#!/usr/bin/python
#
# Demonstration script to count the number of GlusterFS (I/O) procedures.
#
# Two steps are needed:
# 1) get the descroption and values for the procedure calls
# 2) analyze each packet and increase the counter for the procedure call
#
# Author: Niels de Vos <ndevos@redhat.com>
# Date: Sat, 23 Feb 2013
#

import sys
import os

if len(sys.argv) != 2:
    print "Usage: %s <network-capture>" % sys.argv[0]
    sys.exit(1)

filename = sys.argv[1]

# build a dict of procedures { "PROCNUM" : ["PROCNAME", 0] }
# the counter in ["PROCNAME", 0] list increase with each matching procedure
procs = dict()

# Gather the procedures and their procnum values, filter on "glusterfs"
output = os.popen("tshark -G values")
for line in output:
    # a line looks like: "V glusterfs.proc  0   NULL"
    parts = line.split()
    if parts[1] == "glusterfs.proc":
        procs[parts[2]] = ["%s (%s)" % (parts[3].strip(), parts[2]), 0]

# tshark command that prints all procedure calls (procnum values)
tshark_command = "tshark -T fields -e glusterfs.proc -r %s" % filename
# filter RPC Calls for GlusterFS
tshark_command += " 'rpc.msgtyp == 0 && glusterfs'"

# read the output from the tshark command
output = os.popen(tshark_command)

for line in output:
    # Bug in certain Wireshark versions causing extra line of output
    if line.startswith("libwireshark.so"):
        continue

    procnum = line.strip()
    procs[procnum][1] += 1

# simple sort function for the proc = ["NAME", count]
def proc_sort(a, b):
    # reverse sort, normal would be: cmp(a, b)
    return cmp(b[1], a[1])

sorted_procs = procs.values()
sorted_procs.sort(proc_sort)

# print a table with the results
print "   count | Procedure"
print "---------+-----------"
for proc in sorted_procs:
    # skip procedures that were not called
    if proc[1] > 0:
        print "%8d | %s" % (proc[1], proc[0])