Find the closest CTAN mirror

best_ctan_server.rb

require 'awesome_print'
require 'http'
require 'net/ping'
require 'uri'
require 'tty-table'

$MIRROR_DOC = 'https://ctan.org/tex-archive/README.mirrors'
$NEAREST = {}

def get_servers(type = 'rsync')
  doc = HTTP.follow.get($MIRROR_DOC).to_s
  URI.extract(doc, [type].flatten)
end

def measure_latency(addr, count=5)
  # shell_out = `ping -n 5 #{addr}`
  # captured = /Pinging\s+(?<host>[^\s]+)\s+\[(?<ip>[^\]]+)\]\s+[^:]+:[\r\n]+((Reply from [\d\.]+: bytes=\d+ time=[\dms]+ TTL=\d+[\r\n]+)+|(Request timed out\.[\r\n]+)+)Ping statistics for [\d\.]+:[\r\n]+\s+Packets: Sent = \d+, Received = \d+, Lost = \d+ \([\d%]+ loss\),[\r\n]+(Approximate round trip times in milli-seconds:[\r\n]+\s+Minimum = (?<minimum>[\dms]+), Maximum = (?<maximum>[\dms]+), Average = (?<average>[\dms]+))?/.match(shell_out)

  # return captured[:average]

  site = Net::Ping::External.new(addr, timeout=2)
  average = 1000.001
  count.times do
    if site.ping
      average = 0.0 if average == 1000.001
      average += site.duration
    end
  end

  return (average/count).round(4)
end

servers = get_servers

servers.each_with_index do |site, index|
  host = URI(site).host
  print "[#{index}/#{servers.length}] Pinging #{host}"
  latency = measure_latency(host)
  print " (took #{latency})\n"
  $NEAREST[site] = latency
end

table = TTY::Table.new do |t|
  t << ['Latency', 'Server']
  $NEAREST.sort_by {|key, value| value}.each do |k,v|
    t << [v, k]
  end
end

puts table.render(:ascii)

out = File.open('mirror.bat', 'w')
out.puts "@echo off"
out.puts "rsync -avL --delete #{$NEAREST.sort_by {|key, value| value}.first[0]}systems/texlive/tlnet/ /a/TexLive/mirror/"
out.puts "pause"
out.close