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author | Mike Bayer <mike_mp@zzzcomputing.com> | 2022-04-05 19:00:19 -0400 |
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committer | mike bayer <mike_mp@zzzcomputing.com> | 2022-04-12 02:09:42 +0000 |
commit | 98eae4e181cb2d1bbc67ec834bfad29dcba7f461 (patch) | |
tree | fc000c3113a4a198b4ddd6bc81fe291dc9ef1ffb /lib/sqlalchemy/ext/asyncio/session.py | |
parent | 15ef11e0ede82e44fb07f31b63d3db0712d8bf48 (diff) | |
download | sqlalchemy-98eae4e181cb2d1bbc67ec834bfad29dcba7f461.tar.gz |
use code generation for scoped_session
our decorator thing generates code in any case,
so point it at the file itself to generate real code
for the blocks rather than doing things dynamically.
this will allow typing tools to have no problem
whatsoever and we also reduce import time overhead.
file size will be a lot bigger though, shrugs.
syntax / dupe method / etc. checking will be accomplished
by our existing linting / typing / formatting tools.
As we are also using "from __future__ import annotations",
we also no longer have to apply quotes to generated
annotations.
Change-Id: I20962cb65bda63ff0fb67357ab346e9b1ef4f108
Diffstat (limited to 'lib/sqlalchemy/ext/asyncio/session.py')
-rw-r--r-- | lib/sqlalchemy/ext/asyncio/session.py | 510 |
1 files changed, 509 insertions, 1 deletions
diff --git a/lib/sqlalchemy/ext/asyncio/session.py b/lib/sqlalchemy/ext/asyncio/session.py index c39a8d6e0..0bd2530b2 100644 --- a/lib/sqlalchemy/ext/asyncio/session.py +++ b/lib/sqlalchemy/ext/asyncio/session.py @@ -4,6 +4,10 @@ # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php +from __future__ import annotations + +from typing import Any + from . import engine from . import result as _result from .base import ReversibleProxy @@ -312,7 +316,9 @@ class AsyncSession(ReversibleProxy): **kw, ): """Execute a statement and return a streaming - :class:`_asyncio.AsyncResult` object.""" + :class:`_asyncio.AsyncResult` object. + + """ if execution_options: execution_options = util.immutabledict(execution_options).union( @@ -629,6 +635,508 @@ class AsyncSession(ReversibleProxy): # TODO: can this use asynccontextmanager ?? return _AsyncSessionContextManager(self) + # START PROXY METHODS AsyncSession + + # code within this block is **programmatically, + # statically generated** by tools/generate_proxy_methods.py + + def __contains__(self, instance): + r"""Return True if the instance is associated with this session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + The instance may be pending or persistent within the Session for a + result of True. + + + """ # noqa: E501 + + return self._proxied.__contains__(instance) + + def __iter__(self): + r"""Iterate over all pending or persistent instances within this + Session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + + """ # noqa: E501 + + return self._proxied.__iter__() + + def add(self, instance: Any, _warn: bool = True) -> None: + r"""Place an object in the ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + Its state will be persisted to the database on the next flush + operation. + + Repeated calls to ``add()`` will be ignored. The opposite of ``add()`` + is ``expunge()``. + + + """ # noqa: E501 + + return self._proxied.add(instance, _warn=_warn) + + def add_all(self, instances): + r"""Add the given collection of instances to this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.add_all(instances) + + def expire(self, instance, attribute_names=None): + r"""Expire the attributes on an instance. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + Marks the attributes of an instance as out of date. When an expired + attribute is next accessed, a query will be issued to the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire all objects in the :class:`.Session` simultaneously, + use :meth:`Session.expire_all`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire` only makes sense for the specific + case that a non-ORM SQL statement was emitted in the current + transaction. + + :param instance: The instance to be refreshed. + :param attribute_names: optional list of string attribute names + indicating a subset of attributes to be expired. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + """ # noqa: E501 + + return self._proxied.expire(instance, attribute_names=attribute_names) + + def expire_all(self): + r"""Expires all persistent instances within this Session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + When any attributes on a persistent instance is next accessed, + a query will be issued using the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire individual objects and individual attributes + on those objects, use :meth:`Session.expire`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire_all` is not usually needed, + assuming the transaction is isolated. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + """ # noqa: E501 + + return self._proxied.expire_all() + + def expunge(self, instance): + r"""Remove the `instance` from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This will free all internal references to the instance. Cascading + will be applied according to the *expunge* cascade rule. + + + """ # noqa: E501 + + return self._proxied.expunge(instance) + + def expunge_all(self): + r"""Remove all object instances from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is equivalent to calling ``expunge(obj)`` on all objects in this + ``Session``. + + + """ # noqa: E501 + + return self._proxied.expunge_all() + + def is_modified(self, instance, include_collections=True): + r"""Return ``True`` if the given instance has locally + modified attributes. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This method retrieves the history for each instrumented + attribute on the instance and performs a comparison of the current + value to its previously committed value, if any. + + It is in effect a more expensive and accurate + version of checking for the given instance in the + :attr:`.Session.dirty` collection; a full test for + each attribute's net "dirty" status is performed. + + E.g.:: + + return session.is_modified(someobject) + + A few caveats to this method apply: + + * Instances present in the :attr:`.Session.dirty` collection may + report ``False`` when tested with this method. This is because + the object may have received change events via attribute mutation, + thus placing it in :attr:`.Session.dirty`, but ultimately the state + is the same as that loaded from the database, resulting in no net + change here. + * Scalar attributes may not have recorded the previously set + value when a new value was applied, if the attribute was not loaded, + or was expired, at the time the new value was received - in these + cases, the attribute is assumed to have a change, even