def extract(cls, get_from_carrier, carrier):
trace_id = format_trace_id(trace.INVALID_TRACE_ID)
span_id = format_span_id(trace.INVALID_SPAN_ID)
sampled = "0"
flags = None
single_header = _extract_first_element(
get_from_carrier(carrier, cls.SINGLE_HEADER_KEY))
if single_header:
# The b3 spec calls for the sampling state to be
# "deferred", which is unspecified. This concept does not
# translate to SpanContext, so we set it as recorded.
sampled = "1"
fields = single_header.split("-", 4)
if len(fields) == 1:
sampled = fields[0]
elif len(fields) == 2:
trace_id, span_id = fields
elif len(fields) == 3:
trace_id, span_id, sampled = fields
elif len(fields) == 4:
trace_id, span_id, sampled, _parent_span_id = fields
else:
return trace.INVALID_SPAN_CONTEXT
else:
trace_id = (_extract_first_element(
get_from_carrier(carrier, cls.TRACE_ID_KEY)) or trace_id)
span_id = (_extract_first_element(
get_from_carrier(carrier, cls.SPAN_ID_KEY)) or span_id)
sampled = (_extract_first_element(
get_from_carrier(carrier, cls.SAMPLED_KEY)) or sampled)
flags = (_extract_first_element(
get_from_carrier(carrier, cls.FLAGS_KEY)) or flags)
options = 0
# The b3 spec provides no defined behavior for both sample and
# flag values set. Since the setting of at least one implies
# the desire for some form of sampling, propagate if either
# header is set to allow.
if sampled in cls._SAMPLE_PROPAGATE_VALUES or flags == "1":
options |= trace.TraceOptions.SAMPLED
return trace.SpanContext(
# trace an span ids are encoded in hex, so must be converted
trace_id=int(trace_id, 16),
span_id=int(span_id, 16),
trace_options=trace.TraceOptions(options),
trace_state=trace.TraceState(),
)
def extract(cls, get_from_carrier: httptextformat.Getter[_T],
carrier: _T) -> trace.SpanContext:
"""Extracts a valid SpanContext from the carrier.
"""
header = get_from_carrier(carrier, cls._TRACEPARENT_HEADER_NAME)
if not header:
return trace.INVALID_SPAN_CONTEXT
match = re.search(cls._TRACEPARENT_HEADER_FORMAT_RE, header[0])
if not match:
return trace.INVALID_SPAN_CONTEXT
version = match.group(1)
trace_id = match.group(2)
span_id = match.group(3)
trace_options = match.group(4)
if trace_id == "0" * 32 or span_id == "0" * 16:
return trace.INVALID_SPAN_CONTEXT
if version == "00":
if match.group(5):
return trace.INVALID_SPAN_CONTEXT
if version == "ff":
return trace.INVALID_SPAN_CONTEXT
tracestate_headers = get_from_carrier(carrier,
cls._TRACESTATE_HEADER_NAME)
tracestate = _parse_tracestate(tracestate_headers)
span_context = trace.SpanContext(
trace_id=int(trace_id, 16),
span_id=int(span_id, 16),
trace_options=trace.TraceOptions(trace_options),
trace_state=tracestate,
)
return span_context
# 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 unittest
from opentelemetry import trace
from opentelemetry.trace import sampling
TO_DEFAULT = trace.TraceOptions(trace.TraceOptions.DEFAULT)
TO_SAMPLED = trace.TraceOptions(trace.TraceOptions.SAMPLED)
class TestSampler(unittest.TestCase):
def test_always_on(self):
no_record_always_on = sampling.ALWAYS_ON.should_sample(
trace.SpanContext(0xDEADBEEF, 0xDEADBEF0,
trace_options=TO_DEFAULT),
0xDEADBEF1,
0xDEADBEF2,
"unsampled parent, sampling on",
)
self.assertTrue(no_record_always_on.sampled)
self.assertEqual(no_record_always_on.attributes, {})