#! perl -slw
use strict;
use IO::Socket::INET;
use Net::Patricia;
use Time::HiRes qw[ time ];

my $pat = Net::Patricia->new;

open I, '<', 'IP-to-ASmapping.txt' or die $!;
$pat->add_string( split ' ', $_ ) while <I>;
close I;

my $listener = IO::Socket::INET->new(
    LocalAddr => 'localhost:88888',
    Listen => 1000,
    Reuse => 1,
) or die "Couldn't listen on localhost:88888; $!";

my $time = time();
my $count = 0;
while( my $client = $listener->accept ) {
    printf "\rRate: %7.3f\t", $count / ( time() -$time ) if ++$count % 100;
    chomp( my $ip = <$client> );
    print { $client } $pat->match_string( $ip ) || 'n/a';
    close $client;
}

__END__
C:\test>623661-s
Rate: 108.149