Optimize ABC caches (#383)

* Optimize ABC negative cache for generics

* Add also positive cache and registry links

* Formatting

* Add ABC optimization to PY2

* Inline internal helper for more speed

* Fix negative cahce setters

* Fix negative cahce setters on PY2

* Make negative caches writable only for non-subscripted generics

Author: ilevkivskyi

python2/typing.py

@@ -929,19 +929,6 @@ def _next_in_mro(cls):
     return next_in_mro
 
 
-def _valid_for_check(cls):
-    """An internal helper to prohibit isinstance([1], List[str]) etc."""
-    if cls is Generic:
-        raise TypeError("Class %r cannot be used with class "
-                        "or instance checks" % cls)
-    if (
-        cls.__origin__ is not None and
-        sys._getframe(3).f_globals['__name__'] not in ['abc', 'functools']
-    ):
-        raise TypeError("Parameterized generics cannot be used with class "
-                        "or instance checks")
-
-
 def _make_subclasshook(cls):
     """Construct a __subclasshook__ callable that incorporates
     the associated __extra__ class in subclass checks performed
@@ -952,7 +939,6 @@ def _make_subclasshook(cls):
         # Registered classes need not be checked here because
         # cls and its extra share the same _abc_registry.
         def __extrahook__(cls, subclass):
-            _valid_for_check(cls)
             res = cls.__extra__.__subclasshook__(subclass)
             if res is not NotImplemented:
                 return res
@@ -967,7 +953,6 @@ def __extrahook__(cls, subclass):
     else:
         # For non-ABC extras we'll just call issubclass().
         def __extrahook__(cls, subclass):
-            _valid_for_check(cls)
             if cls.__extra__ and issubclass(subclass, cls.__extra__):
                 return True
             return NotImplemented
@@ -1045,6 +1030,7 @@ def __new__(cls, name, bases, namespace,
         # remove bare Generic from bases if there are other generic bases
         if any(isinstance(b, GenericMeta) and b is not Generic for b in bases):
             bases = tuple(b for b in bases if b is not Generic)
+        namespace.update({'__origin__': origin, '__extra__': extra})
         self = super(GenericMeta, cls).__new__(cls, name, bases, namespace)
 
         self.__parameters__ = tvars
@@ -1053,8 +1039,6 @@ def __new__(cls, name, bases, namespace,
         self.__args__ = tuple(Ellipsis if a is _TypingEllipsis else
                               () if a is _TypingEmpty else
                               a for a in args) if args else None
-        self.__origin__ = origin
-        self.__extra__ = extra
         # Speed hack (https://github.com/python/typing/issues/196).
         self.__next_in_mro__ = _next_in_mro(self)
         # Preserve base classes on subclassing (__bases__ are type erased now).
@@ -1082,6 +1066,42 @@ def __init__(self, *args, **kwargs):
         super(GenericMeta, self).__init__(*args, **kwargs)
         if isinstance(self.__extra__, abc.ABCMeta):
             self._abc_registry = self.__extra__._abc_registry
+            self._abc_cache = self.__extra__._abc_cache
+        elif self.__origin__ is not None:
+            self._abc_registry = self.__origin__._abc_registry
+            self._abc_cache = self.__origin__._abc_cache
+
+    # _abc_negative_cache and _abc_negative_cache_version
+    # realised as descriptors, since GenClass[t1, t2, ...] always
+    # share subclass info with GenClass.
+    # This is an important memory optimization.
+    @property
+    def _abc_negative_cache(self):
+        if isinstance(self.__extra__, abc.ABCMeta):
+            return self.__extra__._abc_negative_cache
+        return _gorg(self)._abc_generic_negative_cache
+
+    @_abc_negative_cache.setter
+    def _abc_negative_cache(self, value):
+        if self.__origin__ is None:
+            if isinstance(self.__extra__, abc.ABCMeta):
+                self.__extra__._abc_negative_cache = value
+            else:
+                self._abc_generic_negative_cache = value
+
+    @property
+    def _abc_negative_cache_version(self):
+        if isinstance(self.__extra__, abc.ABCMeta):
+            return self.__extra__._abc_negative_cache_version
+        return _gorg(self)._abc_generic_negative_cache_version
+
+    @_abc_negative_cache_version.setter
+    def _abc_negative_cache_version(self, value):
+        if self.__origin__ is None:
+            if isinstance(self.__extra__, abc.ABCMeta):
+                self.__extra__._abc_negative_cache_version = value
+            else:
+                self._abc_generic_negative_cache_version = value
 
     def _get_type_vars(self, tvars):
         if self.__origin__ and self.__parameters__:
@@ -1181,6 +1201,17 @@ def __getitem__(self, params):
                               extra=self.__extra__,
                               orig_bases=self.__orig_bases__)
 
