chore: NoneSpan

ddtrace/_trace/span.py

@@ -660,6 +660,22 @@ def __repr__(self):
         )
 
 
+class NoneSpan(Span):
+    def __init__(self):
+        super(NoneSpan, self).__init__("NoneSpan", trace_id=0, span_id=0, parent_id=0, start=0)
+
+    def __bool__(self):
+        return False
+
+    @property
+    def sampled(self):
+        return True
+
+    @sampled.setter
+    def sampled(self, value):
+        pass
+
+
 def _is_top_level(span):
     # type: (Span) -> bool
     """Return whether the span is a "top level" span.

ddtrace/_trace/tracer.py

@@ -26,6 +26,7 @@
 from ddtrace._trace.processor import TraceSamplingProcessor
 from ddtrace._trace.processor import TraceTagsProcessor
 from ddtrace._trace.provider import DefaultContextProvider
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import Span
 from ddtrace.appsec._constants import APPSEC
 from ddtrace.constants import ENV_KEY
@@ -941,7 +942,7 @@ def trace(
             span_api=span_api,
         )
 
-    def current_root_span(self) -> Optional[Span]:
+    def current_root_span(self) -> Span:
         """Returns the root span of the current execution.
 
         This is useful for attaching information related to the trace as a
@@ -956,19 +957,21 @@ def current_root_span(self) -> Optional[Span]:
                 root_span.set_tag('host', '127.0.0.1')
         """
         span = self.current_span()
-        if span is None:
-            return None
+        if isinstance(span, NoneSpan):
+            return span
+        if span._local_root is None:
+            return NoneSpan()
         return span._local_root
 
-    def current_span(self) -> Optional[Span]:
+    def current_span(self) -> Span:
         """Return the active span in the current execution context.
 
         Note that there may be an active span represented by a context object
         (like from a distributed trace) which will not be returned by this
         method.
         """
         active = self.context_provider.active()
-        return active if isinstance(active, Span) else None
+        return active if isinstance(active, Span) else NoneSpan()
 
     @property
     def agent_trace_url(self) -> Optional[str]:

ddtrace/appsec/_exploit_prevention/stack_traces.py

@@ -6,6 +6,7 @@
 from typing import List
 from typing import Optional
 
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import Span
 from ddtrace.appsec._constants import EXPLOIT_PREVENTION
 from ddtrace.settings.asm import config as asm_config
@@ -29,7 +30,7 @@ def report_stack(
         return None
     if span is None:
         span = ddtrace.tracer.current_span()
-    if span is None or stack_id is None:
+    if isinstance(span, NoneSpan) or stack_id is None:
         return None
     root_span = span._local_root or span
     appsec_traces = root_span.get_struct_tag(EXPLOIT_PREVENTION.STACK_TRACES) or {}

ddtrace/appsec/_trace_utils.py

@@ -2,6 +2,7 @@
 
 from ddtrace import Tracer
 from ddtrace import constants
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import Span
 from ddtrace.appsec import _asm_request_context
 from ddtrace.appsec._constants import APPSEC
@@ -44,7 +45,7 @@ def _track_user_login_common(
 ) -> Optional[Span]:
     if span is None:
         span = tracer.current_root_span()
-    if span:
+    if not isinstance(span, NoneSpan):
         success_str = "success" if success else "failure"
         tag_prefix = "%s.%s" % (APPSEC.USER_LOGIN_EVENT_PREFIX, success_str)
 
@@ -173,7 +174,7 @@ def track_user_signup_event(
     tracer: Tracer, user_id: str, success: bool, login_events_mode: str = LOGIN_EVENTS_MODE.SDK
 ) -> None:
     span = tracer.current_root_span()
-    if span:
+    if not isinstance(span, NoneSpan):
         success_str = "true" if success else "false"
         span.set_tag_str(APPSEC.USER_SIGNUP_EVENT, success_str)
         span.set_tag_str(user.ID, user_id)
@@ -212,7 +213,7 @@ def track_custom_event(tracer: Tracer, event_name: str, metadata: dict) -> None:
         return
 
     span = tracer.current_root_span()
-    if not span:
+    if isinstance(span, NoneSpan):
         log.warning(
             "No root span in the current execution. Skipping track_custom_event tags. "
             "See https://docs.datadoghq.com/security_platform/application_security"
@@ -249,7 +250,7 @@ def should_block_user(tracer: Tracer, userid: str) -> bool:
 
