell Java how many bytes we've processed.
-            (*env)->SetIntField(env, obj, consumedID, sourceLength - stream->avail_in);
-            return destinationLength - stream->avail_out;
-        case Z_BUF_ERROR:
-            // This is not fatal. Just say we need more data. Usually this applies to the next_out buffer,
-            // which NativeVelocityCompressor will notice and will expand the buffer.
-            return 0;
-        default:
-            throwException(env, "java/util/zip/DataFormatException", stream->msg);
-            return 0;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_com_velocitypowered_natives_compression_NativeZlibDeflate_reset(JNIEnv *env,
-    jobject obj,
-    jlong ctx)
-{
-    z_stream* stream = (z_stream*) ctx;
-    int ret = deflateReset(stream);
-    assert(ret == Z_OK);
 }

native/src/main/c/jni_zlib_inflate.c

@@ -2,50 +2,21 @@
 #include <jni.h>
 #include <stdbool.h>
 #include <stdlib.h>
-#include <zlib.h>
+#include <libdeflate.h>
 #include "jni_util.h"
-#include "jni_zlib_common.h"
-
-static jfieldID finishedID;
-static jfieldID consumedID;
-
-JNIEXPORT void JNICALL
-Java_com_velocitypowered_natives_compression_NativeZlibInflate_initIDs(JNIEnv *env, jclass cls)
-{
-    finishedID = (*env)->GetFieldID(env, cls, "finished", "Z");
-    consumedID = (*env)->GetFieldID(env, cls, "consumed", "I");
-}
 
 JNIEXPORT jlong JNICALL
 Java_com_velocitypowered_natives_compression_NativeZlibInflate_init(JNIEnv *env,
     jobject obj)
 {
-    z_stream* stream = calloc(1, sizeof(z_stream));
+    struct libdeflate_decompressor *decompress = libdeflate_alloc_decompressor();
-
+    if (decompress == NULL) {
-    if (stream == 0) {
         // Out of memory!
-        throwException(env, "java/lang/OutOfMemoryError", "zlib allocate stream");
+        throwException(env, "java/lang/OutOfMemoryError", "libdeflate allocate decompressor");
         return 0;
     }
 
-    int ret = inflateInit(stream);
+    return (jlong) decompress;
-    if (ret == Z_OK) {
-        return (jlong) stream;
-    } else {
-        const char *zlib_msg = stream->msg;
-        free(stream);
-        switch (ret) {
-            case Z_MEM_ERROR:
-                throwException(env, "java/lang/OutOfMemoryError", "zlib init");
-                return 0;
-            case Z_STREAM_ERROR:
-                throwException(env, "java/lang/IllegalArgumentException", "stream clobbered?");
-                return 0;
-            default:
-                throwException(env, "java/util/zip/DataFormatException", zlib_msg);
-                return 0;
-        }
-    }
 }
 
 JNIEXPORT void JNICALL
@@ -53,51 +24,34 @@ Java_com_velocitypowered_natives_compression_NativeZlibInflate_free(JNIEnv *env,
     jobject obj,
     jlong ctx)
 {
-    z_stream* stream = (z_stream*) ctx;
+    libdeflate_free_decompressor((struct libdeflate_decompressor *) ctx);
-    check_zlib_free(env, stream, false);
 }
 
-JNIEXPORT int JNICALL
+JNIEXPORT jboolean JNICALL
 Java_com_velocitypowered_natives_compression_NativeZlibInflate_process(JNIEnv *env,
     jobject obj,
     jlong ctx,
     jlong sourceAddress,
     jint sourceLength,
     jlong destinationAddress,
-    jint destinationLength)
+    jint destinationLength,
+    jlong maximumSize)
 {
-    z_stream* stream = (z_stream*) ctx;
+    struct libdeflate_decompressor *decompress = (struct libdeflate_decompressor *) ctx;
-    stream->next_in = (Bytef *) sourceAddress;
+    enum libdeflate_result result = libdeflate_zlib_decompress(decompress, (void *) sourceAddress,
-    stream->next_out = (Bytef *) destinationAddress;
+        sourceLength, (void *) destinationAddress, destinationLength, NULL);
-    stream->avail_in = sourceLength;
-    stream->avail_out = destinationLength;
 
-    int res = inflate(stream, Z_PARTIAL_FLUSH);
+    switch (result) {
-    switch (res) {
+        case LIBDEFLATE_SUCCESS:
-        case Z_STREAM_END:
+            // We are happy
-            // The stream has ended
+            return JNI_TRUE;
-            (*env)->SetBooleanField(env, obj, finishedID, JNI_TRUE);
+        case LIBDEFLATE_BAD_DATA:
-            // fall-through
+            throwException(env, "java/util/zip/DataFormatException", "inflate data is bad");
-        case Z_OK:
+            return JNI_FALSE;
-            // Not yet completed, but progress has been made. Tell Java how many bytes we've processed.
+        case LIBDEFLATE_SHORT_OUTPUT:
-            (*env)->SetIntField(env, obj, consumedID, sourceLength - stream->avail_in);
+        case LIBDEFLATE_INSUFFICIENT_SPACE:
-            return destinationLength - stream->avail_out;
+            // These cases are the same for us. We expect the full uncompressed size to be known.
-        case Z_BUF_ERROR:
+            throwException(env, "java/util/zip/DataFormatException", "uncompressed size is inaccurate");
-            // This is not fatal. Just say we need more data. Usually this applies to the next_out buffer,
+            return JNI_FALSE;
-            // which NativeVelocityCompressor will notice and will expand the buffer.
-            return 0;
-        default:
-            throwException(env, "java/util/zip/DataFormatException", stream->msg);
-            return 0;
     }
-}
-
-JNIEXPORT void JNICALL
-Java_com_velocitypowered_natives_compression_NativeZlibInflate_reset(JNIEnv *env,
-    jobject obj,
-    jlong ctx)
-{
-    z_stream* stream = (z_stream*) ctx;
-    int ret = inflateReset(stream);
-    assert(ret == Z_OK);
 }

native/src/main/java/com/velocitypowered/natives/compression/Java11VelocityCompressor.java

@@ -54,7 +54,8 @@ public class Java11VelocityCompressor implements VelocityCompressor {
   }
 
   @Override
-  public void inflate(ByteBuf source, ByteBuf destination, int max) throws DataFormatException {
+  public void inflate(ByteBuf source, ByteBuf destination, int uncompressedSize)
+      throws DataFormatException {
     ensureNotDisposed();
 
     // We (probably) can't nicely deal with >=1 buffer nicely, so let's scream loudly.
@@ -67,7 +68,7 @@ public class Java11VelocityCompressor implements VelocityCompressor {
 
       while (!inflater.finished() && inflater.getBytesRead() < source.readableBytes()) {
         if (!destination.isWritable()) {
-          ensureMaxSize(destination, max);
+          ensureMaxSize(destination, uncompressedSize);
           destination.ensureWritable(ZLIB_BUFFER_SIZE);
         }
 

native/src/main/java/com/velocitypowered/natives/compression/JavaVelocityCompressor.java

