summaryrefslogtreecommitdiff
path: root/venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py
diff options
context:
space:
mode:
authorcyfraeviolae <cyfraeviolae>2024-04-03 03:10:44 -0400
committercyfraeviolae <cyfraeviolae>2024-04-03 03:10:44 -0400
commit6d7ba58f880be618ade07f8ea080fe8c4bf8a896 (patch)
treeb1c931051ffcebd2bd9d61d98d6233ffa289bbce /venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py
parent4f884c9abc32990b4061a1bb6997b4b37e58ea0b (diff)
venv
Diffstat (limited to 'venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py')
-rw-r--r--venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py298
1 files changed, 298 insertions, 0 deletions
diff --git a/venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py b/venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py
new file mode 100644
index 0000000..7496e5c
--- /dev/null
+++ b/venv/lib/python3.11/site-packages/sqlalchemy/orm/dynamic.py
@@ -0,0 +1,298 @@
+# orm/dynamic.py
+# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+
+"""Dynamic collection API.
+
+Dynamic collections act like Query() objects for read operations and support
+basic add/delete mutation.
+
+.. legacy:: the "dynamic" loader is a legacy feature, superseded by the
+ "write_only" loader.
+
+
+"""
+
+from __future__ import annotations
+
+from typing import Any
+from typing import Iterable
+from typing import Iterator
+from typing import List
+from typing import Optional
+from typing import Tuple
+from typing import Type
+from typing import TYPE_CHECKING
+from typing import TypeVar
+from typing import Union
+
+from . import attributes
+from . import exc as orm_exc
+from . import relationships
+from . import util as orm_util
+from .base import PassiveFlag
+from .query import Query
+from .session import object_session
+from .writeonly import AbstractCollectionWriter
+from .writeonly import WriteOnlyAttributeImpl
+from .writeonly import WriteOnlyHistory
+from .writeonly import WriteOnlyLoader
+from .. import util
+from ..engine import result
+
+
+if TYPE_CHECKING:
+ from . import QueryableAttribute
+ from .mapper import Mapper
+ from .relationships import _RelationshipOrderByArg
+ from .session import Session
+ from .state import InstanceState
+ from .util import AliasedClass
+ from ..event import _Dispatch
+ from ..sql.elements import ColumnElement
+
+_T = TypeVar("_T", bound=Any)
+
+
+class DynamicCollectionHistory(WriteOnlyHistory[_T]):
+ def __init__(
+ self,
+ attr: DynamicAttributeImpl,
+ state: InstanceState[_T],
+ passive: PassiveFlag,
+ apply_to: Optional[DynamicCollectionHistory[_T]] = None,
+ ) -> None:
+ if apply_to:
+ coll = AppenderQuery(attr, state).autoflush(False)
+ self.unchanged_items = util.OrderedIdentitySet(coll)
+ self.added_items = apply_to.added_items
+ self.deleted_items = apply_to.deleted_items
+ self._reconcile_collection = True
+ else:
+ self.deleted_items = util.OrderedIdentitySet()
+ self.added_items = util.OrderedIdentitySet()
+ self.unchanged_items = util.OrderedIdentitySet()
+ self._reconcile_collection = False
+
+
+class DynamicAttributeImpl(WriteOnlyAttributeImpl):
+ _supports_dynamic_iteration = True
+ collection_history_cls = DynamicCollectionHistory[Any]
+ query_class: Type[AppenderMixin[Any]] # type: ignore[assignment]
+
+ def __init__(
+ self,
+ class_: Union[Type[Any], AliasedClass[Any]],
+ key: str,
+ dispatch: _Dispatch[QueryableAttribute[Any]],
+ target_mapper: Mapper[_T],
+ order_by: _RelationshipOrderByArg,
+ query_class: Optional[Type[AppenderMixin[_T]]] = None,
+ **kw: Any,
+ ) -> None:
+ attributes.AttributeImpl.__init__(
+ self, class_, key, None, dispatch, **kw
+ )
+ self.target_mapper = target_mapper
+ if order_by:
+ self.order_by = tuple(order_by)
+ if not query_class:
+ self.query_class = AppenderQuery
+ elif AppenderMixin in query_class.mro():
+ self.query_class = query_class
+ else:
+ self.query_class = mixin_user_query(query_class)
+
+
+@relationships.RelationshipProperty.strategy_for(lazy="dynamic")
+class DynaLoader(WriteOnlyLoader):
+ impl_class = DynamicAttributeImpl
+
+
+class AppenderMixin(AbstractCollectionWriter[_T]):
+ """A mixin that expects to be mixing in a Query class with
+ AbstractAppender.
+
+
+ """
+
+ query_class: Optional[Type[Query[_T]]] = None
+ _order_by_clauses: Tuple[ColumnElement[Any], ...]
