bindings/python/examples/histogram.py

   1 # histogram.py
   2 #
   3 # Babeltrace histogram example script
   4 #
   5 # Copyright 2012 EfficiOS Inc.
   6 #
   7 # Author: Danny Serres <danny.serres@efficios.com>
   8 #
   9 # Permission is hereby granted, free of charge, to any person obtaining a copy
  10 # of this software and associated documentation files (the "Software"), to deal
  11 # in the Software without restriction, including without limitation the rights
  12 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13 # copies of the Software, and to permit persons to whom the Software is
  14 # furnished to do so, subject to the following conditions:
  15 #
  16 # The above copyright notice and this permission notice shall be included in
  17 # all copies or substantial portions of the Software.
  18
  19 # The script checks the number of events in the trace
  20 # and outputs a table and a .svg histogram for the specified
  21 # range (microseconds) or the total trace if no range specified.
  22 # The graph is generated using the cairoplot module.
  23
  24 import sys
  25 from babeltrace import *
  26 from output_format_modules import cairoplot
  27 from output_format_modules.pprint_table import pprint_table as pprint
  28
  29 # ------------------------------------------------
  30 #               Output settings
  31
  32 # number of intervals:
  33 nbDiv = 25      # Should not be over 150
  34                 # for usable graph output
  35
  36 # table output stream (file-like object):
  37 out = sys.stdout
  38 # -------------------------------------------------
  39
  40 if len(sys.argv) < 2 or len(sys.argv) > 4:
  41         raise TypeError("Usage: python histogram.py [ start_time [end_time] ] path/to/trace")
  42
  43 ctx = Context()
  44 ret = ctx.add_trace(sys.argv[len(sys.argv)-1], "ctf")
  45 if ret is None:
  46         raise IOError("Error adding trace")
  47
  48 # Check when to start/stop graphing
  49 sinceBegin = True
  50 beginTime = 0.0
  51 if len(sys.argv) > 2:
  52         sinceBegin = False
  53         beginTime = float(sys.argv[1])
  54 untilEnd = True
  55 if len(sys.argv) == 4:
  56         untilEnd = False
  57
  58 # Setting iterator
  59 bp = IterPos(SEEK_BEGIN)
  60 ctf_it = ctf.Iterator(ctx, bp)
  61
  62 # Reading events
  63 event = ctf_it.read_event()
  64 start_time = event.get_timestamp()
  65 time = 0
  66 count = {}
  67
  68 while(event is not None):
  69         # Microsec.
  70         time = (event.get_timestamp() - start_time)/1000.0
  71
  72         # Check if in range
  73         if not sinceBegin:
  74                 if time < beginTime:
  75                         # Next Event
  76                         ret = ctf_it.next()
  77                         if ret < 0:
  78                                 break
  79                         event = ctf_it.read_event()
  80                         continue
  81         if not untilEnd:
  82                 if time > float(sys.argv[2]):
  83                         break
  84
  85         # Counting events per timestamp:
  86         if time in count:
  87                 count[time] += 1
  88         else:
  89                 count[time] = 1
  90
  91         # Next Event
  92         ret = ctf_it.next()
  93         if ret < 0:
  94                 break
  95         event = ctf_it.read_event()
  96
  97 del ctf_it
  98
  99 # Setting data for output
 100 interval = (time - beginTime)/nbDiv
 101 div_begin_time = beginTime
 102 div_end_time = beginTime + interval
 103 data = {}
 104
 105 # Prefix for string sorting, considering
 106 # there should not be over 150 intervals.
 107 # This would work up to 9999 intervals.
 108 # If needed, add zeros.
 109 prefix = 0.0001
 110
 111 while div_end_time <= time:
 112         key = str(prefix) + '[' + str(div_begin_time) + ';' + str(div_end_time) + '['
 113         for tmp in count:
 114                 if tmp >= div_begin_time and tmp < div_end_time:
 115                         if key in data:
 116                                 data[key] += count[tmp]
 117                         else:
 118                                 data[key] = count[tmp]
 119         if not key in data:
 120                 data[key] = 0
 121         div_begin_time = div_end_time
 122         div_end_time += interval
 123         # Prefix increment
 124         prefix += 0.001
 125
 126 table = []
 127 x_labels = []
 128 for key in sorted(data):
 129         table.append([key[key.find('['):], data[key]])
 130         x_labels.append(key[key.find('['):])
 131
 132 # Table output
 133 table.insert(0, ["INTERVAL (us)", "COUNT"])
 134 pprint(table, 1, out)
 135
 136 # Graph output
 137 cairoplot.vertical_bar_plot ( 'histogram.svg', data, 50 + 150*nbDiv, 50*nbDiv,
 138         border = 20, display_values = True, grid = True,
 139         x_labels = x_labels, rounded_corners = True )