Akka/Scala example source code file (MessageContainerSerializer.scala)

This example Akka source code file (MessageContainerSerializer.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, actorselectionmessage, akka, anyref, array, boolean, cannot, child_name, child_pattern, collection, option, parent, remote, selectparent, serialization, serialize

The MessageContainerSerializer.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.remote.serialization

import scala.collection.immutable
import com.google.protobuf.ByteString
import akka.actor.ActorSelectionMessage
import akka.actor.ExtendedActorSystem
import akka.actor.SelectChildName
import akka.actor.SelectChildPattern
import akka.actor.SelectParent
import akka.actor.SelectionPathElement
import akka.remote.ContainerFormats
import akka.serialization.SerializationExtension
import akka.serialization.Serializer

class MessageContainerSerializer(val system: ExtendedActorSystem) extends Serializer {

  def identifier: Int = 6

  def includeManifest: Boolean = false

  def toBinary(obj: AnyRef): Array[Byte] = obj match {
    case sel: ActorSelectionMessage ⇒ serializeSelection(sel)
    case _                          ⇒ throw new IllegalArgumentException(s"Cannot serialize object of type [${obj.getClass.getName}]")
  }

  import ContainerFormats.PatternType._

  private def serializeSelection(sel: ActorSelectionMessage): Array[Byte] = {
    val builder = ContainerFormats.SelectionEnvelope.newBuilder()
    val message = sel.msg.asInstanceOf[AnyRef]
    val serializer = SerializationExtension(system).findSerializerFor(message)
    builder.
      setEnclosedMessage(ByteString.copyFrom(serializer.toBinary(message))).
      setSerializerId(serializer.identifier).
      setWildcardFanOut(sel.wildcardFanOut)

    if (serializer.includeManifest)
      builder.setMessageManifest(ByteString.copyFromUtf8(message.getClass.getName))

    sel.elements.foreach {
      case SelectChildName(name) ⇒
        builder.addPattern(buildPattern(Some(name), CHILD_NAME))
      case SelectChildPattern(patternStr) ⇒
        builder.addPattern(buildPattern(Some(patternStr), CHILD_PATTERN))
      case SelectParent ⇒
        builder.addPattern(buildPattern(None, PARENT))
    }

    builder.build().toByteArray
  }

  private def buildPattern(matcher: Option[String], tpe: ContainerFormats.PatternType): ContainerFormats.Selection.Builder = {
    val builder = ContainerFormats.Selection.newBuilder().setType(tpe)
    matcher foreach builder.setMatcher
    builder
  }

  def fromBinary(bytes: Array[Byte], manifest: Option[Class[_]]): AnyRef = {
    val selectionEnvelope = ContainerFormats.SelectionEnvelope.parseFrom(bytes)
    val msg = SerializationExtension(system).deserialize(
      selectionEnvelope.getEnclosedMessage.toByteArray,
      selectionEnvelope.getSerializerId,
      if (selectionEnvelope.hasMessageManifest)
        Some(system.dynamicAccess.getClassFor[AnyRef](selectionEnvelope.getMessageManifest.toStringUtf8).get) else None).get

    import scala.collection.JavaConverters._
    val elements: immutable.Iterable[SelectionPathElement] = selectionEnvelope.getPatternList.asScala.map { x ⇒
      x.getType match {
        case CHILD_NAME    ⇒ SelectChildName(x.getMatcher)
        case CHILD_PATTERN ⇒ SelectChildPattern(x.getMatcher)
        case PARENT        ⇒ SelectParent
      }

    }(collection.breakOut)
    val wildcardFanOut = if (selectionEnvelope.hasWildcardFanOut) selectionEnvelope.getWildcardFanOut else false
    ActorSelectionMessage(msg, elements, wildcardFanOut)
  }
}