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|
import importlib
import logging
from django.db.backends.postgresql.base import ( # isort:skip
DatabaseWrapper as Psycopg2DatabaseWrapper,
)
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
logger = logging.getLogger(__name__)
def backend():
"""Gets the base class for the custom database back-end.
This should be the Django PostgreSQL back-end. However,
some people are already using a custom back-end from
another package. We are nice people and expose an option
that allows them to configure the back-end we base upon.
As long as the specified base eventually also has
the PostgreSQL back-end as a base, then everything should
work as intended.
"""
base_class_name = getattr(
settings,
"TIMESCALE_DB_BACKEND_BASE",
"django.contrib.gis.db.backends.postgis",
)
base_class_module = importlib.import_module(base_class_name + ".base")
base_class = getattr(base_class_module, "DatabaseWrapper", None)
if not base_class:
raise ImproperlyConfigured(
(
"'%s' is not a valid database back-end."
" The module does not define a DatabaseWrapper class."
" Check the value of TIMESCALE_EXTRA_DB_BACKEND_BASE."
)
% base_class_name
)
if isinstance(base_class, Psycopg2DatabaseWrapper):
raise ImproperlyConfigured(
(
"'%s' is not a valid database back-end."
" It does inherit from the PostgreSQL back-end."
" Check the value of TIMESCALE_EXTRA_DB_BACKEND_BASE."
)
% base_class_name
)
return base_class
def schema_editor():
"""Gets the base class for the schema editor.
We have to use the configured base back-end's schema editor for
this.
"""
return backend().SchemaEditorClass
def introspection():
"""Gets the base class for the introspection class.
We have to use the configured base back-end's introspection class
for this.
"""
return backend().introspection_class
def operations():
"""Gets the base class for the operations class.
We have to use the configured base back-end's operations class for
this.
"""
return backend().ops_class
|
