The last sign of life of something which announces itself.
Whatever announces itself periodically -- a page displaying the traces, the wx interface, any other interlocutor -- is known to be there by the freshness of its last sign of life, and by nothing else. A crash, a kill or a closed tab stops the signs: the silence is the answer. Nothing has to announce a death nobody is left alive to announce.
>>> beat = sppasHeartbeat(max_age=90.)
>>> beat.ping()
>>> beat.alive()
> True
Create a sppasHeartbeat instance.
def __init__(self, max_age: float=40.0):
"""Create a sppasHeartbeat instance.
:param max_age: (float) Age of the last sign of life, in seconds,
above which the interlocutor is considered gone.
"""
self.__max_age = float(max_age)
self.__seen = None
self.__lock = threading.Lock()
Return the age above which the interlocutor is considered gone.
def get_max_age(self) -> float:
"""Return the age above which the interlocutor is considered gone."""
return self.__max_age
Store the time of a sign of life.
def ping(self) -> None:
"""Store the time of a sign of life."""
with self.__lock:
self.__seen = time.time()
Drop the last sign of life: the interlocutor announced its end.
def forget(self) -> None:
"""Drop the last sign of life: the interlocutor announced its end."""
with self.__lock:
self.__seen = None
Return True if the last sign of life is recent enough.
def alive(self, max_age: float | None=None) -> bool:
"""Return True if the last sign of life is recent enough.
:param max_age: (float) Override the age given at creation
:return: (bool)
"""
if max_age is None:
max_age = self.__max_age
with self.__lock:
if self.__seen is None:
return False
return time.time() - self.__seen < max_age
Return the age of the last sign of life, or None.
def age(self) -> float | None:
"""Return the age of the last sign of life, or None."""
with self.__lock:
if self.__seen is None:
return None
return time.time() - self.__seen