gpt4free/venv/lib/python3.9/site-packages/async_generator/_impl.py

456 lines
16 KiB
Python

import sys
from functools import wraps
from types import coroutine
import inspect
from inspect import (
getcoroutinestate, CORO_CREATED, CORO_CLOSED, CORO_SUSPENDED
)
import collections.abc
class YieldWrapper:
def __init__(self, payload):
self.payload = payload
def _wrap(value):
return YieldWrapper(value)
def _is_wrapped(box):
return isinstance(box, YieldWrapper)
def _unwrap(box):
return box.payload
# This is the magic code that lets you use yield_ and yield_from_ with native
# generators.
#
# The old version worked great on Linux and MacOS, but not on Windows, because
# it depended on _PyAsyncGenValueWrapperNew. The new version segfaults
# everywhere, and I'm not sure why -- probably my lack of understanding
# of ctypes and refcounts.
#
# There are also some commented out tests that should be re-enabled if this is
# fixed:
#
# if sys.version_info >= (3, 6):
# # Use the same box type that the interpreter uses internally. This allows
# # yield_ and (more importantly!) yield_from_ to work in built-in
# # generators.
# import ctypes # mua ha ha.
#
# # We used to call _PyAsyncGenValueWrapperNew to create and set up new
# # wrapper objects, but that symbol isn't available on Windows:
# #
# # https://github.com/python-trio/async_generator/issues/5
# #
# # Fortunately, the type object is available, but it means we have to do
# # this the hard way.
#
# # We don't actually need to access this, but we need to make a ctypes
# # structure so we can call addressof.
# class _ctypes_PyTypeObject(ctypes.Structure):
# pass
# _PyAsyncGenWrappedValue_Type_ptr = ctypes.addressof(
# _ctypes_PyTypeObject.in_dll(
# ctypes.pythonapi, "_PyAsyncGenWrappedValue_Type"))
# _PyObject_GC_New = ctypes.pythonapi._PyObject_GC_New
# _PyObject_GC_New.restype = ctypes.py_object
# _PyObject_GC_New.argtypes = (ctypes.c_void_p,)
#
# _Py_IncRef = ctypes.pythonapi.Py_IncRef
# _Py_IncRef.restype = None
# _Py_IncRef.argtypes = (ctypes.py_object,)
#
# class _ctypes_PyAsyncGenWrappedValue(ctypes.Structure):
# _fields_ = [
# ('PyObject_HEAD', ctypes.c_byte * object().__sizeof__()),
# ('agw_val', ctypes.py_object),
# ]
# def _wrap(value):
# box = _PyObject_GC_New(_PyAsyncGenWrappedValue_Type_ptr)
# raw = ctypes.cast(ctypes.c_void_p(id(box)),
# ctypes.POINTER(_ctypes_PyAsyncGenWrappedValue))
# raw.contents.agw_val = value
# _Py_IncRef(value)
# return box
#
# def _unwrap(box):
# assert _is_wrapped(box)
# raw = ctypes.cast(ctypes.c_void_p(id(box)),
# ctypes.POINTER(_ctypes_PyAsyncGenWrappedValue))
# value = raw.contents.agw_val
# _Py_IncRef(value)
# return value
#
# _PyAsyncGenWrappedValue_Type = type(_wrap(1))
# def _is_wrapped(box):
# return isinstance(box, _PyAsyncGenWrappedValue_Type)
# The magic @coroutine decorator is how you write the bottom level of
# coroutine stacks -- 'async def' can only use 'await' = yield from; but
# eventually we must bottom out in a @coroutine that calls plain 'yield'.
@coroutine
def _yield_(value):
return (yield _wrap(value))
# But we wrap the bare @coroutine version in an async def, because async def
# has the magic feature that users can get warnings messages if they forget to
# use 'await'.
async def yield_(value=None):
return await _yield_(value)
async def yield_from_(delegate):
