[pypy-dev] cppyy use case question

[wlavrijsen at lbl.gov]

Hi Armin,

> But IMHO the main slow part that should be optimized (probably by
> being rewritten from scratch) is the correspondance between the proxy
> PyObject structures and the real PyPy objects, which is exactly the
> part that interests you too.  It should be possible at least to cope
> with only one dict lookup instead of at least two to do the roundtrip
> "pypy obj -> cpyext obj -> pypy obj".

I'll need to understand first in more detail how cpyext works, but it is
good motivation to know that a dict lookup can be removed. In cppyy, I
have a similar, but reversed, problem: keeping track of all C++ objects
to guarantee object identity. Since the bound object carries a pointer
to the C++ object, a round trip has only one dict lookup, the other
"lookup" being a data member access.

If I understand correctly what you describe above, then perhaps giving
the "PyPyObject by pointer" as payload to the PyObject could help, too.

Best regards,
            Wim
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