+    def __subclasscheck__(self, cls):
+        if self.__origin__ is not None:
+            if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']:
+                raise TypeError("Parameterized generics cannot be used with class "
+                                "or instance checks")
+            return False
+        if self is Generic:
+            raise TypeError("Class %r cannot be used with class "
+                            "or instance checks" % self)
+        return super(GenericMeta, self).__subclasscheck__(cls)
+
     def __instancecheck__(self, instance):
         # Since we extend ABC.__subclasscheck__ and
         # ABC.__instancecheck__ inlines the cache checking done by the

src/typing.py

@@ -856,19 +856,6 @@ def _next_in_mro(cls):
     return next_in_mro
 
 
-def _valid_for_check(cls):
-    """An internal helper to prohibit isinstance([1], List[str]) etc."""
-    if cls is Generic:
-        raise TypeError("Class %r cannot be used with class "
-                        "or instance checks" % cls)
-    if (
-        cls.__origin__ is not None and
-        sys._getframe(3).f_globals['__name__'] not in ['abc', 'functools']
-    ):
-        raise TypeError("Parameterized generics cannot be used with class "
-                        "or instance checks")
-
-
 def _make_subclasshook(cls):
     """Construct a __subclasshook__ callable that incorporates
     the associated __extra__ class in subclass checks performed
@@ -879,7 +866,6 @@ def _make_subclasshook(cls):
         # Registered classes need not be checked here because
         # cls and its extra share the same _abc_registry.
         def __extrahook__(subclass):
-            _valid_for_check(cls)
             res = cls.__extra__.__subclasshook__(subclass)
             if res is not NotImplemented:
                 return res
@@ -894,7 +880,6 @@ def __extrahook__(subclass):
     else:
         # For non-ABC extras we'll just call issubclass().
         def __extrahook__(subclass):
-            _valid_for_check(cls)
             if cls.__extra__ and issubclass(subclass, cls.__extra__):
                 return True
             return NotImplemented
@@ -981,6 +966,7 @@ def __new__(cls, name, bases, namespace,
         # remove bare Generic from bases if there are other generic bases
         if any(isinstance(b, GenericMeta) and b is not Generic for b in bases):
             bases = tuple(b for b in bases if b is not Generic)
+        namespace.update({'__origin__': origin, '__extra__': extra})
         self = super().__new__(cls, name, bases, namespace, _root=True)
 
         self.__parameters__ = tvars
@@ -989,8 +975,6 @@ def __new__(cls, name, bases, namespace,
         self.__args__ = tuple(... if a is _TypingEllipsis else
                               () if a is _TypingEmpty else
                               a for a in args) if args else None
-        self.__origin__ = origin
-        self.__extra__ = extra
         # Speed hack (https://github.com/python/typing/issues/196).
         self.__next_in_mro__ = _next_in_mro(self)
         # Preserve base classes on subclassing (__bases__ are type erased now).
@@ -1009,13 +993,49 @@ def __new__(cls, name, bases, namespace,
             self.__subclasshook__ = _make_subclasshook(self)
         if isinstance(extra, abc.ABCMeta):
             self._abc_registry = extra._abc_registry
+            self._abc_cache = extra._abc_cache
+        elif origin is not None:
+            self._abc_registry = origin._abc_registry
+            self._abc_cache = origin._abc_cache
 
         if origin and hasattr(origin, '__qualname__'):  # Fix for Python 3.2.
             self.__qualname__ = origin.__qualname__
         self.__tree_hash__ = (hash(self._subs_tree()) if origin else
                               super(GenericMeta, self).__hash__())
         return self
 
+    # _abc_negative_cache and _abc_negative_cache_version
+    # realised as descriptors, since GenClass[t1, t2, ...] always
+    # share subclass info with GenClass.
+    # This is an important memory optimization.
+    @property
+    def _abc_negative_cache(self):
+        if isinstance(self.__extra__, abc.ABCMeta):
+            return self.__extra__._abc_negative_cache
+        return _gorg(self)._abc_generic_negative_cache
+
+    @_abc_negative_cache.setter
+    def _abc_negative_cache(self, value):
+        if self.__origin__ is None:
+            if isinstance(self.__extra__, abc.ABCMeta):
+                self.__extra__._abc_negative_cache = value
+            else:
+                self._abc_generic_negative_cache = value
+
+    @property
+    def _abc_negative_cache_version(self):
+        if isinstance(self.__extra__, abc.ABCMeta):
+            return self.__extra__._abc_negative_cache_version
+        return _gorg(self)._abc_generic_negative_cache_version
+
+    @_abc_negative_cache_version.setter
+    def _abc_negative_cache_version(self, value):
+        if self.__origin__ is None:
+            if isinstance(self.__extra__, abc.ABCMeta):
+                self.__extra__._abc_negative_cache_version = value
+            else:
+                self._abc_generic_negative_cache_version = value
+
     def _get_type_vars(self, tvars):
         if self.__origin__ and self.__parameters__:
             _get_type_vars(self.__parameters__, tvars)
@@ -1114,6 +1134,17 @@ def __getitem__(self, params):
                               extra=self.__extra__,
                               orig_bases=self.__orig_bases__)
 
+    def __subclasscheck__(self, cls):
+        if self.__origin__ is not None:
+            if sys._getframe(1).f_globals['__name__'] not in ['abc', 'functools']:
+                raise TypeError("Parameterized generics cannot be used with class "
+                                "or instance checks")
+            return False
+        if self is Generic:
+            raise TypeError("Class %r cannot be used with class "
+                            "or instance checks" % self)
+        return super().__subclasscheck__(cls)
+
     def __instancecheck__(self, instance):
         # Since we extend ABC.__subclasscheck__ and
         # ABC.__instancecheck__ inlines the cache checking done by the