#!/usr/bin/perl
# Draw spectrum of HTTP transaction lengths from netgrind output
# (c) 2003 Martin Mares <mj@ucw.cz>, GPL'ed

use strict;
use warnings;
use POSIX;

my @k = ( 0, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 1000000000 );
my @v = map { 0 } @k;

while (<>) {
	chomp;
	/^#/ && next;
	my ($t1, $t2, $src, $dst, $ffor, $result, $cache, $queue, $length, $totaltime, $waittime, $ctype, $method, $url) = split /\s+/;
	if ($result =~ /^\d+$/) {
		my $i = 0;
		while ($length >= $k[$i+1]) {
			$i++;
		}
		$v[$i]++;
	}
}

my $datafile = "gp.tmp";
open D, ">$datafile" or die;
for(my $i=0; $i<$#k; $i++) {
	print D $k[$i], "\t", $v[$i], "\n";
}
close D;

open GP, "|gnuplot" or die;
print GP <<EOF
set terminal png
set grid
set style data boxes
set title "HTTP Transactions: Length Histogram"
set xlabel "Length in bytes"
set ylabel "Number of transactions"
set logscale x 2
plot	"$datafile" using 1:2 title "Histogram"
EOF
;
close GP;