35 lines
1.1 KiB
Python
35 lines
1.1 KiB
Python
import asyncio
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import functools
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import os
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from django.core.exceptions import SynchronousOnlyOperation
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def async_unsafe(message):
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"""
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Decorator to mark functions as async-unsafe. Someone trying to access
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the function while in an async context will get an error message.
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"""
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def decorator(func):
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@functools.wraps(func)
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def inner(*args, **kwargs):
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if not os.environ.get('DJANGO_ALLOW_ASYNC_UNSAFE'):
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# Detect a running event loop in this thread.
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try:
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event_loop = asyncio.get_event_loop()
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except RuntimeError:
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pass
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else:
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if event_loop.is_running():
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raise SynchronousOnlyOperation(message)
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# Pass onwards.
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return func(*args, **kwargs)
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return inner
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# If the message is actually a function, then be a no-arguments decorator.
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if callable(message):
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func = message
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message = 'You cannot call this from an async context - use a thread or sync_to_async.'
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return decorator(func)
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else:
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return decorator
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