Journal and Snapshots

Add the following to your application.conf to use akka-persistence-mapdb as the persistence backend:

akka {
  persistence {
    journal {
      plugin = "mapdb-journal"
    }
    snapshot-store {
      plugin = "mapdb-snapshot"
    }
  }
}

This is the minimum required configuration you need to use akka-persistence-mapdb. No further configuration is needed to get it running. Be aware that this by default stores data in memory, check out the Configuration page on how to do that.

Tagging

To support tagging you need to provide an event adapter that wraps your payload using the akka.persistence.journal.Tagged class.

Implementing the event adapter:

package docs.mapdb

import akka.persistence.journal.{EventAdapter, EventSeq, Tagged}

final case class TestEvent(name: String, tag: String)

class TestEventAdapter extends EventAdapter {

  override def fromJournal(event: Any, manifest: String): EventSeq = {
    event match {
      case e: TestEvent => EventSeq.single(e)
    }
  }

  override def manifest(event: Any): String = ""

  override def toJournal(event: Any): Any = {
    event match {
      case e: TestEvent   => Tagged(e, Set(e.tag))
    }
  }

}

Then in order to use it configure the event adapter in your application.conf:

mapdb-journal {
  event-adapters {
    tagging = "docs.mapdb.TaggingEventAdapter"
  }

  event-adapter-bindings {
    "docs.mapdb.TestEvent" = tagging
  }
}