     # Early check to avoid calling the WAF if the request is already blocked
     span = tracer.current_root_span()
-    if not span:
+    if isinstance(span, NoneSpan):
         log.warning(
             "No root span in the current execution. should_block_user returning False"
             "See https://docs.datadoghq.com/security_platform/application_security"
@@ -293,7 +294,7 @@ def block_request_if_user_blocked(tracer: Tracer, userid: str) -> None:
 
     if should_block_user(tracer, userid):
         span = tracer.current_root_span()
-        if span:
+        if not isinstance(span, NoneSpan):
             span.set_tag_str(user.ID, str(userid))
         _asm_request_context.block_request()
 

ddtrace/contrib/aws_lambda/patch.py

@@ -90,16 +90,12 @@ def _crash_flush(self, _, __):
         self.crashed = True
 
         root_span = tracer.current_root_span()
-        if root_span is not None:
-            root_span.error = 1
-            root_span.set_tag_str(ERROR_MSG, "Datadog detected an Impending Timeout")
-            root_span.set_tag_str(ERROR_TYPE, "Impending Timeout")
-        else:
-            log.warning("An impending timeout was reached, but no root span was found. No error will be tagged.")
+        root_span.error = 1
+        root_span.set_tag_str(ERROR_MSG, "Datadog detected an Impending Timeout")
+        root_span.set_tag_str(ERROR_TYPE, "Impending Timeout")
 
         current_span = tracer.current_span()
-        if current_span is not None:
-            current_span.finish_with_ancestors()
+        current_span.finish_with_ancestors()
 
     def _remove_alarm_signal(self):
         """Removes the handler set for the signal `SIGALRM`."""

ddtrace/debugging/_signal/tracing.py

@@ -3,6 +3,7 @@
 import attr
 
 import ddtrace
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import Span
 from ddtrace.constants import ORIGIN_KEY
 from ddtrace.debugging._expressions import DDExpressionEvaluationError
@@ -89,7 +90,7 @@ def _decorate_span(self, _locals: t.Dict[str, t.Any]) -> None:
             log.error("Invalid target span for span decoration: %s", probe.target_span)
             return
 
-        if span is not None:
+        if not isinstance(span, NoneSpan):
             log.debug("Decorating span %r according to span decoration probe %r", span, probe)
             for d in probe.decorations:
                 try:

ddtrace/llmobs/_llmobs.py

@@ -9,6 +9,7 @@
 from ddtrace import Span
 from ddtrace import config
 from ddtrace import patch
+from ddtrace._trace.span import NoneSpan
 from ddtrace.ext import SpanTypes
 from ddtrace.internal import atexit
 from ddtrace.internal import telemetry
@@ -239,7 +240,7 @@ def export_span(cls, span: Optional[Span] = None) -> Optional[ExportedLLMObsSpan
                 log.warning("Failed to export span. Span must be a valid Span object.")
                 return None
         span = cls._instance.tracer.current_span()
-        if span is None:
+        if span is None or isinstance(span, NoneSpan):  # Redundant check as current_span() should never return None now
             log.warning("No span provided and no active LLMObs-generated span found.")
             return None
         if span.span_type != SpanTypes.LLM:

ddtrace/llmobs/_utils.py

@@ -3,6 +3,7 @@
 import ddtrace
 from ddtrace import Span
 from ddtrace import config
+from ddtrace._trace.span import NoneSpan
 from ddtrace.ext import SpanTypes
 from ddtrace.internal.logger import get_logger
 from ddtrace.llmobs._constants import LANGCHAIN_APM_SPAN_NAME
@@ -74,7 +75,7 @@ def _get_session_id(span: Span) -> str:
 def _inject_llmobs_parent_id(span_context):
     """Inject the LLMObs parent ID into the span context for reconnecting distributed LLMObs traces."""
     span = ddtrace.tracer.current_span()
-    if span is None:
+    if not isinstance(span, NoneSpan):
         log.warning("No active span to inject LLMObs parent ID info.")
         return
     if span.context is not span_context:

ddtrace/opentracer/tracer.py

@@ -13,6 +13,7 @@
 import ddtrace
 from ddtrace import Tracer as DatadogTracer
 from ddtrace._trace.context import Context as DatadogContext  # noqa:F401
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import Span as DatadogSpan
 from ddtrace.internal.constants import SPAN_API_OPENTRACING
 from ddtrace.internal.utils.config import get_application_name
@@ -274,7 +275,7 @@ def start_span(
                     dd_parent = dd_parent_span
             else:
                 dd_parent = active_dd_parent
-        elif ot_parent is not None and isinstance(ot_parent, Span):
+        elif ot_parent and isinstance(ot_parent, Span) and not isinstance(ot_parent, NoneSpan):
             # a span is given to use as a parent
             ot_parent_context = ot_parent.context
             dd_parent = ot_parent._dd_span
@@ -327,7 +328,7 @@ def active_span(self):
         else:
             dd_span = self._dd_tracer.current_span()
             ot_span = None  # type: Optional[Span]
-            if dd_span:
+            if not isinstance(dd_span, NoneSpan):
                 ot_span = Span(self, None, dd_span.name)
                 ot_span._associate_dd_span(dd_span)
             return ot_span

ddtrace/propagation/http.py

@@ -10,6 +10,7 @@
 from typing import cast  # noqa:F401
 
 import ddtrace
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import Span  # noqa:F401
 