@@ -25,20 +25,21 @@ public class JavaVelocityCompressor implements VelocityCompressor {
   }
 
   @Override
-  public void inflate(ByteBuf source, ByteBuf destination, int max) throws DataFormatException {
+  public void inflate(ByteBuf source, ByteBuf destination, int uncompressedSize)
+      throws DataFormatException {
     ensureNotDisposed();
 
     final int available = source.readableBytes();
     this.setInflaterInput(source);
 
     if (destination.hasArray()) {
-      this.inflateDestinationIsHeap(destination, available, max);
+      this.inflateDestinationIsHeap(destination, available, uncompressedSize);
     } else {
       if (buf.length == 0) {
         buf = new byte[ZLIB_BUFFER_SIZE];
       }
       while (!inflater.finished() && inflater.getBytesRead() < available) {
-        ensureMaxSize(destination, max);
+        ensureMaxSize(destination, uncompressedSize);
         int read = inflater.inflate(buf);
         destination.writeBytes(buf, 0, read);
       }

native/src/main/java/com/velocitypowered/natives/compression/LibdeflateVelocityCompressor.java

@@ -0,0 +1,87 @@
+package com.velocitypowered.natives.compression;
+
+import com.google.common.base.Preconditions;
+import com.velocitypowered.natives.util.BufferPreference;
+import io.netty.buffer.ByteBuf;
+import java.util.zip.DataFormatException;
+
+public class LibdeflateVelocityCompressor implements VelocityCompressor {
+
+  public static final VelocityCompressorFactory FACTORY = LibdeflateVelocityCompressor::new;
+
+  private final NativeZlibInflate inflate = new NativeZlibInflate();
+  private final long inflateCtx;
+  private final NativeZlibDeflate deflate = new NativeZlibDeflate();
+  private final long deflateCtx;
+  private boolean disposed = false;
+
+  private LibdeflateVelocityCompressor(int level) {
+    int correctedLevel = level == -1 ? 6 : level;
+    if (correctedLevel > 12 || correctedLevel < 1) {
+      throw new IllegalArgumentException("Invalid compression level " + level);
+    }
+
+    this.inflateCtx = inflate.init();
+    this.deflateCtx = deflate.init(level == -1 ? 6 : level);
+  }
+
+  @Override
+  public void inflate(ByteBuf source, ByteBuf destination, int uncompressedSize)
+      throws DataFormatException {
+    ensureNotDisposed();
+    source.memoryAddress();
+    destination.memoryAddress();
+
+    // libdeflate recommends we work with a known uncompressed size - so we work strictly within
+    // those parameters. If the uncompressed size doesn't match the compressed size, then we will
+    // throw an exception from native code.
+    destination.ensureWritable(uncompressedSize);
+
+    long sourceAddress = source.memoryAddress() + source.readerIndex();
+    long destinationAddress = destination.memoryAddress() + destination.writerIndex();
+
+    inflate.process(inflateCtx, sourceAddress, source.readableBytes(), destinationAddress,
+        uncompressedSize);
+    destination.writerIndex(destination.writerIndex() + uncompressedSize);
+  }
+
+  @Override
+  public void deflate(ByteBuf source, ByteBuf destination) throws DataFormatException {
+    ensureNotDisposed();
+    source.memoryAddress();
+    destination.memoryAddress();
+
+    while (true) {
+      long sourceAddress = source.memoryAddress() + source.readerIndex();
+      long destinationAddress = destination.memoryAddress() + destination.writerIndex();
+
+      int produced = deflate.process(deflateCtx, sourceAddress, source.readableBytes(),
+          destinationAddress, destination.writableBytes());
+      if (produced > 0) {
+        destination.writerIndex(destination.writerIndex() + produced);
+        return;
+      }
+
+      // Insufficient room - enlarge the buffer.
+      destination.capacity(destination.capacity() * 2);
+    }
+  }
+
+  private void ensureNotDisposed() {
+    Preconditions.checkState(!disposed, "Object already disposed");
+  }
+
+  @Override
+  public void dispose() {
+    if (!disposed) {
+      inflate.free(inflateCtx);
+      deflate.free(deflateCtx);
+    }
+    disposed = true;
+  }
+
+  @Override
+  public BufferPreference preferredBufferType() {
+    return BufferPreference.DIRECT_REQUIRED;
+  }
+}

native/src/main/java/com/velocitypowered/natives/compression/NativeVelocityCompressor.java

@@ -1,89 +0,0 @@
-package com.velocitypowered.natives.compression;
-
-import static com.velocitypowered.natives.compression.CompressorUtils.ZLIB_BUFFER_SIZE;
-import static com.velocitypowered.natives.compression.CompressorUtils.ensureMaxSize;
-
-import com.google.common.base.Preconditions;
-import com.velocitypowered.natives.util.BufferPreference;
-import io.netty.buffer.ByteBuf;
-import java.util.zip.DataFormatException;
-
-public class NativeVelocityCompressor implements VelocityCompressor {
-
-  public static final VelocityCompressorFactory FACTORY = NativeVelocityCompressor::new;
-
-  private final NativeZlibInflate inflate = new NativeZlibInflate();
-  private final long inflateCtx;
-  private final NativeZlibDeflate deflate = new NativeZlibDeflate();
-  private final long deflateCtx;
-  private boolean disposed = false;
-
-  private NativeVelocityCompressor(int level) {
-    this.inflateCtx = inflate.init();
-    this.deflateCtx = deflate.init(level);
-  }
-
-  @Override
-  public void inflate(ByteBuf source, ByteBuf destination, int max) throws DataFormatException {
-    ensureNotDisposed();
-    source.memoryAddress();
-    destination.memoryAddress();
-
-    while (!inflate.finished && source.isReadable()) {
-      if (!destination.isWritable()) {
-        ensureMaxSize(destination, max);
-        destination.ensureWritable(ZLIB_BUFFER_SIZE);
-      }
-      int produced = inflate.process(inflateCtx, source.memoryAddress() + source.readerIndex(),
-          source.readableBytes(), destination.memoryAddress() + destination.writerIndex(),
-          destination.writableBytes());
-      source.readerIndex(source.readerIndex() + inflate.consumed);
-      destination.writerIndex(destination.writerIndex() + produced);
-    }
-
-    inflate.reset(inflateCtx);
-    inflate.consumed = 0;
-    inflate.finished = false;
-  }
-
-  @Override
-  public void deflate(ByteBuf source, ByteBuf destination) throws DataFormatException {
-    ensureNotDisposed();
-    source.memoryAddress();
-    destination.memoryAddress();
-
-    while (!deflate.finished) {
-      if (!destination.isWritable()) {
-        destination.ensureWritable(ZLIB_BUFFER_SIZE);
-      }
-      int produced = deflate.process(deflateCtx, source.memoryAddress() + source.readerIndex(),
-          source.readableBytes(),
-          destination.memoryAddress() + destination.writerIndex(), destination.writableBytes(),
-          true);
-      source.readerIndex(source.readerIndex() + deflate.consumed);
-      destination.writerIndex(destination.writerIndex() + produced);
-    }
-
-    deflate.reset(deflateCtx);
-    deflate.consumed = 0;
-    deflate.finished = false;
-  }
-
-  private void ensureNotDisposed() {
-    Preconditions.checkState(!disposed, "Object already disposed");
-  }
-
-  @Override
-  public void dispose() {
-    if (!disposed) {
-      inflate.free(inflateCtx);
-      deflate.free(deflateCtx);
-    }
-    disposed = true;
-  }
-
-  @Override
-  public BufferPreference preferredBufferType() {
-    return BufferPreference.DIRECT_REQUIRED;
-  }
-}

