diff options
Diffstat (limited to 'lib/sqlalchemy/event/attr.py')
| -rw-r--r-- | lib/sqlalchemy/event/attr.py | 92 |
1 files changed, 39 insertions, 53 deletions
diff --git a/lib/sqlalchemy/event/attr.py b/lib/sqlalchemy/event/attr.py index be2a82208..ed1dca644 100644 --- a/lib/sqlalchemy/event/attr.py +++ b/lib/sqlalchemy/event/attr.py @@ -40,17 +40,21 @@ import weakref import collections -class RefCollection(object): - @util.memoized_property - def ref(self): +class RefCollection(util.MemoizedSlots): + __slots__ = 'ref', + + def _memoized_attr_ref(self): return weakref.ref(self, registry._collection_gced) -class _DispatchDescriptor(RefCollection): - """Class-level attributes on :class:`._Dispatch` classes.""" +class _ClsLevelDispatch(RefCollection): + """Class-level events on :class:`._Dispatch` classes.""" + + __slots__ = ('name', 'arg_names', 'has_kw', + 'legacy_signatures', '_clslevel') def __init__(self, parent_dispatch_cls, fn): - self.__name__ = fn.__name__ + self.name = fn.__name__ argspec = util.inspect_getargspec(fn) self.arg_names = argspec.args[1:] self.has_kw = bool(argspec.keywords) @@ -60,11 +64,9 @@ class _DispatchDescriptor(RefCollection): key=lambda s: s[0] ) )) - self.__doc__ = fn.__doc__ = legacy._augment_fn_docs( - self, parent_dispatch_cls, fn) + fn.__doc__ = legacy._augment_fn_docs(self, parent_dispatch_cls, fn) self._clslevel = weakref.WeakKeyDictionary() - self._empty_listeners = weakref.WeakKeyDictionary() def _adjust_fn_spec(self, fn, named): if named: @@ -152,34 +154,23 @@ class _DispatchDescriptor(RefCollection): def for_modify(self, obj): """Return an event collection which can be modified. - For _DispatchDescriptor at the class level of + For _ClsLevelDispatch at the class level of a dispatcher, this returns self. """ return self - def __get__(self, obj, cls): - if obj is None: - return self - elif obj._parent_cls in self._empty_listeners: - ret = self._empty_listeners[obj._parent_cls] - else: - self._empty_listeners[obj._parent_cls] = ret = \ - _EmptyListener(self, obj._parent_cls) - # assigning it to __dict__ means - # memoized for fast re-access. but more memory. - obj.__dict__[self.__name__] = ret - return ret +class _InstanceLevelDispatch(RefCollection): + __slots__ = () -class _HasParentDispatchDescriptor(object): def _adjust_fn_spec(self, fn, named): return self.parent._adjust_fn_spec(fn, named) -class _EmptyListener(_HasParentDispatchDescriptor): - """Serves as a class-level interface to the events - served by a _DispatchDescriptor, when there are no +class _EmptyListener(_InstanceLevelDispatch): + """Serves as a proxy interface to the events + served by a _ClsLevelDispatch, when there are no instance-level events present. Is replaced by _ListenerCollection when instance-level @@ -187,14 +178,17 @@ class _EmptyListener(_HasParentDispatchDescriptor): """ + propagate = frozenset() + listeners = () + + __slots__ = 'parent', 'parent_listeners', 'name' + def __init__(self, parent, target_cls): if target_cls not in parent._clslevel: parent.update_subclass(target_cls) - self.parent = parent # _DispatchDescriptor + self.parent = parent # _ClsLevelDispatch self.parent_listeners = parent._clslevel[target_cls] - self.name = parent.__name__ - self.propagate = frozenset() - self.listeners = () + self.name = parent.name def for_modify(self, obj): """Return an event collection which can be modified. @@ -205,9 +199,11 @@ class _EmptyListener(_HasParentDispatchDescriptor): and returns it. """ - result = _ListenerCollection(self.parent, obj._parent_cls) - if obj.__dict__[self.name] is self: - obj.__dict__[self.name] = result + result = _ListenerCollection(self.parent, obj._instance_cls) + if getattr(obj, self.name) is self: + setattr(obj, self.name, result) + else: + assert isinstance(getattr(obj, self.name), _JoinedListener) return result def _needs_modify(self, *args, **kw): @@ -233,11 +229,12 @@ class _EmptyListener(_HasParentDispatchDescriptor): __nonzero__ = __bool__ -class _CompoundListener(_HasParentDispatchDescriptor): +class _CompoundListener(_InstanceLevelDispatch): _exec_once = False - @util.memoized_property - def _exec_once_mutex(self): + __slots__ = '_exec_once_mutex', + + def _memoized_attr__exec_once_mutex(self): return threading.Lock() def exec_once(self, *args, **kw): @@ -272,7 +269,7 @@ class _CompoundListener(_HasParentDispatchDescriptor): __nonzero__ = __bool__ -class _ListenerCollection(RefCollection, _CompoundListener): +class _ListenerCollection(_CompoundListener): """Instance-level attributes on instances of :class:`._Dispatch`. Represents a collection of listeners. @@ -282,12 +279,14 @@ class _ListenerCollection(RefCollection, _CompoundListener): """ + __slots__ = 'parent_listeners', 'parent', 'name', 'listeners', 'propagate' + def __init__(self, parent, target_cls): if target_cls not in parent._clslevel: parent.update_subclass(target_cls) self.parent_listeners = parent._clslevel[target_cls] self.parent = parent - self.name = parent.__name__ + self.name = parent.name self.listeners = collections.deque() self.propagate = set() @@ -339,24 +338,11 @@ class _ListenerCollection(RefCollection, _CompoundListener): self.listeners.clear() -class _JoinedDispatchDescriptor(object): - def __init__(self, name): - self.name = name - - def __get__(self, obj, cls): - if obj is None: - return self - else: - obj.__dict__[self.name] = ret = _JoinedListener( - obj.parent, self.name, - getattr(obj.local, self.name) - ) - return ret - - class _JoinedListener(_CompoundListener): _exec_once = False + __slots__ = 'parent', 'name', 'local', 'parent_listeners' + def __init__(self, parent, name, local): self.parent = parent self.name = name |