open-telemetry · toumorokoshi · Aug 16, 2019 · Sep 3, 2019 · Sep 3, 2019 · Sep 3, 2019
diff --git a/opentelemetry-api/src/opentelemetry/context/__init__.py b/opentelemetry-api/src/opentelemetry/context/__init__.py
@@ -11,8 +11,6 @@
 # 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 context module provides abstraction layer on top of
 thread-local storage and contextvars. The long term direction is to switch to
@@ -27,9 +25,8 @@
     >>> Context.foo
     2
 
-When explicit thread is used, a helper function
-``Context.with_current_context`` can be used to carry the context across
-threads::
+When explicit thread is used, a helper function `BaseRuntimeContext.with_current_context`
+can be used to carry the context across threads::
 
     from threading import Thread
     from opentelemetry.context import Context
@@ -138,20 +135,26 @@ async def main():
         asyncio.run(main())
 """
 
-import typing
-
 from .base_context import BaseRuntimeContext
 
 __all__ = ["Context"]
 
 
-Context = None  # type: typing.Optional[BaseRuntimeContext]
+def create_context() -> BaseRuntimeContext:
+    """Create a new context object.
+
+    Return a new RuntimeContext, instantiating the variant that
+    is the most appropriate for the version of Python being used.
+    """
+
+    try:
+        from .async_context import AsyncRuntimeContext
+
+        return AsyncRuntimeContext()
+    except ImportError:
+        from .thread_local_context import ThreadLocalRuntimeContext
 
-try:
-    from .async_context import AsyncRuntimeContext
+        return ThreadLocalRuntimeContext()
 
-    Context = AsyncRuntimeContext()
-except ImportError:
-    from .thread_local_context import ThreadLocalRuntimeContext
 
-    Context = ThreadLocalRuntimeContext()
+Context = create_context()
diff --git a/opentelemetry-api/src/opentelemetry/context/propagation/__init__.py b/opentelemetry-api/src/opentelemetry/context/propagation/__init__.py
diff --git a/opentelemetry-api/src/opentelemetry/context/propagation/binaryformat.py b/opentelemetry-api/src/opentelemetry/context/propagation/binaryformat.py
diff --git a/opentelemetry-api/src/opentelemetry/distributedcontext/propagation/__init__.py b/opentelemetry-api/src/opentelemetry/distributedcontext/propagation/__init__.py
diff --git a/opentelemetry-api/src/opentelemetry/distributedcontext/propagation/httptextformat.py b/opentelemetry-api/src/opentelemetry/distributedcontext/propagation/httptextformat.py
diff --git a/...src/opentelemetry/sdk/context/__init__.py → .../src/opentelemetry/propagator/__init__.py b/...src/opentelemetry/sdk/context/__init__.py → .../src/opentelemetry/propagator/__init__.py
diff --git a/...ibutedcontext/propagation/binaryformat.py → .../opentelemetry/propagator/binaryformat.py b/...ibutedcontext/propagation/binaryformat.py → .../opentelemetry/propagator/binaryformat.py
@@ -13,9 +13,8 @@
 # limitations under the License.
 
 import abc
-import typing
 
-from opentelemetry.distributedcontext import DistributedContext
+from opentelemetry.context import BaseRuntimeContext
 
 
 class BinaryFormat(abc.ABC):
@@ -27,14 +26,14 @@ class BinaryFormat(abc.ABC):
 
     @staticmethod
     @abc.abstractmethod
-    def to_bytes(context: DistributedContext) -> bytes:
-        """Creates a byte representation of a DistributedContext.
+    def to_bytes(context: BaseRuntimeContext) -> bytes:
+        """Creates a byte representation of a Context.
 
-        to_bytes should read values from a DistributedContext and return a data
+        to_bytes should read values from a Context and return a data
         format to represent it, in bytes.
 
         Args:
-            context: the DistributedContext to serialize
+            context: the Context to serialize.
 
         Returns:
             A bytes representation of the DistributedContext.
@@ -44,19 +43,15 @@ def to_bytes(context: DistributedContext) -> bytes:
     @staticmethod
     @abc.abstractmethod
     def from_bytes(
-        byte_representation: bytes
-    ) -> typing.Optional[DistributedContext]:
-        """Return a DistributedContext that was represented by bytes.
+        context: BaseRuntimeContext, byte_representation: bytes
+    ) -> None:
+        """Populate context with context data that existed in the byte representation.
 
-        from_bytes should return back a DistributedContext that was constructed
-        from the data serialized in the byte_representation passed. If it is
-        not possible to read in a proper DistributedContext, return None.
+        from_bytes should add values into the context from the data serialized in the
+        byte_representation passed. If it is not possible to read in a proper
+        DistributedContext, return None.
 
         Args:
-            byte_representation: the bytes to deserialize
-
-        Returns:
-            A bytes representation of the DistributedContext if it is valid.
-            Otherwise return None.
-
+            context: the Context to add values into.
+            byte_representation: the bytes to deserialize.
         """