Reduce heartbeatbuild logic duplication

be2-scala/src/main/scala/ch/epfl/pop/Server.scala

@@ -12,7 +12,7 @@ import akka.util.Timeout
 import ch.epfl.pop.authentication.{GetRequestHandler, PopchaWebSocketResponseHandler}
 import ch.epfl.pop.config.RuntimeEnvironment
 import ch.epfl.pop.config.RuntimeEnvironment._
-import ch.epfl.pop.decentralized.{ConnectionMediator, HeartbeatGenerator, Monitor}
+import ch.epfl.pop.decentralized.{ConnectionMediator, Monitor}
 import ch.epfl.pop.pubsub.{MessageRegistry, PubSubMediator, PublishSubscribe}
 import ch.epfl.pop.storage.{DbActor, SecurityModuleActor}
 import org.iq80.leveldb.Options
@@ -49,8 +49,7 @@ object Server {
       val securityModuleActorRef: AskableActorRef = system.actorOf(Props(SecurityModuleActor(RuntimeEnvironment.securityPath)))
 
       // Create necessary actors for server-server communications
-      val heartbeatGenRef: ActorRef = system.actorOf(HeartbeatGenerator.props(dbActorRef))
-      val monitorRef: ActorRef = system.actorOf(Monitor.props(heartbeatGenRef))
+      val monitorRef: ActorRef = system.actorOf(Monitor.props(dbActorRef))
       val connectionMediatorRef: ActorRef = system.actorOf(ConnectionMediator.props(monitorRef, pubSubMediatorRef, dbActorRef, securityModuleActorRef, messageRegistry))
 
       // Setup routes

be2-scala/src/main/scala/ch/epfl/pop/decentralized/Monitor.scala

@@ -3,27 +3,34 @@ package ch.epfl.pop.decentralized
 import akka.NotUsed
 import akka.actor.{Actor, ActorLogging, ActorRef, Props, Timers}
 import akka.event.LoggingReceive
+import akka.pattern.{AskableActorRef, ask}
 import akka.stream.scaladsl.Sink
 import ch.epfl.pop.config.RuntimeEnvironment.{readServerPeers, serverPeersListPath}
 import ch.epfl.pop.decentralized.Monitor.TriggerHeartbeat
 import ch.epfl.pop.model.network.JsonRpcRequest
-import ch.epfl.pop.model.network.method.ParamsWithMap
+import ch.epfl.pop.model.network.method.{Heartbeat, ParamsWithMap}
+import ch.epfl.pop.model.objects.{Channel, Hash}
+import ch.epfl.pop.pubsub.AskPatternConstants
 import ch.epfl.pop.pubsub.graph.GraphMessage
+import ch.epfl.pop.storage.DbActor
 
+import java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY
 import java.nio.file.{Path, WatchService}
-import java.nio.file.StandardWatchEventKinds.{ENTRY_CREATE, ENTRY_MODIFY}
+import scala.collection.immutable.HashMap
+import scala.concurrent.Await
 import scala.concurrent.duration.{DurationInt, FiniteDuration}
 import scala.jdk.CollectionConverters.CollectionHasAsScala
+import scala.util.Success
 
 //This actor is tasked with scheduling heartbeats.
-// To that end it sees every messages the system receives.
+// To that end it sees every message the system receives.
 // When a message is seen it schedule a heartbeat in the next heartbeatRate seconds.
 // Periodic heartbeats are sent with a period of messageDelay seconds.
 final case class Monitor(
-    heartbeatGenRef: ActorRef,
+    dbActorRef: AskableActorRef,
     heartbeatRate: FiniteDuration,
     messageDelay: FiniteDuration
-) extends Actor with ActorLogging with Timers {
+) extends Actor with ActorLogging with Timers with AskPatternConstants() {
 
