def get_item_assigned(self, index):
try:
item_assigned = self.repo.event_store.get_event(
originator_id=self.id, position=index)
except IndexError as e:
raise ArrayIndexError(e)
else:
return item_assigned
def __setitem__(self, index, item):
"""
Sets item in array, at given index.
Won't overrun the end of the array, because
the position is fixed to be less than base_size.
"""
size = self.repo.array_size
if size and index >= size:
raise ArrayIndexError("Index is {}, but size is {}".format(
index, size))
event = ItemAssigned(originator_id=self.id, index=index, item=item)
publish([event])
def __getitem__(self, item):
"""
Returns item at index, or items in slice.
"""
assert isinstance(item, (six.integer_types, slice))
array_size = self.repo.array_size
if isinstance(item, six.integer_types):
if item < 0:
index = array_size + item
if index < 0:
raise ArrayIndexError(
"Array index out of range: {}".format(item))
else:
index = item
event = self.get_item_assigned(index)
assert isinstance(event, ItemAssigned)
return event.item
elif isinstance(item, slice):
assert item.step in (None, 1), "Slice stepping not supported, yet"
if item.start is None:
start_index = 0
elif item.start < 0:
start_index = max(array_size + item.start, 0)
else:
start_index = item.start
if not isinstance(item.stop, six.integer_types):
stop_index = array_size
elif item.stop < 0:
stop_index = array_size + item.stop
else:
stop_index = item.stop
if stop_index is not None:
if stop_index <= 0:
return []
# Avoid passing massive integers into the database.
if array_size is not None:
stop_index = min(stop_index, self.repo.array_size)
items_assigned = self.get_items_assigned(stop_index=stop_index,
start_index=start_index)
items_dict = {
str(i.originator_version): i.item
for i in items_assigned
}
items = [
items_dict.get(str(i)) for i in range(start_index, stop_index)
]
return items
def calc_required_height(self, n, size):
if size <= 0:
raise ValueError("Size must be greater than 0")
capacity = size**size
if n + 1 > capacity:
raise ArrayIndexError("Contents can't be greater than capacity")
if n == 0 or n == 1:
return 1
min_capacity = max(int(size), int(n + 1))
required_height = log(min_capacity, int(size))
# Quash numerical error before calling ceil.
# - this is occasionally required, for example
# with base size of 1000 numerical error
# makes the required height one greater
# than the correct value, which causes
# an index error when assigning apex
# ID to the root sequence.
required_height = round(required_height, 10)
return int(ceil(required_height))