Add kqueue support (#996)

gradle/libs.versions.toml

@@ -46,6 +46,7 @@ netty-codec-haproxy = { module = "io.netty:netty-codec-haproxy", version.ref = "
 netty-codec-http = { module = "io.netty:netty-codec-http", version.ref = "netty" }
 netty-handler = { module = "io.netty:netty-handler", version.ref = "netty" }
 netty-transport-native-epoll = { module = "io.netty:netty-transport-native-epoll", version.ref = "netty" }
+netty-transport-native-kqueue = { module = "io.netty:netty-transport-native-kqueue", version.ref = "netty" }
 nightconfig = "com.electronwill.night-config:toml:3.6.6"
 slf4j = "org.slf4j:slf4j-api:2.0.7"
 spotbugs-annotations = "com.github.spotbugs:spotbugs-annotations:4.7.3"

proxy/build.gradle.kts

@@ -101,6 +101,9 @@ dependencies {
     implementation(libs.netty.transport.native.epoll)
     implementation(variantOf(libs.netty.transport.native.epoll) { classifier("linux-x86_64") })
     implementation(variantOf(libs.netty.transport.native.epoll) { classifier("linux-aarch_64") })
+    implementation(libs.netty.transport.native.kqueue)
+    implementation(variantOf(libs.netty.transport.native.kqueue) { classifier("osx-x86_64") })
+    implementation(variantOf(libs.netty.transport.native.kqueue) { classifier("osx-aarch_64") })
 
     implementation(libs.jopt)
     implementation(libs.terminalconsoleappender)

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

@@ -125,8 +125,8 @@ public final class ConnectionManager {
     if (address instanceof InetSocketAddress) {
       bootstrap.childOption(ChannelOption.TCP_NODELAY, true)
           .childOption(ChannelOption.IP_TOS, 0x18);
-      if (transportType == TransportType.EPOLL && server.getConfiguration().useTcpFastOpen()) {
-        bootstrap.option(EpollChannelOption.TCP_FASTOPEN, 3);
+      if (server.getConfiguration().useTcpFastOpen()) {
+        bootstrap.option(ChannelOption.TCP_FASTOPEN, 3);
       }
     }
 
@@ -190,8 +190,8 @@ public final class ConnectionManager {
             this.server.getConfiguration().getConnectTimeout())
         .group(group == null ? this.workerGroup : group)
         .resolver(this.resolver.asGroup());
-    if (transportType == TransportType.EPOLL && server.getConfiguration().useTcpFastOpen()) {
-      bootstrap.option(EpollChannelOption.TCP_FASTOPEN_CONNECT, true);
+    if (server.getConfiguration().useTcpFastOpen()) {
+      bootstrap.option(ChannelOption.TCP_FASTOPEN_CONNECT, true);
     }
     return bootstrap;
   }

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

@@ -29,6 +29,13 @@ import io.netty.channel.epoll.EpollEventLoopGroup;
 import io.netty.channel.epoll.EpollServerDomainSocketChannel;
 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.KQueueDomainSocketChannel;
+import io.netty.channel.kqueue.KQueueEventLoopGroup;
+import io.netty.channel.kqueue.KQueueServerDomainSocketChannel;
+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;
@@ -58,7 +65,13 @@ public enum TransportType {
       EpollDatagramChannel::new,
       EpollServerDomainSocketChannel::new,
       EpollDomainSocketChannel::new,
-      (name, type) -> new EpollEventLoopGroup(0, createThreadFactory(name, type)));
+      (name, type) -> new EpollEventLoopGroup(0, createThreadFactory(name, type))),
+  KQUEUE("kqueue", KQueueServerSocketChannel::new,
+      KQueueSocketChannel::new,
+      KQueueDatagramChannel::new,
+      KQueueServerDomainSocketChannel::new,
+      KQueueDomainSocketChannel::new,
+      (name, type) -> new KQueueEventLoopGroup(0, createThreadFactory(name, type)));
 
   final String name;
   final ChannelFactory<? extends ServerSocketChannel> serverSocketChannelFactory;
@@ -145,6 +158,10 @@ public enum TransportType {
       return EPOLL;
     }
 
+    if (KQueue.isAvailable()) {
+      return KQUEUE;
+    }
+
     return NIO;
   }