/* * Copyright 2017 Heiko Seeberger * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package de.heikoseeberger.wtat import akka.actor.Scheduler import akka.actor.typed.{ ActorRef, Behavior } import akka.actor.typed.scaladsl.Actor import akka.actor.typed.scaladsl.AskPattern.Askable import akka.cluster.Cluster import akka.cluster.ddata.{ ORSet, ORSetKey } import akka.cluster.ddata.Replicator.WriteLocal import akka.cluster.ddata.typed.scaladsl.{ DistributedData, Replicator } import akka.persistence.query.EventEnvelope import akka.persistence.query.scaladsl.EventsByPersistenceIdQuery import akka.stream.Materializer import akka.stream.scaladsl.Sink import akka.util.Timeout import cats.instances.string._ import cats.syntax.eq._ import org.apache.logging.log4j.scala.Logging import scala.concurrent.duration.FiniteDuration object UserProjection extends Logging { import akka.actor.typed.scaladsl.adapter._ sealed trait Command final case object Stop extends Command private final case object HandleEventStreamComplete extends Command abstract class EventStreamCompleteException extends IllegalStateException("Event stream completed unexpectedly!") private final case object EventStreamCompleteException extends EventStreamCompleteException final val Name = "user-projection" final val usersKey: ORSetKey[User] = ORSetKey("users") def apply(readJournal: EventsByPersistenceIdQuery, userView: ActorRef[UserView.Command], askTimeout: FiniteDuration)(implicit mat: Materializer): Behavior[Command] = Actor.deferred { context => implicit val c: Cluster = Cluster(context.system.toUntyped) implicit val s: Scheduler = context.system.scheduler implicit val t: Timeout = askTimeout val replicator = DistributedData(context.system).replicator val self = context.self readJournal .eventsByPersistenceId(UserRepository.Name, 0, Long.MaxValue) .collect { case EventEnvelope(_, _, _, event: UserRepository.Event) => event } .mapAsync(1) { case UserRepository.UserAdded(user) => replicator ? Replicator.Update(usersKey, ORSet.empty[User], WriteLocal)(_ + user) case UserRepository.UserRemoved(username) => replicator ? Replicator.Update(usersKey, ORSet.empty[User], WriteLocal) { users => users.elements.find(_.username.value === username).fold(users)(users - _) } } .runWith(Sink.onComplete(_ => self ! HandleEventStreamComplete)) logger.debug("Running event stream") Actor.immutable { case (_, Stop) => Actor.stopped case (_, HandleEventStreamComplete) => throw EventStreamCompleteException } } }