text: # Copyright The OpenTelemetry 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.
  
  """
  The OpenTelemetry tracing API describes the classes used to generate
  distributed traces.
  
  The :class:`.Tracer` class controls access to the execution context, and
  manages span creation. Each operation in a trace is represented by a
  :class:`.Span`, which records the start, end time, and metadata associated with
  the operation.
  
  This module provides abstract (i.e. unimplemented) classes required for
  tracing, and a concrete no-op :class:`.NonRecordingSpan` that allows applications
  to use the API package alone without a supporting implementation.
  
  To get a tracer, you need to provide the package name from which you are
  calling the tracer APIs to OpenTelemetry by calling `TracerProvider.get_tracer`
  with the calling module name and the version of your package.
  
  The tracer supports creating spans that are "attached" or "detached" from the
  context. New spans are "attached" to the context in that they are
  created as children of the currently active span, and the newly-created span
  can optionally become the new active span::
  
      from opentelemetry import trace
  
      tracer = trace.get_tracer(__name__)
  
      # Create a new root span, set it as the current span in context
      with tracer.start_as_current_span("parent"):
          # Attach a new child and update the current span
          with tracer.start_as_current_span("child"):
              do_work():
          # Close child span, set parent as current
      # Close parent span, set default span as current
  
  When creating a span that's "detached" from the context the active span doesn't
  change, and the caller is responsible for managing the span's lifetime::
  
      # Explicit parent span assignment is done via the Context
      from opentelemetry.trace import set_span_in_context
  
      context = set_span_in_context(parent)
      child = tracer.start_span("child", context=context)
  
      try:
          do_work(span=child)
      finally:
          child.end()
  
  Applications should generally use a single global TracerProvider, and use
  either implicit or explicit context propagation consistently throughout.
  
  .. versionadded:: 0.1.0
  .. versionchanged:: 0.3.0
      `TracerProvider` was introduced and the global ``tracer`` getter was
      replaced by ``tracer_provider``.
  .. versionchanged:: 0.5.0
      ``tracer_provider`` was replaced by `get_tracer_provider`,
      ``set_preferred_tracer_provider_implementation`` was replaced by
      `set_tracer_provider`.
  """
  
  
  import os
  import typing
  from abc import ABC, abstractmethod
  from contextlib import contextmanager
  from enum import Enum
  from logging import getLogger
  from typing import Iterator, Optional, Sequence, cast
  
  from deprecated import deprecated
  
  from opentelemetry import context as context_api
  from opentelemetry.attributes import BoundedAttributes  # type: ignore
  from opentelemetry.context.context import Context
  from opentelemetry.environment_variables import OTEL_PYTHON_TRACER_PROVIDER
  from opentelemetry.trace.propagation import (
      _SPAN_KEY,
      get_current_span,
      set_span_in_context,
  )
  from opentelemetry.trace.span import (
      DEFAULT_TRACE_OPTIONS,
      DEFAULT_TRACE_STATE,
      INVALID_SPAN,
      INVALID_SPAN_CONTEXT,
      INVALID_SPAN_ID,
      INVALID_TRACE_ID,
      NonRecordingSpan,
      Span,
      SpanContext,
      TraceFlags,
      TraceState,
      format_span_id,
      format_trace_id,
  )
  from opentelemetry.trace.status import Status, StatusCode
  from opentelemetry.util import types
  from opentelemetry.util._once import Once
  from opentelemetry.util._providers import _load_provider
  
  logger = getLogger(__name__)
  
  
  class _LinkBase(ABC):
      def __init__(self, context: "SpanContext") -> None:
          self._context = context
  
      @property
      def context(self) -> "SpanContext":
          return self._context
  
      @property
      @abstractmethod
      def attributes(self) -> types.Attributes:
          pass
  
  
  class Link(_LinkBase):
      """A link to a `Span`. The attributes of a Link are immutable.
  
      Args:
          context: `SpanContext` of the `Span` to link to.
          attributes: Link's attributes.
      """
  
      def __init__(
          self,
          context: "SpanContext",
          attributes: types.Attributes = None,
      ) -> None:
          super().__init__(context)
          self._attributes = BoundedAttributes(
              attributes=attributes
          )  # type: types.Attributes
  
      @property
      def attributes(self) -> types.Attributes:
          return self._attributes
  
  
  _Links = Optional[Sequence[Link]]
  
  
  class SpanKind(Enum):
      """Specifies additional details on how this span relates to its parent span.
  
