def __init__(self, db_file: bin_py.BinFile, row_length: int = 0, filename: str = ""):
self.file = bin_py.BinFile("rollback_journal.log")
if filename != "":
self.file = bin_py.BinFile(filename)
self.first_rollback_index = 16
self.block_count = 0
self.db_file = db_file
self.block_size = 0
if row_length:
self.row_length = row_length
self.block_size = 12 + 512 * row_length
def read_file(self) -> typing.NoReturn:
signature_len = self.file.read_integer(0, 1)
signature_result = self.file.read_str(1, signature_len)
if self.signature != signature_result:
raise exception.WrongFileFormat()
self.tables_count = self.file.read_integer(14, 2)
metafiles_list = self.__get_files_by_mask("*.table_meta")
for metafile in metafiles_list:
table_obj = Table()
table_obj.metafile_name = metafile
table_obj.metafile = bin_py.BinFile(table_obj.metafile_name)
table_obj.metafile.open("r+")
table_obj.storage_name = table_obj.metafile_name.replace(".table_meta", ".storage")
table_obj.storage_file = bin_py.BinFile(table_obj.storage_name)
table_obj.storage_file.open("r+")
table_obj.read_file()
table_obj.open_transaction_registry()
self.tables.append(table_obj)
def __init__(self, create_default_file: bool = True, db_filename: str = ""):
self.tables_count = 0
self.signature = "#VDBSignature"
self.tables = []
self.meta_db_filename = ""
self.file = None
if create_default_file:
self.meta_db_filename = "zhavoronkov.vdb.db_meta"
self.file = bin_py.BinFile(self.meta_db_filename)
self.file.open("w+")
self.write_file()
self.write_table_count(self.tables_count)
elif db_filename != "":
self.meta_db_filename = db_filename
if os.path.isfile(self.meta_db_filename + ".db_meta"):
self.connect_to_db(self.meta_db_filename + ".db_meta")
else:
self.file = bin_py.BinFile(self.meta_db_filename + ".db_meta")
self.file.open("w+")
self.write_file()
self.write_table_count(self.tables_count)
def create_table(self, table_name: str, fields: typing.Dict, is_versioning: bool = False) -> typing.List:
new_table = Table()
new_table.name = table_name
new_table.metafile_name = self.meta_db_filename + "_"+ new_table.name + ".table_meta"
new_table.metafile = bin_py.BinFile(new_table.metafile_name)
new_table.metafile.open("w+")
new_table.storage_name = self.meta_db_filename + "_" + table_name + ".storage"
new_table.storage_file = bin_py.BinFile(new_table.storage_name)
new_table.storage_file.open("w+")
if is_versioning:
new_table.is_versioning = True
new_table.fill_table_fields(fields)
new_table.calc_row_size()
new_table.create_transaction_registry()
new_table.write_file()
self.tables.append(new_table)
self.tables_count += 1
self.write_table_count(self.tables_count)
table_index = self.tables.index(new_table)
self.tables[table_index].create_block()
return self.tables[table_index]
def connect_to_db(self, filename: str) -> typing.NoReturn:
file = bin_py.BinFile(filename)
if not file.is_file_exist():
raise exception.DBFileNotExists()
self.file = file
self.file.open("r+")
signature_len = self.file.read_integer(0, 1)
signature_str = self.file.read_str(1, signature_len)
if signature_str != self.signature:
raise exception.WrongSignature()
self.read_file()
if self.__check_journal():
self.wide_rollback()
def test_binfile():
test_file = bin_py.BinFile("test.bin")
test_file.open("w+")
test_file.write_integer(22, 0, 1)
test_file.write_bool(False, 1)
test_file.write_str("vadik", 2, 32)
test_file.write_float(2.006, 35)
test_file.write_fixed_integer(877776, 44)
test_file.write_long_long(2036854775807, 48)
result_int = test_file.read_integer(0, 1)
result_bool = test_file.read_bool(1)
result_str = test_file.read_str(2, 32)
result_float = test_file.read_float(35)
result_fixed_int = test_file.read_fixed_integer(44)
result_long_long = test_file.read_long_long(48)
test_file.close()
os.remove("test.bin")
assert result_int == 22
assert not result_bool
assert result_str == "vadik"
assert result_float == 2.006
assert result_fixed_int == 877776
assert result_long_long == 2036854775807
def __init__(self, table: Table):
self.table = table
self.registry_filename = f"transaction_{self.table.name}.rg"
self.registry_file = bin_py.BinFile(self.registry_filename)
self.row_size = 20
self.rows_count = 0