def test_insertion_happens_as_expected(self):
# k = 5 and input values 1..10
k = 5
tree = BTree(k)
for i in range(1, 18):
tree.insert(i, None)
print(f'Inserted {i} into tree. root: {tree.get_root()}')
print('---')
result = tree.get_root()
self.assertTrue(result.keys == [9])
first_child_layer = result.children
self.assertTrue(len(first_child_layer) == 2)
self.assertTrue(first_child_layer[0].keys == [3, 6])
self.assertTrue(first_child_layer[1].keys == [12, 15])
for i in first_child_layer:
self.assertFalse(i.is_leaf)
# first 3 leafs
self.assertEquals([1, 2], first_child_layer[0].children[0].keys)
self.assertEquals([4, 5], first_child_layer[0].children[1].keys)
self.assertEquals([7, 8], first_child_layer[0].children[2].keys)
self.assertEquals(True, first_child_layer[0].children[0].is_leaf)
self.assertEquals(True, first_child_layer[0].children[1].is_leaf)
self.assertEquals(True, first_child_layer[0].children[2].is_leaf)
# last 3 leafs
self.assertEquals([10, 11], first_child_layer[1].children[0].keys)
self.assertEquals([13, 14], first_child_layer[1].children[1].keys)
self.assertEquals([16, 17], first_child_layer[1].children[2].keys)
self.assertEquals(True, first_child_layer[1].children[0].is_leaf)
self.assertEquals(True, first_child_layer[1].children[1].is_leaf)
self.assertEquals(True, first_child_layer[1].children[2].is_leaf)
def test_buggy_split(self):
# this didn't work before
tree = BTree(k=5)
root = BNode([3, 6])
root.add_child(BNode([1, 2]), BNode([4, 5]), BNode([7, 8, 9, 10]))
tree.root = root
print(f'result: {tree._split(11, root.children[2])}')
new_root = tree.get_root()
self.assertTrue([3, 6, 9] == new_root.keys)
self.assertTrue(len(new_root.children) == 4)
self.assertTrue([1, 2] == new_root.children[0].keys)
self.assertTrue([4, 5] == new_root.children[1].keys)
self.assertTrue([7, 8] == new_root.children[2].keys)
self.assertTrue([10, 11] == new_root.children[3].keys)
def test_split_balances_parents_parent(self):
# k = 5 and input values 1..5
k = 5
input_node = BNode([3, 6, 9, 12])
a = BNode([1, 2])
b = BNode([4, 5])
c = BNode([7, 8])
d = BNode([10, 11])
e = BNode([13, 14, 15, 16])
a.is_leaf = True
b.is_leaf = True
b.is_leaf = True
c.is_leaf = True
d.is_leaf = True
e.is_leaf = True
input_node.add_child(a, b, c, d, e)
tree = BTree(k)
tree._split(17, e)
result = tree.get_root()
self.assertTrue(len(result.keys) == 1)
self.assertTrue(result.keys == [9])
first_child_layer = result.children
self.assertTrue(len(first_child_layer) == 2)
self.assertTrue(first_child_layer[0].keys == [3, 6])
self.assertTrue(first_child_layer[1].keys == [12, 15])
for i in first_child_layer:
self.assertFalse(i.is_leaf)
# first 3 leafs
self.assertEquals([1, 2], first_child_layer[0].children[0].keys)
self.assertEquals([4, 5], first_child_layer[0].children[1].keys)
self.assertEquals([7, 8], first_child_layer[0].children[2].keys)
self.assertEquals(True, first_child_layer[0].children[0].is_leaf)
self.assertEquals(True, first_child_layer[0].children[1].is_leaf)
self.assertEquals(True, first_child_layer[0].children[2].is_leaf)
# last 3 leafs
self.assertEquals([10, 11], first_child_layer[1].children[0].keys)
self.assertEquals([13, 14], first_child_layer[1].children[1].keys)
self.assertEquals([16, 17], first_child_layer[1].children[2].keys)
self.assertEquals(True, first_child_layer[1].children[0].is_leaf)
self.assertEquals(True, first_child_layer[1].children[1].is_leaf)
self.assertEquals(True, first_child_layer[1].children[2].is_leaf)
def test_finds_proper_node_that_holds_our_key(self):
# k = 5 and input values 1..5
k = 3
tree = BTree(k)
for i in range(1, 32):
tree.insert(i, None)
root = tree.get_root()
self.assertTrue(
8 in tree._get_next_biggest_smallest_child(3, root).keys)
self.assertTrue(4 in tree._get_next_biggest_smallest_child(
3, root.children[0]).keys)
self.assertTrue(2 in tree._get_next_biggest_smallest_child(
3, root.children[0].children[0]).keys)
self.assertTrue(3 in tree._get_next_biggest_smallest_child(
3, root.children[0].children[0].children[0]).keys)