      Note that this enumeration is experimental and likely to change. See
      https://github.com/open-telemetry/opentelemetry-specification/pull/226.
      """
  
      #: Default value. Indicates that the span is used internally in the
      # application.
      INTERNAL = 0
  
      #: Indicates that the span describes an operation that handles a remote
      # request.
      SERVER = 1
  
      #: Indicates that the span describes a request to some remote service.
      CLIENT = 2
  
      #: Indicates that the span describes a producer sending a message to a
      #: broker. Unlike client and server, there is usually no direct critical
      #: path latency relationship between producer and consumer spans.
      PRODUCER = 3
  
      #: Indicates that the span describes a consumer receiving a message from a
      #: broker. Unlike client and server, there is usually no direct critical
      #: path latency relationship between producer and consumer spans.
      CONSUMER = 4
  
  
  class TracerProvider(ABC):
      @abstractmethod
      def get_tracer(
          self,
          instrumenting_module_name: str,
          instrumenting_library_version: typing.Optional[str] = None,
          schema_url: typing.Optional[str] = None,
      ) -> "Tracer":
          """Returns a `Tracer` for use by the given instrumentation library.
  
          For any two calls it is undefined whether the same or different
          `Tracer` instances are returned, even for different library names.
  
          This function may return different `Tracer` types (e.g. a no-op tracer
          vs.  a functional tracer).
  
          Args:
              instrumenting_module_name: The name of the instrumenting module
                  (usually just ``__name__``).
  
                  This should *not* be the name of the module that is
                  instrumented but the name of the module doing the instrumentation.
                  E.g., instead of ``"requests"``, use
                  ``"opentelemetry.instrumentation.requests"``.
  
              instrumenting_library_version: Optional. The version string of the
                  instrumenting library.  Usually this should be the same as
                  ``pkg_resources.get_distribution(instrumenting_library_name).version``.
  
              schema_url: Optional. Specifies the Schema URL of the emitted telemetry.
          """
  
  
  class NoOpTracerProvider(TracerProvider):
      """The default TracerProvider, used when no implementation is available.
  
      All operations are no-op.
      """
  
      def get_tracer(
          self,
          instrumenting_module_name: str,
          instrumenting_library_version: typing.Optional[str] = None,
          schema_url: typing.Optional[str] = None,
      ) -> "Tracer":
          # pylint:disable=no-self-use,unused-argument
          return NoOpTracer()
  
  
  @deprecated(version="1.9.0", reason="You should use NoOpTracerProvider")  # type: ignore
  class _DefaultTracerProvider(NoOpTracerProvider):
      """The default TracerProvider, used when no implementation is available.
  
      All operations are no-op.
      """
  
  
  class ProxyTracerProvider(TracerProvider):
      def get_tracer(
          self,
          instrumenting_module_name: str,
          instrumenting_library_version: typing.Optional[str] = None,
          schema_url: typing.Optional[str] = None,
      ) -> "Tracer":
          if _TRACER_PROVIDER:
              return _TRACER_PROVIDER.get_tracer(
                  instrumenting_module_name,
                  instrumenting_library_version,
                  schema_url,
              )
          return ProxyTracer(
              instrumenting_module_name,
              instrumenting_library_version,
              schema_url,
          )
  
  
  class Tracer(ABC):
      """Handles span creation and in-process context propagation.
  
      This class provides methods for manipulating the context, creating spans,
      and controlling spans' lifecycles.
      """
  
      @abstractmethod
      def start_span(
          self,
          name: str,
          context: Optional[Context] = None,
          kind: SpanKind = SpanKind.INTERNAL,
          attributes: types.Attributes = None,
          links: _Links = None,
          start_time: Optional[int] = None,
          record_exception: bool = True,
          set_status_on_exception: bool = True,
      ) -> "Span":
          """Starts a span.
  
          Create a new span. Start the span without setting it as the current
          span in the context. To start the span and use the context in a single
          method, see :meth:`start_as_current_span`.
  
          By default the current span in the context will be used as parent, but an
          explicit context can also be specified, by passing in a `Context` containing
          a current `Span`. If there is no current span in the global `Context` or in
          the specified context, the created span will be a root span.
  
          The span can be used as a context manager. On exiting the context manager,
          the span's end() method will be called.
  
          Example::
  
              # trace.get_current_span() will be used as the implicit parent.
              # If none is found, the created span will be a root instance.
              with tracer.start_span("one") as child:
                  child.add_event("child's event")
  
          Args:
              name: The name of the span to be created.
              context: An optional Context containing the span's parent. Defaults to the
                  global context.
              kind: The span's kind (relationship to parent). Note that is
                  meaningful even if there is no parent.
              attributes: The span's attributes.
              links: Links span to other spans
              start_time: Sets the start time of a span
              record_exception: Whether to record any exceptions raised within the
                  context as error event on the span.
              set_status_on_exception: Only relevant if the returned span is used
                  in a with/context manager. Defines wether the span status will
                  be automatically set to ERROR when an uncaught exception is
                  raised in the span with block. The span status won't be set by
                  this mechanism if it was previously set manually.
  