native/src/main/java/com/velocitypowered/natives/compression/NativeZlibDeflate.java

@@ -5,21 +5,10 @@ package com.velocitypowered.natives.compression;
  */
 class NativeZlibDeflate {
 
-  boolean finished;
-  int consumed;
-
   native long init(int level);
 
   native long free(long ctx);
 
   native int process(long ctx, long sourceAddress, int sourceLength, long destinationAddress,
-      int destinationLength, boolean finish);
+      int destinationLength);
-
-  native void reset(long ctx);
-
-  static {
-    initIDs();
-  }
-
-  private static native void initIDs();
 }

native/src/main/java/com/velocitypowered/natives/compression/NativeZlibInflate.java

@@ -1,25 +1,16 @@
 package com.velocitypowered.natives.compression;
 
+import java.util.zip.DataFormatException;
+
 /**
  * Represents a native interface for zlib's inflate functions.
  */
 class NativeZlibInflate {
 
-  boolean finished;
-  int consumed;
-
   native long init();
 
   native long free(long ctx);
 
-  native int process(long ctx, long sourceAddress, int sourceLength, long destinationAddress,
+  native boolean process(long ctx, long sourceAddress, int sourceLength, long destinationAddress,
-      int destinationLength);
+      int destinationLength) throws DataFormatException;
-
-  native void reset(long ctx);
-
-  static {
-    initIDs();
-  }
-
-  private static native void initIDs();
 }

native/src/main/java/com/velocitypowered/natives/compression/VelocityCompressor.java

@@ -6,10 +6,12 @@ import io.netty.buffer.ByteBuf;
 import java.util.zip.DataFormatException;
 
 /**
- * Provides an interface to inflate and deflate {@link ByteBuf}s using zlib.
+ * Provides an interface to inflate and deflate {@link ByteBuf}s using zlib or a compatible
+ * implementation.
  */
 public interface VelocityCompressor extends Disposable, Native {
-  void inflate(ByteBuf source, ByteBuf destination, int max) throws DataFormatException;
+  void inflate(ByteBuf source, ByteBuf destination, int uncompressedSize)
+      throws DataFormatException;
 
   void deflate(ByteBuf source, ByteBuf destination) throws DataFormatException;
 }

native/src/main/java/com/velocitypowered/natives/util/NativeConstraints.java

@@ -7,6 +7,7 @@ import java.util.function.BooleanSupplier;
 public class NativeConstraints {
   private static final boolean NATIVES_ENABLED = !Boolean.getBoolean("velocity.natives-disabled");
   private static final boolean IS_AMD64;
+  private static final boolean IS_AARCH64;
   private static final boolean CAN_GET_MEMORYADDRESS;
 
   static {
@@ -21,20 +22,21 @@ public class NativeConstraints {
     // HotSpot on Intel macOS prefers x86_64, but OpenJ9 on macOS and HotSpot/OpenJ9 elsewhere
     // give amd64.
     IS_AMD64 = osArch.equals("amd64") || osArch.equals("x86_64");
+    IS_AARCH64 = osArch.equals("aarch64");
   }
 
-  static final BooleanSupplier MACOS = () -> {
+  static final BooleanSupplier NATIVE_BASE = () -> NATIVES_ENABLED && CAN_GET_MEMORYADDRESS;
-    return NATIVES_ENABLED
+
-        && CAN_GET_MEMORYADDRESS
+  static final BooleanSupplier LINUX_X86_64 = () -> {
-        && System.getProperty("os.name", "").equalsIgnoreCase("Mac OS X")
+    return NATIVE_BASE.getAsBoolean()
+        && System.getProperty("os.name", "").equalsIgnoreCase("Linux")
         && IS_AMD64;
   };
 
-  static final BooleanSupplier LINUX = () -> {
+  static final BooleanSupplier LINUX_AARCH64 = () -> {
-    return NATIVES_ENABLED
+    return NATIVE_BASE.getAsBoolean()
-        && CAN_GET_MEMORYADDRESS
         && System.getProperty("os.name", "").equalsIgnoreCase("Linux")
-        && IS_AMD64;
+        && IS_AARCH64;
   };
 
   static final BooleanSupplier JAVA_11 = () -> {

native/src/main/java/com/velocitypowered/natives/util/Natives.java

@@ -4,7 +4,7 @@ import com.google.common.collect.ImmutableList;
 import com.velocitypowered.natives.NativeSetupException;
 import com.velocitypowered.natives.compression.Java11VelocityCompressor;
 import com.velocitypowered.natives.compression.JavaVelocityCompressor;
-import com.velocitypowered.natives.compression.NativeVelocityCompressor;
+import com.velocitypowered.natives.compression.LibdeflateVelocityCompressor;
 import com.velocitypowered.natives.compression.VelocityCompressorFactory;
 import com.velocitypowered.natives.encryption.JavaVelocityCipher;
 import com.velocitypowered.natives.encryption.NativeVelocityCipher;
@@ -62,12 +62,14 @@ public class Natives {
 
   public static final NativeCodeLoader<VelocityCompressorFactory> compress = new NativeCodeLoader<>(
       ImmutableList.of(
-          new NativeCodeLoader.Variant<>(NativeConstraints.MACOS,
+          new NativeCodeLoader.Variant<>(NativeConstraints.LINUX_X86_64,
-              copyAndLoadNative("/macosx/velocity-compress.dylib"), "native (macOS)",
+              copyAndLoadNative("/linux_x86_64/velocity-compress.so"),
-              NativeVelocityCompressor.FACTORY),
+              "libdeflate (Linux x86_64)",
-          new NativeCodeLoader.Variant<>(NativeConstraints.LINUX,
+              LibdeflateVelocityCompressor.FACTORY),
-              copyAndLoadNative("/linux_x64/velocity-compress.so"), "native (Linux amd64)",
+          new NativeCodeLoader.Variant<>(NativeConstraints.LINUX_AARCH64,
-              NativeVelocityCompressor.FACTORY),
+              copyAndLoadNative("/linux_aarch64/velocity-compress.so"),
+              "libdeflate (Linux aarch64)",
+              LibdeflateVelocityCompressor.FACTORY),
           new NativeCodeLoader.Variant<>(NativeConstraints.JAVA_11, () -> {
           }, "Java 11", () -> Java11VelocityCompressor.FACTORY),
           new NativeCodeLoader.Variant<>(NativeCodeLoader.ALWAYS, () -> {
@@ -77,12 +79,12 @@ public class Natives {
 
