nb

#!/usr/bin/env perl
use common::sense;
use EV;
use AnyEvent;
use AnyEvent::DNS;
use Coro;
use Coro::AnyEvent;
use Data::Dump 'pp';
use Getopt::Long;

my $usage = qq{A tool for benchmarking nameservers

Usage:
  nb <CONCURRENCY> <COUNT> <HOSTNAME>...

Example:

  Using 100 coroutines, see how long it takes to lookup the ip_addr
  for slashdot.org 10000 times:

    /usr/bin/time nb 100 10000 slashdot.org

};
if (!@ARGV) {
  print $usage;
  exit 1
}

my $c = shift || 1;
my $n = shift || 1;

my @hosts = @ARGV;
if (!@hosts) {
  print $usage;
  exit 2;
}

my $count_per_coro = int($n / $c);
my $remainder = $n % $c;

my $done = 0;

sub lookup {
  my $count = shift;
  my $i;
  for ($i = 0; $i < $count; $i++) {
    my $cv = AE::cv;
    AnyEvent::DNS::a $hosts[int(rand(scalar(@hosts)))], $cv;
    my @addrs = $cv->recv;
    $done++;
    #warn "$done @addrs";
    exit if $done == $n;
  }
}

#warn pp \@hosts;
warn "concurrency: $c, count, $n, count_per_coro: $count_per_coro, remainder: $remainder";

if ($remainder) {
  for ( 1 .. ($c - $remainder) ) {
    async {
      lookup $count_per_coro;
    };
  }
  for ( 1 .. $remainder ) {
    async {
      lookup $count_per_coro + 1;
    }
  }
} else {
  for ( 1 .. $c ) {
    async {
      lookup $count_per_coro;
    };
  }
}

AE::cv->recv;