def __check_state_base(self, opname):
if self._state is TransactionState.COMMITTED:
raise errors.InterfaceError(
f'cannot {opname}; the transaction is already committed')
if self._state is TransactionState.ROLLEDBACK:
raise errors.InterfaceError(
f'cannot {opname}; the transaction is already rolled back')
if self._state is TransactionState.FAILED:
raise errors.InterfaceError(
f'cannot {opname}; the transaction is in error state')
async def __aenter__(self):
if self._managed:
raise errors.InterfaceError(
'cannot enter context: already in an `async with` block')
self._managed = True
await self.start()
return self
async def _ensure_transaction(self):
if not self._managed:
raise errors.InterfaceError(
"Only managed retriable transactions are supported. "
"Use `async with transaction:`")
if not self.__started:
self.__started = True
if self._connection.is_closed():
await self._connection.connect(
single_attempt=self.__iteration != 0)
await self.start()
def _make_start_query(self):
self.__check_state_base('start')
if self._state is TransactionState.STARTED:
raise errors.InterfaceError(
'cannot start; the transaction is already started')
return self._make_start_query_inner()
def __check_state(self, opname):
if self._state is not TransactionState.STARTED:
if self._state is TransactionState.NEW:
raise errors.InterfaceError(
f'cannot {opname}; the transaction is not yet started')
self.__check_state_base(opname)
async def rollback(self) -> None:
if self._managed:
raise errors.InterfaceError(
'cannot manually rollback from within an `async with` block')
await self._rollback()
async def commit(self) -> None:
if self._managed:
raise errors.InterfaceError(
'cannot manually commit from within an `async with` block')
await self._commit()