Re: [Jython-dev] question about Python C extensions

[Ype K. <yk...@xs...>]

On Thursday 19 June 2003 11:52, David T. Byrd wrote:
> thanks for the feedback, Ype!
>
> I'm sure we won't find any java library to replace our C++ extension.
> that extension exposes the C API into our proprietary product to Python=
=2E

I seem to be getting lost a bit concerning the interface(s) at which
replacements are to be done...

> Now we want to write a Python adapter to our EAI framework (JMS based),
> and are hoping to carry that API along for free.

In that case it seems best to try and write a thin layer in C/C++ between
this API and JNI/Java. That would allow to access the API from Jython,
see below. Yould then use Jython code between this interface and JMS.

> I agree with you that the JNI wrapper could be a lot of work, which is =
why
> we are hoping to avoid it.  But when you say that getting our extension=
 to
> work depends on "what it does", are there some more specific questions

I meant the amount of java code freely available to reimplement your C++
extension.

> that can help determine the level of difficulty?  What are the basic
> challenges/issues
> that we know about when adding support for C/C++ extensions to Jython?

Since jython access to java is almost seamless, supporting jython boils
down to supporting java, ie. writing a JNI interface from C/C++.

Java package private things, overloaded methods, and interfaces
overriding class private methods sometimes give small problems
when accessed from Jython.
All of these are easily solved, though. They don't influence higher
level design.

Regards,
Ype

=2E..
> > > We are evaluating the use of Jython for a project we have here.
> > >
> > > Our principle objective is basically to merge a JMS framework with
> > > another
> > > framework that utilizes a C/C++ extension to CPython.  With this
> > > extension,
> > > programmers can work in python to access a (locally written) C++ AP=
I.
> > > Questions is,  Will we have any significant
> > > challenge to get our C++ Python extension to work with Jython?
> >
> > That depends on what is does.
> >
> > > Or will we have to resort to a JNI wrapper, which will then be
> > > available to Jython?
> >
> > The JNI wrapper could be quite a bit of work.
> >
> > Step 1 in such cases is to look for Java Library that might be used t=
o
> > (help to) replace the C/C++ extension.
> > So, would it be possible to replace the framework that utilizes the C=
/C++
> > extension by the JMS framework? Or reimplement it in JMS?
> >
=2E..