42 lines
1.4 KiB
Python
42 lines
1.4 KiB
Python
from concurrent.futures import ThreadPoolExecutor
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from functools import partial
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from trollius import get_event_loop, coroutine
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def wrap_with_threadpool(obj, worker_threads=1):
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"""
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Wraps a class in an async executor so that it can be safely used in an event loop like trollius.
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"""
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async_executor = ThreadPoolExecutor(worker_threads)
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return AsyncWrapper(obj, executor=async_executor), async_executor
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class AsyncWrapper(object):
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""" Wrapper class which will transform a syncronous library to one that can be used with
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trollius coroutines.
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"""
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def __init__(self, delegate, loop=None, executor=None):
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self._loop = loop if loop is not None else get_event_loop()
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self._delegate = delegate
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self._executor = executor
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def __getattr__(self, attrib):
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delegate_attr = getattr(self._delegate, attrib)
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if not callable(delegate_attr):
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return delegate_attr
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def wrapper(*args, **kwargs):
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""" Wraps the delegate_attr with primitives that will transform sync calls to ones shelled
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out to a thread pool.
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"""
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callable_delegate_attr = partial(delegate_attr, *args, **kwargs)
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return self._loop.run_in_executor(self._executor, callable_delegate_attr)
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return wrapper
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@coroutine
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def __call__(self, *args, **kwargs):
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callable_delegate_attr = partial(self._delegate, *args, **kwargs)
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return self._loop.run_in_executor(self._executor, callable_delegate_attr)
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