You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
84 lines
2.7 KiB
84 lines
2.7 KiB
3 years ago
|
from contextvars import ContextVar
|
||
|
|
from typing import Optional
|
||
|
|
import sys
|
||
|
|
|
||
|
|
current_async_library_cvar = ContextVar(
|
||
|
|
"current_async_library_cvar", default=None
|
||
|
|
) # type: ContextVar[Optional[str]]
|
||
|
|
|
||
|
|
|
||
|
|
class AsyncLibraryNotFoundError(RuntimeError):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
def current_async_library() -> str:
|
||
|
|
"""Detect which async library is currently running.
|
||
|
|
|
||
|
|
The following libraries are currently supported:
|
||
|
|
|
||
|
|
================ =========== ============================
|
||
|
|
Library Requires Magic string
|
||
|
|
================ =========== ============================
|
||
|
|
**Trio** Trio v0.6+ ``"trio"``
|
||
|
|
**Curio** - ``"curio"``
|
||
|
|
**asyncio** ``"asyncio"``
|
||
|
|
**Trio-asyncio** v0.8.2+ ``"trio"`` or ``"asyncio"``,
|
||
|
|
depending on current mode
|
||
|
|
================ =========== ============================
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
A string like ``"trio"``.
|
||
|
|
|
||
|
|
Raises:
|
||
|
|
AsyncLibraryNotFoundError: if called from synchronous context,
|
||
|
|
or if the current async library was not recognized.
|
||
|
|
|
||
|
|
Examples:
|
||
|
|
|
||
|
|
.. code-block:: python3
|
||
|
|
|
||
|
|
from sniffio import current_async_library
|
||
|
|
|
||
|
|
async def generic_sleep(seconds):
|
||
|
|
library = current_async_library()
|
||
|
|
if library == "trio":
|
||
|
|
import trio
|
||
|
|
await trio.sleep(seconds)
|
||
|
|
elif library == "asyncio":
|
||
|
|
import asyncio
|
||
|
|
await asyncio.sleep(seconds)
|
||
|
|
# ... and so on ...
|
||
|
|
else:
|
||
|
|
raise RuntimeError(f"Unsupported library {library!r}")
|
||
|
|
|
||
|
|
"""
|
||
|
|
value = current_async_library_cvar.get()
|
||
|
|
if value is not None:
|
||
|
|
return value
|
||
|
|
|
||
|
|
# Sniff for curio (for now)
|
||
|
|
if 'curio' in sys.modules:
|
||
|
|
from curio.meta import curio_running
|
||
|
|
if curio_running():
|
||
|
|
return 'curio'
|
||
|
|
|
||
|
|
# Need to sniff for asyncio
|
||
|
|
if "asyncio" in sys.modules:
|
||
|
|
import asyncio
|
||
|
|
try:
|
||
|
|
current_task = asyncio.current_task # type: ignore[attr-defined]
|
||
|
|
except AttributeError:
|
||
|
|
current_task = asyncio.Task.current_task # type: ignore[attr-defined]
|
||
|
|
try:
|
||
|
|
if current_task() is not None:
|
||
|
|
if (3, 7) <= sys.version_info:
|
||
|
|
# asyncio has contextvars support, and we're in a task, so
|
||
|
|
# we can safely cache the sniffed value
|
||
|
|
current_async_library_cvar.set("asyncio")
|
||
|
|
return "asyncio"
|
||
|
|
except RuntimeError:
|
||
|
|
pass
|
||
|
|
raise AsyncLibraryNotFoundError(
|
||
|
|
"unknown async library, or not in async context"
|
||
|
|
)
|