[Libvir] [PATCH] Add Python binding for virGetVersion

[Mark McLoughlin]

Hey,
	So, the semantics for virGetVersion() are:

  - virGetVersion(&ver, NULL, NULL) returns the libvirt version only

  - virGetVersion(&ver, NULL, &xenVer) returns the libvirt version and
    the xen version

  - virGetVersion(&ver, "foo", &fooVer) returns the libvirt version and 
    the version of the "foo" driver

	Now, your python version:

  - virGetVersion() isn't allowed

  - virGetVersion(None) returns the libvirt version only

  - virGetVersion("foo") returns the libvirt version and the version of 
    the "foo" driver, or throws an exception if the driver isn't
    available

	I'd suggest:

  - virGetVersion() returns the libvirt version only, perhaps as a 
    single integer

  - virGetVersion(None) returns the libvirt version and the Xen version,
    or throws an exception if xen isn't available

  - virGetVersion("foo") returns the libvirt version and the version of 
    the "foo" driver, or throws an exception if the driver isn't
    available

	i.e.

static PyObject *
libvirt_virGetVersion (PyObject *self ATTRIBUTE_UNUSED, PyObject *args)
{
    char *type = NULL;
    unsigned long libVer, typeVer = 0;
    int noTypeVer = 0;
    int c_retval;

    if (PyTuple_Size(args) == 0)
        noTypeVer = 1
    else if (!PyArg_ParseTuple (args, (char *) "z", &type))
        return NULL;

    LIBVIRT_BEGIN_ALLOW_THREADS;

    if (noTypeVer)
        c_retval = virGetVersion (&libVer, NULL, NULL);
    else
        c_retval = virGetVersion (&libVer, type, &typeVer);

    LIBVIRT_END_ALLOW_THREADS;

    if (c_retval == -1) {
        Py_INCREF(Py_None);
        return (Py_None);
    }

    if (noTypeVer)
        return PyInt_FromLong(libVer);
    else
        return Py_BuildValue ((char *) "kk", libVer, typeVer);
}

Cheers,
Mark.