   // These keys are used to keep track of the timers states
   private val periodicHbKey = 0
@@ -51,7 +58,15 @@ final case class Monitor(
     case Monitor.TriggerHeartbeat =>
       log.info("triggering a heartbeat")
       timers.cancel(singleHbKey)
-      heartbeatGenRef ! Monitor.GenerateAndSendHeartbeat(connectionMediatorRef)
+
+      val askForHeartbeat = dbActorRef ? DbActor.GenerateHeartbeat()
+      val heartbeat: HashMap[Channel, Set[Hash]] =
+        Await.ready(askForHeartbeat, duration).value.get match
+          case Success(DbActor.DbActorGenerateHeartbeatAck(map)) => map
+          case _                                                 => HashMap.empty[Channel, Set[Hash]] // Handle anything else
+
+      if (heartbeat.nonEmpty)
+        connectionMediatorRef ! Heartbeat(heartbeat)
 
     case Right(jsonRpcMessage: JsonRpcRequest) =>
       jsonRpcMessage.getParams match {
@@ -74,8 +89,8 @@ final case class Monitor(
 }
 
 object Monitor {
-  def props(heartbeatGenRef: ActorRef, heartbeatRate: FiniteDuration = 15.seconds, messageDelay: FiniteDuration = 1.seconds): Props =
-    Props(new Monitor(heartbeatGenRef, heartbeatRate, messageDelay))
+  def props(dbActorRef: AskableActorRef, heartbeatRate: FiniteDuration = 15.seconds, messageDelay: FiniteDuration = 1.seconds): Props =
+    Props(new Monitor(dbActorRef, heartbeatRate, messageDelay))
 
   def sink(monitorRef: ActorRef): Sink[GraphMessage, NotUsed] = {
     Sink.actorRef(
@@ -90,7 +105,6 @@ object Monitor {
   sealed trait Event
   final case class AtLeastOneServerConnected() extends Event
   final case class NoServerConnected() extends Event
-  final case class GenerateAndSendHeartbeat(connectionMediatorRef: ActorRef) extends Event
   final case class TriggerHeartbeat() extends Event
   private final case class DoNothing() extends Event
 }

be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/ParamsWithMapHandler.scala

@@ -24,41 +24,22 @@ object ParamsWithMapHandler extends AskPatternConstants {
       /** first step is to retrieve the received heartbeat from the jsonRpcRequest */
       val receivedHeartBeat: Map[Channel, Set[Hash]] = jsonRpcMessage.getParams.asInstanceOf[Heartbeat].channelsToMessageIds
 
-      /** second step is to retrieve the local set of channels */
-      var setOfChannels: Set[Channel] = Set()
-      val ask = dbActorRef ? DbActor.GetAllChannels()
-      Await.ready(ask, duration).value match {
-        case Some(Success(DbActor.DbActorGetAllChannelsAck(channels))) =>
-          setOfChannels = channels
-        case Some(Failure(ex: DbActorNAckException)) =>
-          Left(PipelineError(ex.code, s"couldn't retrieve local set of channels", jsonRpcMessage.getId))
+      /** finally, we only keep from the received heartbeat the message ids that are not contained in the locally extracted heartbeat. */
+      val ask = dbActorRef ? DbActor.GenerateHeartbeat()
+      Await.ready(ask, duration).value.get match
+        case Success(DbActor.DbActorGenerateHeartbeatAck(map)) =>
+          var missingIdsMap: HashMap[Channel, Set[Hash]] = HashMap()
+          receivedHeartBeat.keys.foreach(channel => {
+            val missingIdsSet = receivedHeartBeat(channel).diff(map.getOrElse(channel, Set.empty))
+            if (missingIdsSet.nonEmpty)
+              missingIdsMap += (channel -> missingIdsSet)
+          })
+          Right(JsonRpcRequest(RpcValidator.JSON_RPC_VERSION, MethodType.get_messages_by_id, GetMessagesById(missingIdsMap), Some(0)))
+
+        case Failure(ex: DbActorNAckException) =>
+          Left(PipelineError(ex.code, s"couldn't retrieve localHeartBeat", jsonRpcMessage.getId))
         case reply =>
           Left(PipelineError(ErrorCodes.SERVER_ERROR.id, s"heartbeatHandler failed : unexpected DbActor reply '$reply'", jsonRpcMessage.getId))
-      }
-
-      /** third step is to ask the DB for the content of each channel in terms of message ids. */
-      val localHeartBeat: mutable.HashMap[Channel, Set[Hash]] = mutable.HashMap()
-      setOfChannels.foreach(channel => {
-        val ask = dbActorRef ? DbActor.ReadChannelData(channel)
-        Await.ready(ask, duration).value match {
-          case Some(Success(DbActor.DbActorReadChannelDataAck(channelData))) =>
-            val setOfIds = channelData.messages.toSet
-            localHeartBeat += (channel -> setOfIds)
-          case Some(Failure(ex: DbActorNAckException)) =>
-            Left(PipelineError(ex.code, s"couldn't readChannelData for local heartbeat", jsonRpcMessage.getId))
-          case reply =>
-            Left(PipelineError(ErrorCodes.SERVER_ERROR.id, s"heartbeatHandler failed : unexpected DbActor reply '$reply'", jsonRpcMessage.getId))
-        }
-      })
-
-      /** finally, we only keep from the received heartbeat the message ids that are not contained in the locally extracted heartbeat. */
-      var missingIdsMap: HashMap[Channel, Set[Hash]] = HashMap()
-      receivedHeartBeat.keys.foreach(channel => {
-        val missingIdsSet = receivedHeartBeat(channel).diff(localHeartBeat.getOrElse(channel, Set.empty))
-        if (missingIdsSet.nonEmpty)
-          missingIdsMap += (channel -> missingIdsSet)
-      })
-      Right(JsonRpcRequest(RpcValidator.JSON_RPC_VERSION, MethodType.get_messages_by_id, GetMessagesById(missingIdsMap), Some(0)))
 
