mirror of
https://github.com/SickGear/SickGear.git
synced 2024-11-16 01:45:08 +00:00
265 lines
8 KiB
Python
265 lines
8 KiB
Python
#
|
|
# Copyright 2012 Facebook
|
|
#
|
|
# 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.
|
|
"""Utilities for working with ``Future`` objects.
|
|
|
|
Tornado previously provided its own ``Future`` class, but now uses
|
|
`asyncio.Future`. This module contains utility functions for working
|
|
with `asyncio.Future` in a way that is backwards-compatible with
|
|
Tornado's old ``Future`` implementation.
|
|
|
|
While this module is an important part of Tornado's internal
|
|
implementation, applications rarely need to interact with it
|
|
directly.
|
|
|
|
"""
|
|
|
|
import asyncio
|
|
from concurrent import futures
|
|
import functools
|
|
import sys
|
|
import types
|
|
|
|
from tornado.log import app_log
|
|
|
|
import typing
|
|
from typing import Any, Callable, Optional, Tuple, Union
|
|
|
|
_T = typing.TypeVar("_T")
|
|
|
|
|
|
class ReturnValueIgnoredError(Exception):
|
|
# No longer used; was previously used by @return_future
|
|
pass
|
|
|
|
|
|
Future = asyncio.Future
|
|
|
|
FUTURES = (futures.Future, Future)
|
|
|
|
|
|
def is_future(x: Any) -> bool:
|
|
return isinstance(x, FUTURES)
|
|
|
|
|
|
class DummyExecutor(futures.Executor):
|
|
def submit(
|
|
self, fn: Callable[..., _T], *args: Any, **kwargs: Any
|
|
) -> "futures.Future[_T]":
|
|
future = futures.Future() # type: futures.Future[_T]
|
|
try:
|
|
future_set_result_unless_cancelled(future, fn(*args, **kwargs))
|
|
except Exception:
|
|
future_set_exc_info(future, sys.exc_info())
|
|
return future
|
|
|
|
def shutdown(self, wait: bool = True) -> None:
|
|
pass
|
|
|
|
|
|
dummy_executor = DummyExecutor()
|
|
|
|
|
|
def run_on_executor(*args: Any, **kwargs: Any) -> Callable:
|
|
"""Decorator to run a synchronous method asynchronously on an executor.
|
|
|
|
Returns a future.
|
|
|
|
The executor to be used is determined by the ``executor``
|
|
attributes of ``self``. To use a different attribute name, pass a
|
|
keyword argument to the decorator::
|
|
|
|
@run_on_executor(executor='_thread_pool')
|
|
def foo(self):
|
|
pass
|
|
|
|
This decorator should not be confused with the similarly-named
|
|
`.IOLoop.run_in_executor`. In general, using ``run_in_executor``
|
|
when *calling* a blocking method is recommended instead of using
|
|
this decorator when *defining* a method. If compatibility with older
|
|
versions of Tornado is required, consider defining an executor
|
|
and using ``executor.submit()`` at the call site.
|
|
|
|
.. versionchanged:: 4.2
|
|
Added keyword arguments to use alternative attributes.
|
|
|
|
.. versionchanged:: 5.0
|
|
Always uses the current IOLoop instead of ``self.io_loop``.
|
|
|
|
.. versionchanged:: 5.1
|
|
Returns a `.Future` compatible with ``await`` instead of a
|
|
`concurrent.futures.Future`.
|
|
|
|
.. deprecated:: 5.1
|
|
|
|
The ``callback`` argument is deprecated and will be removed in
|
|
6.0. The decorator itself is discouraged in new code but will
|
|
not be removed in 6.0.
|
|
|
|
.. versionchanged:: 6.0
|
|
|
|
The ``callback`` argument was removed.
|
|
"""
|
|
# Fully type-checking decorators is tricky, and this one is
|
|
# discouraged anyway so it doesn't have all the generic magic.
|
|
def run_on_executor_decorator(fn: Callable) -> Callable[..., Future]:
|
|
executor = kwargs.get("executor", "executor")
|
|
|
|
@functools.wraps(fn)
|
|
def wrapper(self: Any, *args: Any, **kwargs: Any) -> Future:
|
|
async_future = Future() # type: Future
|
|
conc_future = getattr(self, executor).submit(fn, self, *args, **kwargs)
|
|
chain_future(conc_future, async_future)
|
|
return async_future
|
|
|
|
return wrapper
|
|
|
|
if args and kwargs:
|
|
raise ValueError("cannot combine positional and keyword args")
|
|
if len(args) == 1:
|
|
return run_on_executor_decorator(args[0])
|
|
elif len(args) != 0:
|
|
raise ValueError("expected 1 argument, got %d", len(args))
|
|
return run_on_executor_decorator
|
|
|
|
|
|
_NO_RESULT = object()
|
|
|
|
|
|
def chain_future(a: "Future[_T]", b: "Future[_T]") -> None:
|
|
"""Chain two futures together so that when one completes, so does the other.
