def test_insert_end(self):
"""Test insertion at the end of a list."""
linked_list = DoublyLinkedList()
new_node = Node(1)
linked_list.insert_end(new_node)
self.assertEqual(new_node, linked_list.first_node)
self.assertEqual(new_node, linked_list.last_node)
self.assertEqual(new_node.object, linked_list.first_node.object)
def test_remove(self):
"""Test removing of a node from a list."""
linked_list = DoublyLinkedList()
first_node = Node(1)
linked_list.insert_beginning(first_node)
node_to_remove = Node(2)
linked_list.insert_after(first_node, node_to_remove)
linked_list.insert_end(Node(3))
linked_list.remove(node_to_remove)
self.assertListItemsEqual(linked_list, [1, 3])
def __init__(self, cache_size):
"""Initialize cache.
:param cache_size: Maximum cache size.
"""
super(LruCache, self).__init__()
self._size = cache_size
self._age_cnt = 0
self._storage = {}
# linked list is used to store items ordered by age
# this allows significantly decrease cost of searching LRU item
self._items_sorted_by_age = DoublyLinkedList()
def test_insert_before(self):
"""Test insertion before a node."""
linked_list = DoublyLinkedList()
linked_list.insert_beginning(Node(1))
node = linked_list.first_node
for i in range(2, 4):
new_node = Node(i)
linked_list.insert_before(node, new_node)
node = new_node
self.assertListItemsEqual(linked_list, [3, 2, 1])
new_node = Node(10)
linked_list.insert_before(linked_list.last_node, new_node)
self.assertListItemsEqual(linked_list, [3, 2, 10, 1])
def test_insert_beginning(self):
"""Test insertion at the beginning of a list."""
linked_list = DoublyLinkedList()
first_node = Node(1)
linked_list.insert_beginning(first_node)
self.assertEqual(first_node, linked_list.first_node)
self.assertEqual(first_node, linked_list.last_node)
self.assertEqual(first_node.object, linked_list.first_node.object)
next_first_node = Node(2)
linked_list.insert_beginning(next_first_node)
self.assertEqual(next_first_node, linked_list.first_node)
self.assertEqual(first_node, linked_list.last_node)
def test_creation_from_list(self):
"""Test list creation."""
linked_list = DoublyLinkedList()
self.assertIsNone(linked_list.first_node)
self.assertIsNone(linked_list.last_node)