Method: Ephem::Excerpt::DAFWriter#add_array

Defined in:

lib/ephem/excerpt.rb

#add_array(name, values, array) ⇒ Object

# File 'lib/ephem/excerpt.rb', line 322

def add_array(name, values, array)
  record_number = @bward
  data = read_record(record_number).dup

  control_data = data[0, 24].unpack(@summary_control_format)
  next_record = control_data[0].to_i
  previous_record = control_data[1].to_i
  n_summaries = control_data[2].to_i

  if n_summaries < @summaries_per_record
    # Add to the existing record
    summary_record = record_number
    data[0, 24] = [next_record, previous_record, n_summaries + 1]
      .pack(@summary_control_format)
    write_record(summary_record, data)
  else
    # Create a new record
    summary_record = ((@free - 1) * 8 + 1023) / 1024 + 1
    name_record = summary_record + 1
    free_record = summary_record + 2

    data[0, 24] = [summary_record, previous_record, n_summaries]
      .pack(@summary_control_format)
    write_record(record_number, data)

    n_summaries = 0
    summaries = [0, record_number, 1]
      .pack(@summary_control_format)
      .ljust(RECORD_SIZE, "\0")
    names = " ".ljust(RECORD_SIZE, "\0")
    write_record(summary_record, summaries)
    write_record(name_record, names)

    @bward = summary_record
    @free = (free_record - 1) * RECORD_SIZE / 8 + 1
  end

  # Convert array to binary data
  array_data = array.pack("#{@double_format}*")

  start_word = @free
  @file.seek((start_word - 1) * 8)
  @file.write(array_data)
  end_word = @file.tell / 8

  @free = end_word + 1
  write_file_record

  # Using values up to nd+ni-2, then adding start_word and end_word
  new_values = values[0, @nd + @ni - 2] + [start_word, end_word]

  base = RECORD_SIZE * (summary_record - 1)
  offset = n_summaries * @summary_step
  @file.seek(base + 24 + offset)  # 24 is summary_control_struct size
  @file.write(new_values.pack(@summary_format))
  @file.seek(base + RECORD_SIZE + offset)
  @file.write(name[0, @summary_length].ljust(@summary_step, " "))
end