# Transcribed with adaptations from:
#
# https://www.python.org/dev/peps/pep-0380/#formal-semantics
#
# This takes advantage of a sneaky trick: if an @async_generator-wrapped
# function calls another async function (like yield_from_), and that
# second async function calls yield_, then because of the hack we use to
# implement yield_, the yield_ will actually propagate through yield_from_
# back to the @async_generator wrapper. So even though we're a regular
# function, we can directly yield values out of the calling async
# generator.
def unpack_StopAsyncIteration(e):
if e.args:
return e.args[0]
else:
return None
_i = type(delegate).__aiter__(delegate)
if hasattr(_i, "__await__"):
_i = await _i
try:
_y = await type(_i).__anext__(_i)
except StopAsyncIteration as _e:
_r = unpack_StopAsyncIteration(_e)
else:
while 1:
try:
_s = await yield_(_y)
except GeneratorExit as _e:
try:
_m = _i.aclose
except AttributeError:
pass
else:
await _m()
raise _e
except BaseException as _e:
_x = sys.exc_info()
try:
_m = _i.athrow
except AttributeError:
raise _e
else:
try:
_y = await _m(*_x)
except StopAsyncIteration as _e:
_r = unpack_StopAsyncIteration(_e)
break
else:
try:
if _s is None:
_y = await type(_i).__anext__(_i)
else:
_y = await _i.asend(_s)
except StopAsyncIteration as _e:
_r = unpack_StopAsyncIteration(_e)
break
return _r
# This is the awaitable / iterator that implements asynciter.__anext__() and
# friends.
#
# Note: we can be sloppy about the distinction between
#
# type(self._it).__next__(self._it)
#
# and
#
# self._it.__next__()
#
# because we happen to know that self._it is not a general iterator object,
# but specifically a coroutine iterator object where these are equivalent.
class ANextIter:
def __init__(self, it, first_fn, *first_args):
self._it = it
self._first_fn = first_fn
self._first_args = first_args
def __await__(self):
return self
def __next__(self):
if self._first_fn is not None:
first_fn = self._first_fn
first_args = self._first_args
self._first_fn = self._first_args = None
return self._invoke(first_fn, *first_args)
else:
return self._invoke(self._it.__next__)
def send(self, value):
return self._invoke(self._it.send, value)
def throw(self, type, value=None, traceback=None):
return self._invoke(self._it.throw, type, value, traceback)
def _invoke(self, fn, *args):
try:
result = fn(*args)
except StopIteration as e:
# The underlying generator returned, so we should signal the end
# of iteration.
raise StopAsyncIteration(e.value)
except StopAsyncIteration as e:
# PEP 479 says: if a generator raises Stop(Async)Iteration, then
# it should be wrapped into a RuntimeError. Python automatically
# enforces this for StopIteration; for StopAsyncIteration we need
# to it ourselves.
raise RuntimeError(
"async_generator raise StopAsyncIteration"
) from e
if _is_wrapped(result):
raise StopIteration(_unwrap(result))
else:
return result
UNSPECIFIED = object()
try:
from sys import get_asyncgen_hooks, set_asyncgen_hooks
except ImportError:
import threading
asyncgen_hooks = collections.namedtuple(
"asyncgen_hooks", ("firstiter", "finalizer")
)
class _hooks_storage(threading.local):
def __init__(self):
self.firstiter = None
self.finalizer = None
_hooks = _hooks_storage()
def get_asyncgen_hooks():
return asyncgen_hooks(
firstiter=_hooks.firstiter, finalizer=_hooks.finalizer
)
def set_asyncgen_hooks(firstiter=UNSPECIFIED, finalizer=UNSPECIFIED):
if firstiter is not UNSPECIFIED:
if firstiter is None or callable(firstiter):
_hooks.firstiter = firstiter
else:
raise TypeError(
"callable firstiter expected, got {}".format(
type(firstiter).__name__
)
)
if finalizer is not UNSPECIFIED:
if finalizer is None or callable(finalizer):
_hooks.finalizer = finalizer
else:
raise TypeError(
"callable finalizer expected, got {}".format(
type(finalizer).__name__
)
)
class AsyncGenerator:
# https://bitbucket.org/pypy/pypy/issues/2786:
# PyPy implements 'await' in a way that requires the frame object
# used to execute a coroutine to keep a weakref to that coroutine.
# During a GC pass, weakrefs to all doomed objects are broken
# before any of the doomed objects' finalizers are invoked.
# If an AsyncGenerator is unreachable, its _coroutine probably
# is too, and the weakref from ag._coroutine.cr_frame to
# ag._coroutine will be broken before ag.__del__ can do its
# one-turn close attempt or can schedule a full aclose() using
# the registered finalization hook. It doesn't look like the
# underlying issue is likely to be fully fixed anytime soon,
# so we work around it by preventing an AsyncGenerator and
# its _coroutine from being considered newly unreachable at
# the same time if the AsyncGenerator's finalizer might want
# to iterate the coroutine some more.
_pypy_issue2786_workaround = set()
def __init__(self, coroutine):
self._coroutine = coroutine
self._it = coroutine.__await__()
