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 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26 # SOFTWARE.
  27
  28 import sys
  29 import tempfile
  30 from babeltrace import *
  31
  32 trace_path = tempfile.mkdtemp()
  33
  34 print("Writing trace at {}".format(trace_path))
  35 writer = CTFWriter.Writer(trace_path)
  36
  37 clock = CTFWriter.Clock("A_clock")
  38 print("Clock name is \"{}\"".format(clock.name))
  39 clock.description = "Simple clock"
  40 print("Clock description is \"{}\"".format(clock.description))
  41 print("Clock frequency is {}".format(clock.frequency))
  42 print("Clock precision is {}".format(clock.precision))
  43 print("Clock offset_seconds is {}".format(clock.offset_seconds))
  44 print("Clock offset is {}".format(clock.offset))
  45 print("Clock is absolute: {}".format(clock.absolute))
  46 print("Clock time is {}".format(clock.time))
  47 print("Clock UUID is {}".format(clock.uuid))
  48
  49 writer.add_clock(clock)
  50 writer.add_environment_field("Python_version", str(sys.version_info))
  51
  52 stream_class = CTFWriter.StreamClass("test_stream")
  53 stream_class.clock = clock
  54
  55 event_class = CTFWriter.EventClass("SimpleEvent")
  56
  57 # Create a int32_t equivalent type
  58 int32_type = CTFWriter.IntegerFieldDeclaration(32)
  59 int32_type.signed = True
  60
  61 # Create a uint16_t equivalent type
  62 uint16_type = CTFWriter.IntegerFieldDeclaration(16)
  63 uint16_type.signed = False
  64
  65 # Add a custom uint16_t field in the stream's packet context
  66 packet_context_type = stream_class.packet_context_type
  67 print("\nFields in default packet context:")
  68 for field in packet_context_type.fields:
  69     print(str(type(field[1])) + " " + field[0])
  70 packet_context_type.add_field(uint16_type, "a_custom_packet_context_field")
  71 stream_class.packet_context_type = packet_context_type
  72
  73 # Create a string type
  74 string_type = CTFWriter.StringFieldDeclaration()
  75
  76 # Create a structure type containing both an integer and a string
  77 structure_type = CTFWriter.StructureFieldDeclaration()
  78 structure_type.add_field(int32_type, "an_integer")
  79 structure_type.add_field(string_type, "a_string_field")
  80 event_class.add_field(structure_type, "structure_field")
  81
  82 # Create a floating point type
  83 floating_point_type = CTFWriter.FloatFieldDeclaration()
  84 floating_point_type.exponent_digits = CTFWriter.FloatFieldDeclaration.FLT_EXP_DIG
  85 floating_point_type.mantissa_digits = CTFWriter.FloatFieldDeclaration.FLT_MANT_DIG
  86 event_class.add_field(floating_point_type, "float_field")
  87
  88 # Create an enumeration type
  89 int10_type = CTFWriter.IntegerFieldDeclaration(10)
  90 enumeration_type = CTFWriter.EnumerationFieldDeclaration(int10_type)
  91 enumeration_type.add_mapping("FIRST_ENTRY", 0, 4)
  92 enumeration_type.add_mapping("SECOND_ENTRY", 5, 5)
  93 enumeration_type.add_mapping("THIRD_ENTRY", 6, 10)
  94 event_class.add_field(enumeration_type, "enum_field")
  95
  96 # Create an array type
  97 array_type = CTFWriter.ArrayFieldDeclaration(int10_type, 5)
  98 event_class.add_field(array_type, "array_field")
  99
 100 # Create a sequence type
 101 sequence_type = CTFWriter.SequenceFieldDeclaration(int32_type, "sequence_len")
 102 event_class.add_field(uint16_type, "sequence_len")
 103 event_class.add_field(sequence_type, "sequence_field")
 104
 105 stream_class.add_event_class(event_class)
 106 stream = writer.create_stream(stream_class)
 107
 108 for i in range(100):
 109     event = CTFWriter.Event(event_class)
 110
 111     clock.time = i * 1000
 112     structure_field = event.payload("structure_field")
 113     integer_field = structure_field.field("an_integer")
 114     integer_field.value = i
 115
 116     string_field = structure_field.field("a_string_field")
 117     string_field.value = "Test string."
 118
 119     float_field = event.payload("float_field")
 120     float_field.value = float(i) + (float(i) / 100.0)
 121
 122     array_field = event.payload("array_field")
 123     for j in range(5):
 124         element = array_field.field(j)
 125         element.value = i + j
 126
 127     event.payload("sequence_len").value = i % 10
 128     sequence_field = event.payload("sequence_field")
 129     sequence_field.length = event.payload("sequence_len")
 130     for j in range(event.payload("sequence_len").value):
 131         sequence_field.field(j).value = i + j
 132
 133     enumeration_field = event.payload("enum_field")
 134     integer_field = enumeration_field.container
 135     enumeration_field.value = i % 10
 136
 137     stream.append_event(event)
 138
 139 # Populate custom packet context field before flushing
 140 packet_context = stream.packet_context
 141 field = packet_context.field("a_custom_packet_context_field")
 142 field.value = 42
 143
 144 stream.flush()