Re: [PATCH 1/4] pylibfdt: add Property.as_stringlist()

[David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>]

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On Wed, Jan 05, 2022 at 04:48:31PM -0600, Rob Herring wrote:
> On Sat, Dec 25, 2021 at 7:26 AM Luca Weiss <luca-IfPCFPJWly+lVyrhU4qvOw@public.gmane.org> wrote:
> >
> > Add a new method for decoding a string list property, useful for e.g.
> > the "reg-names" property.
> >
> > Also add a test for the new method.
> >
> > Signed-off-by: Luca Weiss <luca-IfPCFPJWly+lVyrhU4qvOw@public.gmane.org>
> > ---
> >  pylibfdt/libfdt.i       | 7 +++++++
> >  tests/pylibfdt_tests.py | 8 ++++++++
> >  2 files changed, 15 insertions(+)
> >
> > diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
> > index 9ccc57b..c81b504 100644
> > --- a/pylibfdt/libfdt.i
> > +++ b/pylibfdt/libfdt.i
> > @@ -724,6 +724,13 @@ class Property(bytearray):
> >              raise ValueError('Property contains embedded nul characters')
> >          return self[:-1].decode('utf-8')
> >
> > +    def as_stringlist(self):
> > +        """Unicode is supported by decoding from UTF-8"""
> > +        if self[-1] != 0:
> > +            raise ValueError('Property lacks nul termination')
> > +        parts = self[:-1].split(b'\x00')
> > +        return list(map(lambda x: x.decode('utf-8'), parts))
> 
> Doesn't this result in multiple decode() calls when a single one would work:
> 
> return data[:-1].decode(encoding='ascii').split('\0')

Uh.. I guess?  I feel like the split-then-decode makes more logical
sense, since it's splitting a bytestring, then decoding the pieces as
utf-8 strings.  That makes sense to me given that raw properties are
bytestrings and can included multiple different datatypes and
encodings in general.

In this specific case, decode-then-split would be fine as well, since
\u00000 works as a separator unambiguously, but it still seems
conceptually muddier to me.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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