iotop/vmstat.py

   1 # This program is free software; you can redistribute it and/or modify
   2 # it under the terms of the GNU General Public License as published by
   3 # the Free Software Foundation; either version 2 of the License, or
   4 # (at your option) any later version.
   5 #
   6 # This program is distributed in the hope that it will be useful,
   7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 # GNU Library General Public License for more details.
  10 #
  11 # You should have received a copy of the GNU General Public License
  12 # along with this program; if not, write to the Free Software
  13 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  14 #
  15 # See the COPYING file for license information.
  16 #
  17 # Copyright (c) 2007 Guillaume Chazarain <guichaz@gmail.com>
  18
  19
  20 class VmStat(object):
  21     def __init__(self):
  22         self.vmstat_file = open('/proc/vmstat')
  23         self.vmstat = self.read()
  24
  25     def read(self):
  26         def extract(line):
  27             return int(line.split()[1]) * 1024
  28
  29         for line in self.vmstat_file:
  30             if line.startswith('pgpgin '):
  31                 pgpgin = extract(line)
  32                 break
  33
  34         for line in self.vmstat_file:
  35             if line.startswith('pgpgout '):
  36                 pgpgout = extract(line)
  37                 break
  38
  39         self.vmstat_file.seek(0)
  40         return pgpgin, pgpgout
  41
  42     def delta(self):
  43         now = self.read()
  44         delta = now[0] - self.vmstat[0], now[1] - self.vmstat[1]
  45         self.vmstat = now
  46         return delta