284 lines
9.1 KiB
Python
284 lines
9.1 KiB
Python
import pkgutil
|
|
from importlib import import_module
|
|
|
|
from django.conf import settings
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
|
|
# For backwards compatibility with Django < 3.2
|
|
from django.utils.connection import ConnectionDoesNotExist # NOQA: F401
|
|
from django.utils.connection import BaseConnectionHandler
|
|
from django.utils.functional import cached_property
|
|
from django.utils.module_loading import import_string
|
|
|
|
DEFAULT_DB_ALIAS = "default"
|
|
DJANGO_VERSION_PICKLE_KEY = "_django_version"
|
|
|
|
|
|
class Error(Exception):
|
|
pass
|
|
|
|
|
|
class InterfaceError(Error):
|
|
pass
|
|
|
|
|
|
class DatabaseError(Error):
|
|
pass
|
|
|
|
|
|
class DataError(DatabaseError):
|
|
pass
|
|
|
|
|
|
class OperationalError(DatabaseError):
|
|
pass
|
|
|
|
|
|
class IntegrityError(DatabaseError):
|
|
pass
|
|
|
|
|
|
class InternalError(DatabaseError):
|
|
pass
|
|
|
|
|
|
class ProgrammingError(DatabaseError):
|
|
pass
|
|
|
|
|
|
class NotSupportedError(DatabaseError):
|
|
pass
|
|
|
|
|
|
class DatabaseErrorWrapper:
|
|
"""
|
|
Context manager and decorator that reraises backend-specific database
|
|
exceptions using Django's common wrappers.
|
|
"""
|
|
|
|
def __init__(self, wrapper):
|
|
"""
|
|
wrapper is a database wrapper.
|
|
|
|
It must have a Database attribute defining PEP-249 exceptions.
|
|
"""
|
|
self.wrapper = wrapper
|
|
|
|
def __enter__(self):
|
|
pass
|
|
|
|
def __exit__(self, exc_type, exc_value, traceback):
|
|
if exc_type is None:
|
|
return
|
|
for dj_exc_type in (
|
|
DataError,
|
|
OperationalError,
|
|
IntegrityError,
|
|
InternalError,
|
|
ProgrammingError,
|
|
NotSupportedError,
|
|
DatabaseError,
|
|
InterfaceError,
|
|
Error,
|
|
):
|
|
db_exc_type = getattr(self.wrapper.Database, dj_exc_type.__name__)
|
|
if issubclass(exc_type, db_exc_type):
|
|
dj_exc_value = dj_exc_type(*exc_value.args)
|
|
# Only set the 'errors_occurred' flag for errors that may make
|
|
# the connection unusable.
|
|
if dj_exc_type not in (DataError, IntegrityError):
|
|
self.wrapper.errors_occurred = True
|
|
raise dj_exc_value.with_traceback(traceback) from exc_value
|
|
|
|
def __call__(self, func):
|
|
# Note that we are intentionally not using @wraps here for performance
|
|
# reasons. Refs #21109.
|
|
def inner(*args, **kwargs):
|
|
with self:
|
|
return func(*args, **kwargs)
|
|
|
|
return inner
|
|
|
|
|
|
def load_backend(backend_name):
|
|
"""
|
|
Return a database backend's "base" module given a fully qualified database
|
|
backend name, or raise an error if it doesn't exist.
|
|
"""
|
|
# This backend was renamed in Django 1.9.
|
|
if backend_name == "django.db.backends.postgresql_psycopg2":
|
|
backend_name = "django.db.backends.postgresql"
|
|
|
|
try:
|
|
return import_module("%s.base" % backend_name)
|
|
except ImportError as e_user:
|
|
# The database backend wasn't found. Display a helpful error message
|
|
# listing all built-in database backends.
|
|
import django.db.backends
|
|
|
|
builtin_backends = [
|
|
name
|
|
for _, name, ispkg in pkgutil.iter_modules(django.db.backends.__path__)
|
|
if ispkg and name not in {"base", "dummy"}
|
|
]
|
|
if backend_name not in ["django.db.backends.%s" % b for b in builtin_backends]:
|
|
backend_reprs = map(repr, sorted(builtin_backends))
|
|
raise ImproperlyConfigured(
|
|
"%r isn't an available database backend or couldn't be "
|
|
"imported. Check the above exception. To use one of the "
|
|
"built-in backends, use 'django.db.backends.XXX', where XXX "
|
|
"is one of:\n"
|
|
" %s" % (backend_name, ", ".join(backend_reprs))
|
|
) from e_user
|
|
else:
|
|
# If there's some other error, this must be an error in Django
|
|
raise
|
|
|
|
|
|
class ConnectionHandler(BaseConnectionHandler):
|
|
settings_name = "DATABASES"
|
|
# Connections needs to still be an actual thread local, as it's truly
|
|
# thread-critical. Database backends should use @async_unsafe to protect
|
|
# their code from async contexts, but this will give those contexts
|
|
# separate connections in case it's needed as well. There's no cleanup
|
|
# after async contexts, though, so we don't allow that if we can help it.
|
|
thread_critical = True
|
|
|
|
def configure_settings(self, databases):
|
|
databases = super().configure_settings(databases)
|
|
if databases == {}:
|
|
databases[DEFAULT_DB_ALIAS] = {"ENGINE": "django.db.backends.dummy"}
|
|
elif DEFAULT_DB_ALIAS not in databases:
|
|
raise ImproperlyConfigured(
|
|
f"You must define a '{DEFAULT_DB_ALIAS}' database."
