premiere-libtorrent/docs/ips.py

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Python
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2011-05-26 19:04:53 +02:00
#/bin/python
import os
import sys
def num_ids(bits, total_bits):
ret = 8;
modulus = 0x100
mod_shift = 6 * 32 / total_bits
while bits >= 0:
ret *= min(1 << bits, 256)
ret = min(ret, modulus)
bits -= 8
modulus <<= mod_shift
return ret
f = open('ip_id_v4.dat', 'w+')
for i in range(0, 33):
print >>f, '%d\t%d\t%d' % (i, num_ids(i, 32), 1 << i)
f.close()
f = open('ip_id_v6.dat', 'w+')
for i in range(0, 65):
print >>f, '%d\t%d\t%d' % (i, num_ids(i, 64), 1 << i)
f.close()
f = open('ip_id.gnuplot', 'w+')
f.write('''
set term png size 600,300
set output "ip_id_v4.png"
set logscale y
set title "Number of possible node IDs"
set ylabel "possible node IDs"
set xlabel "bits controlled in IPv4"
set xtics 4
set grid
plot "ip_id_v4.dat" using 1:2 title "octet-wise modulus" with lines, \
"ip_id_v4.dat" using 1:3 title "hash of IP" with lines
set output "ip_id_v6.png"
set title "Number of possible node IDs"
set xlabel "bits controlled in IPv6"
plot "ip_id_v6.dat" using 1:2 title "octet-wise modulus" with lines, \
"ip_id_v6.dat" using 1:3 title "hash of IP" with lines
''')
f.close()
os.system('gnuplot ip_id.gnuplot')