 
@@ -992,7 +993,7 @@ def parent_call():
             else:
                 root_span = ddtrace.tracer.current_root_span()
 
-            if root_span is not None and root_span.context.sampling_priority is None:
+            if root_span and not isinstance(root_span, NoneSpan) and root_span.context.sampling_priority is None:
                 ddtrace.tracer.sample(root_span)
         else:
             log.error("ddtrace.tracer.sample is not available, unable to sample span.")

scripts/profiles/flask-simple/app/app.py

@@ -12,16 +12,18 @@
 def entry_point():
     if environ.get("DUPLICATE_TAGS_SCENARIO", None):
         from ddtrace import tracer
+        from ddtrace._trace.span import NoneSpan
 
         span = tracer.current_span()
-        if span:
+        if not isinstance(span, NoneSpan):
             for _ in range(100):
                 span.set_tag(_, "a" * 100)
     elif environ.get("UNIQUE_TAGS_SCENARIO", None):
         from ddtrace import tracer
+        from ddtrace._trace.span import NoneSpan
 
         span = tracer.current_span()
-        if span:
+        if not isinstance(span, NoneSpan):
             for num in range(100):
                 span.set_tag(str(num), "".join(random.choices(string.ascii_letters, k=100)))
 

tests/tracer/test_tracer.py

@@ -19,6 +19,7 @@
 
 import ddtrace
 from ddtrace._trace.context import Context
+from ddtrace._trace.span import NoneSpan
 from ddtrace._trace.span import _is_top_level
 from ddtrace._trace.tracer import Tracer
 from ddtrace.constants import AUTO_KEEP
@@ -1596,20 +1597,20 @@ def test_get_report_hostname_default(get_hostname, tracer, test_spans):
 
 def test_non_active_span(tracer, test_spans):
     with tracer.start_span("test", activate=False):
-        assert tracer.current_span() is None
-        assert tracer.current_root_span() is None
-    assert tracer.current_span() is None
-    assert tracer.current_root_span() is None
+        assert isinstance(tracer.current_span(), NoneSpan)
+        assert isinstance(tracer.current_root_span(), NoneSpan)
+    assert isinstance(tracer.current_span(), NoneSpan)
+    assert isinstance(tracer.current_root_span(), NoneSpan)
     traces = test_spans.pop_traces()
     assert len(traces) == 1
     assert len(traces[0]) == 1
 
     with tracer.start_span("test1", activate=False):
         with tracer.start_span("test2", activate=False):
-            assert tracer.current_span() is None
-            assert tracer.current_root_span() is None
-    assert tracer.current_span() is None
-    assert tracer.current_root_span() is None
+            assert isinstance(tracer.current_span(), NoneSpan)
+            assert isinstance(tracer.current_root_span(), NoneSpan)
+    assert isinstance(tracer.current_span(), NoneSpan)
+    assert isinstance(tracer.current_root_span(), NoneSpan)
     traces = test_spans.pop_traces()
     assert len(traces) == 2
 
@@ -1758,16 +1759,16 @@ def test_closing_other_context_spans_single_span(tracer, test_spans):
     """
 
     def _target(span):
-        assert tracer.current_span() is None
+        assert isinstance(tracer.current_span(), NoneSpan)
         span.finish()
-        assert tracer.current_span() is None
+        assert isinstance(tracer.current_span(), NoneSpan)
 
     span = tracer.trace("main thread")
     assert tracer.current_span() is span
     t1 = threading.Thread(target=_target, args=(span,))
     t1.start()
     t1.join(60)
-    assert tracer.current_span() is None
+    assert isinstance(tracer.current_span(), NoneSpan)
 
     spans = test_spans.pop()
     assert len(spans) == 1
@@ -1780,9 +1781,9 @@ def test_closing_other_context_spans_multi_spans(tracer, test_spans):
     """
 
     def _target(span):
-        assert tracer.current_span() is None
+        assert isinstance(tracer.current_span(), NoneSpan)
         span.finish()
-        assert tracer.current_span() is None
+        assert isinstance(tracer.current_span(), NoneSpan)
 
     root = tracer.trace("root span")
     span = tracer.trace("child span")