#2309 Instantiate MapDB blocking

Signed-off-by: Merlin Rabens <merlin.rabens@intenthq.com>

Author: Merlin Rabens

src/main/scala/com/intenthq/action_processor/integrations/aggregations/Aggregate.scala

@@ -2,7 +2,7 @@ package com.intenthq.action_processor.integrations.aggregations
 
 import java.util.concurrent.ConcurrentMap
 
-import cats.effect.{IO, Resource}
+import cats.effect.{Blocker, ContextShift, IO, Resource, SyncIO}
 import com.intenthq.action_processor.integrations.config.MapDbSettings
 import com.intenthq.action_processor.integrations.feeds.FeedContext
 import com.intenthq.action_processor.integrations.repositories.MapDBRepository
@@ -14,9 +14,12 @@ import scala.jdk.CollectionConverters._
 
 object Aggregate {
 
+  private lazy val blocker = Blocker[SyncIO].allocated.unsafeRunSync()._1
+  implicit private val contextShift: ContextShift[IO] = IO.contextShift(scala.concurrent.ExecutionContext.global)
+
   def noop[I]: fs2.Pipe[IO, I, (I, Long)] = _.map(_ -> 1L)
 
-  private def loadAggRepository[K](mapDbSettings: MapDbSettings): Resource[IO, HTreeMap[K, Long]] = {
+  private def loadAggRepository[K](mapDbSettings: MapDbSettings)(blocker: Blocker): Resource[IO, HTreeMap[K, Long]] = {
 
     val serializer: Serializer[K] = new GroupSerializerObjectArray[K] {
       val elsaSerializer: ElsaSerializer = new ElsaMaker().make
@@ -25,7 +28,7 @@ object Aggregate {
     }
 
     MapDBRepository
-      .load(mapDbSettings)
+      .load(mapDbSettings)(blocker)
       .map(db =>
         db.hashMap("stuff", serializer, Serializer.LONG.asInstanceOf[Serializer[Long]])
           .layout(mapDbSettings.segments, mapDbSettings.nodeSize, mapDbSettings.levels)
@@ -52,7 +55,7 @@ object Aggregate {
           )
           .map(e => (e.getKey, e.getValue))
 
-      fs2.Stream.resource[IO, ConcurrentMap[K, Long]](loadAggRepository(feedContext.mapDbSettings)).flatMap { aggRepository =>
+      fs2.Stream.resource[IO, ConcurrentMap[K, Long]](loadAggRepository(feedContext.mapDbSettings)(blocker)).flatMap { aggRepository =>
         sourceStream.evalMap { i =>
           put(aggRepository, i)
         }.drain ++ streamKeyValue(aggRepository)

src/main/scala/com/intenthq/action_processor/integrations/repositories/MapDBRepository.scala

@@ -1,19 +1,19 @@
 package com.intenthq.action_processor.integrations.repositories
 
 import java.io.File
-import java.nio.file.Paths
+import java.nio.file.{Files, Paths}
 import java.time.LocalDateTime
 
-import cats.effect.{IO, Resource}
+import cats.effect.{Blocker, ContextShift, IO, Resource}
 import com.intenthq.action_processor.integrations.config.MapDbSettings
 import org.mapdb.{DB, DBMaker}
 
 object MapDBRepository {
-  def load(mapDBSettings: MapDbSettings): Resource[IO, DB] = {
-    val dbCreated = for {
+
+  def load(mapDBSettings: MapDbSettings)(blocker: Blocker)(implicit cs: ContextShift[IO]): Resource[IO, DB] = {
+    val dbInitOp = for {
       now <- IO.delay(LocalDateTime.now())
       dbFile <- IO.delay(new File(Paths.get(mapDBSettings.dbPath.toString, s"dbb-${now.toLocalDate}-${now.toLocalTime}").toUri))
-      _ <- IO.delay(dbFile.deleteOnExit())
       createDb <- IO.delay {
         DBMaker
           .fileDB(dbFile.getAbsolutePath)
@@ -25,7 +25,7 @@ object MapDBRepository {
           .fileDeleteAfterClose()
           .make()
       }
-    } yield createDb
-    Resource.make(dbCreated)(db => IO.delay(db.close()))
+    } yield (createDb, dbFile)
+    Resource.make(blocker.blockOn(dbInitOp))(db => IO.delay(db._1.close()).guarantee(IO.delay(Files.deleteIfExists(db._2.toPath)).void)).map(_._1)
   }
 }