console process feedback with ETA in ruby

eta-snippet.rb

module EtaReport
  def total
    @total ||= whatever.count
  end

  def started_at
    @started_at ||= Time.now
  end

  def progress_feedback(processed)
    if processed.modulo(1000).zero? && processed.nonzero?
      time_taken = Time.now - started_at
      speed = processed/time_taken
      remaining = total - processed
      time_remaining = remaining / speed.to_f
      puts "Completed #{processed}/#{total} #{eta_str(time_remaining)} (#{speed.round(2)} stuffs/s)"
    else
      putc "."
    end
  end

  def eta_str(eta_seconds)
    eta_days = (eta_seconds / 1.day).floor
    eta_days_str = if eta_days.nonzero?
      "#{eta_days} days "
    end
    eta_h_m_s = eta_seconds.modulo(1.day)
    "ETA: #{eta_days_str}#{Time.at(eta_h_m_s.modulo(24.hours)).utc.strftime('%H:%M:%S')}"
  end
end

output.txt

........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
Completed 1000/10000 2 days 23:40:12 (23 stuffs/s)
.........

rough-example.rb

# use

def total
  10000
end

def run
  10000.times do |n| 
    progress_feedback(n)
    do_stuff
  end
end