self.ag_running = False
self._finalizer = None
self._closed = False
self._hooks_inited = False
# On python 3.5.0 and 3.5.1, __aiter__ must be awaitable.
# Starting in 3.5.2, it should not be awaitable, and if it is, then it
# raises a PendingDeprecationWarning.
# See:
# https://www.python.org/dev/peps/pep-0492/#api-design-and-implementation-revisions
# https://docs.python.org/3/reference/datamodel.html#async-iterators
# https://bugs.python.org/issue27243
if sys.version_info < (3, 5, 2):
async def __aiter__(self):
return self
else:
def __aiter__(self):
return self
################################################################
# Introspection attributes
################################################################
@property
def ag_code(self):
return self._coroutine.cr_code
@property
def ag_frame(self):
return self._coroutine.cr_frame
################################################################
# Core functionality
################################################################
# These need to return awaitables, rather than being async functions,
# to match the native behavior where the firstiter hook is called
# immediately on asend()/etc, even if the coroutine that asend()
# produces isn't awaited for a bit.
def __anext__(self):
return self._do_it(self._it.__next__)
def asend(self, value):
return self._do_it(self._it.send, value)
def athrow(self, type, value=None, traceback=None):
return self._do_it(self._it.throw, type, value, traceback)
def _do_it(self, start_fn, *args):
if not self._hooks_inited:
self._hooks_inited = True
(firstiter, self._finalizer) = get_asyncgen_hooks()
if firstiter is not None:
firstiter(self)
if sys.implementation.name == "pypy":
self._pypy_issue2786_workaround.add(self._coroutine)
# On CPython 3.5.2 (but not 3.5.0), coroutines get cranky if you try
# to iterate them after they're exhausted. Generators OTOH just raise
# StopIteration. We want to convert the one into the other, so we need
# to avoid iterating stopped coroutines.
if getcoroutinestate(self._coroutine) is CORO_CLOSED:
raise StopAsyncIteration()
async def step():
if self.ag_running:
raise ValueError("async generator already executing")
try:
self.ag_running = True
return await ANextIter(self._it, start_fn, *args)
except StopAsyncIteration:
self._pypy_issue2786_workaround.discard(self._coroutine)
raise
finally:
self.ag_running = False
return step()
################################################################
# Cleanup
################################################################
async def aclose(self):
state = getcoroutinestate(self._coroutine)
if state is CORO_CLOSED or self._closed:
return
# Make sure that even if we raise "async_generator ignored
# GeneratorExit", and thus fail to exhaust the coroutine,
# __del__ doesn't complain again.
self._closed = True
if state is CORO_CREATED:
# Make sure that aclose() on an unstarted generator returns
# successfully and prevents future iteration.
self._it.close()
return
try:
await self.athrow(GeneratorExit)
except (GeneratorExit, StopAsyncIteration):
self._pypy_issue2786_workaround.discard(self._coroutine)
else:
raise RuntimeError("async_generator ignored GeneratorExit")
def __del__(self):
self._pypy_issue2786_workaround.discard(self._coroutine)
if getcoroutinestate(self._coroutine) is CORO_CREATED:
# Never started, nothing to clean up, just suppress the "coroutine
# never awaited" message.
self._coroutine.close()
if getcoroutinestate(self._coroutine
) is CORO_SUSPENDED and not self._closed:
if self._finalizer is not None:
self._finalizer(self)
else:
# Mimic the behavior of native generators on GC with no finalizer:
# throw in GeneratorExit, run for one turn, and complain if it didn't
# finish.
thrower = self.athrow(GeneratorExit)
try:
thrower.send(None)
except (GeneratorExit, StopAsyncIteration):
pass
except StopIteration:
raise RuntimeError("async_generator ignored GeneratorExit")
else:
raise RuntimeError(
"async_generator {!r} awaited during finalization; install "
"a finalization hook to support this, or wrap it in "
"'async with aclosing(...):'"
.format(self.ag_code.co_name)
)
finally:
thrower.close()
if hasattr(collections.abc, "AsyncGenerator"):
collections.abc.AsyncGenerator.register(AsyncGenerator)
def async_generator(coroutine_maker):
@wraps(coroutine_maker)
def async_generator_maker(*args, **kwargs):
return AsyncGenerator(coroutine_maker(*args, **kwargs))
async_generator_maker._async_gen_function = id(async_generator_maker)
return async_generator_maker
def isasyncgen(obj):
if hasattr(inspect, "isasyncgen"):
if inspect.isasyncgen(obj):
return True
return isinstance(obj, AsyncGenerator)
def isasyncgenfunction(obj):
if hasattr(inspect, "isasyncgenfunction"):
if inspect.isasyncgenfunction(obj):
return True
return getattr(obj, "_async_gen_function", -1) == id(obj)