if there is + ultimately no net change against its database value. SQLAlchemy in + most cases does not need the "old" value when a set event occurs, so + it skips the expense of a SQL call if the old value isn't present, + based on the assumption that an UPDATE of the scalar value is + usually needed, and in those few cases where it isn't, is less + expensive on average than issuing a defensive SELECT. + + The "old" value is fetched unconditionally upon set only if the + attribute container has the ``active_history`` flag set to ``True``. + This flag is set typically for primary key attributes and scalar + object references that are not a simple many-to-one. To set this + flag for any arbitrary mapped column, use the ``active_history`` + argument with :func:`.column_property`. + + :param instance: mapped instance to be tested for pending changes. + :param include_collections: Indicates if multivalued collections + should be included in the operation. Setting this to ``False`` is a + way to detect only local-column based properties (i.e. scalar columns + or many-to-one foreign keys) that would result in an UPDATE for this + instance upon flush. + + + """ # noqa: E501 + + return self._proxied.is_modified( + instance, include_collections=include_collections + ) + + def in_transaction(self): + r"""Return True if this :class:`_orm.Session` has begun a transaction. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionadded:: 1.4 + + .. seealso:: + + :attr:`_orm.Session.is_active` + + + + """ # noqa: E501 + + return self._proxied.in_transaction() + + def in_nested_transaction(self): + r"""Return True if this :class:`_orm.Session` has begun a nested + transaction, e.g. SAVEPOINT. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionadded:: 1.4 + + + """ # noqa: E501 + + return self._proxied.in_nested_transaction() + + @property + def dirty(self) -> Any: + r"""The set of all persistent instances considered dirty. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + E.g.:: + + some_mapped_object in session.dirty + + Instances are considered dirty when they were modified but not + deleted. + + Note that this 'dirty' calculation is 'optimistic'; most + attribute-setting or collection modification operations will + mark an instance as 'dirty' and place it in this set, even if + there is no net change to the attribute's value. At flush + time, the value of each attribute is compared to its + previously saved value, and if there's no net change, no SQL + operation will occur (this is a more expensive operation so + it's only done at flush time). + + To check if an instance has actionable net changes to its + attributes, use the :meth:`.Session.is_modified` method. + + + """ # noqa: E501 + + return self._proxied.dirty + + @property + def deleted(self) -> Any: + r"""The set of all instances marked as 'deleted' within this ``Session`` + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.deleted + + @property + def new(self) -> Any: + r"""The set of all instances marked as 'new' within this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.new + + @property + def identity_map(self) -> identity.IdentityMap: + r"""Proxy for the :attr:`_orm.Session.identity_map` attribute + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.identity_map + + @identity_map.setter + def identity_map(self, attr: identity.IdentityMap) -> None: + self._proxied.identity_map = attr + + @property + def is_active(self) -> Any: + r"""True if this :class:`.Session` not in "partial rollback" state. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionchanged:: 1.4 The :class:`_orm.Session` no longer begins + a new transaction immediately, so this attribute will be False + when the :class:`_orm.Session` is first instantiated. + + "partial rollback" state typically indicates that the flush process + of the :class:`_orm.Session` has failed, and that the + :meth:`_orm.Session.rollback` method must be emitted in order to + fully roll back the transaction. + + If this :class:`_orm.Session` is not in a transaction at all, the + :class:`_orm.Session` will autobegin when it is first used, so in this + case :attr:`_orm.Session.is_active` will return True. + + Otherwise, if this :class:`_orm.Session` is within a transaction, + and that transaction has not been rolled back internally, the + :attr:`_orm.Session.is_active` will also return True. + + .. seealso:: + + :ref:`faq_session_rollback` + + :meth:`_orm.Session.in_transaction` + + + """ # noqa: E501 + + return self._proxied.is_active + + @property + def autoflush(self) -> bool: + r"""Proxy for the :attr:`_orm.Session.autoflush` attribute + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.autoflush + + @autoflush.setter + def autoflush(self, attr: bool) -> None: + self._proxied.autoflush = attr + + @property + def no_autoflush(self) -> Any: + r"""Return a context manager that disables autoflush. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + e.g.:: + + with session.no_autoflush: + + some_object = SomeClass() + session.add(some_object) + # won't autoflush + some_object.related_thing = session.query(SomeRelated).first() + + Operations that proceed within the ``with:`` block + will not be subject to flushes occurring upon query + access. This is useful when initializing a series + of objects which involve existing database queries, + where the uncompleted object should not yet be flushed. + + + """ # noqa: E501 + + return self._proxied.no_autoflush + + @property + def info(self) -> Any: + r"""A user-modifiable dictionary. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + The initial value of this dictionary can be populated using the + ``info`` argument to the :class:`.Session` constructor or + :class:`.sessionmaker` constructor or factory methods. The dictionary + here is always local to this :class:`.Session` and can be modified + independently of all other :class:`.Session` objects. + + + """ # noqa: E501 + + return self._proxied.info + + @classmethod + def object_session(cls, instance: Any) -> "Session": + r"""Return the :class:`.Session` to which an object belongs. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is an alias of :func:`.object_session`. + + + """ # noqa: E501 + + return Session.object_session(instance) + + @classmethod + def identity_key( + cls, + class_=None, + ident=None, + *, + instance=None, + row=None, + identity_token=None, + ) -> _IdentityKeyType: + r"""Return an identity key. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is an alias of :func:`.util.identity_key`. + + + """ # noqa: E501 + + return Session.identity_key( + class_=class_, + ident=ident, + instance=instance, + row=row, + identity_token=identity_token, + ) + + # END PROXY METHODS AsyncSession + class _AsyncSessionContextManager: def __init__(self, async_session): |