[Cython] Speedup module-level lookup

[Vitja Makarov]

2012/1/19 Vitja Makarov <vitja.makarov at gmail.com>:
> 2012/1/19 Robert Bradshaw <robertwb at math.washington.edu>:
>> I think the right thing to do here is make all module-level globals
>> into "cdef public" attributes, i.e. C globals with getters and setters
>> for Python space. I'm not sure whether this would best be done by
>> creating a custom dict or module subclass, but it would probably be
>> cleaner and afford much more than a 1.6x speedup.
>>
>> - Robert
>>
>> On Wed, Jan 18, 2012 at 12:30 PM, Vitja Makarov <vitja.makarov at gmail.com> wrote:
>>> I tried to optimize module lookups (__pyx_m) by caching internal PyDict state.
>>>
>>> In this example bar() is 1.6 time faster (500us against 842us):
>>>
>>> C = 123
>>> def foo(a):
>>>     return C * adef bar():
>>>     for i in range(10000):        foo(i)
>>> Here is proof of
>>> concept:https://github.com/vitek/cython/commit/1d134fe54a74e6fc6d39d09973db499680b2a8d9
>>>
>>> So the question is: does it worth it?
>>>
>
> Yes, nice idea.
> It's possible to subclass PyModuleObject and I didn't find any use of
> PyModule_CheckExact() in CPython's sources:
>
> import types
> import sys
>
> global_foo = 1234
>
> class CustomModule(types.ModuleType):
>    def __init__(self, name):
>        types.ModuleType.__init__(self, name)
>        sys.modules[name] = self
>
>    @property
>    def foo(self):
>        return global_foo
>
>    @foo.setter
>    def foo(self, value):
>        global global_foo
>        global_foo = value
>
> CustomModule('foo')
>
> import foo
> print foo.foo
>

But this seems to break globals().

-- 
vitja.