Overview:
  if cache's modification time is less than 60 seconds old, or less than 120 seconds old when it's busy being updated {
    load cached hash
  else
    load information via API and save hash to speed up subsequent look ups

##</code><code>##

my $cache_ttl = 60;
my $cachefile = '/tmp/mtapi.'.$router.'.cache';
my $lockfile  = '/tmp/mtapi.'.$router.'.lock';
my %bgp_peer;
my $cached = 0;
my $modified = (stat($cachefile))[9];
if (defined $modified) {
  if (($modified >= (time-$cache_ttl)) || ((-e $lockfile) && ($modified >= (time-($cache_ttl*2))))) {
    if (%bgp_peer = %{lock_retrieve($cachefile)}) { $cached = 1 };
  }
}
if ($cached == 0) {
  open (LOCK, ">$lockfile");
  flock(LOCK, LOCK_EX);
  my $api = MikroTik::API->new (
    {
      host     => $router,
      username => $api_user,
      password => $api_passwd,
      use_ssl  => 1,
    }
  );
  %bgp_peer = $api->get_by_key('/routing/bgp/peer/print', 'name');
  $api->logout();
  lock_nstore \%bgp_peer, $cachefile;
  chmod 0660, $cachefile;
  close LOCK;
  unlink $lockfile;
}