66 lines
1.7 KiB
Python
66 lines
1.7 KiB
Python
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# retoor <retoor@molodetz.nl>
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import asyncio
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import logging
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logger = logging.getLogger(__name__)
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class BackgroundQueue:
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def __init__(self, max_size=10000):
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self.max_size = max_size
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self._queue = None
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self._task = None
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@property
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def running(self):
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return self._task is not None and not self._task.done()
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def start(self):
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if self.running:
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return
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self._queue = asyncio.Queue(maxsize=self.max_size)
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self._task = asyncio.get_running_loop().create_task(self._consume())
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def submit(self, fn, *args, **kwargs):
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if not self.running:
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self._run(fn, args, kwargs)
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return
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try:
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self._queue.put_nowait((fn, args, kwargs))
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except asyncio.QueueFull:
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self._run(fn, args, kwargs)
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async def stop(self):
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if self._task is None:
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return
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self._task.cancel()
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try:
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await self._task
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except asyncio.CancelledError:
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pass
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self._task = None
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self.drain()
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def drain(self):
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if self._queue is None:
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return
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while not self._queue.empty():
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fn, args, kwargs = self._queue.get_nowait()
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self._run(fn, args, kwargs)
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async def _consume(self):
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while True:
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fn, args, kwargs = await self._queue.get()
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self._run(fn, args, kwargs)
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self._queue.task_done()
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@staticmethod
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def _run(fn, args, kwargs):
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try:
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fn(*args, **kwargs)
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except Exception:
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logger.exception("background task %s failed", getattr(fn, "__name__", fn))
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background = BackgroundQueue()
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