[PyKDE] Sip support for FILE */PyFileObject

[Nigel Stewart]

Hello all,

We'd like to be able to mix C++ and Python for reading
and writing of heavy-weight streams of data.  Although
QFile can be used across both C++ and Python using PyQt,
it is somewhat more appealing to use native python files
in Python and native FILE * in C/C++.

We've come up with a working solution to convert
a PyFileObject to a FILE * using sip:

     MyWriter(SIP_PYOBJECT);
%MethodCode
         if (PyFile_Check(a0))
             sipCpp = new MyWriter(PyFile_AsFile(a0));
         else
         {
             sipCpp = NULL;
             sipIsErr = 1;
             PyErr_SetNone(PyExc_TypeError);
         }
%End

We can think of two other variations that would
require changes to sip, but would reduce the need
for method code...

(a)

     MyWriter(SIP_PYFILE);
%MethodCode
         sipCpp = new MyWriter(PyFile_AsFile(a0));
%End

(b)

     MyWriter(FILE *);

Another thing we've tried is creating a binding
for struct FILE, but the sip-generated code
is inclined to delete it once passed to
MyWriter...

struct FILE
{
%TypeHeaderCode
#include <cstdio>
using namespace std;
%End

private:
     FILE();
     FILE(const FILE &);
     ~FILE();

%ConvertToTypeCode

     if (sipIsErr == NULL)
         return PyFile_Check(sipPy);

     if (PyFile_Check(sipPy))
     {
        *sipCppPtr = PyFile_AsFile(sipPy);
        return 1;
     }

     *sipIsErr = 1;
     return 0;
%End
};

Any hints or suggestions appreciated.

Regards,

Nigel Stewart