Intermediate changes

11 files changed, 542 insertions, 0 deletions

diff --git a/contrib/python/sniffio/.dist-info/METADATA b/contrib/python/sniffio/.dist-info/METADATA
new file mode 100644
index 0000000000..22520c72af
--- /dev/null
+++ b/contrib/python/sniffio/.dist-info/METADATA
@@ -0,0 +1,102 @@
+Metadata-Version: 2.1
+Name: sniffio
+Version: 1.3.0
+Summary: Sniff out which async library your code is running under
+Home-page: https://github.com/python-trio/sniffio
+Author: Nathaniel J. Smith
+Author-email: njs@pobox.com
+License: MIT OR Apache-2.0
+Keywords: async,trio,asyncio
+Classifier: License :: OSI Approved :: MIT License
+Classifier: License :: OSI Approved :: Apache Software License
+Classifier: Framework :: Trio
+Classifier: Framework :: AsyncIO
+Classifier: Operating System :: POSIX :: Linux
+Classifier: Operating System :: MacOS :: MacOS X
+Classifier: Operating System :: Microsoft :: Windows
+Classifier: Programming Language :: Python :: 3 :: Only
+Classifier: Programming Language :: Python :: Implementation :: CPython
+Classifier: Programming Language :: Python :: Implementation :: PyPy
+Classifier: Intended Audience :: Developers
+Classifier: Development Status :: 5 - Production/Stable
+Requires-Python: >=3.7
+License-File: LICENSE
+License-File: LICENSE.APACHE2
+License-File: LICENSE.MIT
+
+.. image:: https://img.shields.io/badge/chat-join%20now-blue.svg
+   :target: https://gitter.im/python-trio/general
+   :alt: Join chatroom
+
+.. image:: https://img.shields.io/badge/docs-read%20now-blue.svg
+   :target: https://sniffio.readthedocs.io/en/latest/?badge=latest
+   :alt: Documentation Status
+
+.. image:: https://img.shields.io/pypi/v/sniffio.svg
+   :target: https://pypi.org/project/sniffio
+   :alt: Latest PyPi version
+   
+.. image:: https://img.shields.io/conda/vn/conda-forge/sniffio.svg
+   :target: https://anaconda.org/conda-forge/sniffio 
+   :alt: Latest conda-forge version   
+
+.. image:: https://travis-ci.org/python-trio/sniffio.svg?branch=master
+   :target: https://travis-ci.org/python-trio/sniffio
+   :alt: Automated test status
+
+.. image:: https://codecov.io/gh/python-trio/sniffio/branch/master/graph/badge.svg
+   :target: https://codecov.io/gh/python-trio/sniffio
+   :alt: Test coverage
+
+=================================================================
+sniffio: Sniff out which async library your code is running under
+=================================================================
+
+You're writing a library. You've decided to be ambitious, and support
+multiple async I/O packages, like `Trio
+<https://trio.readthedocs.io>`__, and `asyncio
+<https://docs.python.org/3/library/asyncio.html>`__, and ... You've
+written a bunch of clever code to handle all the differences. But...
+how do you know *which* piece of clever code to run?
+
+This is a tiny package whose only purpose is to let you detect which
+async library your code is running under.
+
+* Documentation: https://sniffio.readthedocs.io
+
+* Bug tracker and source code: https://github.com/python-trio/sniffio
+
+* License: MIT or Apache License 2.0, your choice
+
+* Contributor guide: https://trio.readthedocs.io/en/latest/contributing.html
+
+* Code of conduct: Contributors are requested to follow our `code of
+  conduct
+  <https://trio.readthedocs.io/en/latest/code-of-conduct.html>`_
+  in all project spaces.
+
+This library is maintained by the Trio project, as a service to the
+async Python community as a whole.
+
+
+Quickstart
+----------
+
+.. code-block:: python3
+
+   from sniffio import current_async_library
+   import trio
+   import asyncio
+
+   async def print_library():
+       library = current_async_library()
+       print("This is:", library)
+
+   # Prints "This is trio"
+   trio.run(print_library)
+
+   # Prints "This is asyncio"
+   asyncio.run(print_library())
+
+For more details, including how to add support to new async libraries,
+`please peruse our fine manual <https://sniffio.readthedocs.io>`__.
