[WIP] Python 3.12 (#27)

* some initial attempts to be able to run tests on 3.12
* trying to workaround runtime issue
* added 3.12 to supported versions
* changelog, warning that Tornado support is going to be removed in future

.github/workflows/tox-tests.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: [ '3.7', '3.8', '3.9', '3.10', '3.11' ]
+        python: [ '3.7', '3.8', '3.9', '3.10', '3.11', '3.12' ]
 
     steps:
       - uses: actions/checkout@v2

CHANGELOG.rst

@@ -1,3 +1,10 @@
+1.2.0
+-----
+
+* Added support for Python 3.12
+* Added warning that support for Tornado is deprecated and will be removed in future
+  (it causes more and more hacks/workarounds while Tornado importance is diminishing).
+
 1.1.5
 -----
 

README.rst

@@ -76,6 +76,9 @@ For configuration options see `Configurability`_.
 You can use ``memoize`` with both `asyncio <https://docs.python.org/3/library/asyncio.html>`_
 and `Tornado <https://github.com/tornadoweb/tornado>`_ -  please see the appropriate example:
 
+.. warning::
+    Support for `Tornado <https://github.com/tornadoweb/tornado>`_ is planned to be removed in the future.
+
 asyncio
 ~~~~~~~
 

memoize/coerced.py

@@ -5,6 +5,7 @@
 import datetime
 import importlib.util
 import logging
+import sys
 
 from memoize.memoize_configuration import force_asyncio
 
@@ -47,9 +48,89 @@ def _timeout_error_type():
 
     logger.info('Using asyncio instead of torando')
 
+    # this backported version of `wait_for` is taken from Python 3.11
+    # and allows to continue having these `coerced` functions working (they are at least partially based on hacks)
+    # in general we need to drop tornado support either way (so this temporary solution would be gone either way)
+    async def wait_for(fut, timeout):
+        """Wait for the single Future or coroutine to complete, with timeout.
+
+        Coroutine will be wrapped in Task.
+
+        Returns result of the Future or coroutine.  When a timeout occurs,
+        it cancels the task and raises TimeoutError.  To avoid the task
+        cancellation, wrap it in shield().
+
+        If the wait is cancelled, the task is also cancelled.
+
+        This function is a coroutine.
+        """
+
+        from asyncio import events, ensure_future, exceptions
+        from asyncio.tasks import _cancel_and_wait, _release_waiter
+        import functools
+        loop = events.get_running_loop()
+
+        if timeout is None:
+            return await fut
+
+        if timeout <= 0:
+            fut = ensure_future(fut, loop=loop)
+
+            if fut.done():
+                return fut.result()
+
+            await _cancel_and_wait(fut)
+            try:
+                return fut.result()
+            except exceptions.CancelledError as exc:
+                raise exceptions.TimeoutError() from exc
+
+        waiter = loop.create_future()
+        timeout_handle = loop.call_later(timeout, _release_waiter, waiter)
+        cb = functools.partial(_release_waiter, waiter)
+
+        fut = ensure_future(fut, loop=loop)
+        fut.add_done_callback(cb)
+
+        try:
+            # wait until the future completes or the timeout
+            try:
+                await waiter
+            except exceptions.CancelledError:
+                if fut.done():
+                    return fut.result()
+                else:
+                    fut.remove_done_callback(cb)
+                    # We must ensure that the task is not running
+                    # after wait_for() returns.
+                    # See https://bugs.python.org/issue32751
+                    await _cancel_and_wait(fut)
+                    raise
+
+            if fut.done():
+                return fut.result()
+            else:
+                fut.remove_done_callback(cb)
+                # We must ensure that the task is not running
+                # after wait_for() returns.
+                # See https://bugs.python.org/issue32751
+                await _cancel_and_wait(fut)
+                # In case task cancellation failed with some
+                # exception, we should re-raise it
+                # See https://bugs.python.org/issue40607
+                try:
+                    return fut.result()
+                except exceptions.CancelledError as exc:
+                    raise exceptions.TimeoutError() from exc
+        finally:
+            timeout_handle.cancel()
+
     # ignore for mypy as types are resolved in runtime
     def _apply_timeout(method_timeout: datetime.timedelta, future: asyncio.Future) -> asyncio.Future:  # type: ignore
-        return asyncio.wait_for(future, method_timeout.total_seconds())
+        if sys.version_info >= (3, 12, 0):
+            return wait_for(future, method_timeout.total_seconds())
+        else:
+            return asyncio.wait_for(future, method_timeout.total_seconds())
 
 
     def _call_later(delay: datetime.timedelta, callback):

setup.py

@@ -1,7 +1,4 @@
-try:
-    from setuptools import setup
-except ImportError:
-    from distutils.core import setup
+from setuptools import setup
 
 
 def prepare_description():
@@ -14,7 +11,7 @@ def prepare_description():
 
 setup(
     name='py-memoize',
-    version='1.1.5',
+    version='1.2.0',
     author='Michal Zmuda',
     author_email='[email protected]',
     url='https://github.com/DreamLab/memoize',
@@ -42,6 +39,7 @@ def prepare_description():
         'Programming Language :: Python :: 3.9',
         'Programming Language :: Python :: 3.10',
         'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
         'Framework :: AsyncIO',
         'Intended Audience :: Developers'
     ]

tox.ini

@@ -3,7 +3,7 @@ skipdist   = True
 
 # py-{asyncio,tornado} are added for GitHub Actions (where we have only one interpreter at the time)
 # py{35,36,37,38,39}-{asyncio,tornado} are added for development purposes (where one has multiple interpreters)
-envlist    = py-{asyncio,tornado},py{37,38,39,310,311}-{asyncio,tornado},coverage-py310,mypy-py310
+envlist    = py-{asyncio,tornado},py{37,38,39,310,311,312}-{asyncio,tornado},coverage-py310,mypy-py310
 
 [testenv]
 setenv        =
@@ -19,6 +19,9 @@ commands      =
   coverage-py37: coverage report
   mypy-py37:     mypy memoize
 deps =
+  setuptools                    # for setup.py to work (distutils is removed from Python 3.12)
+  tornado:  backports.ssl-match-hostname  # for tornado-based tests to run with Python 3.12
+  asyncio:  backports.ssl-match-hostname  # unit tests that run for asyncio are still based on tornado.testing
   asyncio:  tornado>4,<5
   tornado:  tornado>4,<5
   coverage: coverage