     case Right(jsonRpcMessage: JsonRpcResponse) =>
       Left(PipelineError(ErrorCodes.SERVER_ERROR.id, "HeartbeatHandler received a 'JsonRpcResponse'", jsonRpcMessage.id))

be2-scala/src/main/scala/ch/epfl/pop/storage/DbActor.scala

@@ -9,15 +9,16 @@ import ch.epfl.pop.json.MessageDataProtocol.GreetLaoFormat
 import ch.epfl.pop.model.network.method.message.Message
 import ch.epfl.pop.model.network.method.message.data.lao.GreetLao
 import ch.epfl.pop.model.network.method.message.data.{ActionType, ObjectType}
+import ch.epfl.pop.model.objects.*
 import ch.epfl.pop.model.objects.Channel.{LAO_DATA_LOCATION, ROOT_CHANNEL_PREFIX}
-import ch.epfl.pop.model.objects._
 import ch.epfl.pop.pubsub.graph.AnswerGenerator.timout
 import ch.epfl.pop.pubsub.graph.{ErrorCodes, JsonString}
 import ch.epfl.pop.pubsub.{MessageRegistry, PubSubMediator, PublishSubscribe}
-import ch.epfl.pop.storage.DbActor._
+import ch.epfl.pop.storage.DbActor.*
 import com.google.crypto.tink.subtle.Ed25519Sign
 
 import java.util.concurrent.TimeUnit
+import scala.collection.immutable.HashMap
 import scala.concurrent.Await
 import scala.concurrent.duration.{Duration, FiniteDuration}
 import scala.util.{Failure, Success, Try}
@@ -130,7 +131,7 @@ final case class DbActor(
 
   @throws[DbActorNAckException]
   private def readElectionData(laoId: Hash, electionId: Hash): ElectionData = {
-    Try(storage.read(storage.DATA_KEY + s"${ROOT_CHANNEL_PREFIX}${laoId.toString}/private/${electionId.toString}")) match {
+    Try(storage.read(storage.DATA_KEY + s"$ROOT_CHANNEL_PREFIX${laoId.toString}/private/${electionId.toString}")) match {
       case Success(Some(json)) => ElectionData.buildFromJson(json)
       case Success(None)       => throw DbActorNAckException(ErrorCodes.SERVER_ERROR.id, s"ElectionData for election $electionId not in the database")
       case Failure(ex)         => throw ex
@@ -243,7 +244,7 @@ final case class DbActor(
 
   @throws[DbActorNAckException]
   private def createElectionData(laoId: Hash, electionId: Hash, keyPair: KeyPair): Unit = {
-    val channel = Channel(s"${ROOT_CHANNEL_PREFIX}${laoId.toString}/private/${electionId.toString}")
+    val channel = Channel(s"$ROOT_CHANNEL_PREFIX${laoId.toString}/private/${electionId.toString}")
     if (!checkChannelExistence(channel)) {
       val pair = (storage.DATA_KEY + channel.toString) -> ElectionData(electionId, keyPair).toJsonString
       storage.write(pair)
@@ -299,7 +300,7 @@ final case class DbActor(
   @throws[DbActorNAckException]
   private def generateLaoDataKey(channel: Channel): String = {
     channel.decodeChannelLaoId match {
-      case Some(data) => storage.DATA_KEY + s"${Channel.ROOT_CHANNEL_PREFIX}$data${LAO_DATA_LOCATION}"
+      case Some(data) => storage.DATA_KEY + s"${Channel.ROOT_CHANNEL_PREFIX}$data$LAO_DATA_LOCATION"
       case None =>
         log.error(s"Actor $self (db) encountered a problem while decoding LAO channel from '$channel'")
         throw DbActorNAckException(ErrorCodes.SERVER_ERROR.id, s"Could not extract the LAO id for channel $channel")
@@ -308,7 +309,7 @@ final case class DbActor(
 
