Rack streaming via puma.

config.ru

# puma
# curl http://localhost:9292/
#
# Note chrome buffers like 1024 or so... meaning the first lots will look missing.

run lambda { |env|
  body = lambda { |io|
    io.sync = true

    10.times do |i|
      n = 2

      str = (i.to_s * (n - 1)) + "\n"
      io.write "#{str.length.to_s 16}\r\n"
      io.write "#{str}\r\n"
      sleep 1
    end

    io.write "0\r\n"
    io.write "\r\n"
    io.close
  }

  headers = {
    "Content-Type" => "text/plain",
    "Cache-Control" => "no-cache",
    "Transfer-Encoding" => "chunked",
    'rack.hijack' => body
  }

  [200, headers, nil]
}