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

This example Akka source code file (SyncWriteJournal.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, akka, boolean, collection, failure, pattern, persistence, persistentrepr, replaymessagesfailure, string, success, syncwritejournal, try, unit, utilities, writemessages

The SyncWriteJournal.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 * Copyright (C) 2012-2013 Eligotech BV.
 */

package akka.persistence.journal

import scala.collection.immutable
import scala.util._

import akka.actor.Actor
import akka.pattern.pipe
import akka.persistence._

/**
 * Abstract journal, optimized for synchronous writes.
 */
trait SyncWriteJournal extends Actor with WriteJournalBase with AsyncRecovery {
  import JournalProtocol._
  import context.dispatcher

  private val extension = Persistence(context.system)
  private val publish = extension.settings.internal.publishPluginCommands

  final def receive = {
    case WriteMessages(resequenceables, processor, actorInstanceId) ⇒
      Try(writeMessages(preparePersistentBatch(resequenceables))) match {
        case Success(_) ⇒
          processor ! WriteMessagesSuccessful
          resequenceables.foreach {
            case p: PersistentRepr ⇒ processor.tell(WriteMessageSuccess(p, actorInstanceId), p.sender)
            case r                 ⇒ processor.tell(LoopMessageSuccess(r.payload, actorInstanceId), r.sender)
          }
        case Failure(e) ⇒
          processor ! WriteMessagesFailed(e)
          resequenceables.foreach {
            case p: PersistentRepr ⇒ processor tell (WriteMessageFailure(p, e, actorInstanceId), p.sender)
            case r                 ⇒ processor tell (LoopMessageSuccess(r.payload, actorInstanceId), r.sender)
          }
          throw e
      }
    case r @ ReplayMessages(fromSequenceNr, toSequenceNr, max, persistenceId, processor, replayDeleted) ⇒
      asyncReplayMessages(persistenceId, fromSequenceNr, toSequenceNr, max) { p ⇒
        if (!p.deleted || replayDeleted) processor.tell(ReplayedMessage(p), p.sender)
      } map {
        case _ ⇒ ReplayMessagesSuccess
      } recover {
        case e ⇒ ReplayMessagesFailure(e)
      } pipeTo (processor) onSuccess {
        case _ if publish ⇒ context.system.eventStream.publish(r)
      }
    case ReadHighestSequenceNr(fromSequenceNr, persistenceId, processor) ⇒
      asyncReadHighestSequenceNr(persistenceId, fromSequenceNr).map {
        highest ⇒ ReadHighestSequenceNrSuccess(highest)
      } recover {
        case e ⇒ ReadHighestSequenceNrFailure(e)
      } pipeTo (processor)
    case WriteConfirmations(confirmationsBatch, requestor) ⇒
      Try(writeConfirmations(confirmationsBatch)) match {
        case Success(_) ⇒ requestor ! WriteConfirmationsSuccess(confirmationsBatch)
        case Failure(e) ⇒ requestor ! WriteConfirmationsFailure(e)
      }
    case d @ DeleteMessages(messageIds, permanent, requestorOption) ⇒
      Try(deleteMessages(messageIds, permanent)) match {
        case Success(_) ⇒
          requestorOption.foreach(_ ! DeleteMessagesSuccess(messageIds))
          if (publish) context.system.eventStream.publish(d)
        case Failure(e) ⇒
          requestorOption.foreach(_ ! DeleteMessagesFailure(e))
      }
    case d @ DeleteMessagesTo(persistenceId, toSequenceNr, permanent) ⇒
      Try(deleteMessagesTo(persistenceId, toSequenceNr, permanent)) match {
        case Success(_) ⇒ if (publish) context.system.eventStream.publish(d)
        case Failure(e) ⇒
      }
    case LoopMessage(message, processor, actorInstanceId) ⇒
      processor forward LoopMessageSuccess(message, actorInstanceId)
  }

  //#journal-plugin-api
  /**
   * Plugin API: synchronously writes a batch of persistent messages to the journal.
   * The batch write must be atomic i.e. either all persistent messages in the batch
   * are written or none.
   */
  def writeMessages(messages: immutable.Seq[PersistentRepr]): Unit

  /**
   * Plugin API: synchronously writes a batch of delivery confirmations to the journal.
   */
  @deprecated("writeConfirmations will be removed, since Channels will be removed.", since = "2.3.4")
  def writeConfirmations(confirmations: immutable.Seq[PersistentConfirmation]): Unit

  /**
   * Plugin API: synchronously deletes messages identified by `messageIds` from the
   * journal. If `permanent` is set to `false`, the persistent messages are marked as
   * deleted, otherwise they are permanently deleted.
   */
  @deprecated("deleteMessages will be removed.", since = "2.3.4")
  def deleteMessages(messageIds: immutable.Seq[PersistentId], permanent: Boolean): Unit

  /**
   * Plugin API: synchronously deletes all persistent messages up to `toSequenceNr`
   * (inclusive). If `permanent` is set to `false`, the persistent messages are marked
   * as deleted, otherwise they are permanently deleted.
   */
  def deleteMessagesTo(persistenceId: String, toSequenceNr: Long, permanent: Boolean): Unit
  //#journal-plugin-api
}