diff --git a/contrib/python/sniffio/.dist-info/top_level.txt b/contrib/python/sniffio/.dist-info/top_level.txt
new file mode 100644
index 0000000000..01c650244d
--- /dev/null
+++ b/contrib/python/sniffio/.dist-info/top_level.txt
@@ -0,0 +1 @@
+sniffio
diff --git a/contrib/python/sniffio/LICENSE b/contrib/python/sniffio/LICENSE
new file mode 100644
index 0000000000..51f3442917
--- /dev/null
+++ b/contrib/python/sniffio/LICENSE
@@ -0,0 +1,3 @@
+This software is made available under the terms of *either* of the
+licenses found in LICENSE.APACHE2 or LICENSE.MIT. Contributions to are
+made under the terms of *both* these licenses.
diff --git a/contrib/python/sniffio/LICENSE.APACHE2 b/contrib/python/sniffio/LICENSE.APACHE2
new file mode 100644
index 0000000000..d645695673
--- /dev/null
+++ b/contrib/python/sniffio/LICENSE.APACHE2
@@ -0,0 +1,202 @@
+
+                                 Apache License
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+
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+   Unless required by applicable law or agreed to in writing, software
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diff --git a/contrib/python/sniffio/LICENSE.MIT b/contrib/python/sniffio/LICENSE.MIT
new file mode 100644
index 0000000000..b8bb971859
--- /dev/null
+++ b/contrib/python/sniffio/LICENSE.MIT
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/contrib/python/sniffio/README.rst b/contrib/python/sniffio/README.rst
new file mode 100644
index 0000000000..2a62cea5a0
--- /dev/null
+++ b/contrib/python/sniffio/README.rst
@@ -0,0 +1,76 @@
+.. image:: https://img.shields.io/badge/chat-join%20now-blue.svg
+   :target: https://gitter.im/python-trio/general
+   :alt: Join chatroom
+
+.. image:: https://img.shields.io/badge/docs-read%20now-blue.svg
+   :target: https://sniffio.readthedocs.io/en/latest/?badge=latest
+   :alt: Documentation Status
+
+.. image:: https://img.shields.io/pypi/v/sniffio.svg
+   :target: https://pypi.org/project/sniffio
+   :alt: Latest PyPi version
+   
+.. image:: https://img.shields.io/conda/vn/conda-forge/sniffio.svg
+   :target: https://anaconda.org/conda-forge/sniffio 
+   :alt: Latest conda-forge version   
+
+.. image:: https://travis-ci.org/python-trio/sniffio.svg?branch=master
+   :target: https://travis-ci.org/python-trio/sniffio
+   :alt: Automated test status
+
+.. image:: https://codecov.io/gh/python-trio/sniffio/branch/master/graph/badge.svg
+   :target: https://codecov.io/gh/python-trio/sniffio
+   :alt: Test coverage
+
+=================================================================
+sniffio: Sniff out which async library your code is running under
+=================================================================
+
+You're writing a library. You've decided to be ambitious, and support
+multiple async I/O packages, like `Trio
+<https://trio.readthedocs.io>`__, and `asyncio
+<https://docs.python.org/3/library/asyncio.html>`__, and ... You've
+written a bunch of clever code to handle all the differences. But...
+how do you know *which* piece of clever code to run?
+
+This is a tiny package whose only purpose is to let you detect which
+async library your code is running under.
+
+* Documentation: https://sniffio.readthedocs.io
+
+* Bug tracker and source code: https://github.com/python-trio/sniffio
+
+* License: MIT or Apache License 2.0, your choice
+
+* Contributor guide: https://trio.readthedocs.io/en/latest/contributing.html
+
+* Code of conduct: Contributors are requested to follow our `code of
+  conduct
+  <https://trio.readthedocs.io/en/latest/code-of-conduct.html>`_
+  in all project spaces.
+
+This library is maintained by the Trio project, as a service to the
+async Python community as a whole.
+
+
+Quickstart
+----------
+
+.. code-block:: python3
+
+   from sniffio import current_async_library
+   import trio
+   import asyncio
+
+   async def print_library():
+       library = current_async_library()
+       print("This is:", library)
+
+   # Prints "This is trio"
+   trio.run(print_library)
+
+   # Prints "This is asyncio"
+   asyncio.run(print_library())
+
+For more details, including how to add support to new async libraries,
+`please peruse our fine manual <https://sniffio.readthedocs.io>`__.
diff --git a/contrib/python/sniffio/sniffio/__init__.py b/contrib/python/sniffio/sniffio/__init__.py
new file mode 100644
index 0000000000..fb3364d7f1
--- /dev/null
+++ b/contrib/python/sniffio/sniffio/__init__.py
@@ -0,0 +1,15 @@
+"""Top-level package for sniffio."""