          Returns:
              The newly-created span.
          """
  
      @contextmanager  # type: ignore
      @abstractmethod
      def start_as_current_span(
          self,
          name: str,
          context: Optional[Context] = None,
          kind: SpanKind = SpanKind.INTERNAL,
          attributes: types.Attributes = None,
          links: _Links = None,
          start_time: Optional[int] = None,
          record_exception: bool = True,
          set_status_on_exception: bool = True,
          end_on_exit: bool = True,
      ) -> Iterator["Span"]:
          """Context manager for creating a new span and set it
          as the current span in this tracer's context.
  
          Exiting the context manager will call the span's end method,
          as well as return the current span to its previous value by
          returning to the previous context.
  
          Example::
  
              with tracer.start_as_current_span("one") as parent:
                  parent.add_event("parent's event")
                  with trace.start_as_current_span("two") as child:
                      child.add_event("child's event")
                      trace.get_current_span()  # returns child
                  trace.get_current_span()      # returns parent
              trace.get_current_span()          # returns previously active span
  
          This is a convenience method for creating spans attached to the
          tracer's context. Applications that need more control over the span
          lifetime should use :meth:`start_span` instead. For example::
  
              with tracer.start_as_current_span(name) as span:
                  do_work()
  
          is equivalent to::
  
              span = tracer.start_span(name)
              with opentelemetry.trace.use_span(span, end_on_exit=True):
                  do_work()
  
          Args:
              name: The name of the span to be created.
              context: An optional Context containing the span's parent. Defaults to the
                  global context.
              kind: The span's kind (relationship to parent). Note that is
                  meaningful even if there is no parent.
              attributes: The span's attributes.
              links: Links span to other spans
              start_time: Sets the start time of a span
              record_exception: Whether to record any exceptions raised within the
                  context as error event on the span.
              set_status_on_exception: Only relevant if the returned span is used
                  in a with/context manager. Defines wether the span status will
                  be automatically set to ERROR when an uncaught exception is
                  raised in the span with block. The span status won't be set by
                  this mechanism if it was previously set manually.
              end_on_exit: Whether to end the span automatically when leaving the
                  context manager.
  
          Yields:
              The newly-created span.
          """
  
  
  class ProxyTracer(Tracer):
      # pylint: disable=W0222,signature-differs
      def __init__(
          self,
          instrumenting_module_name: str,
          instrumenting_library_version: typing.Optional[str] = None,
          schema_url: typing.Optional[str] = None,
      ):
          self._instrumenting_module_name = instrumenting_module_name
          self._instrumenting_library_version = instrumenting_library_version
          self._schema_url = schema_url
          self._real_tracer: Optional[Tracer] = None
          self._noop_tracer = NoOpTracer()
  
      @property
      def _tracer(self) -> Tracer:
          if self._real_tracer:
              return self._real_tracer
  
          if _TRACER_PROVIDER:
              self._real_tracer = _TRACER_PROVIDER.get_tracer(
                  self._instrumenting_module_name,
                  self._instrumenting_library_version,
                  self._schema_url,
              )
              return self._real_tracer
          return self._noop_tracer
  
      def start_span(self, *args, **kwargs) -> Span:  # type: ignore
          return self._tracer.start_span(*args, **kwargs)  # type: ignore
  
      def start_as_current_span(self, *args, **kwargs) -> Span:  # type: ignore
          return self._tracer.start_as_current_span(*args, **kwargs)  # type: ignore
  
  
  class NoOpTracer(Tracer):
      """The default Tracer, used when no Tracer implementation is available.
  
      All operations are no-op.
      """
  
      def start_span(
          self,
          name: str,
          context: Optional[Context] = None,
          kind: SpanKind = SpanKind.INTERNAL,
          attributes: types.Attributes = None,
          links: _Links = None,
          start_time: Optional[int] = None,
          record_exception: bool = True,
          set_status_on_exception: bool = True,
      ) -> "Span":
          # pylint: disable=unused-argument,no-self-use
          return INVALID_SPAN
  
      @contextmanager  # type: ignore
      def start_as_current_span(
          self,
          name: str,
          context: Optional[Context] = None,
          kind: SpanKind = SpanKind.INTERNAL,
          attributes: types.Attributes = None,
          links: _Links = None,
          start_time: Optional[int] = None,
          record_exception: bool = True,
          set_status_on_exception: bool = True,
          end_on_exit: bool = True,
      ) -> Iterator["Span"]:
          # pylint: disable=unused-argument,no-self-use
          yield INVALID_SPAN
  
  
  @deprecated(version="1.9.0", reason="You should use NoOpTracer")  # type: ignore
  class _DefaultTracer(NoOpTracer):
      """The default Tracer, used when no Tracer implementation is available.
  
