Roo gem performance problems

I am getting unacceptable performace problems by using the roo gem for
reading a file by using XLSX or XLS library from this gem.

Someone may suggest me an alternative about how to parse an .XLSX file?

parsed_file = Excel.new(filename,false, :ignore) if (file_format.upcase == "XLS") parsed_file = Excelx.new(filename,false, :ignore) if (file_format.upcase == "XLSX") raise t "#{filename} is not an Excel file!" if (!parsed_file)
  parsed_file.default_sheet =

parsed_file.sheets[0]#‘Sheet2’#oo.sheets[1]

  first_row = parsed_file.first_row
  last_row = parsed_file.last_row
  first_column = parsed_file.first_column
  last_column = parsed_file.last_column
  #logger.info "#### Total Rows:#{last_row}, first_row:#{first_row},

last_row:#{last_row}, first_column:#{first_column},
last_column:#{last_column}"

  first_row.upto(last_row) do |current_line|
          # Stuff ....
  end

Thanks

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