csv_memory.rb

# partially taken from https://dalibornasevic.com/posts/68-processing-large-csv-files-with-ruby
# thanks!

require 'csv'
require 'benchmark'
require 'tempfile'

def print_memory_usage
  memory_before = `ps -o rss= -p #{Process.pid}`.to_i
  yield
  memory_after = `ps -o rss= -p #{Process.pid}`.to_i

  puts "Memory: #{((memory_after - memory_before) / 1024.0).round(2)} MB"
end

def print_time_spent
  time = Benchmark.realtime do
    yield
  end

  puts "Time: #{time.round(2)}"
end

headers = ['id', 'name', 'email', 'city', 'street', 'country']

print_memory_usage do
  Tempfile.open("tmp.csv") do |tempfile|
    # tempfile ||= "tmp.csv"

    CSV.open(tempfile, 'wb') do |csv|
      print_time_spent do
        line = [
          "Pink Panther",
          "pink.panther@example.com",
          "Pink City",
          "Pink Road",
          "Pink Country",
        ]

        1_000_000.times do |i|
          csv << line
        end
      end
    end

    # puts File.read(tempfile)
  end
end