[Libguestfs] Re: [PATCH nbdkit v2] pattern: Accurately update b & offset in loop

On Mon, Nov 06, 2023 at 09:09:28AM +0000, Daniel P. Berrangé wrote: > On Fri, Nov 03, 2023 at 03:44:44PM -0500, Eric Blake wrote: > > On Fri, Nov 03, 2023 at 08:32:41PM +0000, Richard W.M. Jones wrote: > > > It's better to update the 'b' pointer and the 'offset' using the > > > calculated increment 'n', rather than using '8-o' which might be > > > larger than the remainder of the buffer. Previously we could create a > > > dangling pointer beyond the end of the output buffer, and this should > > > not matter, but it's best not to do this if we can easily avoid it. > > > > > > Also improve the test by replacing qemu-io with nbdsh. It is able to > > > make non-aligned requests so we can now test those. > > > --- > > > plugins/pattern/pattern.c | 4 +- > > > tests/test-pattern.sh | 129 ++++++++++++++++++++++---------------- > > > 2 files changed, 77 insertions(+), 56 deletions(-) > > > > > > + > > > +# Run nbdkit-pattern-plugin. Use a disk > 4G so we can test 2G and 4G > > > +# boundaries. > > > +nbdkit pattern 5G --run 'nbdsh -u "$uri" -c -' <<EOF > > > + > > > +# Generate the expected pattern in the given range. > > > +# This only works for 8-byte aligned ranges. > > > +def generated_expected(start,end): > > > > I think Python prefers a space after that comma. > > FWIW, rather than reviewing code style, I can recommend just feeding > any python code through 'black'. It is an opinionated python code > formatter intended to bring a consistent style to all python programs. We use flake8 in the test suite, but it doesn't catch code embedded inside shell scripts as happens here. I had a look at the documentation just now but it doesn't seem there's any way to do that.