def flow_control(self) -> FlowControlEvent:
"""Internal flow control.
This object controls flow into stream queues,
and can also clear all buffers.
"""
return FlowControlEvent(loop=self.loop)
async def test_suspend_resume__initially_suspended(self):
flow_control = FlowControlEvent(initially_suspended=True)
queue = FlowControlQueue(flow_control=flow_control)
asyncio.ensure_future(self._resume_soon(0.2, flow_control))
time_now = monotonic()
await queue.put(1)
assert await queue.get() == 1
assert monotonic() - time_now > 0.1
async def test_clear__cancels_waiting_putter(self):
flow_control = FlowControlEvent(initially_suspended=False)
queue = ThrowableQueue(flow_control=flow_control, maxsize=1)
await queue.put(1)
async def clear_queue():
queue.clear()
asyncio.ensure_future(clear_queue())
with pytest.raises(asyncio.CancelledError):
await queue.put(1)
def FlowControlQueue(
self,
maxsize: int = None,
*,
clear_on_resume: bool = False,
loop: asyncio.AbstractEventLoop = None) -> ThrowableQueue:
"""Like :class:`asyncio.Queue`, but can be suspended/resumed."""
return ThrowableQueue(
maxsize=maxsize,
flow_control=FlowControlEvent(initially_suspended=False, loop=self.loop),
clear_on_resume=clear_on_resume,
loop=loop or self.loop,
)
async def test_suspend_resume(self):
flow_control = FlowControlEvent()
queue = FlowControlQueue(flow_control=flow_control)
flow_control.resume()
await queue.put(1)
flow_control.suspend()
asyncio.ensure_future(self._resume_soon(0.2, flow_control))
time_now = monotonic()
await queue.put(2)
assert monotonic() - time_now > 0.1
assert await queue.get() == 1
assert await queue.get() == 2
async def test_get__throw_first_in_buffer(self):
flow_control = FlowControlEvent(initially_suspended=False)
queue = ThrowableQueue(flow_control=flow_control)
await queue.put(1)
await queue.put(2)
assert await queue.get() == 1
assert await queue.get() == 2
await queue.put(3)
await queue.put(4)
await queue.throw(KeyError('foo'))
with pytest.raises(KeyError):
await queue.get()
assert await queue.get() == 3
assert await queue.get() == 4
await queue.throw(ValueError('bar'))
with pytest.raises(ValueError):
await queue.get()
async def test_throw__notify_pending_waiters(self):
flow_control = FlowControlEvent(initially_suspended=False)
queue = ThrowableQueue(flow_control=flow_control, maxsize=1)
raised = 0
async def waiter():
try:
await queue.get()
except KeyError:
nonlocal raised
raised += 1
queue._getters.append(done_future())
fut = asyncio.ensure_future(waiter())
await asyncio.sleep(0.01)
await queue.throw(KeyError())
await asyncio.gather(fut)
assert raised == 1
def flow_control(self) -> FlowControlEvent:
return FlowControlEvent(loop=self.loop)
async def test_suspend_resume__initially_resumed(self):
flow_control = FlowControlEvent(initially_suspended=False)
queue = FlowControlQueue(flow_control=flow_control)
await queue.put(1)
assert await queue.get() == 1
def test_loop__custom(self):
loop = Mock(name='loop')
assert FlowControlEvent(loop=loop).loop is loop
def test_loop__default(self):
assert FlowControlEvent().loop is None
def test_constructor(self):
assert not FlowControlEvent(initially_suspended=True).is_active()
assert FlowControlEvent(initially_suspended=False).is_active()
def test_get_nowait_empty(self):
flow_control = FlowControlEvent(initially_suspended=False)
queue = ThrowableQueue(flow_control=flow_control)
with pytest.raises(asyncio.QueueEmpty):
queue.get_nowait()
