bindings/python/examples/ctf_writer.py

   1 #!/usr/bin/env python3
   2 # ctf_writer.py
   3 #
   4 # Babeltrace CTF Writer example script.
   5 #
   6 # Copyright 2013 EfficiOS Inc.
   7 #
   8 # Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
   9 #
  10 # Permission is hereby granted, free of charge, to any person obtaining a copy
  11 # of this software and associated documentation files (the "Software"), to deal
  12 # in the Software without restriction, including without limitation the rights
  13 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14 # copies of the Software, and to permit persons to whom the Software is
  15 # furnished to do so, subject to the following conditions:
  16 #
  17 # The above copyright notice and this permission notice shall be included in
  18 # all copies or substantial portions of the Software.
  19
  20 import sys
  21 import tempfile
  22 from babeltrace import *
  23
  24 trace_path = tempfile.mkdtemp()
  25
  26 print("Writing trace at {}".format(trace_path))
  27 writer = CTFWriter.Writer(trace_path)
  28
  29 clock = CTFWriter.Clock("A_clock")
  30 print("Clock name is \"{}\"".format(clock.name))
  31 clock.description = "Simple clock"
  32 print("Clock description is \"{}\"".format(clock.description))
  33 print("Clock frequency is {}".format(clock.frequency))
  34 print("Clock precision is {}".format(clock.precision))
  35 print("Clock offset_seconds is {}".format(clock.offset_seconds))
  36 print("Clock offset is {}".format(clock.offset))
  37 print("Clock is absolute: {}".format(clock.absolute))
  38 print("Clock time is {}".format(clock.time))
  39 print("Clock UUID is {}".format(clock.uuid))
  40
  41 writer.add_clock(clock)
  42 writer.add_environment_field("Python_version", str(sys.version_info))
  43
  44 stream_class = CTFWriter.StreamClass("test_stream")
  45 stream_class.clock = clock
  46
  47 event_class = CTFWriter.EventClass("SimpleEvent")
  48
  49 # Create a int32_t equivalent type
  50 int32_type = CTFWriter.IntegerFieldDeclaration(32)
  51 int32_type.signed = True
  52
  53 # Create a uint16_t equivalent type
  54 uint16_type = CTFWriter.IntegerFieldDeclaration(16)
  55 uint16_type.signed = False
  56
  57 # Add a custom uint16_t field in the stream's packet context
  58 packet_context_type = stream_class.packet_context_type
  59 print("\nFields in default packet context:")
  60 for field in packet_context_type.fields:
  61     print(str(type(field[1])) + " " + field[0])
  62 packet_context_type.add_field(uint16_type, "a_custom_packet_context_field")
  63 stream_class.packet_context_type = packet_context_type
  64
  65 # Create a string type
  66 string_type = CTFWriter.StringFieldDeclaration()
  67
  68 # Create a structure type containing both an integer and a string
  69 structure_type = CTFWriter.StructureFieldDeclaration()
  70 structure_type.add_field(int32_type, "an_integer")
  71 structure_type.add_field(string_type, "a_string_field")
  72 event_class.add_field(structure_type, "structure_field")
  73
  74 # Create a floating point type
  75 floating_point_type = CTFWriter.FloatFieldDeclaration()
  76 floating_point_type.exponent_digits = CTFWriter.FloatFieldDeclaration.FLT_EXP_DIG
  77 floating_point_type.mantissa_digits = CTFWriter.FloatFieldDeclaration.FLT_MANT_DIG
  78 event_class.add_field(floating_point_type, "float_field")
  79
  80 # Create an enumeration type
  81 int10_type = CTFWriter.IntegerFieldDeclaration(10)
  82 enumeration_type = CTFWriter.EnumerationFieldDeclaration(int10_type)
  83 enumeration_type.add_mapping("FIRST_ENTRY", 0, 4)
  84 enumeration_type.add_mapping("SECOND_ENTRY", 5, 5)
  85 enumeration_type.add_mapping("THIRD_ENTRY", 6, 10)
  86 event_class.add_field(enumeration_type, "enum_field")
  87
  88 # Create an array type
  89 array_type = CTFWriter.ArrayFieldDeclaration(int10_type, 5)
  90 event_class.add_field(array_type, "array_field")
  91
  92 # Create a sequence type
  93 sequence_type = CTFWriter.SequenceFieldDeclaration(int32_type, "sequence_len")
  94 event_class.add_field(uint16_type, "sequence_len")
  95 event_class.add_field(sequence_type, "sequence_field")
  96
  97 stream_class.add_event_class(event_class)
  98 stream = writer.create_stream(stream_class)
  99
 100 for i in range(100):
 101     event = CTFWriter.Event(event_class)
 102
 103     clock.time = i * 1000
 104     structure_field = event.payload("structure_field")
 105     integer_field = structure_field.field("an_integer")
 106     integer_field.value = i
 107
 108     string_field = structure_field.field("a_string_field")
 109     string_field.value = "Test string."
 110
 111     float_field = event.payload("float_field")
 112     float_field.value = float(i) + (float(i) / 100.0)
 113
 114     array_field = event.payload("array_field")
 115     for j in range(5):
 116         element = array_field.field(j)
 117         element.value = i + j
 118
 119     event.payload("sequence_len").value = i % 10
 120     sequence_field = event.payload("sequence_field")
 121     sequence_field.length = event.payload("sequence_len")
 122     for j in range(event.payload("sequence_len").value):
 123         sequence_field.field(j).value = i + j
 124
 125     enumeration_field = event.payload("enum_field")
 126     integer_field = enumeration_field.container
 127     enumeration_field.value = i % 10
 128
 129     stream.append_event(event)
 130
 131 # Populate custom packet context field before flushing
 132 packet_context = stream.packet_context
 133 field = packet_context.field("a_custom_packet_context_field")
 134 field.value = 42
 135
 136 stream.flush()