bindings/python/examples/example-api-test.py

   1 # example_api_test.py
   2 #
   3 # Babeltrace example script based on the Babeltrace API test 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 # This example uses the babeltrace python module
  20 # to partially test the api.
  21
  22 import sys
  23 from babeltrace import *
  24
  25 # Check for path arg:
  26 if len(sys.argv) < 2:
  27         raise TypeError("Usage: python example-api-test.py path/to/file")
  28
  29 # Create context and add trace:
  30 ctx = Context()
  31 trace_handle = ctx.add_trace(sys.argv[1], "ctf")
  32 if trace_handle is None:
  33         raise IOError("Error adding trace")
  34
  35 # Listing events
  36 lst = ctf.get_event_decl_list(trace_handle, ctx)
  37 print("--- Event list ---")
  38 for item in lst:
  39         print("event : {}".format(item.get_name()))
  40 print("--- Done ---")
  41
  42 # Iter trace
  43 bp = IterPos(SEEK_BEGIN)
  44 ctf_it = ctf.Iterator(ctx,bp)
  45 event = ctf_it.read_event()
  46
  47 while(event is not None):
  48         print("TS: {}, {} : {}".format(event.get_timestamp(),
  49                 event.get_cycles(), event.get_name()))
  50
  51         if event.get_name() == "sched_switch":
  52                 sco = event.get_top_level_scope(ctf.scope.EVENT_FIELDS)
  53                 prev_field = event.get_field(sco, "_prev_comm")
  54                 prev_comm = prev_field.get_char_array()
  55
  56                 if ctf.field_error():
  57                         print("ERROR: Missing prev_comm context info")
  58                 else:
  59                         print("sched_switch prev_comm: {}".format(prev_comm))
  60
  61         if event.get_name() == "exit_syscall":
  62                 sco = event.get_top_level_scope(ctf.scope.EVENT_FIELDS)
  63                 ret_field = event.get_field(sco, "_ret")
  64                 ret_code = ret_field.get_int64()
  65
  66                 if ctf.field_error():
  67                         print("ERROR: Unable to extract ret")
  68                 else:
  69                         print("exit_syscall ret: {}".format(ret_code))
  70
  71         ret = ctf_it.next()
  72         if ret < 0:
  73                 break
  74         else:
  75                 event = ctf_it.read_event()
  76
  77 del ctf_it