      All operations are no-op.
      """
  
  
  _TRACER_PROVIDER_SET_ONCE = Once()
  _TRACER_PROVIDER: Optional[TracerProvider] = None
  _PROXY_TRACER_PROVIDER = ProxyTracerProvider()
  
  
  def get_tracer(
      instrumenting_module_name: str,
      instrumenting_library_version: typing.Optional[str] = None,
      tracer_provider: Optional[TracerProvider] = None,
      schema_url: typing.Optional[str] = None,
  ) -> "Tracer":
      """Returns a `Tracer` for use by the given instrumentation library.
  
      This function is a convenience wrapper for
      opentelemetry.trace.TracerProvider.get_tracer.
  
      If tracer_provider is omitted the current configured one is used.
      """
      if tracer_provider is None:
          tracer_provider = get_tracer_provider()
      return tracer_provider.get_tracer(
          instrumenting_module_name, instrumenting_library_version, schema_url
      )
  
  
  def _set_tracer_provider(tracer_provider: TracerProvider, log: bool) -> None:
      def set_tp() -> None:
          global _TRACER_PROVIDER  # pylint: disable=global-statement
          _TRACER_PROVIDER = tracer_provider
  
      did_set = _TRACER_PROVIDER_SET_ONCE.do_once(set_tp)
  
      if log and not did_set:
          logger.warning("Overriding of current TracerProvider is not allowed")
  
  
  def set_tracer_provider(tracer_provider: TracerProvider) -> None:
      """Sets the current global :class:`~.TracerProvider` object.
  
      This can only be done once, a warning will be logged if any furter attempt
      is made.
      """
      _set_tracer_provider(tracer_provider, log=True)
  
  
  def get_tracer_provider() -> TracerProvider:
      """Gets the current global :class:`~.TracerProvider` object."""
      if _TRACER_PROVIDER is None:
          # if a global tracer provider has not been set either via code or env
          # vars, return a proxy tracer provider
          if OTEL_PYTHON_TRACER_PROVIDER not in os.environ:
              return _PROXY_TRACER_PROVIDER
  
          tracer_provider: TracerProvider = _load_provider(
              OTEL_PYTHON_TRACER_PROVIDER, "tracer_provider"
          )
          _set_tracer_provider(tracer_provider, log=False)
      # _TRACER_PROVIDER will have been set by one thread
      return cast("TracerProvider", _TRACER_PROVIDER)
  
  
  @contextmanager  # type: ignore
  def use_span(
      span: Span,
      end_on_exit: bool = False,
      record_exception: bool = True,
      set_status_on_exception: bool = True,
  ) -> Iterator[Span]:
      """Takes a non-active span and activates it in the current context.
  
      Args:
          span: The span that should be activated in the current context.
          end_on_exit: Whether to end the span automatically when leaving the
              context manager scope.
          record_exception: Whether to record any exceptions raised within the
              context as error event on the span.
          set_status_on_exception: Only relevant if the returned span is used
              in a with/context manager. Defines wether the span status will
              be automatically set to ERROR when an uncaught exception is
              raised in the span with block. The span status won't be set by
              this mechanism if it was previously set manually.
      """
      try:
          token = context_api.attach(context_api.set_value(_SPAN_KEY, span))
          try:
              yield span
          finally:
              context_api.detach(token)
  
      except Exception as exc:  # pylint: disable=broad-except
          if isinstance(span, Span) and span.is_recording():
              # Record the exception as an event
              if record_exception:
                  span.record_exception(exc)
  
              # Set status in case exception was raised
              if set_status_on_exception:
                  span.set_status(
                      Status(
                          status_code=StatusCode.ERROR,
                          description=f"{type(exc).__name__}: {exc}",
                      )
                  )
          raise
  
      finally:
          if end_on_exit:
              span.end()
  
  
  __all__ = [
      "DEFAULT_TRACE_OPTIONS",
      "DEFAULT_TRACE_STATE",
      "INVALID_SPAN",
      "INVALID_SPAN_CONTEXT",
      "INVALID_SPAN_ID",
      "INVALID_TRACE_ID",
      "NonRecordingSpan",
      "Link",
      "Span",
      "SpanContext",
      "SpanKind",
      "TraceFlags",
      "TraceState",
      "TracerProvider",
      "Tracer",
      "format_span_id",
      "format_trace_id",
      "get_current_span",
      "get_tracer",
      "get_tracer_provider",
      "set_tracer_provider",
      "set_span_in_context",
      "use_span",
      "Status",
      "StatusCode",
  ]
  