   public static final NativeCodeLoader<VelocityCipherFactory> cipher = new NativeCodeLoader<>(
       ImmutableList.of(
-          new NativeCodeLoader.Variant<>(NativeConstraints.MACOS,
+            new NativeCodeLoader.Variant<>(NativeConstraints.LINUX_X86_64,
-              copyAndLoadNative("/macosx/velocity-cipher.dylib"), "mbed TLS (macOS)",
+              copyAndLoadNative("/linux_x86_64/velocity-cipher.so"),
-              NativeVelocityCipher.FACTORY),
+              "mbed TLS (Linux x86_64)", NativeVelocityCipher.FACTORY),
-            new NativeCodeLoader.Variant<>(NativeConstraints.LINUX,
+          new NativeCodeLoader.Variant<>(NativeConstraints.LINUX_AARCH64,
-              copyAndLoadNative("/linux_x64/velocity-cipher.so"), "mbed TLS (Linux amd64)",
+              copyAndLoadNative("/linux_aarch64/velocity-cipher.so"),
-              NativeVelocityCipher.FACTORY),
+              "mbed TLS (Linux aarch64)", NativeVelocityCipher.FACTORY),
           new NativeCodeLoader.Variant<>(NativeCodeLoader.ALWAYS, () -> {
           }, "Java", JavaVelocityCipher.FACTORY)
       )

native/src/test/java/com/velocitypowered/natives/compression/VelocityCompressorTest.java

@@ -33,13 +33,13 @@ class VelocityCompressorTest {
   }
 
   @Test
-  @EnabledOnOs({MAC, LINUX})
+  @EnabledOnOs({LINUX})
   void sanityCheckNative() {
     assertThrows(IllegalArgumentException.class, () -> Natives.compress.get().create(-42));
   }
 
   @Test
-  @EnabledOnOs({MAC, LINUX})
+  @EnabledOnOs({LINUX})
   void nativeIntegrityCheck() throws DataFormatException {
     VelocityCompressor compressor = Natives.compress.get().create(Deflater.DEFAULT_COMPRESSION);
     if (compressor.preferredBufferType() != BufferPreference.DIRECT_REQUIRED) {
@@ -86,10 +86,11 @@ class VelocityCompressorTest {
     ByteBuf decompressed = bufSupplier.get();
 
     source.writeBytes(TEST_DATA);
+    int uncompressedData = source.readableBytes();
 
     try {
       compressor.deflate(source, dest);
-      compressor.inflate(dest, decompressed, Integer.MAX_VALUE);
+      compressor.inflate(dest, decompressed, uncompressedData);
       source.readerIndex(0);
       assertTrue(ByteBufUtil.equals(source, decompressed));
     } finally {

proxy/build.gradle

@@ -48,8 +48,7 @@ dependencies {
     compile "io.netty:netty-handler:${nettyVersion}"
     compile "io.netty:netty-transport-native-epoll:${nettyVersion}"
     compile "io.netty:netty-transport-native-epoll:${nettyVersion}:linux-x86_64"
-    compile "io.netty:netty-transport-native-kqueue:${nettyVersion}"
+    compile "io.netty:netty-transport-native-epoll:${nettyVersion}:linux-aarch64"
-    compile "io.netty:netty-transport-native-kqueue:${nettyVersion}:osx-x86_64"
     compile "io.netty:netty-resolver-dns:${nettyVersion}"
 
     compile "org.apache.logging.log4j:log4j-api:${log4jVersion}"

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

@@ -120,12 +120,12 @@ public class VelocityServer implements ProxyServer {
   }
 
   public KeyPair getServerKeyPair() {
-    return ensureInitialized(serverKeyPair);
+    return serverKeyPair;
   }
 
   @Override
   public VelocityConfiguration getConfiguration() {
-    return ensureInitialized(this.configuration);
+    return this.configuration;
   }
 
   @Override
@@ -229,7 +229,6 @@ public class VelocityServer implements ProxyServer {
     Metrics.VelocityMetrics.startMetrics(this, configuration.getMetrics());
   }
 
-  @RequiresNonNull({"pluginManager", "eventManager"})
   private void loadPlugins() {
     logger.info("Loading plugins...");
 
@@ -443,18 +442,11 @@ public class VelocityServer implements ProxyServer {
   }
 
   public AsyncHttpClient getAsyncHttpClient() {
-    return ensureInitialized(cm).getHttpClient();
+    return cm.getHttpClient();
   }
 
   public Ratelimiter getIpAttemptLimiter() {
-    return ensureInitialized(ipAttemptLimiter);
+    return ipAttemptLimiter;
-  }
-
-  private static <T> T ensureInitialized(T o) {
-    if (o == null) {
-      throw new IllegalStateException("The proxy isn't fully initialized.");
-    }
-    return o;
   }
 
   /**

proxy/src/main/java/com/velocitypowered/proxy/config/VelocityConfiguration.java

@@ -465,7 +465,7 @@ public class VelocityConfiguration extends AnnotatedConfig implements ProxyConfi
     Advanced advanced = new Advanced(toml.getTable("advanced"));
     Query query = new Query(toml.getTable("query"));
     Metrics metrics = new Metrics(toml.getTable("metrics"));
-    byte[] forwardingSecret = toml.getString("forwarding-secret", "5up3r53cr3t")
+    byte[] forwardingSecret = toml.getString("forwarding-secret", generateRandomString(12))
         .getBytes(StandardCharsets.UTF_8);
 
     String forwardingModeName = toml.getString("player-info-forwarding-mode", "MODERN")

proxy/src/main/java/com/velocitypowered/proxy/connection/MinecraftConnection.java

@@ -16,7 +16,6 @@ import com.velocitypowered.natives.encryption.VelocityCipher;
 import com.velocitypowered.natives.encryption.VelocityCipherFactory;
 import com.velocitypowered.natives.util.Natives;
 import com.velocitypowered.proxy.VelocityServer;
-import com.velocitypowered.proxy.network.netty.DiscardHandler;
 import com.velocitypowered.proxy.protocol.MinecraftPacket;
 import com.velocitypowered.proxy.protocol.StateRegistry;
 import com.velocitypowered.proxy.protocol.netty.MinecraftCipherDecoder;
@@ -125,6 +124,13 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
     }
   }
 
