Re: [RFC PATCH 02/10] Move textconv_object to be with other textconv methods

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> The specific helpers have less visibility, which is good. The public
> functions a() and b() were already public, so no change. But now the
> common helper is public, too, even though nobody except a() and b() care
> about it.
>
> So it's a tradeoff. And the important question is: is the bleed-over
> between a() and b() worse than the common bits being made public?

At this point you are saying the same thing as I said ;-) 

I haven't touched diff.c for a while, but my impression was that it
was already a smallest logical unit, especially since some bits like
diff-lib.c (the interface for the front-end programs to drive the
machinery via the three standard pairs of sources) and ws.c (diff
subsystem to deal with whitespace errors) are already split out (and
needless to say, the diffcore transformations are all in their own
separate files).  Over time people may have added what does not
belong there merely for convenience, which may want to get ejected,
but I do not think of many instances of them offhand.

    ... goes and looks ...

It appears that the textconv related helpers (which was where this
discussion thread started from) could be first restructured so that
they do not depend on diff_filespec and turned into a more generic
"I have this path and a blob object name, please run textconv to it
and..." interface and then moved out of the file into its own
textconv.[ch].  It does not need access to quite a few fields in
diff_filespec structure (e.g.  it shouldn't care what filemode the
thing has).  The diff machinery wants the result in a contiguous
piece of memory and that could be a good starting point, but I said
"and..." above because I am not sure if it is the best generic
thing the restructured interface can do to the result.