iotop/vmstat.py

   1 import os
   2
   3 class VmStat(object):
   4     def __init__(self):
   5         self.vmstat_file = open('/proc/vmstat')
   6         self.vmstat = self.read()
   7
   8     def read(self):
   9         def extract(line):
  10             return int(line.split()[1]) * 1024
  11
  12         for line in self.vmstat_file:
  13             if line.startswith('pgpgin '):
  14                 pgpgin = extract(line)
  15                 break
  16
  17         for line in self.vmstat_file:
  18             if line.startswith('pgpgout '):
  19                 pgpgout = extract(line)
  20                 break
  21
  22         self.vmstat_file.seek(0)
  23         return pgpgin, pgpgout
  24
  25     def delta(self):
  26         now = self.read()
  27         delta = now[0] - self.vmstat[0], now[1] - self.vmstat[1]
  28         self.vmstat = now
  29         return delta
  30