Decrease visibility of internals to private[io], clean up imports

akka-io/src/main/scala/akka/io/Tcp.scala

@@ -128,7 +128,7 @@ object Tcp extends ExtensionKey[TcpExt] {
   }
 
   /// COMMANDS
-  sealed trait Command
+  trait Command
 
   case class Connect(remoteAddress: InetSocketAddress,
                      localAddress: Option[InetSocketAddress] = None,
@@ -180,20 +180,6 @@ object Tcp extends ExtensionKey[TcpExt] {
   case object ConfirmedClosed extends ConnectionClosed
   case object PeerClosed extends ConnectionClosed
   case class ErrorClose(cause: String) extends ConnectionClosed
-
-  /// INTERNAL
-  case class RegisterOutgoingConnection(channel: SocketChannel)
-  case class RegisterServerSocketChannel(channel: ServerSocketChannel)
-  case class RegisterIncomingConnection(channel: SocketChannel, handler: ActorRef,
-                                        options: Traversable[SocketOption]) extends Command
-  case class Retry(command: Command, retriesLeft: Int) { require(retriesLeft >= 0) }
-  case object ChannelConnectable
-  case object ChannelAcceptable
-  case object ChannelReadable
-  case object ChannelWritable
-  case object AcceptInterest
-  case object ReadInterest
-  case object WriteInterest
 }
 
 class TcpExt(system: ExtendedActorSystem) extends IO.Extension {

akka-io/src/main/scala/akka/io/TcpConnection.scala

@@ -7,19 +7,19 @@ package akka.io
 import java.net.InetSocketAddress
 import java.io.IOException
 import java.nio.channels.SocketChannel
+import java.nio.ByteBuffer
+import scala.annotation.tailrec
 import scala.util.control.NonFatal
-import scala.collection.immutable
 import scala.concurrent.duration._
 import akka.actor._
 import akka.util.ByteString
 import Tcp._
-import annotation.tailrec
+import TcpSelector._
-import java.nio.ByteBuffer
 
 /**
  * Base class for TcpIncomingConnection and TcpOutgoingConnection.
  */
-abstract class TcpConnection(val selector: ActorRef,
+private[io] abstract class TcpConnection(val selector: ActorRef,
                                          val channel: SocketChannel,
                                          val tcp: TcpExt) extends Actor with ActorLogging with WithBufferPool {
   import tcp.Settings._

akka-io/src/main/scala/akka/io/TcpIncomingConnection.scala

@@ -5,7 +5,6 @@
 package akka.io
 
 import java.nio.channels.SocketChannel
-import scala.collection.immutable
 import akka.actor.ActorRef
 import Tcp.SocketOption
 
@@ -13,7 +12,7 @@ import Tcp.SocketOption
  * An actor handling the connection state machine for an incoming, already connected
  * SocketChannel.
  */
-class TcpIncomingConnection(_selector: ActorRef,
+private[io] class TcpIncomingConnection(_selector: ActorRef,
                                         _channel: SocketChannel,
                                         _tcp: TcpExt,
                                         handler: ActorRef,

akka-io/src/main/scala/akka/io/TcpListener.scala

@@ -7,12 +7,12 @@ package akka.io
 import java.net.InetSocketAddress
 import java.nio.channels.ServerSocketChannel
 import scala.annotation.tailrec
-import scala.collection.immutable
 import scala.util.control.NonFatal
 import akka.actor.{ ActorLogging, ActorRef, Actor }
+import TcpSelector._
 import Tcp._
 
-class TcpListener(selector: ActorRef,
+private[io] class TcpListener(selector: ActorRef,
                               handler: ActorRef,
                               endpoint: InetSocketAddress,
                               backlog: Int,

akka-io/src/main/scala/akka/io/TcpManager.scala

@@ -43,7 +43,7 @@ import Tcp._
  * with a [[akka.io.Tcp.CommandFailed]] message. This message contains the original command for reference.
  *
  */
-class TcpManager(tcp: TcpExt) extends Actor with ActorLogging {
+private[io] class TcpManager(tcp: TcpExt) extends Actor with ActorLogging {
 
   val selectorPool = context.actorOf(
     props = Props(new TcpSelector(self, tcp)).withRouter(RandomRouter(tcp.Settings.NrOfSelectors)),

akka-io/src/main/scala/akka/io/TcpOutgoingConnection.scala

@@ -8,13 +8,14 @@ import java.net.InetSocketAddress
 import java.io.IOException
 import java.nio.channels.SocketChannel
 import akka.actor.ActorRef
+import TcpSelector._
 import Tcp._
 
 /**
  * An actor handling the connection state machine for an outgoing connection
  * to be established.
  */
-class TcpOutgoingConnection(_selector: ActorRef,
+private[io] class TcpOutgoingConnection(_selector: ActorRef,
                                         _tcp: TcpExt,
                                         commander: ActorRef,
                                         remoteAddress: InetSocketAddress,

akka-io/src/main/scala/akka/io/TcpSelector.scala

@@ -14,7 +14,8 @@ import scala.concurrent.duration._
 import akka.actor._
 import Tcp._
 
-class TcpSelector(manager: ActorRef, tcp: TcpExt) extends Actor with ActorLogging {
+private[io] class TcpSelector(manager: ActorRef, tcp: TcpExt) extends Actor with ActorLogging {
+  import TcpSelector._
   import tcp.Settings._
 
   @volatile var childrenKeys = HashMap.empty[String, SelectionKey]
@@ -223,3 +224,19 @@ class TcpSelector(manager: ActorRef, tcp: TcpExt) extends Actor with ActorLoggin
     }
   }
 }
+
+private[io] object TcpSelector {
+  case class RegisterOutgoingConnection(channel: SocketChannel)
+  case class RegisterServerSocketChannel(channel: ServerSocketChannel)
+  case class RegisterIncomingConnection(channel: SocketChannel, handler: ActorRef,
+                                        options: Traversable[SocketOption]) extends Tcp.Command
+  case class Retry(command: Command, retriesLeft: Int) { require(retriesLeft >= 0) }
+
+  case object ChannelConnectable
+  case object ChannelAcceptable
+  case object ChannelReadable
+  case object ChannelWritable
+  case object AcceptInterest
+  case object ReadInterest
+  case object WriteInterest
+}

akka-io/src/test/scala/akka/io/TcpConnectionSpec.scala

@@ -18,6 +18,7 @@ import akka.actor.{ PoisonPill, ActorRef, Terminated }
 import akka.testkit.{ TestProbe, TestActorRef, AkkaSpec }
 import akka.util.ByteString
 import TestUtils._
+import TcpSelector._
 import Tcp._
 
 class TcpConnectionSpec extends AkkaSpec("akka.io.tcp.register-timeout = 500ms") {

akka-io/src/test/scala/akka/io/TcpListenerSpec.scala

@@ -8,6 +8,7 @@ import java.net.Socket
 import scala.concurrent.duration._
 import akka.actor.{ Terminated, SupervisorStrategy, Actor, Props }
 import akka.testkit.{ TestProbe, TestActorRef, AkkaSpec }
+import TcpSelector._
 import Tcp._
 
 class TcpListenerSpec extends AkkaSpec("akka.io.tcp.batch-accept-limit = 2") {