EntityTypeKey in typed Cluster Sharding, #23690

akka-typed-tests/src/test/scala/akka/typed/cluster/sharding/ClusterShardingSpec.scala

@@ -62,6 +62,7 @@ class ClusterShardingSpec extends TypedSpec(ClusterShardingSpec.config) with Sca
   implicit val untypedSystem = system.toUntyped
   private val untypedCluster = akka.cluster.Cluster(untypedSystem)
 
+  val typeKey = EntityTypeKey[TestProtocol]("envelope-shard")
   val behavior = Actor.immutable[TestProtocol] {
     case (_, StopPlz()) ⇒
       Actor.stopped
@@ -74,6 +75,8 @@ class ClusterShardingSpec extends TypedSpec(ClusterShardingSpec.config) with Sca
       toMe ! "Hello!"
       Actor.same
   }
+
+  val typeKey2 = EntityTypeKey[IdTestProtocol]("no-envelope-shard")
   val behaviorWithId = Actor.immutable[IdTestProtocol] {
     case (_, IdStopPlz(_)) ⇒
       Actor.stopped
@@ -95,7 +98,7 @@ class ClusterShardingSpec extends TypedSpec(ClusterShardingSpec.config) with Sca
       val ref = sharding.spawn(
         behavior,
         Props.empty,
-        "envelope-shard",
+        typeKey,
         ClusterShardingSettings(system),
         10,
         StopPlz())
@@ -110,7 +113,7 @@ class ClusterShardingSpec extends TypedSpec(ClusterShardingSpec.config) with Sca
       val ref = sharding.spawn(
         behaviorWithId,
         Props.empty,
-        "no-envelope-shard",
+        typeKey2,
         ClusterShardingSettings(system),
         ShardingMessageExtractor.noEnvelope[IdTestProtocol](10, _.id),
         IdStopPlz("THE_ID_HERE"))
@@ -140,8 +143,7 @@ class ClusterShardingSpec extends TypedSpec(ClusterShardingSpec.config) with Sca
     untypedCluster.join(untypedCluster.selfAddress)
 
     def `11 EntityRef - tell`(): Unit = {
-      val charlieRef: EntityRef[TestProtocol] =
+      val charlieRef = sharding.entityRefFor(typeKey, "charlie")
-        sharding.entityRefFor[TestProtocol]("envelope-shard", "charlie")
 
       val p = TestProbe[String]()
 
@@ -154,11 +156,9 @@ class ClusterShardingSpec extends TypedSpec(ClusterShardingSpec.config) with Sca
       charlieRef ! StopPlz()
     }
 
-    def `11 EntityRef - ask`(): Unit = {
+    def `12 EntityRef - ask`(): Unit = {
-      val bobRef: EntityRef[TestProtocol] =
+      val bobRef = sharding.entityRefFor(typeKey, "bob")
-        sharding.entityRefFor[TestProtocol]("envelope-shard", "bob")
+      val charlieRef = sharding.entityRefFor(typeKey, "charlie")
-      val charlieRef: EntityRef[TestProtocol] =
-        sharding.entityRefFor[TestProtocol]("envelope-shard", "charlie")
 
       val p = TestProbe[String]()
 

akka-typed/src/main/scala/akka/typed/cluster/sharding/ClusterSharding.scala

@@ -12,6 +12,7 @@ import akka.typed.scaladsl.adapter.PropsAdapter
 import akka.typed.{ ActorRef, ActorSystem, Behavior, Extension, ExtensionId, Props }
 
 import scala.language.implicitConversions
+import scala.reflect.ClassTag
 
 /**
  * Default envelope type that may be used with Cluster Sharding.
@@ -63,8 +64,7 @@ object ShardingMessageExtractor {
    */
   def noEnvelope[A](
     maxNumberOfShards: Int,
-    extractEntityId:   A ⇒ String
+    extractEntityId:   A ⇒ String): ShardingMessageExtractor[A, A] =
-  ): ShardingMessageExtractor[A, A] =
     new HashCodeNoEnvelopeMessageExtractor[A](maxNumberOfShards) {
       // TODO catch MatchError here and return null for those to yield an "unhandled" when partial functions are used?
       def entityId(message: A) = extractEntityId(message)
@@ -143,6 +143,28 @@ abstract class HashCodeNoEnvelopeMessageExtractor[A](maxNumberOfShards: Int) ext
   override def toString = s"HashCodeNoEnvelopeMessageExtractor($maxNumberOfShards)"
 }
 
