Method DivideReservationBetweenColumns

be/src/exec/hdfs-columnar-scanner.cc:293–324

}

Status HdfsColumnarScanner::DivideReservationBetweenColumns(
    const ColumnRangeLengths& col_range_lengths,
    ColumnReservations& reservation_per_column) {
  io::DiskIoMgr* io_mgr = ExecEnv::GetInstance()->disk_io_mgr();
  const int64_t min_buffer_size = io_mgr->min_buffer_size();
  const int64_t max_buffer_size = io_mgr->max_buffer_size();
  // The HdfsScanNode reservation calculation in the planner ensures that we have
  // reservation for at least one buffer per column.
  if (context_->total_reservation() < min_buffer_size * col_range_lengths.size()) {
    return Status(TErrorCode::INTERNAL_ERROR,
        Substitute("Not enough reservation in columnar scanner for file '$0'. "
                   "Need at least $1 bytes per column for $2 columns but had $3 bytes",
            filename(), min_buffer_size, col_range_lengths.size(),
            context_->total_reservation()));
  }

  // The scanner-wide stream was used only to read the file footer.  Each column has added
  // its own stream. We can use the total reservation now that 'stream_''s resources have
  // been released. We may benefit from increasing reservation further, so let's compute
  // the ideal reservation to scan all the columns.
  int64_t ideal_reservation = ComputeIdealReservation(col_range_lengths);
  if (ideal_reservation > context_->total_reservation()) {
    context_->TryIncreaseReservation(ideal_reservation);
  }
  columnar_scanner_actual_reservation_counter_->UpdateCounter(
      context_->total_reservation());
  columnar_scanner_ideal_reservation_counter_->UpdateCounter(ideal_reservation);

  reservation_per_column = DivideReservationBetweenColumnsHelper(
      min_buffer_size, max_buffer_size, col_range_lengths, context_->total_reservation());
  return Status::OK();
}

void HdfsColumnarScanner::AddSyncReadBytesCounter(int64_t total_bytes) {
  io_sync_request_->Add(1);