event-store-adapter-scala

This library(Scala wrapper for j5ik2o/event-store-adapter-java) is designed to turn DynamoDB into an Event Store for CQRS/Event Sourcing.

日本語

Installation

Add the following to your build.sbt (2.13.x, 3.0.x):

val version = "..."

libraryDependencies += Seq(
  "com.github.j5ik2o" %% "event-store-adapter-scala" % version,
)

Usage

You can easily implement an Event Sourcing-enabled repository using EventStore.

class UserAccountRepositoryAsync(
    eventStoreAsync: EventStoreAsync[UserAccountId, UserAccount, UserAccountEvent]
) {

  def store(userAccountEvent: UserAccountEvent, version: Long)
    (implicit ec: ExecutionContext): Future[Unit] =
    eventStoreAsync.persistEvent(userAccountEvent, version)

  def store(userAccountEvent: UserAccountEvent, userAccount: UserAccount)
    (implicit ec: ExecutionContext): Future[Unit] =
    eventStoreAsync.persistEventAndSnapshot(userAccountEvent, userAccount)

  def findById(id: UserAccountId)
    (implicit ec: ExecutionContext): Future[Option[UserAccount]] = {
    eventStoreAsync.getLatestSnapshotById(classOf[UserAccount], id).flatMap {
      case Some((userAccount, version)) =>
        eventStoreAsync
          .getEventsByIdSinceSequenceNumber(
            classOf[UserAccountEvent], id, userAccount.sequenceNumber + 1).map { events =>
            Some(UserAccount.replay(events, userAccount, version))
          }
      case None =>
        Future.successful(None)
    }
  }

}

The following is an example of the repository usage.

val eventStore = EventStoreAsync.ofDynamoDB[UserAccountId, UserAccount, UserAccountEvent](
  dynamodbClient,
  journalTableName,
  snapshotTableName,
  journalAidIndexName,
  snapshotAidIndexName,
  32
)
val repository = new UserAccountRepositoryAsync(eventStore)

val id                 = UserAccountId(UUID.randomUUID().toString)
val (aggregate, event) = UserAccount.create(id, "test-1")

val result = for {
  _ <- repository.store(event, aggregate)
  aggregate <- repository.findById(id)
} yield aggregate

Table Specifications

See docs/DATABASE_SCHEMA.md.

License.

MIT License. See LICENSE for details.

Links

• Common Documents