def insert_record(table_name, attributes):
RecordManager.set_file_dir('schema/tables/' + table_name + '/')
metadata = load_metadata()
position = RecordManager.insert(table_name,
metadata.tables[table_name].fmt,
tuple(attributes))
for index_name, index in metadata.tables[table_name].indexes.items():
file_path = RecordManager.file_dir + index_name + '.index'
fmt = ''.join(metadata.tables[table_name].columns[column].fmt
for column in index.columns)
manager = IndexManager(file_path, fmt)
key_pos = list(metadata.tables[table_name].columns.keys()).index(
index.columns[0])
key_list = list()
key_list.append(attributes[key_pos])
try:
manager.insert(
key_list, position) # index can be set on single attribute
manager.dump_header()
except ValueError: # duplicated key, the inserted record should be deleted
RecordManager.delete(table_name,
metadata.tables[table_name].fmt,
with_index=True,
record_offset=position)
raise
def test_find_all(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
manager.insert([42, 7.6], 212)
manager.insert([233, 66.6], 7)
results = manager.find([42, 7.6])
self.assertEqual(sorted(results), [212, 518])
def test_shrinking_delete(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
manager.insert([233, 66.6], 7)
manager.delete([233, 66.6])
manager.delete([42, 7.6])
self.assertEqual(manager.root, 0)
self.assertEqual(manager.first_deleted_block, 1)
self.assertEqual(manager.total_blocks, 2)
def test_initial_insert(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
self.assertEqual(manager.root, 1)
self.assertEqual(manager.first_deleted_block, 0)
self.assertEqual(manager.total_blocks, 2)
block = BufferManager().get_file_block('spam', 1)
Node = manager.Node
node = Node.frombytes(block.read())
self.assertEqual(node.is_leaf, True)
self.assertEqual(node.keys, [(42, 7.6)])
self.assertEqual(node.children, [518, 0])
def test_multiple_delete(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
manager.insert([42, 7.6], 212)
manager.insert([233, 66.6], 7)
deleted_num = manager.delete([42, 7.6])
self.assertEqual(deleted_num, 2)
self.assertEqual(manager.root, 1)
self.assertEqual(manager.first_deleted_block, 0)
self.assertEqual(manager.total_blocks, 2)
block = BufferManager().get_file_block('spam', 1)
Node = manager.Node
node = Node.frombytes(block.read())
self.assertEqual(node.is_leaf, True)
self.assertEqual(node.keys, [(233, 66.6)])
self.assertEqual(node.children, [7, 0])
def test_persistence(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
manager.insert([233, 66.6], 7)
manager.delete([42, 7.6])
manager.dump_header()
manager._manager.flush_all()
del manager
manager = IndexManager('spam', '<id')
self.assertEqual(manager.root, 1)
self.assertEqual(manager.first_deleted_block, 0)
self.assertEqual(manager.total_blocks, 2)
block = BufferManager().get_file_block('spam', 1)
Node = manager.Node
node = Node.frombytes(block.read())
self.assertEqual(node.is_leaf, True)
self.assertEqual(node.keys, [(233, 66.6)])
self.assertEqual(node.children, [7, 0])
def create_index(table_name, index_name, column_name):
RecordManager.set_file_dir('schema/tables/' + table_name + '/')
offset = -1
metadata = load_metadata()
metadata.add_index(table_name, index_name, column_name)
records = RecordManager.select(table_name,
metadata.tables[table_name].fmt,
with_index=False,
conditions={})
file_path = RecordManager.file_dir + index_name + '.index'
table_target = metadata.tables[table_name]
fmt = ''.join(table_target.columns[column].fmt
for column in table_target.indexes[index_name].columns)
manager = IndexManager(file_path, fmt)
key_pos = list(
metadata.tables[table_name].columns.keys()).index(column_name)
for record in records:
key_list = list()
key_list.append(record[key_pos])
offset += 1
manager.insert(key_list, offset)
metadata.dump()
manager.dump_header()
class TestAdjustingDeletion(unittest.TestCase):
def setUp(self):
try:
os.remove('spam')
except FileNotFoundError:
pass
self.manager = IndexManager('spam', '<i')
self.manager.Node.n = 4
def tearDown(self):
try:
os.remove('spam')
except FileNotFoundError:
pass
del self.manager
def test_delete_transfer(self):
self.manager.Node.n = 4
self.manager.insert(2, 32)
self.manager.insert(24, 67)
self.manager.insert(7, 87)
self.manager.insert(15, 45)
self.manager.insert(11, 43)
self.manager.delete(24)
self.assertEqual(self.manager.root, 3)
Node = self.manager.Node
root_block = BufferManager().get_file_block(self.manager.index_file_path, self.manager.root)
root_node = Node.frombytes(root_block.read())
self.assertEqual(root_node.keys, [(11,)])
left_block = BufferManager().get_file_block(self.manager.index_file_path, 1)
left_node = Node.frombytes(left_block.read())
self.assertEqual(left_node.keys, _convert_to_tuple_list([2, 7]))
self.assertEqual(left_node.children, [32, 87, 2])
right_block = BufferManager().get_file_block(self.manager.index_file_path, 2)
right_node = Node.frombytes(right_block.read())
self.assertEqual(right_node.keys, _convert_to_tuple_list([11, 15]))
self.assertEqual(right_node.children, [43, 45, 0])
def test_delete_fuse(self):
self.manager.Node.n = 4
self.manager.insert(2, 32)
self.manager.insert(24, 67)
self.manager.insert(7, 87)
self.manager.insert(15, 45)
self.manager.insert(11, 43)
self.manager.delete(24)
self.manager.delete(11)
self.assertEqual(self.manager.root, 1)
Node = self.manager.Node
root_block = BufferManager().get_file_block(self.manager.index_file_path, self.manager.root)
root_node = Node.frombytes(root_block.read())
self.assertEqual(root_node.is_leaf, True)
self.assertEqual(root_node.keys, _convert_to_tuple_list([2, 7, 15]))
self.assertEqual(root_node.children, [32, 87, 45, 0])
def test_unsuccessful_delete(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
manager.insert([233, 66.6], 7)
with self.assertRaises(ValueError):
manager.delete([2, 3.3])
def test_find_not_exists(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
manager.insert([233, 66.6], 7)
result = manager.find([233, 7.6])
self.assertEqual(next(result), ((233, 66.6), 7))
def test_insert_duplicate(self):
manager = IndexManager('spam', '<id')
manager.insert([42, 7.6], 518)
with self.assertRaises(ValueError):
manager.insert([42, 7.6], 233)