File size: 1,809 Bytes
5b76e0f | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | import asyncio
from time import monotonic
"""
A module that serves as the single source of truth for everything time-related in a Textual app.
Having this logic centralised makes it easier to simulate time in integration tests,
by mocking the few functions exposed by this module.
"""
# N.B. This class and its singleton instance have to be hidden APIs because we want to be able to mock time,
# even for Python modules that imported functions such as `get_time` *before* we mocked this internal _Clock.
# (so mocking public APIs such as `get_time` wouldn't affect direct references to then that were done during imports)
class _Clock:
async def get_time(self) -> float:
return self.get_time_no_wait()
def get_time_no_wait(self) -> float:
return monotonic()
async def sleep(self, seconds: float) -> None:
await asyncio.sleep(seconds)
# That's our target for mocking time! :-)
_clock = _Clock()
def get_time_no_wait() -> float:
"""
Get the current wall clock time.
Returns:
float: the value (in fractional seconds) of a monotonic clock, i.e. a clock that cannot go backwards.
"""
return _clock.get_time_no_wait()
async def get_time() -> float:
"""
Asynchronous version of `get_time`. Useful in situations where we want asyncio to be
able to "do things" elsewhere right before we fetch the time.
Returns:
float: the value (in fractional seconds) of a monotonic clock, i.e. a clock that cannot go backwards.
"""
return await _clock.get_time()
async def sleep(seconds: float) -> None:
"""
Coroutine that completes after a given time (in seconds).
Args:
seconds (float): the duration we should wait for before unblocking the awaiter
"""
return await _clock.sleep(seconds)
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