Reactive ZMQ

This is akka-stream API for zmq. Currently it only supports receiving data via unidirectional ZMQ sockets of types:

• ZMQ.PULL
• ZMQ.SUB

Supported Scala versions

• Scala 2.11.11+
• Scala 2.12.3+

ZMQ compatibility

See jeromq documentation.

30 seconds start

Add the following settings to your build.sbt:

libraryDependencies += "io.github.2gis" %% "reactive-zmq" % "0.5.0"

Create zmq context and Source:

import org.zeromq.ZMQ
val context = ZMQ.context(1)
val source = ZMQSource(context,
  mode = ZMQ.PULL,
  timeout = 1 second,
  addresses = List("tcp://127.0.0.1:12345")
)

Now you may use source in your graphs:

implicit val as = ActorSystem()
implicit val m = ActorMaterializer()
source
  .map { x: ByteString => println(x); x }
  .to(Sink.ignore)
  .run()

Full example is available here

Stopping

To stop the Source you should use the materialized Control object:

val (control, finish) = source
  .map { x: ByteString => println(x); x }
  .toMat(Sink.ignore)(Keep.both)
  .run()

The Control object exposes a gracefulStop method that closes an underlying ZMQ socket and completes the Source:

val stopFuture: Future[Unit] = control.gracefulStop()

implicit val ec = as.dispatcher
Future.sequence(Seq(stopFuture, finish)).onComplete { _ =>
  as.terminate()
  context.close()
}

Bleeding edge

Add the following settings to your build.sbt to use a SNAPSHOT version:

resolvers += "Sonatype OSS Snapshots" at "https://s01.oss.sonatype.org/content/repositories/snapshots"

libraryDependencies += "io.github.2gis" %% "reactive-zmq" % "0.6.0-SNAPSHOT"