+/**
+ * The key of an entity type, the `name` must be unique.
+ */
+abstract class EntityTypeKey[T] {
+  def name: String
+}
+
+object EntityTypeKey {
+  /**
+   * Scala API: Creates an `EntityTypeKey`. The `name` must be unique.
+   */
+  def apply[T](name: String)(implicit tTag: ClassTag[T]): EntityTypeKey[T] =
+    AdaptedClusterShardingImpl.EntityTypeKeyImpl(name, implicitly[ClassTag[T]].runtimeClass.getName)
+
+  /**
+   * Java API: Creates an `EntityTypeKey`. The `name` must be unique.
+   */
+  def create[T](messageClass: Class[T], name: String): EntityTypeKey[T] =
+    AdaptedClusterShardingImpl.EntityTypeKeyImpl(name, messageClass.getName)
+
+}
+
 object ClusterSharding extends ExtensionId[ClusterSharding] {
 
   override def createExtension(system: ActorSystem[_]): ClusterSharding =
@@ -152,6 +174,15 @@ object ClusterSharding extends ExtensionId[ClusterSharding] {
   def get(system: ActorSystem[_]): ClusterSharding = apply(system)
 }
 
+/**
+ * INTERNAL API
+ */
+@InternalApi private[akka] object AdaptedClusterShardingImpl {
+  final case class EntityTypeKeyImpl[T](name: String, messageClassName: String) extends EntityTypeKey[T] {
+    override def toString: String = s"EntityTypeKey[$messageClassName]($name)"
+  }
+}
+
 /** INTERNAL API */
 @InternalApi
 final class AdaptedClusterShardingImpl(system: ActorSystem[_]) extends ClusterSharding {
@@ -165,27 +196,27 @@ final class AdaptedClusterShardingImpl(system: ActorSystem[_]) extends ClusterSh
   override def spawn[A](
     behavior:           Behavior[A],
     entityProps:        Props,
-    typeName:           String,
+    typeKey:            EntityTypeKey[A],
     settings:           ClusterShardingSettings,
     maxNumberOfShards:  Int,
     handOffStopMessage: A): ActorRef[ShardingEnvelope[A]] = {
     val extractor = new HashCodeMessageExtractor[A](maxNumberOfShards)
-    spawn(behavior, entityProps, typeName, settings, extractor, defaultShardAllocationStrategy(settings), handOffStopMessage)
+    spawn(behavior, entityProps, typeKey, settings, extractor, defaultShardAllocationStrategy(settings), handOffStopMessage)
   }
 
   override def spawn[E, A](
     behavior:           Behavior[A],
     entityProps:        Props,
-    typeName:           String,
+    typeKey:            EntityTypeKey[A],
     settings:           ClusterShardingSettings,
     messageExtractor:   ShardingMessageExtractor[E, A],
     handOffStopMessage: A): ActorRef[E] =
-    spawn(behavior, entityProps, typeName, settings, messageExtractor, defaultShardAllocationStrategy(settings), handOffStopMessage)
+    spawn(behavior, entityProps, typeKey, settings, messageExtractor, defaultShardAllocationStrategy(settings), handOffStopMessage)
 
   override def spawn[E, A](
     behavior:           Behavior[A],
     entityProps:        Props,
-    typeName:           String,
+    typeKey:            EntityTypeKey[A],
     settings:           ClusterShardingSettings,
     extractor:          ShardingMessageExtractor[E, A],
     allocationStrategy: ShardAllocationStrategy,
@@ -197,35 +228,30 @@ final class AdaptedClusterShardingImpl(system: ActorSystem[_]) extends ClusterSh
       if (settings.shouldHostShard(cluster)) {
         system.log.info("Starting Shard Region [{}]...")
         untypedSharding.start(
-          typeName,
+          typeKey.name,
           PropsAdapter(behavior, entityProps),
           untypedSettings,
           extractor, extractor,
           defaultShardAllocationStrategy(settings),
-          handOffStopMessage
+          handOffStopMessage)
-        )
       } else {
         system.log.info("Starting Shard Region Proxy [{}] (no actors will be hosted on this node)...")
 
