def get_backend_manager(self):
"""Return the database backend manager.
.. note:: this is not the actual backend, but a manager class that is necessary for database operations that
go around the actual ORM. For example when the schema version has not yet been validated.
:return: the database backend manager
:rtype: :class:`aiida.backend.manager.BackendManager`
"""
if self._backend_manager is None:
from aiida.backends import get_backend_manager
self._backend_manager = get_backend_manager(self.get_profile().database_backend)
return self._backend_manager
def _load_backend(self, schema_check: bool = True) -> 'Backend':
"""Load the backend for the currently configured profile and return it.
.. note:: this will reconstruct the `Backend` instance in `self._backend` so the preferred method to load the
backend is to call `get_backend` which will create it only when not yet instantiated.
:param schema_check: force a database schema check if the database environment has not yet been loaded
:return: the database backend
"""
from aiida.backends import BACKEND_DJANGO, BACKEND_SQLA
from aiida.common import ConfigurationError, InvalidOperation
from aiida.common.log import configure_logging
from aiida.manage import configuration
profile = self.get_profile()
if profile is None:
raise ConfigurationError(
'Could not determine the current profile. Consider loading a profile using `aiida.load_profile()`.'
)
if configuration.BACKEND_UUID is not None and configuration.BACKEND_UUID != profile.uuid:
raise InvalidOperation(
'cannot load backend because backend of another profile is already loaded'
)
# Do NOT reload the backend environment if already loaded, simply reload the backend instance after
if configuration.BACKEND_UUID is None:
from aiida.backends import get_backend_manager
backend_manager = get_backend_manager(profile.database_backend)
backend_manager.load_backend_environment(
profile, validate_schema=schema_check)
configuration.BACKEND_UUID = profile.uuid
backend_type = profile.database_backend
# Can only import the backend classes after the backend has been loaded
if backend_type == BACKEND_DJANGO:
from aiida.orm.implementation.django.backend import DjangoBackend
self._backend = DjangoBackend()
elif backend_type == BACKEND_SQLA:
from aiida.orm.implementation.sqlalchemy.backend import SqlaBackend
self._backend = SqlaBackend()
# Reconfigure the logging with `with_orm=True` to make sure that profile specific logging configuration options
# are taken into account and the `DbLogHandler` is configured.
configure_logging(with_orm=True)
return self._backend
def get_backend_manager(self) -> 'BackendManager':
"""Return the database backend manager.
.. note:: this is not the actual backend, but a manager class that is necessary for database operations that
go around the actual ORM. For example when the schema version has not yet been validated.
:return: the database backend manager
"""
from aiida.backends import get_backend_manager
from aiida.common import ConfigurationError
if self._backend_manager is None:
self._load_backend()
profile = self.get_profile()
if profile is None:
raise ConfigurationError(
'Could not determine the current profile. Consider loading a profile using `aiida.load_profile()`.'
)
self._backend_manager = get_backend_manager(
profile.database_backend)
return self._backend_manager