+
+__all__ = [
+    "current_async_library", "AsyncLibraryNotFoundError",
+    "current_async_library_cvar"
+]
+
+from ._version import __version__
+
+from ._impl import (
+    current_async_library,
+    AsyncLibraryNotFoundError,
+    current_async_library_cvar,
+    thread_local,
+)
diff --git a/contrib/python/sniffio/sniffio/_impl.py b/contrib/python/sniffio/sniffio/_impl.py
new file mode 100644
index 0000000000..c1a7bbf218
--- /dev/null
+++ b/contrib/python/sniffio/sniffio/_impl.py
@@ -0,0 +1,95 @@
+from contextvars import ContextVar
+from typing import Optional
+import sys
+import threading
+
+current_async_library_cvar = ContextVar(
+    "current_async_library_cvar", default=None
+)  # type: ContextVar[Optional[str]]
+
+
+class _ThreadLocal(threading.local):
+    # Since threading.local provides no explicit mechanism is for setting
+    # a default for a value, a custom class with a class attribute is used
+    # instead.
+    name = None  # type: Optional[str]
+
+
+thread_local = _ThreadLocal()
+
+
+class AsyncLibraryNotFoundError(RuntimeError):
+    pass
+
+
+def current_async_library() -> str:
+    """Detect which async library is currently running.
+
+    The following libraries are currently supported:
+
+    ================   ===========  ============================
+    Library             Requires     Magic string
+    ================   ===========  ============================
+    **Trio**            Trio v0.6+   ``"trio"``
+    **Curio**           -            ``"curio"``
+    **asyncio**                      ``"asyncio"``
+    **Trio-asyncio**    v0.8.2+     ``"trio"`` or ``"asyncio"``,
+                                    depending on current mode
+    ================   ===========  ============================
+
+    Returns:
+      A string like ``"trio"``.
+
+    Raises:
+      AsyncLibraryNotFoundError: if called from synchronous context,
+        or if the current async library was not recognized.
+
+    Examples:
+
+        .. code-block:: python3
+
+           from sniffio import current_async_library
+
+           async def generic_sleep(seconds):
+               library = current_async_library()
+               if library == "trio":
+                   import trio
+                   await trio.sleep(seconds)
+               elif library == "asyncio":
+                   import asyncio
+                   await asyncio.sleep(seconds)
+               # ... and so on ...
+               else:
+                   raise RuntimeError(f"Unsupported library {library!r}")
+
+    """
+    value = thread_local.name
+    if value is not None:
+        return value
+
+    value = current_async_library_cvar.get()
+    if value is not None:
+        return value
+
+    # Need to sniff for asyncio
+    if "asyncio" in sys.modules:
+        import asyncio
+        try:
+            current_task = asyncio.current_task  # type: ignore[attr-defined]
+        except AttributeError:
+            current_task = asyncio.Task.current_task  # type: ignore[attr-defined]
+        try:
+            if current_task() is not None:
+                return "asyncio"
+        except RuntimeError:
+            pass
+
+    # Sniff for curio (for now)
+    if 'curio' in sys.modules:
+        from curio.meta import curio_running
+        if curio_running():
+            return 'curio'
+
+    raise AsyncLibraryNotFoundError(
+        "unknown async library, or not in async context"
+    )
diff --git a/contrib/python/sniffio/sniffio/_version.py b/contrib/python/sniffio/sniffio/_version.py
new file mode 100644
index 0000000000..5a5f906bbf
--- /dev/null
+++ b/contrib/python/sniffio/sniffio/_version.py
@@ -0,0 +1,3 @@
+# This file is imported from __init__.py and exec'd from setup.py
+
+__version__ = "1.3.0"
diff --git a/contrib/python/sniffio/sniffio/py.typed b/contrib/python/sniffio/sniffio/py.typed
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/contrib/python/sniffio/sniffio/py.typed
diff --git a/contrib/python/sniffio/ya.make b/contrib/python/sniffio/ya.make
new file mode 100644
index 0000000000..d0e376d4ca
--- /dev/null
+++ b/contrib/python/sniffio/ya.make
@@ -0,0 +1,25 @@
+# Generated by devtools/yamaker (pypi).
+
+PY3_LIBRARY()
+
+VERSION(1.3.0)
+
+LICENSE(Apache-2.0 AND MIT)
+
+NO_LINT()
+
+PY_SRCS(
+    TOP_LEVEL
+    sniffio/__init__.py
+    sniffio/_impl.py
+    sniffio/_version.py
+)
+
+RESOURCE_FILES(
+    PREFIX contrib/python/sniffio/
+    .dist-info/METADATA
+    .dist-info/top_level.txt
+    sniffio/py.typed
+)
+
+END()