+  @Override
+  public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
+    if (sessionHandler != null) {
+      sessionHandler.readCompleted();
+    }
+  }
+
   @Override
   public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
     if (ctx.channel().isActive()) {
@@ -145,7 +151,6 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
         }
       }
 
-      installDiscardHandler(ctx);
       ctx.close();
     }
   }
@@ -161,18 +166,6 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
     Preconditions.checkState(this.channel.eventLoop().inEventLoop(), "Not in event loop");
   }
 
-  private void installDiscardHandler(ChannelHandlerContext ctx) {
-    if (ctx.pipeline().get("discard") == null) {
-      ctx.pipeline().addBefore(MINECRAFT_DECODER, "discard", DiscardHandler.HANDLER);
-    }
-  }
-
-  private void installDiscardHandler() {
-    if (channel.pipeline().get("discard") == null) {
-      channel.pipeline().addBefore(MINECRAFT_DECODER, "discard", DiscardHandler.HANDLER);
-    }
-  }
-
   public EventLoop eventLoop() {
     return channel.eventLoop();
   }
@@ -212,9 +205,10 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
    */
   public void closeWith(Object msg) {
     if (channel.isActive()) {
-      knownDisconnect = true;
+      channel.eventLoop().execute(() -> {
-      installDiscardHandler();
+        knownDisconnect = true;
-      channel.writeAndFlush(msg).addListener(ChannelFutureListener.CLOSE);
+        channel.writeAndFlush(msg).addListener(ChannelFutureListener.CLOSE);
+      });
     }
   }
 
@@ -223,7 +217,6 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
    */
   public void close() {
     if (channel.isActive()) {
-      installDiscardHandler();
       channel.close();
     }
   }

proxy/src/main/java/com/velocitypowered/proxy/connection/MinecraftSessionHandler.java

@@ -70,6 +70,10 @@ public interface MinecraftSessionHandler {
 
   }
 
+  default void readCompleted() {
+
+  }
+
   default boolean handle(AvailableCommands commands) {
     return false;
   }

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

@@ -188,12 +188,17 @@ public class BackendPlaySessionHandler implements MinecraftSessionHandler {
     if (packet instanceof PluginMessage) {
       ((PluginMessage) packet).retain();
     }
-    playerConnection.write(packet);
+    playerConnection.delayedWrite(packet);
   }
 
   @Override
   public void handleUnknown(ByteBuf buf) {
-    playerConnection.write(buf.retain());
+    playerConnection.delayedWrite(buf.retain());
+  }
+
+  @Override
+  public void readCompleted() {
+    playerConnection.flush();
   }
 
   @Override

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

@@ -170,59 +170,45 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
   public boolean handle(PluginMessage packet) {
     VelocityServerConnection serverConn = player.getConnectedServer();
     MinecraftConnection backendConn = serverConn != null ? serverConn.getConnection() : null;
-    if (serverConn != null && backendConn != null) {
+    if (serverConn == null || backendConn == null) {
-      if (backendConn.getState() != StateRegistry.PLAY) {
+      return true;
-        logger.warn("A plugin message was received while the backend server was not "
-            + "ready. Channel: {}. Packet discarded.", packet.getChannel());
-      } else if (PluginMessageUtil.isRegister(packet)) {
-        player.getKnownChannels().addAll(PluginMessageUtil.getChannels(packet));
-        backendConn.write(packet.retain());
-      } else if (PluginMessageUtil.isUnregister(packet)) {
-        player.getKnownChannels().removeAll(PluginMessageUtil.getChannels(packet));
-        backendConn.write(packet.retain());
-      } else if (PluginMessageUtil.isMcBrand(packet)) {
-        backendConn.write(PluginMessageUtil
-            .rewriteMinecraftBrand(packet, server.getVersion(), player.getProtocolVersion()));
-      } else {
-        if (serverConn.getPhase() == BackendConnectionPhases.IN_TRANSITION) {
-          // We must bypass the currently-connected server when forwarding Forge packets.
-          VelocityServerConnection inFlight = player.getConnectionInFlight();
-          if (inFlight != null) {
-            player.getPhase().handle(player, packet, inFlight);
-          }
-          return true;
-        }
-
-        if (!player.getPhase().handle(player, packet, serverConn)) {
-          if (!player.getPhase().consideredComplete() || !serverConn.getPhase()
-              .consideredComplete()) {
-            // The client is trying to send messages too early. This is primarily caused by mods,
-            // but further aggravated by Velocity. To work around these issues, we will queue any
-            // non-FML handshake messages to be sent once the FML handshake has completed or the
-            // JoinGame packet has been received by the proxy, whichever comes first.
-            //
-            // We also need to make sure to retain these packets so they can be flushed
-            // appropriately.
-            loginPluginMessages.add(packet.retain());
-          } else {
-            ChannelIdentifier id = server.getChannelRegistrar().getFromId(packet.getChannel());
-            if (id == null) {
-              backendConn.write(packet.retain());
-            } else {
-              byte[] copy = ByteBufUtil.getBytes(packet.content());
-              PluginMessageEvent event = new PluginMessageEvent(player, serverConn, id,
-                  ByteBufUtil.getBytes(packet.content()));
-              server.getEventManager().fire(event).thenAcceptAsync(pme -> {
-                PluginMessage message = new PluginMessage(packet.getChannel(),
-                    Unpooled.wrappedBuffer(copy));
-                backendConn.write(message);
-              }, backendConn.eventLoop());
-            }
-          }
-        }
-      }
     }
 
+    if (backendConn.getState() != StateRegistry.PLAY) {
+      logger.warn("A plugin message was received while the backend server was not "
+          + "ready. Channel: {}. Packet discarded.", packet.getChannel());
+      return true;
+    }
+
+    if (this.tryHandleVanillaPluginMessageChannel(packet, backendConn)) {
+      return true;
+    }
+
+    if (serverConn.getPhase() == BackendConnectionPhases.IN_TRANSITION) {
+      // We must bypass the currently-connected server when forwarding Forge packets.
+      VelocityServerConnection inFlight = player.getConnectionInFlight();
+      if (inFlight != null) {
+        if (player.getPhase().handle(player, packet, inFlight)) {
+          return true;
+        }
+      }
+    } else if (!this.tryHandleForgeMessage(packet, serverConn)) {
+      return true;
+    }
+
+    ChannelIdentifier id = server.getChannelRegistrar().getFromId(packet.getChannel());
+    if (id == null) {
+      backendConn.write(packet.retain());
+    } else {
+      byte[] copy = ByteBufUtil.getBytes(packet.content());
+      PluginMessageEvent event = new PluginMessageEvent(player, serverConn, id,
+          ByteBufUtil.getBytes(packet.content()));
+      server.getEventManager().fire(event).thenAcceptAsync(pme -> {
+        PluginMessage message = new PluginMessage(packet.getChannel(),
+            Unpooled.wrappedBuffer(copy));
+        backendConn.write(message);
+      }, backendConn.eventLoop());
+    }
     return true;
   }
 
