private[kusto] def estimateRowsCount()

in connector/src/main/scala/com/microsoft/kusto/spark/utils/KustoDataSourceUtils.scala [865:902]

34 lines of code
7 McCabe index (conditional complexity)


  private[kusto] def estimateRowsCount(
      client: Client,
      query: String,
      database: String,
      crp: ClientRequestProperties): Int = {
    val estimationResult: util.List[AnyRef] = Await.result(
      Future {
        val res =
          client.execute(database, generateEstimateRowsCountQuery(query), crp).getPrimaryResults
        res.next()
        res.getCurrentRow
      },
      KustoConstants.TimeoutForCountCheck)
    val maybeEstimatedCount = Option(estimationResult.get(1))
    /*
     Check if the result is null or an empty string return a 0 , else return the numeric value
     */
    val estimatedCount = maybeEstimatedCount match {
      case Some(ecStr: String) =>
        if (StringUtils.isBlank(ecStr) || !StringUtils.isNumeric(ecStr)) /* Empty estimate */ 0
        else ecStr.toInt
      case Some(ecInt: java.lang.Number) =>
        ecInt.intValue() // Is a numeric , get the int value back
      case None => 0 // No value
    }
    // We cannot be finitely determine the count , or have a 0 count. Recheck using a 'query | count()'
    if (estimatedCount == 0) {
      Await.result(
        Future {
          val res = client.execute(database, generateCountQuery(query), crp).getPrimaryResults
          res.next()
          res.getInt(0)
        },
        KustoConstants.TimeoutForCountCheck)
    } else {
      estimatedCount
    }
  }