scala.actors.ReactChannel.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2005-2010, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.actors
/**
* The ReactChannel trait.
*
* @author Philipp Haller
*/
private[actors] class ReactChannel[Msg](receiver: ReplyReactor) extends InputChannel[Msg] {
private case class SendToReactor(channel: ReactChannel[Msg], msg: Msg)
/**
* Sends a message to this ReactChannel.
*
* @param msg the message to be sent
*/
def !(msg: Msg) {
receiver ! SendToReactor(this, msg)
}
/**
* Sends a message to this ReactChannel
* (asynchronous) supplying explicit reply destination.
*
* @param msg the message to send
* @param replyTo the reply destination
*/
def send(msg: Msg, replyTo: OutputChannel[Any]) {
receiver.send(SendToReactor(this, msg), replyTo)
}
/**
* Forwards msg to this keeping the
* last sender as sender instead of self.
*/
def forward(msg: Msg) {
receiver forward SendToReactor(this, msg)
}
/**
* Receives a message from this ReactChannel.
*
* This method never returns. Therefore, the rest of the computation
* has to be contained in the actions of the partial function.
*
* @param f a partial function with message patterns and actions
*/
def react(f: PartialFunction[Msg, Unit]): Nothing = {
val C = this
receiver.react {
case SendToReactor(C, msg) if (f.isDefinedAt(msg.asInstanceOf[Msg])) =>
f(msg.asInstanceOf[Msg])
}
}
/**
* Receives a message from this ReactChannel within
* a certain time span.
*
* This method never returns. Therefore, the rest of the computation
* has to be contained in the actions of the partial function.
*
* @param msec the time span before timeout
* @param f a partial function with message patterns and actions
*/
def reactWithin(msec: Long)(f: PartialFunction[Any, Unit]): Nothing = {
val C = this
val recvActor = receiver.asInstanceOf[Actor]
recvActor.reactWithin(msec) {
case C ! msg if (f.isDefinedAt(msg.asInstanceOf[Msg])) =>
f(msg.asInstanceOf[Msg])
case TIMEOUT => f(TIMEOUT)
}
}
/**
* Receives a message from this ReactChannel.
*
* @param f a partial function with message patterns and actions
* @return result of processing the received value
*/
def receive[R](f: PartialFunction[Msg, R]): R = {
val C = this
val recvActor = receiver.asInstanceOf[Actor]
recvActor.receive {
case C ! msg if (f.isDefinedAt(msg.asInstanceOf[Msg])) =>
f(msg.asInstanceOf[Msg])
}
}
/**
* Receives a message from this ReactChannel within a certain
* time span.
*
* @param msec the time span before timeout
* @param f a partial function with message patterns and actions
* @return result of processing the received value
*/
def receiveWithin[R](msec: Long)(f: PartialFunction[Any, R]): R = {
val C = this
val recvActor = receiver.asInstanceOf[Actor]
recvActor.receiveWithin(msec) {
case C ! msg if (f.isDefinedAt(msg.asInstanceOf[Msg])) =>
f(msg.asInstanceOf[Msg])
case TIMEOUT => f(TIMEOUT)
}
}
/**
* Receives the next message from this ReactChannel.
*/
def ? : Msg = receive {
case x => x
}
}