+
+ def __init__(
+ self, attr: DynamicAttributeImpl, state: InstanceState[_T]
+ ) -> None:
+ Query.__init__(
+ self, # type: ignore[arg-type]
+ attr.target_mapper,
+ None,
+ )
+ super().__init__(attr, state)
+
+ @property
+ def session(self) -> Optional[Session]:
+ sess = object_session(self.instance)
+ if sess is not None and sess.autoflush and self.instance in sess:
+ sess.flush()
+ if not orm_util.has_identity(self.instance):
+ return None
+ else:
+ return sess
+
+ @session.setter
+ def session(self, session: Session) -> None:
+ self.sess = session
+
+ def _iter(self) -> Union[result.ScalarResult[_T], result.Result[_T]]:
+ sess = self.session
+ if sess is None:
+ state = attributes.instance_state(self.instance)
+ if state.detached:
+ util.warn(
+ "Instance %s is detached, dynamic relationship cannot "
+ "return a correct result. This warning will become "
+ "a DetachedInstanceError in a future release."
+ % (orm_util.state_str(state))
+ )
+
+ return result.IteratorResult(
+ result.SimpleResultMetaData([self.attr.class_.__name__]),
+ self.attr._get_collection_history( # type: ignore[arg-type]
+ attributes.instance_state(self.instance),
+ PassiveFlag.PASSIVE_NO_INITIALIZE,
+ ).added_items,
+ _source_supports_scalars=True,
+ ).scalars()
+ else:
+ return self._generate(sess)._iter()
+
+ if TYPE_CHECKING:
+
+ def __iter__(self) -> Iterator[_T]: ...
+
+ def __getitem__(self, index: Any) -> Union[_T, List[_T]]:
+ sess = self.session
+ if sess is None:
+ return self.attr._get_collection_history(
+ attributes.instance_state(self.instance),
+ PassiveFlag.PASSIVE_NO_INITIALIZE,
+ ).indexed(index)
+ else:
+ return self._generate(sess).__getitem__(index) # type: ignore[no-any-return] # noqa: E501
+
+ def count(self) -> int:
+ sess = self.session
+ if sess is None:
+ return len(
+ self.attr._get_collection_history(
+ attributes.instance_state(self.instance),
+ PassiveFlag.PASSIVE_NO_INITIALIZE,
+ ).added_items
+ )
+ else:
+ return self._generate(sess).count()
+
+ def _generate(
+ self,
+ sess: Optional[Session] = None,
+ ) -> Query[_T]:
+ # note we're returning an entirely new Query class instance
+ # here without any assignment capabilities; the class of this
+ # query is determined by the session.
+ instance = self.instance
+ if sess is None:
+ sess = object_session(instance)
+ if sess is None:
+ raise orm_exc.DetachedInstanceError(
+ "Parent instance %s is not bound to a Session, and no "
+ "contextual session is established; lazy load operation "
+ "of attribute '%s' cannot proceed"
+ % (orm_util.instance_str(instance), self.attr.key)
+ )
+
+ if self.query_class:
+ query = self.query_class(self.attr.target_mapper, session=sess)
+ else:
+ query = sess.query(self.attr.target_mapper)
+
+ query._where_criteria = self._where_criteria
+ query._from_obj = self._from_obj
+ query._order_by_clauses = self._order_by_clauses
+
+ return query
+
+ def add_all(self, iterator: Iterable[_T]) -> None:
+ """Add an iterable of items to this :class:`_orm.AppenderQuery`.
+
+ The given items will be persisted to the database in terms of
+ the parent instance's collection on the next flush.
+
+ This method is provided to assist in delivering forwards-compatibility
+ with the :class:`_orm.WriteOnlyCollection` collection class.
+
+ .. versionadded:: 2.0
+
+ """
+ self._add_all_impl(iterator)
+
+ def add(self, item: _T) -> None:
+ """Add an item to this :class:`_orm.AppenderQuery`.
+
+ The given item will be persisted to the database in terms of
+ the parent instance's collection on the next flush.
+
+ This method is provided to assist in delivering forwards-compatibility
+ with the :class:`_orm.WriteOnlyCollection` collection class.
+
+ .. versionadded:: 2.0
+
+ """
+ self._add_all_impl([item])
+
+ def extend(self, iterator: Iterable[_T]) -> None:
+ """Add an iterable of items to this :class:`_orm.AppenderQuery`.
+
+ The given items will be persisted to the database in terms of
+ the parent instance's collection on the next flush.
+
+ """
+ self._add_all_impl(iterator)
+
+ def append(self, item: _T) -> None:
+ """Append an item to this :class:`_orm.AppenderQuery`.
+
+ The given item will be persisted to the database in terms of
+ the parent instance's collection on the next flush.
+
+ """
+ self._add_all_impl([item])
+
+ def remove(self, item: _T) -> None:
+ """Remove an item from this :class:`_orm.AppenderQuery`.
+
+ The given item will be removed from the parent instance's collection on
+ the next flush.
+
+ """
+ self._remove_impl(item)
+
+
+class AppenderQuery(AppenderMixin[_T], Query[_T]): # type: ignore[misc]
+ """A dynamic query that supports basic collection storage operations.
+
+ Methods on :class:`.AppenderQuery` include all methods of
+ :class:`_orm.Query`, plus additional methods used for collection
+ persistence.
+
+
+ """
+
+
+def mixin_user_query(cls: Any) -> type[AppenderMixin[Any]]:
+ """Return a new class with AppenderQuery functionality layered over."""
+ name = "Appender" + cls.__name__
+ return type(name, (AppenderMixin, cls), {"query_class": cls})