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author | Jeffrey Yasskin <jyasskin@gmail.com> | 2008-02-13 17:58:04 (GMT) |
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committer | Jeffrey Yasskin <jyasskin@gmail.com> | 2008-02-13 17:58:04 (GMT) |
commit | 57bd60b465bddf801d0deb094f5ea671ab89068a (patch) | |
tree | 3b4216a873bddb5a8852cecb177f831a0a49d2d7 | |
parent | 0a40ffb1b30a904eef00bb0c7ce4e18e7ca3dc75 (diff) | |
download | cpython-57bd60b465bddf801d0deb094f5ea671ab89068a.zip cpython-57bd60b465bddf801d0deb094f5ea671ab89068a.tar.gz cpython-57bd60b465bddf801d0deb094f5ea671ab89068a.tar.bz2 |
Working on issue #1762: Brought
./python.exe -m timeit -s 'from fractions import Fraction; f = Fraction(3, 2)' 'isinstance(3, Fraction); isinstance(f, Fraction)'
from 12.3 usec/loop to 3.44 usec/loop and
./python.exe -m timeit -s 'from fractions import Fraction' 'Fraction(3, 2)'
from 48.8 usec to 23.6 usec by avoiding genexps and sets in __instancecheck__
and inlining the common case from __subclasscheck__.
-rw-r--r-- | Lib/abc.py | 16 | ||||
-rw-r--r-- | Lib/test/test_abc.py | 10 |
2 files changed, 24 insertions, 2 deletions
@@ -163,8 +163,20 @@ class ABCMeta(type): def __instancecheck__(cls, instance): """Override for isinstance(instance, cls).""" - return any(cls.__subclasscheck__(c) - for c in set([instance.__class__, type(instance)])) + # Inline the cache checking for new-style classes. + subclass = instance.__class__ + if subclass in cls._abc_cache: + return True + subtype = type(instance) + if subtype is subclass: + if (cls._abc_negative_cache_version == + ABCMeta._abc_invalidation_counter and + subclass in cls._abc_negative_cache): + return False + # Fall back to the subclass check. + return cls.__subclasscheck__(subclass) + return (cls.__subclasscheck__(subclass) or + cls.__subclasscheck__(subtype)) def __subclasscheck__(cls, subclass): """Override for issubclass(subclass, cls).""" diff --git a/Lib/test/test_abc.py b/Lib/test/test_abc.py index 272f61d..ac5f7ee 100644 --- a/Lib/test/test_abc.py +++ b/Lib/test/test_abc.py @@ -83,6 +83,16 @@ class TestABC(unittest.TestCase): self.assertEqual(issubclass(C, A), True) self.assertEqual(isinstance(c, A), True) + def test_isinstance_invalidation(self): + class A: + __metaclass__ = abc.ABCMeta + class B(object): + pass + b = B() + self.assertEqual(isinstance(b, A), False) + A.register(B) + self.assertEqual(isinstance(b, A), True) + def test_registration_builtins(self): class A: __metaclass__ = abc.ABCMeta |