309 lines
9.6 KiB
Python
309 lines
9.6 KiB
Python
import pkgutil
|
|
from importlib import import_module
|
|
from pathlib import Path
|
|
from threading import local
|
|
|
|
from django.conf import settings
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
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.
|
|
backend_dir = str(Path(__file__).parent / 'backends')
|
|
builtin_backends = [
|
|
name for _, name, ispkg in pkgutil.iter_modules([backend_dir])
|
|
if ispkg and name not in {'base', 'dummy', 'postgresql_psycopg2'}
|
|
]
|
|
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.\n"
|
|
"Try using '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 ConnectionDoesNotExist(Exception):
|
|
pass
|
|
|
|
|
|
class ConnectionHandler:
|
|
def __init__(self, databases=None):
|
|
"""
|
|
databases is an optional dictionary of database definitions (structured
|
|
like settings.DATABASES).
|
|
"""
|
|
self._databases = databases
|
|
self._connections = local()
|
|
|
|
@cached_property
|
|
def databases(self):
|
|
if self._databases is None:
|
|
self._databases = settings.DATABASES
|
|
if self._databases == {}:
|
|
self._databases = {
|
|
DEFAULT_DB_ALIAS: {
|
|
'ENGINE': 'django.db.backends.dummy',
|
|
},
|
|
}
|
|
if self._databases[DEFAULT_DB_ALIAS] == {}:
|
|
self._databases[DEFAULT_DB_ALIAS]['ENGINE'] = 'django.db.backends.dummy'
|
|
|
|
if DEFAULT_DB_ALIAS not in self._databases:
|
|
raise ImproperlyConfigured("You must define a '%s' database" % DEFAULT_DB_ALIAS)
|
|
return self._databases
|
|
|
|
def ensure_defaults(self, alias):
|
|
"""
|
|
Put the defaults into the settings dictionary for a given connection
|
|
where no settings is provided.
|
|
"""
|
|
try:
|
|
conn = self.databases[alias]
|
|
except KeyError:
|
|
raise ConnectionDoesNotExist("The connection %s doesn't exist" % alias)
|
|
|
|
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('OPTIONS', {})
|
|
conn.setdefault('TIME_ZONE', None)
|
|
for setting in ['NAME', 'USER', 'PASSWORD', 'HOST', 'PORT']:
|
|
conn.setdefault(setting, '')
|
|
|
|
def prepare_test_settings(self, alias):
|
|
"""
|
|
Make sure the test settings are available in the 'TEST' sub-dictionary.
|
|
"""
|
|
try:
|
|
conn = self.databases[alias]
|
|
except KeyError:
|
|
raise ConnectionDoesNotExist("The connection %s doesn't exist" % alias)
|
|
|
|
test_settings = conn.setdefault('TEST', {})
|
|
for key in ['CHARSET', 'COLLATION', 'NAME', 'MIRROR']:
|
|
test_settings.setdefault(key, None)
|
|
|
|
def __getitem__(self, alias):
|
|
if hasattr(self._connections, alias):
|
|
return getattr(self._connections, alias)
|
|
|
|
self.ensure_defaults(alias)
|
|
self.prepare_test_settings(alias)
|
|
db = self.databases[alias]
|
|
backend = load_backend(db['ENGINE'])
|
|
conn = backend.DatabaseWrapper(db, alias)
|
|
setattr(self._connections, alias, conn)
|
|
return conn
|
|
|
|
def __setitem__(self, key, value):
|
|
setattr(self._connections, key, value)
|
|
|
|
def __delitem__(self, key):
|
|
delattr(self._connections, key)
|
|
|
|
def __iter__(self):
|
|
return iter(self.databases)
|
|
|
|
def all(self):
|
|
return [self[alias] for alias in self]
|
|
|
|
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)]
|