On Sat, 2010-08-14 at 19:42 +0100, Richard W.M. Jones wrote:
> On Fri, Aug 13, 2010 at 02:20:51PM -0400, David Malcolm wrote:
> > (Sorry about the length of this email)
> >
> > Python 2.7 deprecated the PyCObject API in favor of a new "capsule" API.
> > http://docs.python.org/dev/whatsnew/2.7.html#capsules
> > (b) try to fix the ones that are self-contained; send fixes upstream
>
> I couldn't really tell from the link above how one can migrate code.
> Any suggestion how to change the code below? Variants of this are
> used in both libvirt and libguestfs.
>
> typedef struct {
> PyObject_HEAD
> guestfs_h *g;
> } Pyguestfs_Object;
>
> static guestfs_h *
> get_handle (PyObject *obj)
> {
> assert (obj);
> assert (obj != Py_None);
> return ((Pyguestfs_Object *) obj)->g;
> }
FWIW, this code looks a little dubious to me: obj is actually a
PyCObject, which is:
typedef struct {
PyObject_HEAD
void *cobject;
void *desc;
void (*destructor)(void *);
} PyCObject;
It works because Pyguestfs_Object->g has the same offset from the top of
the struct as the PyCObject->cobject field, but if PyCObject had changed
layout it would crash.
Do you use Pyguestfs_Object elsewhere in the code? Looking at
libguestfs-1.5.2/src/generator.ml it doesn't seem to be, so it looks
like get_handle should have read:
static guestfs_h *
get_handle (PyObject *obj)
{
assert (obj);
assert (obj != Py_None);
return (guestfs_h*)PyCObject_AsVoidPtr(obj);
}
> static PyObject *
> put_handle (guestfs_h *g)
> {
> assert (g);
> return
> PyCObject_FromVoidPtrAndDesc ((void *) g, (char *) "guestfs_h", NULL);
> }
Porting to the capsule API, I believe the code needs to look something
like this (caution: untested):
static guestfs_h *
get_handle (PyObject *obj)
{
assert (obj);
assert (obj != Py_None);
return (guestfs_h*)PyCapsule_GetPointer(obj, "guestfs_h");
}
static PyObject *
put_handle (guestfs_h *g)
{
assert (g);
return PyCapsule_New((void *) g, "guestfs_h", NULL);
}
--
devel mailing list
[email protected]
https://admin.fedoraproject.org/mailman/listinfo/devel