   // generates the key of the RollCallData to store in the database
   private def generateRollCallDataKey(laoId: Hash): String = {
-    storage.DATA_KEY + s"${ROOT_CHANNEL_PREFIX}${laoId.toString}/rollcall"
+    storage.DATA_KEY + s"$ROOT_CHANNEL_PREFIX${laoId.toString}/rollcall"
   }
 
   @throws[DbActorNAckException]
@@ -369,6 +370,20 @@ final case class DbActor(
     (publicKey, privateKey)
   }
 
+  @throws[DbActorNAckException]
+  private def generateHeartbeat(): HashMap[Channel, Set[Hash]] = {
+    val setOfChannels = getAllChannels
+    if (setOfChannels.isEmpty) return HashMap()
+    val heartbeatMap: HashMap[Channel, Set[Hash]] = setOfChannels.foldLeft(HashMap.empty[Channel, Set[Hash]]) {
+      (acc, channel) =>
+        readChannelData(channel).messages.toSet match {
+          case setOfIds if setOfIds.nonEmpty => acc + (channel -> setOfIds)
+          case _                             => acc
+        }
+    }
+    heartbeatMap
+  }
+
   override def receive: Receive = LoggingReceive {
     case Write(channel, message) =>
       log.info(s"Actor $self (db) received a WRITE request on channel '$channel'")
@@ -543,6 +558,13 @@ final case class DbActor(
         case failure             => sender() ! failure.recover(Status.Failure(_))
       }
 
+    case GenerateHeartbeat() =>
+      log.info(s"Actor $self (db) received a GenerateHeartbeat request")
+      Try(generateHeartbeat()) match {
+        case Success(heartbeat) => sender() ! DbActorGenerateHeartbeatAck(heartbeat)
+        case failure            => sender() ! failure.recover(Status.Failure(_))
+      }
+
     case m =>
       log.info(s"Actor $self (db) received an unknown message")
       sender() ! Status.Failure(DbActorNAckException(ErrorCodes.INVALID_ACTION.id, s"database actor received a message '$m' that it could not recognize"))
@@ -758,6 +780,9 @@ object DbActor {
     */
   final case class ReadServerPrivateKey() extends Event
 
+  /** Request to generate a local heartbeat */
+  final case class GenerateHeartbeat() extends Event
+
   // DbActor DbActorMessage correspond to messages the actor may emit
   sealed trait DbActorMessage
 
@@ -832,6 +857,13 @@ object DbActor {
     */
   final case class DbActorReadServerPrivateKeyAck(privateKey: PrivateKey) extends DbActorMessage
 
+  /** Response for a [[GenerateHeartbeat]] db request Receiving [[DbActorGenerateHeartbeatAck]] works as an acknowledgement that the request was successful
+    *
+    * @param heartbeatMap
+    *   requested heartbeat as a map from the channels to message ids
+    */
+  final case class DbActorGenerateHeartbeatAck(heartbeatMap: HashMap[Channel, Set[Hash]]) extends DbActorMessage
+
   /** Response for a general db actor ACK
     */
   final case class DbActorAck() extends DbActorMessage

be2-scala/src/test/scala/ch/epfl/pop/decentralized/FailingToyDbActor.scala

@@ -1,15 +1,12 @@
 package ch.epfl.pop.decentralized
 
 import akka.actor.Actor
-import ch.epfl.pop.model.objects.{Channel, DbActorNAckException}
-import ch.epfl.pop.pubsub.graph.ErrorCodes.SERVER_ERROR
-import ch.epfl.pop.storage.DbActor
+import ch.epfl.pop.model.objects.DbActorNAckException
 
 class FailingToyDbActor extends Actor {
   override def receive: Receive = {
-    case _ => {
+    case _ =>
       sender() ! DbActorNAckException(0, "")
-    }
   }
 
 }