Source code for opencensus.trace.trace_options
# Copyright 2017, OpenCensus Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
# Enabled field is the least significant bit of trace options.
_ENABLED_BITMASK = 1 << 0
# Default trace options
DEFAULT = '1'
[docs]class TraceOptions(object):
"""A class that represents global trace options.
:type trace_options_byte: str
:param trace_options_byte: 1 byte bitmap for trace options.
"""
def __init__(self, trace_options_byte=None):
if trace_options_byte is None:
trace_options_byte = DEFAULT
self.trace_options_byte = self.check_trace_options(trace_options_byte)
self.enabled = self.get_enabled()
def check_trace_options(self, trace_options_byte):
trace_options_int = int(trace_options_byte)
if trace_options_int < 0 or trace_options_int > 255:
logging.warning("Trace options invalid, should be 1 byte.")
trace_options_byte = DEFAULT
return trace_options_byte
def __repr__(self):
fmt = '{}(enabled={})'
return fmt.format(
type(self).__name__,
self.get_enabled(),
)
[docs] def get_enabled(self):
"""Get the last bit from the trace options which is the enabled field.
:type trace_options: byte
:param trace_options: 1 byte field which indicates 8 trace options,
currently only have the enabled option. 1 means
enabled, 0 means not enabled.
:rtype: bool
:returns: Enabled tracing or not.
"""
enabled = bool(int(self.trace_options_byte) & _ENABLED_BITMASK)
return enabled
[docs] def set_enabled(self, enabled):
"""Update the last bit of the trace options byte str.
:type enabled: bool
:param enabled: Whether enable tracing in this span context or not.
"""
enabled_bit = '1' if enabled else '0'
self.trace_options_byte = str(
self.trace_options_byte)[:-1] + enabled_bit
self.enabled = self.get_enabled()