Function get_from_identity

lib/sqlalchemy/orm/loading.py:458–493

Look up the given key in the given session's identity map, check the object for expired state if found.

(
    session: Session,
    mapper: Mapper[_O],
    key: _IdentityKeyType[_O],
    passive: PassiveFlag,
)

def get_from_identity(
    session: Session,
    mapper: Mapper[_O],
    key: _IdentityKeyType[_O],
    passive: PassiveFlag,
) -> Union[LoaderCallableStatus, Optional[_O]]:
    """Look up the given key in the given session's identity map,
    check the object for expired state if found.

    """
    instance = session.identity_map.get(key)
    if instance is not None:
        state = attributes.instance_state(instance)

        if mapper.inherits and not state.mapper.isa(mapper):
            return attributes.PASSIVE_CLASS_MISMATCH

        # expired - ensure it still exists
        if state.expired:
            if not passive & attributes.SQL_OK:
                # TODO: no coverage here
                return attributes.PASSIVE_NO_RESULT
            elif not passive & attributes.RELATED_OBJECT_OK:
                # this mode is used within a flush and the instance's
                # expired state will be checked soon enough, if necessary.
                # also used by immediateloader for a mutually-dependent
                # o2m->m2m load, :ticket:`6301`
                return instance
            try:
                state._load_expired(state, passive)
            except orm_exc.ObjectDeletedError:
                session._remove_newly_deleted([state])
                return None
        return instance
    else:
        return None


def _load_on_ident(