Update vendored windows libs

libs/win/autocommand/autoasync.py

@@ -0,0 +1,142 @@
+# Copyright 2014-2015 Nathan West
+#
+# This file is part of autocommand.
+#
+# autocommand is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# autocommand is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with autocommand.  If not, see <http://www.gnu.org/licenses/>.
+
+from asyncio import get_event_loop, iscoroutine
+from functools import wraps
+from inspect import signature
+
+
+async def _run_forever_coro(coro, args, kwargs, loop):
+    '''
+    This helper function launches an async main function that was tagged with
+    forever=True. There are two possibilities:
+
+    - The function is a normal function, which handles initializing the event
+      loop, which is then run forever
+    - The function is a coroutine, which needs to be scheduled in the event
+      loop, which is then run forever
+      - There is also the possibility that the function is a normal function
+        wrapping a coroutine function
+
+    The function is therefore called unconditionally and scheduled in the event
+    loop if the return value is a coroutine object.
+
+    The reason this is a separate function is to make absolutely sure that all
+    the objects created are garbage collected after all is said and done; we
+    do this to ensure that any exceptions raised in the tasks are collected
+    ASAP.
+    '''
+
+    # Personal note: I consider this an antipattern, as it relies on the use of
+    # unowned resources. The setup function dumps some stuff into the event
+    # loop where it just whirls in the ether without a well defined owner or
+    # lifetime. For this reason, there's a good chance I'll remove the
+    # forever=True feature from autoasync at some point in the future.
+    thing = coro(*args, **kwargs)
+    if iscoroutine(thing):
+        await thing
+
+
+def autoasync(coro=None, *, loop=None, forever=False, pass_loop=False):
+    '''
+    Convert an asyncio coroutine into a function which, when called, is
+    evaluted in an event loop, and the return value returned. This is intented
+    to make it easy to write entry points into asyncio coroutines, which
+    otherwise need to be explictly evaluted with an event loop's
+    run_until_complete.
+
+    If `loop` is given, it is used as the event loop to run the coro in. If it
+    is None (the default), the loop is retreived using asyncio.get_event_loop.
+    This call is defered until the decorated function is called, so that
+    callers can install custom event loops or event loop policies after
+    @autoasync is applied.
+
+    If `forever` is True, the loop is run forever after the decorated coroutine
+    is finished. Use this for servers created with asyncio.start_server and the
+    like.
+
+    If `pass_loop` is True, the event loop object is passed into the coroutine
+    as the `loop` kwarg when the wrapper function is called. In this case, the
+    wrapper function's __signature__ is updated to remove this parameter, so
+    that autoparse can still be used on it without generating a parameter for
+    `loop`.
+
+    This coroutine can be called with ( @autoasync(...) ) or without
+    ( @autoasync ) arguments.
+
+    Examples:
+
+    @autoasync
+    def get_file(host, port):
+        reader, writer = yield from asyncio.open_connection(host, port)
+        data = reader.read()
+        sys.stdout.write(data.decode())
+
+    get_file(host, port)
+
+    @autoasync(forever=True, pass_loop=True)
+    def server(host, port, loop):
+        yield_from loop.create_server(Proto, host, port)
+
+    server('localhost', 8899)
+
+    '''
+    if coro is None:
+        return lambda c: autoasync(
+            c, loop=loop,
+            forever=forever,
+            pass_loop=pass_loop)
+
+    # The old and new signatures are required to correctly bind the loop
+    # parameter in 100% of cases, even if it's a positional parameter.
+    # NOTE: A future release will probably require the loop parameter to be
+    # a kwonly parameter.
+    if pass_loop:
+        old_sig = signature(coro)
+        new_sig = old_sig.replace(parameters=(
+            param for name, param in old_sig.parameters.items()
+            if name != "loop"))
+
+    @wraps(coro)
+    def autoasync_wrapper(*args, **kwargs):
+        # Defer the call to get_event_loop so that, if a custom policy is
+        # installed after the autoasync decorator, it is respected at call time
+        local_loop = get_event_loop() if loop is None else loop
+
+        # Inject the 'loop' argument. We have to use this signature binding to
+        # ensure it's injected in the correct place (positional, keyword, etc)
+        if pass_loop:
+            bound_args = old_sig.bind_partial()
+            bound_args.arguments.update(
+                loop=local_loop,
+                **new_sig.bind(*args, **kwargs).arguments)
+            args, kwargs = bound_args.args, bound_args.kwargs
+
+        if forever:
+            local_loop.create_task(_run_forever_coro(
+                coro, args, kwargs, local_loop
+            ))
+            local_loop.run_forever()
+        else:
+            return local_loop.run_until_complete(coro(*args, **kwargs))
+
+    # Attach the updated signature. This allows 'pass_loop' to be used with
+    # autoparse
+    if pass_loop:
+        autoasync_wrapper.__signature__ = new_sig
+
+    return autoasync_wrapper