feat: optimize get_flag_name_c (#403)

* feat: optimize get_flag_name_c.py

* chore: `black .`

* fix: circular import

* fix: .pxd discrepancy

* fix: cant assign to const

* fix: circular import

* fix: circular import

* chore: `black .`

* fix: NameError _await

* fix: incorrect definition _await

* chore: `black .`

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

a_sync/a_sync/_helpers.pxd

@@ -1,2 +1,3 @@
-cpdef object _await(object awaitable)
+cpdef object get_event_loop()
+cdef object _await(object awaitable)
 cdef object _asyncify(object func, object executor)

a_sync/a_sync/_helpers.pyi

@@ -1,3 +1,5 @@
 from a_sync._typing import *
 from a_sync import exceptions as exceptions
-def _await(awaitable: Awaitable[T]) -> T:...
+
+def get_event_loop() -> asyncio.AbstractEventLoop: ...
+def _await(awaitable: Awaitable[T]) -> T: ...

a_sync/a_sync/_helpers.pyx

@@ -6,13 +6,23 @@ and converting synchronous functions to asynchronous ones.
 import asyncio
 import functools
 
-import a_sync.asyncio
 from a_sync import exceptions
 from a_sync._typing import *
 
-cdef object get_event_loop = a_sync.asyncio.get_event_loop
 
-cpdef object _await(object awaitable):
+cpdef object get_event_loop():
+    cdef object loop
+    try:
+        return asyncio.get_event_loop()
+    except RuntimeError as e:  # Necessary for use with multi-threaded applications.
+        if not str(e).startswith("There is no current event loop in thread"):
+            raise
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+    return loop
+
+
+cdef object _await(object awaitable):
     """
     Await an awaitable object in a synchronous context.
 

a_sync/a_sync/_kwargs.pxd

@@ -1,2 +1,2 @@
-cdef object get_flag_name_c(dict kwargs)
+cdef str get_flag_name_c(dict kwargs)
 cdef bint is_sync(str flag, dict kwargs, bint pop_flag)

a_sync/a_sync/_kwargs.pyx

@@ -34,14 +34,14 @@ def get_flag_name(kwargs: dict) -> Optional[str]:
         >>> get_flag_name({})
         None
     """
-    return get_flag_name_c(kwargs)
+    return get_flag_name_c(kwargs) or None
 
 
-cdef object get_flag_name_c(dict kwargs):
+cdef str get_flag_name_c(dict kwargs):
     cdef list present_flags = [flag for flag in VIABLE_FLAGS if flag in kwargs]
     cdef uint8_t flags_count = len(present_flags)
     if flags_count == 0:
-        return None
+        return ""  # indicates no flag is present
     elif flags_count == 1:
         return present_flags[0]
     raise exceptions.TooManyFlags("kwargs", present_flags)

a_sync/a_sync/abstract.pyx

@@ -87,8 +87,8 @@ class ASyncABC(metaclass=ASyncMeta):
             False
         """
 
-        cdef object flag
-        if flag := _kwargs.get_flag_name_c(kwargs):
+        cdef str flag = _kwargs.get_flag_name_c(kwargs)
+        if flag:
             return _kwargs.is_sync(<str>flag, kwargs, pop_flag=True)
 
         cdef ShouldAwaitCache cache
@@ -176,9 +176,9 @@ class ASyncABC(metaclass=ASyncMeta):
             cls.__name__,
         )
 
-        cdef object flag
+        cdef str flag = _kwargs.get_flag_name_c(kwargs)
         cdef bint sync
-        if flag := _kwargs.get_flag_name_c(kwargs):
+        if flag:
             sync = _kwargs.is_sync(<str>flag, kwargs, pop_flag=False)  # type: ignore [arg-type]
             logger.debug(
                 "kwargs indicate the new instance created with args %s %s is %ssynchronous",

a_sync/a_sync/function.pyx

@@ -139,8 +139,8 @@ cdef bint _run_sync(object function, dict kwargs):
     See Also:
         - :func:`_kwargs.get_flag_name`
     """
-    cdef object flag
-    if flag := _kwargs.get_flag_name_c(kwargs):
+    cdef str flag = _kwargs.get_flag_name_c(kwargs)
+    if flag:
         # If a flag was specified in the kwargs, we will defer to it.
         return _kwargs.is_sync(<str>flag, kwargs, pop_flag=True)
     else:

a_sync/a_sync/method.pyx

@@ -769,8 +769,8 @@ class ASyncBoundMethod(ASyncFunction[P, T], Generic[I, P, T]):
             >>> bound_method = ASyncBoundMethod(instance, my_function, True)
             >>> should_await = bound_method._should_await(kwargs)
         """
-        cdef object flag
-        if flag := _kwargs.get_flag_name_c(kwargs):
+        cdef str flag = _kwargs.get_flag_name_c(kwargs)
+        if flag:
             return _kwargs.is_sync(<str>flag, kwargs, pop_flag=True)  # type: ignore [arg-type]
         elif self.default:
             return self.default == "sync"

a_sync/asyncio/__init__.py

@@ -14,10 +14,10 @@
     - `asyncio <https://docs.python.org/3/library/asyncio.html>`_: The standard asyncio library documentation for more details on the original functions.
 """
 
+from a_sync.a_sync._helpers import get_event_loop
 from a_sync.asyncio.create_task import create_task
 from a_sync.asyncio.as_completed import as_completed
 from a_sync.asyncio.gather import gather
-from a_sync.asyncio.utils import get_event_loop
 
 __all__ = ["create_task", "gather", "as_completed", "get_event_loop"]