77 lines
2.2 KiB
Python
77 lines
2.2 KiB
Python
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from asgiref.local import Local
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from django.conf import settings as django_settings
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from django.utils.functional import cached_property
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class ConnectionProxy:
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"""Proxy for accessing a connection object's attributes."""
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def __init__(self, connections, alias):
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self.__dict__['_connections'] = connections
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self.__dict__['_alias'] = alias
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def __getattr__(self, item):
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return getattr(self._connections[self._alias], item)
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def __setattr__(self, name, value):
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return setattr(self._connections[self._alias], name, value)
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def __delattr__(self, name):
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return delattr(self._connections[self._alias], name)
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def __contains__(self, key):
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return key in self._connections[self._alias]
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def __eq__(self, other):
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return self._connections[self._alias] == other
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class ConnectionDoesNotExist(Exception):
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pass
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class BaseConnectionHandler:
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settings_name = None
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exception_class = ConnectionDoesNotExist
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thread_critical = False
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def __init__(self, settings=None):
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self._settings = settings
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self._connections = Local(self.thread_critical)
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@cached_property
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def settings(self):
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self._settings = self.configure_settings(self._settings)
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return self._settings
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def configure_settings(self, settings):
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if settings is None:
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settings = getattr(django_settings, self.settings_name)
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return settings
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def create_connection(self, alias):
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raise NotImplementedError('Subclasses must implement create_connection().')
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def __getitem__(self, alias):
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try:
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return getattr(self._connections, alias)
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except AttributeError:
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if alias not in self.settings:
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raise self.exception_class(f"The connection '{alias}' doesn't exist.")
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conn = self.create_connection(alias)
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setattr(self._connections, alias, conn)
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return conn
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def __setitem__(self, key, value):
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setattr(self._connections, key, value)
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def __delitem__(self, key):
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delattr(self._connections, key)
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def __iter__(self):
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return iter(self.settings)
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def all(self):
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return [self[alias] for alias in self]
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