def decrease(counter_name, allow_negative=False):
"""
Decrease the counter value in the database.
If the counter does not exist yet, create the counter.
Also checks whether the counter is allowed to become negative.
:param counter_name: The name/identifier of the counter
:param allow_negative: Whether the counter can become negative
:return: the new integer value of the counter
"""
counter = EventCounter.query.filter_by(counter_name=counter_name).first()
if not counter:
counter = EventCounter(counter_name, 0)
counter.save()
counter.decrease(allow_negative)
return counter.counter_value
def decrease(counter_name, allow_negative=False):
"""
Decrease the counter value in the database.
If the counter does not exist yet, create the counter.
Also checks whether the counter is allowed to become negative.
:param counter_name: The name/identifier of the counter
:param allow_negative: Whether the counter can become negative. Note that even if this flag is not set,
the counter may become negative due to concurrent queries.
:return: None
"""
node = get_privacyidea_node()
counter = EventCounter.query.filter_by(counter_name=counter_name,
node=node).first()
if not counter:
counter = EventCounter(counter_name, 0, node=node)
counter.save()
# We are allowed to decrease the current counter object only if the overall
# counter value is positive (because individual rows may be negative then),
# or if we allow negative values. Otherwise, we need to reset all rows of all nodes.
if read(counter_name) > 0 or allow_negative:
counter.decrease()
else:
_reset_counter_on_all_nodes(counter_name)