         untypedSharding.startProxy(
-          typeName,
+          typeKey.name,
           settings.role,
           dataCenter = None, // TODO what about the multi-dc value here?
           extractShardId = extractor,
-          extractEntityId = extractor
+          extractEntityId = extractor)
-        )
       }
 
     ActorRefAdapter(ref)
   }
 
-  override def entityRefFor[A](typeName: String, entityId: String): EntityRef[A] = {
+  override def entityRefFor[A](typeKey: EntityTypeKey[A], entityId: String): EntityRef[A] = {
-    new AdaptedEntityRefImpl[A](untypedSharding.shardRegion(typeName), entityId)
+    new AdaptedEntityRefImpl[A](untypedSharding.shardRegion(typeKey.name), entityId)
   }
 
-  override def getEntityRefFor[A](msgClass: Class[A], typeName: String, entityId: String): EntityRef[A] =
-    entityRefFor[A](typeName, entityId)
-
   override def defaultShardAllocationStrategy(settings: ClusterShardingSettings): ShardAllocationStrategy = {
     val threshold = settings.tuningParameters.leastShardAllocationRebalanceThreshold
     val maxSimultaneousRebalance = settings.tuningParameters.leastShardAllocationMaxSimultaneousRebalance
@@ -259,7 +285,7 @@ sealed trait ClusterSharding extends Extension {
    * [[akka.cluster.sharding.ShardCoordinator.LeastShardAllocationStrategy]] will be used for shard allocation strategy.
    *
    * @param behavior The behavior for entities
-   * @param typeName A name that uniquely identifies the type of entity in this cluster
+   * @param typeKey A key that uniquely identifies the type of entity in this cluster
    * @param handOffStopMessage Message sent to an entity to tell it to stop
    * @tparam A The type of command the entity accepts
    */
@@ -268,7 +294,7 @@ sealed trait ClusterSharding extends Extension {
   def spawn[A](
     behavior:           Behavior[A],
     props:              Props,
-    typeName:           String,
+    typeKey:            EntityTypeKey[A],
     settings:           ClusterShardingSettings,
     maxNumberOfShards:  Int,
     handOffStopMessage: A): ActorRef[ShardingEnvelope[A]]
@@ -277,7 +303,7 @@ sealed trait ClusterSharding extends Extension {
    * Spawn a shard region or a proxy depending on if the settings require role and if this node has such a role.
    *
    * @param behavior The behavior for entities
-   * @param typeName A name that uniquely identifies the type of entity in this cluster
+   * @param typeKey A key that uniquely identifies the type of entity in this cluster
    * @param entityProps Props to apply when starting an entity
    * @param allocationStrategy Allocation strategy which decides on which nodes to allocate new shards
    * @param handOffStopMessage Message sent to an entity to tell it to stop
@@ -287,18 +313,17 @@ sealed trait ClusterSharding extends Extension {
   def spawn[E, A](
     behavior:           Behavior[A],
     entityProps:        Props,
-    typeName:           String,
+    typeKey:            EntityTypeKey[A],
     settings:           ClusterShardingSettings,
     messageExtractor:   ShardingMessageExtractor[E, A],
     allocationStrategy: ShardAllocationStrategy,
-    handOffStopMessage: A
+    handOffStopMessage: A): ActorRef[E]
-  ): ActorRef[E]
 
   /**
    * Spawn a shard region or a proxy depending on if the settings require role and if this node has such a role.
    *
    * @param behavior The behavior for entities
-   * @param typeName A name that uniquely identifies the type of entity in this cluster
+   * @param typeKey A key that uniquely identifies the type of entity in this cluster
    * @param entityProps Props to apply when starting an entity
    * @param handOffStopMessage Message sent to an entity to tell it to stop
    * @tparam E A possible envelope around the message the entity accepts
@@ -307,11 +332,10 @@ sealed trait ClusterSharding extends Extension {
   def spawn[E, A](
     behavior:           Behavior[A],
     entityProps:        Props,
-    typeName:           String,
+    typeKey:            EntityTypeKey[A],
     settings:           ClusterShardingSettings,
     messageExtractor:   ShardingMessageExtractor[E, A],
-    handOffStopMessage: A
+    handOffStopMessage: A): ActorRef[E]
-  ): ActorRef[E]
 
