unambiguous tracking of all object lifecycle state transitions
in terms of the :class:`.Session` itself, e.g. pending,
transient, persistent, detached. The state of the object
within each event is also defined.
fixes#2677
- Added a new session lifecycle state :term:`deleted`. This new state
represents an object that has been deleted from the :term:`persistent`
state and will move to the :term:`detached` state once the transaction
is committed. This resolves the long-standing issue that objects
which were deleted existed in a gray area between persistent and
detached. The :attr:`.InstanceState.persistent` accessor will
**no longer** report on a deleted object as persistent; the
:attr:`.InstanceState.deleted` accessor will instead be True for
these objects, until they become detached.
- The :paramref:`.Session.weak_identity_map` parameter is deprecated.
See the new recipe at :ref:`session_referencing_behavior` for
an event-based approach to maintaining strong identity map behavior.
references #3517
attached to session X" would fail to prevent the object from
also being attached to the new session, in the case that execution
continued after the error raise occurred.
fixes#3301
to :meth:`.Session.close`, except also calls
:meth:`.Connection.invalidate`
on all connections, guaranteeing that they will not be returned to
the connection pool. This is useful in situations e.g. dealing
with gevent timeouts when it is not safe to use the connection further,
even for rollbacks.
references #3258
the given object if the object had been subject to a delete
operation that was flushed, but not committed. This would also
affect related operations like :func:`.make_transient`.
fixes#3139
"binds" (e.g. engines to use), such engines can be associated with
mixin classes, concrete subclasses, as well as a wider variety
of table metadata such as joined inheritance tables.
fixes#3035
N occurrences of a parameterized string. This allows parameterized
warnings that can refer to their arguments to be delivered a fixed
number of times until allowing Python warning filters to squelch them,
and prevents memory from growing unbounded within Python's
warning registries.
fixes#3178
be used to manufacture objects that behave as though they were loaded
from a session, then detached. Attributes that aren't present
are marked as expired, and the object can be added to a Session
where it will act like a persistent one. fix#3017
this is a dictionary where applications can store arbitrary
data local to a :class:`.Session`.
The contents of :attr:`.Session.info` can be also be initialized
using the ``info`` argument of :class:`.Session` or
:class:`.sessionmaker`.
the creation of strong references within the Session;
an object will no longer have an internal reference cycle
created if it's in the transient state or moves into the
detached state - the strong ref is created only when the
object is attached to a Session and is removed when the
object is detached. This makes it somewhat safer for an
object to have a `__del__()` method, even though this is
not recommended, as relationships with backrefs produce
cycles too. A warning has been added when a class with
a `__del__()` method is mapped.
[ticket:2708]
if the given object was the subject of a :meth:`.Session.delete`
operation.
- An object that's deleted from a session will be de-associated with
that session fully after the transaction is committed, that is
the :func:`.object_session` function will return None.
[ticket:2658]
state post-flush due to event listeners;
any states that are marked as "dirty" from an
attribute perspective, usually via column-attribute
set events within after_insert(), after_update(),
etc., will get the "history" flag reset
in all cases, instead of only those instances
that were part of the flush. This has the effect
that this "dirty" state doesn't carry over
after the flush and won't result in UPDATE
statements. A warning is emitted to this
effect; the set_committed_state()
method can be used to assign attributes on objects
without producing history events. [ticket:2582]
when unsupported methods are used inside the
"execute" portion of the flush. These are
the familiar methods add(), delete(), etc.
as well as collection and related-object
manipulations, as called within mapper-level
flush events
like after_insert(), after_update(), etc.
It's been prominently documented for a long
time that SQLAlchemy cannot guarantee
results when the Session is manipulated within
the execution of the flush plan,
however users are still doing it, so now
there's a warning. Maybe someday the Session
will be enhanced to support these operations
inside of the flush, but for now, results
can't be guaranteed.
become an externally usable package but still remains within the main sqlalchemy parent package.
in this system, we use kind of an ugly hack to get the noseplugin imported outside of the
"sqlalchemy" package, while still making it available within sqlalchemy for usage by
third party libraries.
no longer has any effect. is_modified() in
all cases looks only at local in-memory
modified flags and will not emit any
SQL or invoke loader callables/initializers.
[ticket:2320]
established after a failed flush would be committed
as part of the subsequent transaction that
begins automatically after manual call
to rollback(). The state of the session is
checked within rollback(), and if new state
is present, a warning is emitted and
restore_snapshot() is called a second time,
discarding those changes. [ticket:2389]
- repaired testing.assert_warnings to also verify
that any warnings were emitted
within it which remain are considered detached again
when they are add()-ed to a new Session.
This is accomplished by an extra check that the previous
"session_key" doesn't actually exist among the pool
of Sessions. [ticket:2281]
all referncing tests to not use globals
- tests that deal with pickle specifically load the fixture classes
from test.lib.pickleable, which gets some more classes added
- removed weird sa05 pickling tests that don't matter
access to the cls/self.tables/classes registries
- express orm/_base.py ORMTest in terms of engine/_base.py TablesTest,
factor out common steps into TablesTest, remove AltEngineTest as a
separate class. will further consolidate these base classes
rare weakref callbacks during iterations.
The mutex has been removed as it apparently
can cause a reentrant (i.e. in one thread) deadlock,
perhaps when gc collects objects at the point of
iteration in order to gain more memory. It is hoped
that "dictionary changed during iteration" will
be exceedingly rare as iteration methods internally
acquire the full list of objects in a single values()
call. [ticket:2087]
normalized via os.path.abspath(), so that directory changes
within the process don't affect the ultimate location
of a relative file path. [ticket:2036]
Jacob MacDonald