@@ -277,9 +263,15 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
 
   @Override
   public void writabilityChanged() {
+    boolean writable = player.getConnection().getChannel().isWritable();
+
+    if (!writable) {
+      // We might have packets queued for the server, so flush them now to free up memory.
+      player.getConnection().flush();
+    }
+
     VelocityServerConnection serverConn = player.getConnectedServer();
     if (serverConn != null) {
-      boolean writable = player.getConnection().getChannel().isWritable();
       MinecraftConnection smc = serverConn.getConnection();
       if (smc != null) {
         smc.setAutoReading(writable);
@@ -287,6 +279,44 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
     }
   }
 
+  private boolean tryHandleVanillaPluginMessageChannel(PluginMessage packet,
+      MinecraftConnection backendConn) {
+    if (PluginMessageUtil.isRegister(packet)) {
+      player.getKnownChannels().addAll(PluginMessageUtil.getChannels(packet));
+      backendConn.write(packet.retain());
+      return true;
+    } else if (PluginMessageUtil.isUnregister(packet)) {
+      player.getKnownChannels().removeAll(PluginMessageUtil.getChannels(packet));
+      backendConn.write(packet.retain());
+      return true;
+    } else if (PluginMessageUtil.isMcBrand(packet)) {
+      backendConn.write(PluginMessageUtil.rewriteMinecraftBrand(packet, server.getVersion(),
+          player.getProtocolVersion()));
+      return true;
+    }
+    return false;
+  }
+
+  private boolean tryHandleForgeMessage(PluginMessage packet, VelocityServerConnection serverConn) {
+    if (player.getPhase().handle(player, packet, serverConn)) {
+      return true;
+    }
+
+    if (!player.getPhase().consideredComplete() || !serverConn.getPhase().consideredComplete()) {
+      // The client is trying to send messages too early. This is primarily caused by mods,
+      // but further aggravated by Velocity. To work around these issues, we will queue any
+      // non-FML handshake messages to be sent once the FML handshake has completed or the
+      // JoinGame packet has been received by the proxy, whichever comes first.
+      //
+      // We also need to make sure to retain these packets so they can be flushed
+      // appropriately.
+      loginPluginMessages.add(packet.retain());
+      return true;
+    } else {
+      return false;
+    }
+  }
+
   /**
    * Handles the {@code JoinGame} packet. This function is responsible for handling the client-side
    * switching servers in Velocity.

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

@@ -6,7 +6,7 @@ import static org.asynchttpclient.Dsl.config;
 import com.google.common.base.Preconditions;
 import com.velocitypowered.natives.util.Natives;
 import com.velocitypowered.proxy.VelocityServer;
-import com.velocitypowered.proxy.network.netty.DnsAddressResolverGroupNameResolverAdapter;
+import com.velocitypowered.proxy.network.netty.SeparatePoolInetNameResolver;
 import com.velocitypowered.proxy.protocol.netty.GS4QueryHandler;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
@@ -18,6 +18,7 @@ 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;
 import java.util.Map;
@@ -48,7 +49,7 @@ public final class ConnectionManager {
   @SuppressWarnings("WeakerAccess")
   public final BackendChannelInitializerHolder backendChannelInitializer;
 
-  private final DnsAddressResolverGroup resolverGroup;
+  private final SeparatePoolInetNameResolver resolver;
   private final AsyncHttpClient httpClient;
 
   /**
@@ -65,21 +66,16 @@ public final class ConnectionManager {
         new ServerChannelInitializer(this.server));
     this.backendChannelInitializer = new BackendChannelInitializerHolder(
         new BackendChannelInitializer(this.server));
-    this.resolverGroup = new DnsAddressResolverGroup(new DnsNameResolverBuilder()
+    this.resolver = new SeparatePoolInetNameResolver(GlobalEventExecutor.INSTANCE);
-        .channelType(this.transportType.datagramChannelClass)
-        .negativeTtl(15)
-        .ndots(1));
     this.httpClient = asyncHttpClient(config()
         .setEventLoopGroup(this.workerGroup)
         .setUserAgent(server.getVersion().getName() + "/" + server.getVersion().getVersion())
         .addRequestFilter(new RequestFilter() {
           @Override
-          public <T> FilterContext<T> filter(FilterContext<T> ctx) throws FilterException {
+          public <T> FilterContext<T> filter(FilterContext<T> ctx) {
             return new FilterContextBuilder<>(ctx)
                 .request(new RequestBuilder(ctx.getRequest())
-                    .setNameResolver(
+                    .setNameResolver(resolver)
-                        new DnsAddressResolverGroupNameResolverAdapter(resolverGroup, workerGroup)
-                    )
                     .build())
                 .build();
           }
@@ -162,7 +158,7 @@ public final class ConnectionManager {
         .option(ChannelOption.CONNECT_TIMEOUT_MILLIS,
             this.server.getConfiguration().getConnectTimeout())
         .group(group == null ? this.workerGroup : group)
-        .resolver(this.resolverGroup);
+        .resolver(this.resolver.asGroup());
     if (transportType == TransportType.EPOLL && server.getConfiguration().useTcpFastOpen()) {
       bootstrap.option(EpollChannelOption.TCP_FASTOPEN_CONNECT, true);
     }
@@ -194,6 +190,8 @@ public final class ConnectionManager {
         Thread.currentThread().interrupt();
       }
     }
+
+    this.resolver.shutdown();
   }
 
   public EventLoopGroup getBossGroup() {

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

@@ -7,11 +7,6 @@ import io.netty.channel.epoll.EpollDatagramChannel;
 import io.netty.channel.epoll.EpollEventLoopGroup;
 import io.netty.channel.epoll.EpollServerSocketChannel;
 import io.netty.channel.epoll.EpollSocketChannel;
-import io.netty.channel.kqueue.KQueue;
-import io.netty.channel.kqueue.KQueueDatagramChannel;
-import io.netty.channel.kqueue.KQueueEventLoopGroup;
-import io.netty.channel.kqueue.KQueueServerSocketChannel;
-import io.netty.channel.kqueue.KQueueSocketChannel;
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.channel.socket.ServerSocketChannel;
@@ -27,11 +22,7 @@ enum TransportType {
       (name, type) -> new NioEventLoopGroup(0, createThreadFactory(name, type))),
   EPOLL("epoll", EpollServerSocketChannel.class, EpollSocketChannel.class,
       EpollDatagramChannel.class,
-      (name, type) -> new EpollEventLoopGroup(0, createThreadFactory(name, type))),
+      (name, type) -> new EpollEventLoopGroup(0, createThreadFactory(name, type)));
-  KQUEUE("Kqueue", KQueueServerSocketChannel.class, KQueueSocketChannel.class,
-      KQueueDatagramChannel.class,
-      (name, type) -> new KQueueEventLoopGroup(0, createThreadFactory(name, type)));
-
 
   final String name;
   final Class<? extends ServerSocketChannel> serverSocketChannelClass;
@@ -71,8 +62,6 @@ enum TransportType {
 
     if (Epoll.isAvailable()) {
       return EPOLL;
-    } else if (KQueue.isAvailable()) {
-      return KQUEUE;
     } else {
       return NIO;
     }