   /**
    * Create an `ActorRef`-like reference to a specific sharded entity.
@@ -324,20 +348,7 @@ sealed trait ClusterSharding extends Extension {
    *
    * For in-depth documentation of its semantics, see [[EntityRef]].
    */
-  def entityRefFor[A](typeName: String, entityId: String): EntityRef[A]
+  def entityRefFor[A](typeKey: EntityTypeKey[A], entityId: String): EntityRef[A]
-
-  /**
-   * Java API: Create an `ActorRef`-like reference to a specific sharded entity.
-   * Messages sent to it will be wrapped in a [[ShardingEnvelope]] and passed to the local shard region or proxy.
-   *
-   * Messages sent through this [[EntityRef]] will be wrapped in a [[ShardingEnvelope]] including the
-   * here provided `entityId`.
-   *
-   * FIXME a more typed version of this API will be explored in https://github.com/akka/akka/issues/23690
-   *
-   * For in-depth documentation of its semantics, see [[EntityRef]].
-   */
-  def getEntityRefFor[A](msgClass: Class[A], typeName: String, entityId: String): EntityRef[A]
 
   /** The default ShardAllocationStrategy currently is [[LeastShardAllocationStrategy]] however could be changed in the future. */
   def defaultShardAllocationStrategy(settings: ClusterShardingSettings): ShardAllocationStrategy

akka-typed/src/main/scala/akka/typed/internal/receptionist/ReceptionistImpl.scala

@@ -30,8 +30,8 @@ private[typed] trait ReceptionistBehaviorProvider {
 @InternalApi
 private[typed] object ReceptionistImpl extends ReceptionistBehaviorProvider {
   // FIXME: make sure to provide serializer
-  case class DefaultServiceKey[T](id: String)(implicit tTag: ClassTag[T]) extends ServiceKey[T] {
+  final case class DefaultServiceKey[T](id: String, typeName: String) extends ServiceKey[T] {
-    override def toString: String = s"ServiceKey[$tTag]($id)"
+    override def toString: String = s"ServiceKey[$typeName]($id)"
   }
 
   /**

akka-typed/src/main/scala/akka/typed/receptionist/Receptionist.scala

@@ -40,8 +40,7 @@ class Receptionist(system: ActorSystem[_]) extends Extension {
         // FIXME: where should that timeout be configured? Shouldn't there be a better `Extension`
         //        implementation that does this dance for us?
 
-        10.seconds
+        10.seconds))
-      ))
   }
 }
 
@@ -84,10 +83,17 @@ object Receptionist extends ExtensionId[Receptionist] {
 
   object ServiceKey {
     /**
-     * Creates a service key. The given ID should uniquely define a service with a given protocol.
+     * Scala API: Creates a service key. The given ID should uniquely define a service with a given protocol.
      */
-    // FIXME: not sure if the ClassTag pulls its weight. It's only used in toString currently.
+    def apply[T](id: String)(implicit tTag: ClassTag[T]): ServiceKey[T] =
-    def apply[T](id: String)(implicit tTag: ClassTag[T]): ServiceKey[T] = ReceptionistImpl.DefaultServiceKey(id)
+      ReceptionistImpl.DefaultServiceKey(id, implicitly[ClassTag[T]].runtimeClass.getName)
+
+    /**
+     * Java API: Creates a service key. The given ID should uniquely define a service with a given protocol.
+     */
+    def create[T](clazz: Class[T], id: String): ServiceKey[T] =
+      ReceptionistImpl.DefaultServiceKey(id, clazz.getName)
+
   }
 
   /** Internal superclass for external and internal commands */

build.sbt

@@ -160,6 +160,7 @@ lazy val streamTestsTck = akkaModule("akka-stream-tests-tck")
 lazy val typed = akkaModule("akka-typed")
   .dependsOn(
     testkit % "compile->compile;test->test",
+    persistence % "provided->compile",
     cluster % "provided->compile",
     clusterTools % "provided->compile",
     clusterSharding % "provided->compile",
@@ -169,11 +170,11 @@ lazy val typedTests = akkaModule("akka-typed-tests")
   .dependsOn(typed, typedTestkit % "compile->compile;test->provided;test->test")
   // the provided dependencies
   .dependsOn(
+    persistence % "compile->compile;test->test",
     cluster % "test->test",
     clusterTools,
     clusterSharding,
-    distributedData,
+    distributedData)
-    persistence % "compile->compile;test->test")
 
 lazy val typedTestkit = akkaModule("akka-typed-testkit")
   .dependsOn(typed, testkit % "compile->compile;test->test")