akka.io.WithUdpSend.scala Maven / Gradle / Ivy
/**
* Copyright (C) 2009-2014 Typesafe Inc.
*/
package akka.io
import java.nio.channels.{ SelectionKey, DatagramChannel }
import akka.actor.{ ActorRef, ActorLogging, Actor }
import akka.io.Udp.{ CommandFailed, Send }
import akka.io.SelectionHandler._
/**
* INTERNAL API
*/
private[io] trait WithUdpSend {
me: Actor with ActorLogging ⇒
private var pendingSend: Send = null
private var pendingCommander: ActorRef = null
// If send fails first, we allow a second go after selected writable, but no more. This flag signals that
// pending send was already tried once.
private var retriedSend = false
private def hasWritePending = pendingSend ne null
def channel: DatagramChannel
def udp: UdpExt
val settings = udp.settings
import settings._
def sendHandlers(registration: ChannelRegistration): Receive = {
case send: Send if hasWritePending ⇒
if (TraceLogging) log.debug("Dropping write because queue is full")
sender() ! CommandFailed(send)
case send: Send if send.payload.isEmpty ⇒
if (send.wantsAck)
sender() ! send.ack
case send: Send ⇒
pendingSend = send
pendingCommander = sender()
doSend(registration)
case ChannelWritable ⇒ if (hasWritePending) doSend(registration)
}
private def doSend(registration: ChannelRegistration): Unit = {
val buffer = udp.bufferPool.acquire()
try {
buffer.clear()
pendingSend.payload.copyToBuffer(buffer)
buffer.flip()
val writtenBytes = channel.send(buffer, pendingSend.target)
if (TraceLogging) log.debug("Wrote [{}] bytes to channel", writtenBytes)
// Datagram channel either sends the whole message, or nothing
if (writtenBytes == 0) {
if (retriedSend) {
pendingCommander ! CommandFailed(pendingSend)
retriedSend = false
pendingSend = null
pendingCommander = null
} else {
registration.enableInterest(SelectionKey.OP_WRITE)
retriedSend = true
}
} else {
if (pendingSend.wantsAck) pendingCommander ! pendingSend.ack
retriedSend = false
pendingSend = null
pendingCommander = null
}
} finally {
udp.bufferPool.release(buffer)
}
}
}