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

@@ -1,17 +0,0 @@
-package com.velocitypowered.proxy.network.netty;
-
-import io.netty.channel.ChannelHandler.Sharable;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
-import io.netty.util.ReferenceCountUtil;
-
-@Sharable
-public class DiscardHandler extends ChannelInboundHandlerAdapter {
-
-  public static final DiscardHandler HANDLER = new DiscardHandler();
-
-  @Override
-  public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-    ReferenceCountUtil.release(msg);
-  }
-}

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

@@ -1,68 +0,0 @@
-package com.velocitypowered.proxy.network.netty;
-
-import io.netty.channel.EventLoopGroup;
-import io.netty.resolver.InetNameResolver;
-import io.netty.resolver.dns.DnsAddressResolverGroup;
-import io.netty.util.concurrent.EventExecutor;
-import io.netty.util.concurrent.FutureListener;
-import io.netty.util.concurrent.ImmediateEventExecutor;
-import io.netty.util.concurrent.Promise;
-import io.netty.util.internal.ThreadExecutorMap;
-import java.net.InetAddress;
-import java.net.InetSocketAddress;
-import java.util.ArrayList;
-import java.util.List;
-
-public class DnsAddressResolverGroupNameResolverAdapter extends InetNameResolver {
-
-  private final DnsAddressResolverGroup resolverGroup;
-  private final EventLoopGroup group;
-
-  /**
-   * Creates a DnsAddressResolverGroupNameResolverAdapter.
-   * @param resolverGroup the resolver group to use
-   * @param group the event loop group
-   */
-  public DnsAddressResolverGroupNameResolverAdapter(
-      DnsAddressResolverGroup resolverGroup, EventLoopGroup group) {
-    super(ImmediateEventExecutor.INSTANCE);
-    this.resolverGroup = resolverGroup;
-    this.group = group;
-  }
-
-  @Override
-  protected void doResolve(String inetHost, Promise<InetAddress> promise) throws Exception {
-    EventExecutor executor = this.findExecutor();
-    resolverGroup.getResolver(executor).resolve(InetSocketAddress.createUnresolved(inetHost, 17))
-        .addListener((FutureListener<InetSocketAddress>) future -> {
-          if (future.isSuccess()) {
-            promise.trySuccess(future.getNow().getAddress());
-          } else {
-            promise.tryFailure(future.cause());
-          }
-        });
-  }
-
-  @Override
-  protected void doResolveAll(String inetHost, Promise<List<InetAddress>> promise)
-      throws Exception {
-    EventExecutor executor = this.findExecutor();
-    resolverGroup.getResolver(executor).resolveAll(InetSocketAddress.createUnresolved(inetHost, 17))
-        .addListener((FutureListener<List<InetSocketAddress>>) future -> {
-          if (future.isSuccess()) {
-            List<InetAddress> addresses = new ArrayList<>(future.getNow().size());
-            for (InetSocketAddress address : future.getNow()) {
-              addresses.add(address.getAddress());
-            }
-            promise.trySuccess(addresses);
-          } else {
-            promise.tryFailure(future.cause());
-          }
-        });
-  }
-
-  private EventExecutor findExecutor() {
-    EventExecutor current = ThreadExecutorMap.currentExecutor();
-    return current == null ? group.next() : current;
-  }
-}

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

@@ -0,0 +1,79 @@
+package com.velocitypowered.proxy.network.netty;
+
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import io.netty.resolver.AddressResolver;
+import io.netty.resolver.AddressResolverGroup;
+import io.netty.resolver.DefaultNameResolver;
+import io.netty.resolver.InetNameResolver;
+import io.netty.util.concurrent.EventExecutor;
+import io.netty.util.concurrent.Future;
+import io.netty.util.concurrent.Promise;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.RejectedExecutionException;
+
+public final class SeparatePoolInetNameResolver extends InetNameResolver {
+
+  private final ExecutorService resolveExecutor;
+  private final InetNameResolver delegate;
+  private AddressResolverGroup<InetSocketAddress> resolverGroup;
+
+  /**
+   * Creates a new instance of {@code SeparatePoolInetNameResolver}.
+   *
+   * @param executor the {@link EventExecutor} which is used to notify the listeners of the {@link
+   *                 Future} returned by {@link #resolve(String)}
+   */
+  public SeparatePoolInetNameResolver(EventExecutor executor) {
+    super(executor);
+    this.resolveExecutor = Executors.newSingleThreadExecutor(
+        new ThreadFactoryBuilder()
+            .setNameFormat("Velocity DNS Resolver")
+            .setDaemon(true)
+            .build());
+    this.delegate = new DefaultNameResolver(executor);
+  }
+
+  @Override
+  protected void doResolve(String inetHost, Promise<InetAddress> promise) throws Exception {
+    try {
+      resolveExecutor.execute(() -> this.delegate.resolve(inetHost, promise));
+    } catch (RejectedExecutionException e) {
+      promise.setFailure(e);
+    }
+  }
+
+  @Override
+  protected void doResolveAll(String inetHost, Promise<List<InetAddress>> promise)
+      throws Exception {
+    try {
+      resolveExecutor.execute(() -> this.delegate.resolveAll(inetHost, promise));
+    } catch (RejectedExecutionException e) {
+      promise.setFailure(e);
+    }
+  }
+
+  public void shutdown() {
+    this.resolveExecutor.shutdown();
+  }
+
+  /**
+   * Returns a view of this resolver as a AddressResolverGroup.
+   *
+   * @return a view of this resolver as a AddressResolverGroup
+   */
+  public AddressResolverGroup<InetSocketAddress> asGroup() {
+    if (this.resolverGroup == null) {
+      this.resolverGroup = new AddressResolverGroup<InetSocketAddress>() {
+        @Override
+        protected AddressResolver<InetSocketAddress> newResolver(EventExecutor executor) {
+          return asAddressResolver();
+        }
+      };
+    }
+    return this.resolverGroup;
+  }
+}

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

@@ -22,7 +22,6 @@ public class MinecraftCipherDecoder extends MessageToMessageDecoder<ByteBuf> {
     try {
       cipher.process(compatible);
       out.add(compatible);
-      in.skipBytes(in.readableBytes());
     } catch (Exception e) {
       compatible.release(); // compatible will never be used if we throw an exception
       throw e;

