Re: [PATCH v4 03/18] kunit: test: add string_stream a std::stream like string builder

From: Brendan Higgins
Date: Tue Jun 04 2019 - 20:23:43 EST

On Fri, May 17, 2019 at 10:43 AM Stephen Boyd <sboyd@xxxxxxxxxx> wrote:
> Quoting Brendan Higgins (2019-05-14 15:16:56)
> > A number of test features need to do pretty complicated string printing
> > where it may not be possible to rely on a single preallocated string
> > with parameters.
> >
> > So provide a library for constructing the string as you go similar to
> > C++'s std::string.
> >
> > Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> > Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> Is there any reason why we can't use the seqfile API for this? These
> both share a similar goal, formatting strings into a buffer to be read
> later. Maybe some new APIs would be needed to extract the buffer
> differently, but I hope we could share the code.

I can see why you are asking. It seems as though they are trying to do
*similar* things, and it seems possible that we might be able to
extract some common functionality out of seq_file that could replace
this; however, it looks like it would be require a significant
refactoring of seq_file to separate out the file system specific bits
from the more general stringbuilder functionality.

In my opinion, a refactoring like this makes no sense in this
patchset; it probably belongs in its own patchset (preferably as a
follow on). I also am not sure if the FS people would appreciate
indirection that serves them no benefit, but I can ask if you like.

> If it can't be used, can you please add the reasoning to the commit text
> here?

Will do.