Source code for opencensus.trace.tracers.noop_tracer
# 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.
from opencensus.trace.tracers import base
from opencensus.trace import blank_span as trace_span
from opencensus.trace.span_context import SpanContext
from opencensus.trace import trace_options
[docs]class NoopTracer(base.Tracer):
"""No-op implementation of the :class:`Tracer` interface, all methods are
no-ops. Should be used when tracing is not enabled or not sampled.
"""
def __init__(self):
self.span_context = SpanContext(
trace_options=trace_options.TraceOptions(0)
)
[docs] def finish(self):
"""End spans and send to reporter."""
return None
[docs] def span(self, name='span'):
"""Create a new span with the trace using the context information.
:type name: str
:param name: The name of the span.
:rtype: :class:`~opencensus.trace.trace_span.Span`
:returns: The Span object.
"""
span = self.start_span(name=name)
return span
[docs] def start_span(self, name='span'):
"""Start a span.
:type name: str
:param name: The name of the span.
:rtype: :class:`~opencensus.trace.trace_span.Span`
:returns: The Span object.
"""
span = trace_span.BlankSpan(name, context_tracer=self)
return span
[docs] def end_span(self):
"""End a span. Remove the span from the span stack, and update the
span_id in TraceContext as the current span_id which is the peek
element in the span stack.
"""
pass
[docs] def current_span(self):
"""Return the current span."""
return trace_span.BlankSpan()
[docs] def add_attribute_to_current_span(self, attribute_key, attribute_value):
"""Add attribute to current span.
:type attribute_key: str
:param attribute_key: Attribute key.
:type attribute_value:str
:param attribute_value: Attribute value.
"""
return
[docs] def list_collected_spans(self):
"""List collected spans."""
return None