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

@@ -13,9 +13,13 @@ import java.util.List;
 
 public class MinecraftCompressDecoder extends MessageToMessageDecoder<ByteBuf> {
 
-  private static final int SOFT_MAXIMUM_UNCOMPRESSED_SIZE = 2 * 1024 * 1024; // 2MiB
+  private static final int VANILLA_MAXIMUM_UNCOMPRESSED_SIZE = 2 * 1024 * 1024; // 2MiB
   private static final int HARD_MAXIMUM_UNCOMPRESSED_SIZE = 16 * 1024 * 1024; // 16MiB
 
+  private static final int UNCOMPRESSED_CAP =
+      Boolean.getBoolean("velocity.increased-compression-cap")
+          ? HARD_MAXIMUM_UNCOMPRESSED_SIZE : VANILLA_MAXIMUM_UNCOMPRESSED_SIZE;
+
   private final int threshold;
   private final VelocityCompressor compressor;
 
@@ -28,21 +32,21 @@ public class MinecraftCompressDecoder extends MessageToMessageDecoder<ByteBuf> {
   protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
     int claimedUncompressedSize = ProtocolUtils.readVarInt(in);
     if (claimedUncompressedSize == 0) {
-      // Strip the now-useless uncompressed size, this message is already uncompressed.
+      // This message is not compressed.
       out.add(in.retainedSlice());
-      in.skipBytes(in.readableBytes());
       return;
     }
 
     checkFrame(claimedUncompressedSize >= threshold, "Uncompressed size %s is less than"
             + " threshold %s", claimedUncompressedSize, threshold);
-    int allowedMax = Math.min(claimedUncompressedSize, HARD_MAXIMUM_UNCOMPRESSED_SIZE);
+    checkFrame(claimedUncompressedSize <= UNCOMPRESSED_CAP,
-    int initialCapacity = Math.min(claimedUncompressedSize, SOFT_MAXIMUM_UNCOMPRESSED_SIZE);
+        "Uncompressed size %s exceeds hard threshold of %s", claimedUncompressedSize,
+        UNCOMPRESSED_CAP);
 
     ByteBuf compatibleIn = ensureCompatible(ctx.alloc(), compressor, in);
-    ByteBuf uncompressed = preferredBuffer(ctx.alloc(), compressor, initialCapacity);
+    ByteBuf uncompressed = preferredBuffer(ctx.alloc(), compressor, claimedUncompressedSize);
     try {
-      compressor.inflate(compatibleIn, uncompressed, allowedMax);
+      compressor.inflate(compatibleIn, uncompressed, claimedUncompressedSize);
       out.add(uncompressed);
     } catch (Exception e) {
       uncompressed.release();

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

@@ -38,8 +38,11 @@ public class MinecraftCompressEncoder extends MessageToByteEncoder<ByteBuf> {
   @Override
   protected ByteBuf allocateBuffer(ChannelHandlerContext ctx, ByteBuf msg, boolean preferDirect)
       throws Exception {
-    int initialBufferSize = msg.readableBytes() <= threshold ? msg.readableBytes() + 1 :
+    // Follow the advice of https://github.com/ebiggers/libdeflate/blob/master/libdeflate.h#L103
-        msg.readableBytes() / 3;
+    // here for compression. The maximum buffer size if the data compresses well (which is almost
+    // always the case) is one less the input buffer.
+    int offset = msg.readableBytes() < threshold ? 1 : -1;
+    int initialBufferSize = msg.readableBytes() + offset;
     return MoreByteBufUtils.preferredBuffer(ctx.alloc(), compressor, initialBufferSize);
   }
 

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

@@ -1,43 +1,88 @@
 package com.velocitypowered.proxy.protocol.netty;
 
-import com.velocitypowered.proxy.protocol.ProtocolUtils;
+import com.velocitypowered.proxy.util.except.QuietException;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
-import io.netty.handler.codec.CorruptedFrameException;
+import io.netty.util.ByteProcessor;
 import java.util.List;
 
 public class MinecraftVarintFrameDecoder extends ByteToMessageDecoder {
 
+  private static final QuietException BAD_LENGTH_CACHED = new QuietException("Bad packet length");
+  private static final QuietException VARINT_BIG_CACHED = new QuietException("VarInt too big");
+  private final VarintByteDecoder reader = new VarintByteDecoder();
+
   @Override
-  protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
+  protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
-    if (!in.isReadable()) {
+    if (!ctx.channel().isActive()) {
+      in.skipBytes(in.readableBytes());
       return;
     }
 
-    int origReaderIndex = in.readerIndex();
+    while (in.isReadable()) {
-    for (int i = 0; i < 3; i++) {
+      reader.reset();
-      if (!in.isReadable()) {
+
-        in.readerIndex(origReaderIndex);
+      int varintEnd = in.forEachByte(reader);
+      if (varintEnd == -1) {
+        // We tried to go beyond the end of the buffer. This is probably a good sign that the
+        // buffer was too short to hold a proper varint.
         return;
       }
 
-      byte read = in.readByte();
+      if (reader.result == DecodeResult.SUCCESS) {
-      if (read >= 0) {
+        if (reader.readVarint < 0) {
-        // Make sure reader index of length buffer is returned to the beginning
+          throw BAD_LENGTH_CACHED;
-        in.readerIndex(origReaderIndex);
+        } else if (reader.readVarint == 0) {
-        int packetLength = ProtocolUtils.readVarInt(in);
+          // skip over the empty packet and ignore it
-
+          in.readerIndex(varintEnd + 1);
-        if (in.readableBytes() >= packetLength) {
-          out.add(in.readRetainedSlice(packetLength));
         } else {
-          in.readerIndex(origReaderIndex);
+          int minimumRead = reader.bytesRead + reader.readVarint;
+          if (in.isReadable(minimumRead)) {
+            out.add(in.retainedSlice(varintEnd + 1, reader.readVarint));
+            in.skipBytes(minimumRead);
+          } else {
+            return;
+          }
         }
-
+      } else if (reader.result == DecodeResult.TOO_BIG) {
-        return;
+        throw VARINT_BIG_CACHED;
+      } else if (reader.result == DecodeResult.TOO_SHORT) {
+        // No-op: we couldn't get a useful result.
+        break;
       }
     }
+  }
 
-    throw new CorruptedFrameException("VarInt too big");
+  private static class VarintByteDecoder implements ByteProcessor {
+    private int readVarint;
+    private int bytesRead;
+    private DecodeResult result = DecodeResult.TOO_SHORT;
+
+    @Override
+    public boolean process(byte k) {
+      readVarint |= (k & 0x7F) << bytesRead++ * 7;
+      if (bytesRead > 3) {
+        result = DecodeResult.TOO_BIG;
+        return false;
+      }
+      if ((k & 0x80) != 128) {
+        result = DecodeResult.SUCCESS;
+        return false;
+      }
+      return true;
+    }
+
+    void reset() {
+      readVarint = 0;
+      bytesRead = 0;
+      result = DecodeResult.TOO_SHORT;
+    }
+  }
+
+  private enum DecodeResult {
+    SUCCESS,
+    TOO_SHORT,
+    TOO_BIG
   }
 }