|
|
)
|
|
elif databases[DEFAULT_DB_ALIAS] == {}:
|
|
databases[DEFAULT_DB_ALIAS]["ENGINE"] = "django.db.backends.dummy"
|
|
|
|
# Configure default settings.
|
|
for conn in databases.values():
|
|
conn.setdefault("ATOMIC_REQUESTS", False)
|
|
conn.setdefault("AUTOCOMMIT", True)
|
|
conn.setdefault("ENGINE", "django.db.backends.dummy")
|
|
if conn["ENGINE"] == "django.db.backends." or not conn["ENGINE"]:
|
|
conn["ENGINE"] = "django.db.backends.dummy"
|
|
conn.setdefault("CONN_MAX_AGE", 0)
|
|
conn.setdefault("CONN_HEALTH_CHECKS", False)
|
|
conn.setdefault("OPTIONS", {})
|
|
conn.setdefault("TIME_ZONE", None)
|
|
for setting in ["NAME", "USER", "PASSWORD", "HOST", "PORT"]:
|
|
conn.setdefault(setting, "")
|
|
|
|
test_settings = conn.setdefault("TEST", {})
|
|
default_test_settings = [
|
|
("CHARSET", None),
|
|
("COLLATION", None),
|
|
("MIGRATE", True),
|
|
("MIRROR", None),
|
|
("NAME", None),
|
|
]
|
|
for key, value in default_test_settings:
|
|
test_settings.setdefault(key, value)
|
|
return databases
|
|
|
|
@property
|
|
def databases(self):
|
|
return self.settings
|
|
|
|
def create_connection(self, alias):
|
|
db = self.settings[alias]
|
|
backend = load_backend(db["ENGINE"])
|
|
return backend.DatabaseWrapper(db, alias)
|
|
|
|
def close_all(self):
|
|
for alias in self:
|
|
try:
|
|
connection = getattr(self._connections, alias)
|
|
except AttributeError:
|
|
continue
|
|
connection.close()
|
|
|
|
|
|
class ConnectionRouter:
|
|
def __init__(self, routers=None):
|
|
"""
|
|
If routers is not specified, default to settings.DATABASE_ROUTERS.
|
|
"""
|
|
self._routers = routers
|
|
|
|
@cached_property
|
|
def routers(self):
|
|
if self._routers is None:
|
|
self._routers = settings.DATABASE_ROUTERS
|
|
routers = []
|
|
for r in self._routers:
|
|
if isinstance(r, str):
|
|
router = import_string(r)()
|
|
else:
|
|
router = r
|
|
routers.append(router)
|
|
return routers
|
|
|
|
def _router_func(action):
|
|
def _route_db(self, model, **hints):
|
|
chosen_db = None
|
|
for router in self.routers:
|
|
try:
|
|
method = getattr(router, action)
|
|
except AttributeError:
|
|
# If the router doesn't have a method, skip to the next one.
|
|
pass
|
|
else:
|
|
chosen_db = method(model, **hints)
|
|
if chosen_db:
|
|
return chosen_db
|
|
instance = hints.get("instance")
|
|
if instance is not None and instance._state.db:
|
|
return instance._state.db
|
|
return DEFAULT_DB_ALIAS
|
|
|
|
return _route_db
|
|
|
|
db_for_read = _router_func("db_for_read")
|
|
db_for_write = _router_func("db_for_write")
|
|
|
|
def allow_relation(self, obj1, obj2, **hints):
|
|
for router in self.routers:
|
|
try:
|
|
method = router.allow_relation
|
|
except AttributeError:
|
|
# If the router doesn't have a method, skip to the next one.
|
|
pass
|
|
else:
|
|
allow = method(obj1, obj2, **hints)
|
|
if allow is not None:
|
|
return allow
|
|
return obj1._state.db == obj2._state.db
|
|
|
|
def allow_migrate(self, db, app_label, **hints):
|
|
for router in self.routers:
|
|
try:
|
|
method = router.allow_migrate
|
|
except AttributeError:
|
|
# If the router doesn't have a method, skip to the next one.
|
|
continue
|
|
|
|
allow = method(db, app_label, **hints)
|
|
|
|
if allow is not None:
|
|
return allow
|
|
return True
|
|
|
|
def allow_migrate_model(self, db, model):
|
|
return self.allow_migrate(
|
|
db,
|
|
model._meta.app_label,
|
|
model_name=model._meta.model_name,
|
|
model=model,
|
|
)
|
|
|
|
def get_migratable_models(self, app_config, db, include_auto_created=False):
|
|
"""Return app models allowed to be migrated on provided db."""
|
|
models = app_config.get_models(include_auto_created=include_auto_created)
|
|
return [model for model in models if self.allow_migrate_model(db, model)]
|