29.08.18 17:33, Matthieu Dartiailh пише:
I tried to look at the public C API for a way to call an unbound method with a
minimal cost (in term of speed and memory). It seems to me, but please correct
me if I am wrong, that one cannot call a MethodDef using only the public API.
To use the public C API, one has to use PyCFunction_Call (or a variant) that
expect a PyCFunctionObject which binds a the MethodDef to an instance. In my
case, to avoid creating a temporary PyCFunctionObject each time I call
list.insert on my custom subclass instance, I have to store that
PyCFunctionObject for each instance. But this means storing 7
PyCFunctionObject per instance (one for each method of list I need to wrap). So
I can either use the public API and increase the memory footprint or slow down
the code by creating PyCFunctionObject for each call
, or use large amount of the private API.
Am I missing something ?
In general, you need to cache the unbound method object, and call it
with self as the first argument.
list_insert = PyObject_GetAttrString((PyObject *)&PyList_Type, "insert");
...
res = PyObject_CallFunctionObjArgs(list_insert, self, index, value, NULL);
But in the particular case of the insert method it will be easier and
more efficient to use PyList_Insert().
--
https://mail.python.org/mailman/listinfo/python-list
