ReactiveMongo query to count documents

Question

I have a problematic mongo query. Problematic because it takes 10-12seconds and that's is why I am looking for a different implementation.

The query is trying to perform a count of how many items are in the collection. I'm sure there is a better way to perform the count.

Current implementation:

def count(criteria: Option[JsObject], skip: Int, limit: Option[Int]): Future[Long] =
    (for {
      col     <- collection
      counted <- col.count(
        selector = criteria,
        limit = limit,
        skip = skip,
        hint = None,
        readConcern = ReadConcern.Majority
      )
    } yield counted) recoverWith {
      case error =>
        logger.error(
          s"failed to count by [${criteria.getOrElse(JsObject.empty)}]" +
          s" with error: [${error.getMessage}]"
        , error)
        Future.failed(MongoExceptionBuilder.buildError(error))
    }

I've gone through documentation and I found aggregateWith command that could cooperate with the count function. I tried to implement it on myself but I failed. http://reactivemongo.org/releases/0.1x/documentation/advanced-topics/aggregation.html#count

  def count(criteria: Option[JsObject], skip: Int, limit: Option[Int]): Future[Long] =
(for {
  col     <- collection
  counted <- col.aggregateWith[Long]() { framework =>
    import framework.{Count, Group, Match}

    (Match(criteria.getOrElse(JsObject.empty)),List(Count("count")))
  }.head
} yield counted) recoverWith {
  case error =>
    logger.error(
      s"failed to count by [${criteria.getOrElse(JsObject.empty)}]" +
      s" with error: [${error.getMessage}]"
    , error)
    Future.failed(MongoExceptionBuilder.buildError(error))
}

The error I see:

lt-dispatcher-4 c.i.d.c.c.m.PlayerProfileDAOapplyOrElse(line:95) failed to count by [{}] with error: [JsResultException(errors:List((,List(JsonValidationError(List(error.expected.jsnumber),WrappedArray())))))] play.api.libs.json.JsResultException: JsResultException(errors:List((,List(JsonValidationError(List(error.expected.jsnumber),WrappedArray())))))

ReactiveMongo query to count documents

0 Answers0