如何使用HTTP::Server同时传输多个文件?

我正在开发一个服务于大文件的HTTP服务。我注意到并行下载是不可能的。该过程一次只提供一个文件,所有其他下载都在等待,直到以前的下载完成。如何同时传输多个文件?

    require "http/server"

    server = HTTP::Server.new(3000) do |context|
      context.response.content_type = "application/data"
      f = File.open "bigfile.bin", "r"
      IO.copy f, context.response.output
    end

    puts "Listening on http://127.0.0.1:3000"
    server.listen

    $ ab -n 10 -c 1 127.0.0.1:3000/

    [...]
    Percentage of the requests served within a certain time (ms)
     50%      9
     66%      9
     75%      9
     80%      9
     90%      9
     95%      9
     98%      9
     99%      9
    100%      9 (longest request)

一次请求10个文件:

    $ ab -n 10 -c 10 127.0.0.1:3000/

    [...]
    Percentage of the requests served within a certain time (ms)
     50%     52
     66%     57
     75%     64
     80%     69
     90%     73
     95%     73
     98%     73
     99%     73
    100%     73 (longest request)