def get_nearest_prev_point(self, point):
"""Return the largest point < some arbitrary point."""
if self.is_on_sequence(point):
return self.get_prev_point(point)
p_iso_point = point_parse(point.value)
prev_cycle_point = None
for recurrence_iso_point in self.recurrence:
# Is recurrence point greater than arbitrary point?
if recurrence_iso_point > p_iso_point:
break
recurrence_cycle_point = ISO8601Point(str(recurrence_iso_point))
if self.exclusions and recurrence_cycle_point in self.exclusions:
break
prev_cycle_point = recurrence_cycle_point
if prev_cycle_point is None:
return None
if prev_cycle_point == point:
raise SequenceDegenerateError(self.recurrence,
WorkflowSpecifics.DUMP_FORMAT,
prev_cycle_point, point)
# Check all exclusions
if self.exclusions and prev_cycle_point in self.exclusions:
return self.get_prev_point(prev_cycle_point)
return prev_cycle_point
def get_next_point_on_sequence(self, point):
"""Return the on-sequence point > point assuming that point is
on-sequence, or None if out of bounds."""
result = None
next_point = self.recurrence.get_next(point_parse(point.value))
if next_point:
result = ISO8601Point(str(next_point))
if result == point:
raise SequenceDegenerateError(self.recurrence,
WorkflowSpecifics.DUMP_FORMAT,
point, result)
# Check it is in the exclusions list now
if result and result in self.exclusions:
return self.get_next_point_on_sequence(result)
return result
def _check_and_cache_next_point(self, point, next_point):
"""Verify and cache the get_next_point return info."""
# Verify next_point != point.
if next_point == point:
raise SequenceDegenerateError(self.recurrence,
WorkflowSpecifics.DUMP_FORMAT,
next_point, point)
# Cache the answer for point -> next_point.
if (len(self._cached_next_point_values) > self._MAX_CACHED_POINTS):
self._cached_next_point_values.popitem()
self._cached_next_point_values[point.value] = next_point.value
# Cache next_point as a valid starting point for this recurrence.
if (len(self._cached_next_point_values) > self._MAX_CACHED_POINTS):
self._cached_recent_valid_points.pop(0)
self._cached_recent_valid_points.append(next_point)
def get_prev_point(self, point):
"""Return the previous point < point, or None if out of bounds."""
# may be None if out of the recurrence bounds
res = None
prev_point = self.recurrence.get_prev(point_parse(point.value))
if prev_point:
res = ISO8601Point(str(prev_point))
if res == point:
raise SequenceDegenerateError(self.recurrence,
WorkflowSpecifics.DUMP_FORMAT,
res, point)
# Check if res point is in the list of exclusions
# If so, check the previous point by recursion.
# Once you have found a point that is *not* in the exclusion
# list, you can return it.
if self.exclusions and res in self.exclusions:
return self.get_prev_point(res)
return res
