[PATCH evemu 08/11] py: Add _callstr() - returns str object

[Benjamin Tissoires]

On Mon, Jan 6, 2014 at 12:56 PM, Daniel Martin <consume.noise at gmail.com>wrote:

> On Fri, Jan 03, 2014 at 11:11:30AM +1000, Peter Hutterer wrote:
> > On Thu, Jan 02, 2014 at 10:47:58PM +0100, Daniel Martin wrote:
> > > Python 3 handles bytes objects differently. Therefor the result check
> in
> > > _call() raises a "TypeError: unorderable types: bytes() < int()".
> > >
> > > Add an additional _callstr() function, which converts the bytes object
> > > to str on its way, to fix this error.
> > >
> > > Signed-off-by: Daniel Martin <consume.noise at gmail.com>
> > > ---
> > >  python/evemu/__init__.py | 2 +-
> > >  python/evemu/base.py     | 7 +++++++
> > >  python/evemu/const.py    | 1 +
> > >  3 files changed, 9 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/python/evemu/__init__.py b/python/evemu/__init__.py
> > > index 21cd22f..20d82b5 100644
> > > --- a/python/evemu/__init__.py
> > > +++ b/python/evemu/__init__.py
> > > @@ -199,7 +199,7 @@ class Device(object):
> > >          """
> > >          func = self._evemu.get_lib().evemu_get_name
> > >          func.restype = ctypes.c_char_p
> > > -        return self._evemu._call(func, self._evemu_device)
> > > +        return self._evemu._callstr(func, self._evemu_device)
> >
> > if you have _callstr it should also handle the func.restype
> automatically.
> > having said that, the _call* interface is rather meh. python allows for a
> > more expressive approach (and it's internal here anyway) so maybe
> something
> > like this would be better:
> >
> > def _call(self, func, return_type=int, allow_zero=True, *parameters):
> >         if return_type == str:
> >                 func.restype = ctypes.c_char_p
> >         result = api_call(*parameters)
> >         if not allow_zero and result == 0 and self.get_c_errno() != 0:
> >                 error...
> >         return result
> >
> > which would allow us to get rid of _call0 which is not intuitive at all
> and
> > have the callers do somethin like:
> >
> >       self._evemu._call(func, return_type=str, self._evemu_device)
> >       self._evemu._call(func, allow_zero=False, self._evemu_device)
>
> I've left this patch in the series. So, that the initial patches don't
> change to much.
>
> But, with the added patches the _call stuff has been replaced, which
> makes it possible to just:
>     self._libevemu.evemu_get_name(self._evemu_device)
>
>
To me, this seems much better than the _call, api (or mess, should I say?).
Why bother adding this patch if you are about to kill it later?

Cheers,
Benjamin


A callback function is registered at such calls to check for an expected
> return value, i.e. for evemu_get_name the callback is expect_not_none().
>
> The wrappers could've even been improved by adding names for the
> arguments. With that it'd be possible to pass keyword arguments, i.e.:
>     self._libevemu.evemu_get_name(dev=self._evemu_device)
> Not usefull for functions with one argument only, but nifty when having
> more and by using kw args the order of arguments becomes irrelevant.
> I've tested it, but didn't added it at the end as it didn't looked that
> necessary to have.
>
> > >
> > >      @property
> > >      def id_bustype(self):
> > > diff --git a/python/evemu/base.py b/python/evemu/base.py
> > > index 0f2fa97..66ea36a 100644
> > > --- a/python/evemu/base.py
> > > +++ b/python/evemu/base.py
> > > @@ -28,6 +28,13 @@ class EvEmuBase(object):
> > >                  api_call.__name__, self.get_c_error()))
> > >          return result
> > >
> > > +    def _callstr(self, api_call, *parameters):
> > > +        result = api_call(*parameters)
> > > +        if result == None and self.get_c_errno() != 0:
> > > +            raise exception.ExecutionError("%s: %s" % (
> > > +                api_call.__name__, self.get_c_error()))
> > > +        return result.decode(const.ENCODING)
> > > +
> > >      def get_c_errno(self):
> > >          return ctypes.get_errno()
> > >
> > > diff --git a/python/evemu/const.py b/python/evemu/const.py
> > > index bd1bcde..257963e 100644
> > > --- a/python/evemu/const.py
> > > +++ b/python/evemu/const.py
> > > @@ -1,3 +1,4 @@
> > > +ENCODING = "iso8859-1"
> > >  LIB = "libevemu.so"
> > >  UINPUT_NODE = "/dev/uinput"
> > >  MAX_EVENT_NODE = 32
> > > --
> > > 1.8.5.2
> > >
> > > _______________________________________________
> > > Input-tools mailing list
> > > Input-tools at lists.freedesktop.org
> > > http://lists.freedesktop.org/mailman/listinfo/input-tools
> _______________________________________________
> Input-tools mailing list
> Input-tools at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/input-tools
>