bwmon/aggregator.py

   1 from subprocess import Popen, PIPE
   2 from datetime import datetime
   3 import re
   4 import collections
   5
   6
   7 class Aggregator():
   8
   9     def __init__(self, args):
  10         self.args = args
  11
  12     def run(self):
  13         line_regex = re.compile('\s*(?P<in>\d+)\s*/\s*(?P<out>\d+)\s*--\s*(?P<proc>.*)')
  14
  15         proc = Popen(self.args, stdin=PIPE, stdout=PIPE, stderr=PIPE, bufsize=1)
  16         records = collections.defaultdict(list)
  17
  18         for line in proc.stdout:
  19
  20             record = self.get_record(line)
  21
  22             if not record:
  23                 continue
  24
  25             records[process].append(record)
  26
  27             if len(records[process]) > 1:
  28                 prev_record = records[process][-2]
  29                 bw = self.get_bandwidth(prev_record, record)
  30                 # process bandwidth
  31
  32
  33     def get_record(line):
  34         match = line_regex.match(line)
  35
  36         if not match:
  37             return None
  38
  39         process = match.group('proc').strip()
  40         bytes_in = int(match.group('in'))
  41         bytes_out = int(match.group('out'))
  42         record = {'timestamp': datetime.now(), 'in': bytes_in, 'out': bytes_out}
  43
  44
  45     def get_bandwidth(rec1, rec2):
  46         """
  47         returns the mean incoming and outgoing bandwidth used between
  48         the two given records.
  49
  50         rec1 represents the earlier, rec2 the later record
  51         """
  52         date_diff = rec2['timestamp'] - rec1['timestamp']
  53         in_diff = rec2['in'] - rec1['diff']
  54         out_diff = rec2['out'] - rec1['out']
  55
  56         in_bw = in_diff / date_diff.seconds
  57         out_bw = out_diff / date_diff.seconds
  58
  59         return (in_bw, out_bw)
  60