[clock] Address PR feedback after the initial implementation of the centralised Clock

This commit is contained in:
Olivier Philippon
2022-05-19 09:55:38 +01:00
parent 4549f2d478
commit aed252874b
5 changed files with 39 additions and 47 deletions

View File

@@ -248,4 +248,4 @@ class Animator:
"""Get the current wall clock time, via the internal Timer."""
# N.B. We could remove this method and always call `self._timer.get_time()` internally,
# but it's handy to have in mocking situations
return _clock.get_time()
return _clock.get_time_no_wait()

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@@ -13,11 +13,11 @@ by mocking the few functions exposed by this module.
# 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:
def get_time(self) -> float:
return monotonic()
async def get_time(self) -> float:
return self.get_time_no_wait()
async def aget_time(self) -> float:
return self.get_time()
def get_time_no_wait(self) -> float:
return monotonic()
async def sleep(self, seconds: float) -> None:
await asyncio.sleep(seconds)
@@ -27,17 +27,17 @@ class _Clock:
_clock = _Clock()
def get_time() -> float:
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()
return _clock.get_time_no_wait()
async def aget_time() -> float:
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.
@@ -45,7 +45,7 @@ async def aget_time() -> float:
Returns:
float: the value (in fractional seconds) of a monotonic clock, i.e. a clock that cannot go backwards.
"""
return await _clock.aget_time()
return await _clock.get_time()
async def sleep(seconds: float) -> None:

View File

@@ -107,15 +107,15 @@ class Timer:
count = 0
_repeat = self._repeat
_interval = self._interval
start = await _clock.aget_time()
start = _clock.get_time_no_wait()
try:
while _repeat is None or count <= _repeat:
next_timer = start + ((count + 1) * _interval)
now = await _clock.aget_time()
now = await _clock.get_time()
if self._skip and next_timer < now:
count += 1
continue
now = await _clock.aget_time()
now = await _clock.get_time()
wait_time = max(0, next_timer - now)
if wait_time:
await _clock.sleep(wait_time)

View File

@@ -39,7 +39,7 @@ class Message:
self.sender = sender
self.name = camel_to_snake(self.__class__.__name__.replace("Message", ""))
self.time = _clock.get_time()
self.time = _clock.get_time_no_wait()
self._forwarded = False
self._no_default_action = False
self._stop_propagation = False

View File

@@ -83,9 +83,7 @@ class AppTest(App):
# run in this one - so the app must also be the active App in our current context:
self._set_active()
await clock_mock.move_clock_forward(
seconds=waiting_duration_after_initialisation
)
await clock_mock.advance_clock(waiting_duration_after_initialisation)
# make sure the App has entered its main loop at this stage:
assert self._driver is not None
@@ -96,12 +94,10 @@ class AppTest(App):
# so it can also do some time-based Textual stuff if it needs to:
yield clock_mock
await clock_mock.move_clock_forward(
seconds=waiting_duration_after_yield
)
await clock_mock.advance_clock(waiting_duration_after_yield)
# Make sure our screen is up to date before exiting the context manager,
# so tests using our `last_display_capture` for example can assert things on an up to date screen:
# Make sure our screen is up-to-date before exiting the context manager,
# so tests using our `last_display_capture` for example can assert things on a fully refreshed screen:
await self.force_full_screen_update()
# End of simulated time: we just shut down ourselves:
@@ -267,66 +263,62 @@ async def let_asyncio_process_some_events() -> None:
class ClockMock(_Clock):
# To avoid issues with floats we will store the current time as an integer internally.
# Tenths of microseconds should be a good enough granularity:
TIME_RESOLUTION = 10_000_000
def __init__(
self,
*,
ticks_granularity_fps: int = 60,
):
self._ticks_granularity_fps = ticks_granularity_fps
self._single_tick_duration = 1.0 / ticks_granularity_fps
self._start_time = self._current_time = None
self._pending_sleep_events: list[tuple[float, asyncio.Event]] = []
self._single_tick_duration = int(self.TIME_RESOLUTION / ticks_granularity_fps)
self._start_time: int = -1
self._current_time: int = -1
self._pending_sleep_events: list[tuple[int, asyncio.Event]] = []
def get_time(self) -> float:
if self._current_time is None:
def get_time_no_wait(self) -> float:
if self._current_time == -1:
self._start_clock()
# let's make the time advance _very_ slightly between 2 consecutive calls of this function,
# within the same order of magnitude than 2 consecutive calls to ` timer.monotonic()`:
self._current_time += 1.1e-06
return self._current_time
return self._current_time / self.TIME_RESOLUTION
async def sleep(self, seconds: float) -> None:
event = asyncio.Event()
target_event_monotonic_time = self._current_time + seconds
internal_waiting_duration = int(seconds * self.TIME_RESOLUTION)
target_event_monotonic_time = self._current_time + internal_waiting_duration
self._pending_sleep_events.append((target_event_monotonic_time, event))
# Ok, let's wait for this Event
# (which can only be "unlocked" by calls to `move_clock_forward()`)
# (which can only be "unlocked" by calls to `advance_clock()`)
await event.wait()
async def move_clock_forward(self, *, seconds: float) -> tuple[float, int]:
async def advance_clock(self, seconds: float) -> None:
"""
Artificially moves the Textual clock forward.
Artificially advance the Textual clock forward.
Args:
seconds: for each second we will artificially tick `ticks_granularity_fps` times
Returns:
tuple[float, int]: a tuple giving the new mocked current time and the number of sleep awaiters
that were unblocked by this call to `move_clock_forward`
"""
if self._current_time is None:
if self._current_time == -1:
self._start_clock()
ticks_count = ceil(seconds * self._ticks_granularity_fps)
activated_timers_count_total = 0
activated_timers_count_total = 0 # useful when debugging this code :-)
for tick_counter in range(ticks_count):
self._current_time += self._single_tick_duration
activated_timers_count = self._check_sleep_timers_to_activate()
activated_timers_count_total += activated_timers_count
# Let's give an opportunity to asyncio-related stuff to happen,
# now that we likely unlocked some occurrences of `await sleep(duration)`:
# Now that we likely unlocked some occurrences of `await sleep(duration)`,
# let's give an opportunity to asyncio-related stuff to happen:
if activated_timers_count:
await let_asyncio_process_some_events()
await let_asyncio_process_some_events()
return self._current_time, activated_timers_count_total
def _start_clock(self) -> None:
# N.B. `start_time` is not used, but it is useful to have when we set breakpoints there :-)
self._start_time = self._current_time = monotonic()
# N.B. `start_time` is not actually used, but it is useful to have when we set breakpoints there :-)
self._start_time = self._current_time = int(monotonic() * self.TIME_RESOLUTION)
def _check_sleep_timers_to_activate(self) -> int:
activated_timers_count = 0