|
|
|
|
The result (success or failure) of ``a`` will be copied to ``b``, unless
|
|
``b`` has already been completed or cancelled by the time ``a`` finishes.
|
|
|
|
.. versionchanged:: 5.0
|
|
|
|
Now accepts both Tornado/asyncio `Future` objects and
|
|
`concurrent.futures.Future`.
|
|
|
|
"""
|
|
|
|
def copy(future: "Future[_T]") -> None:
|
|
assert future is a
|
|
if b.done():
|
|
return
|
|
if hasattr(a, "exc_info") and a.exc_info() is not None: # type: ignore
|
|
future_set_exc_info(b, a.exc_info()) # type: ignore
|
|
else:
|
|
a_exc = a.exception()
|
|
if a_exc is not None:
|
|
b.set_exception(a_exc)
|
|
else:
|
|
b.set_result(a.result())
|
|
|
|
if isinstance(a, Future):
|
|
future_add_done_callback(a, copy)
|
|
else:
|
|
# concurrent.futures.Future
|
|
from tornado.ioloop import IOLoop
|
|
|
|
IOLoop.current().add_future(a, copy)
|
|
|
|
|
|
def future_set_result_unless_cancelled(
|
|
future: "Union[futures.Future[_T], Future[_T]]", value: _T
|
|
) -> None:
|
|
"""Set the given ``value`` as the `Future`'s result, if not cancelled.
|
|
|
|
Avoids ``asyncio.InvalidStateError`` when calling ``set_result()`` on
|
|
a cancelled `asyncio.Future`.
|
|
|
|
.. versionadded:: 5.0
|
|
"""
|
|
if not future.cancelled():
|
|
future.set_result(value)
|
|
|
|
|
|
def future_set_exception_unless_cancelled(
|
|
future: "Union[futures.Future[_T], Future[_T]]", exc: BaseException
|
|
) -> None:
|
|
"""Set the given ``exc`` as the `Future`'s exception.
|
|
|
|
If the Future is already canceled, logs the exception instead. If
|
|
this logging is not desired, the caller should explicitly check
|
|
the state of the Future and call ``Future.set_exception`` instead of
|
|
this wrapper.
|
|
|
|
Avoids ``asyncio.InvalidStateError`` when calling ``set_exception()`` on
|
|
a cancelled `asyncio.Future`.
|
|
|
|
.. versionadded:: 6.0
|
|
|
|
"""
|
|
if not future.cancelled():
|
|
future.set_exception(exc)
|
|
else:
|
|
app_log.error("Exception after Future was cancelled", exc_info=exc)
|
|
|
|
|
|
def future_set_exc_info(
|
|
future: "Union[futures.Future[_T], Future[_T]]",
|
|
exc_info: Tuple[
|
|
Optional[type], Optional[BaseException], Optional[types.TracebackType]
|
|
],
|
|
) -> None:
|
|
"""Set the given ``exc_info`` as the `Future`'s exception.
|
|
|
|
Understands both `asyncio.Future` and the extensions in older
|
|
versions of Tornado to enable better tracebacks on Python 2.
|
|
|
|
.. versionadded:: 5.0
|
|
|
|
.. versionchanged:: 6.0
|
|
|
|
If the future is already cancelled, this function is a no-op.
|
|
(previously ``asyncio.InvalidStateError`` would be raised)
|
|
|
|
"""
|
|
if exc_info[1] is None:
|
|
raise Exception("future_set_exc_info called with no exception")
|
|
future_set_exception_unless_cancelled(future, exc_info[1])
|
|
|
|
|
|
@typing.overload
|
|
def future_add_done_callback(
|
|
future: "futures.Future[_T]", callback: Callable[["futures.Future[_T]"], None]
|
|
) -> None:
|
|
pass
|
|
|
|
|
|
@typing.overload # noqa: F811
|
|
def future_add_done_callback(
|
|
future: "Future[_T]", callback: Callable[["Future[_T]"], None]
|
|
) -> None:
|
|
pass
|
|
|
|
|
|
def future_add_done_callback( # noqa: F811
|
|
future: "Union[futures.Future[_T], Future[_T]]", callback: Callable[..., None]
|
|
) -> None:
|
|
"""Arrange to call ``callback`` when ``future`` is complete.
|
|
|
|
``callback`` is invoked with one argument, the ``future``.
|
|
|
|
If ``future`` is already done, ``callback`` is invoked immediately.
|
|
This may differ from the behavior of ``Future.add_done_callback``,
|
|
which makes no such guarantee.
|
|
|
|
.. versionadded:: 5.0
|
|
"""
|
|
if future.done():
|
|
callback(future)
|
|
else:
|
|
future.add_done_callback(callback)
|