Re: [Monotone-devel] Request for help adding monotone output to cvs2svn [was: cvs_import feature sponsored]

[Markus Schiltknecht]

Hello Michael,

sorry for not responding to your private mails earlier, I've been ill
the last few days.

Michael Haggerty wrote:
> Graydon Hoare wrote:
> > It probably does not require mentioning, but if possible of course I'd
> > encourage you to do this with a clean enough interface to monotone that
> > other projects can reuse it.

That's worth a thought, although it's certainly a second step. My
primary focus currently is on monotone.

> > While I'm always pleased to have monotone be "best" at something,
> > extracting latent structure from a CVS archive is as you know
> > research-grade inference work, and if you can condense what you learn
> > into a reusable tool it'll probably have greater visibility and longevity.

Agreed, I'm discussing the issue with Michael.

> The tool you are wishing for already exists: cvs2svn [1].  All that is
> missing is a backend to output to monotone, but that should be hackable
> in a day or two.

I've been well aware of cvs2svn at the point I've started my
cvsimport branch for monotone. Back then I've decided *not* to used it
for several reasons:

 - it was heavily disk based, where today conversion can easily be done
in memory.

 - it seemed to be very subversion specific in various aspects, which
also targeted performance.

 - I wanted to learn C++, not python ;-)

> cvs2svn is evolving into a generic tool for making sense of CVS
> repositories and converting to other SCMs.  I've refactored it
> considerably to allow output to other SCMs via output modules, and
> recently added an experimental git backend [2] in only one or two days
> of work.

I'm glad that cvs2svn is also evolving. I've seen your efforts and
appreciate that. Maybe cvs2svn is coming closer to being able to export
to monotone.

But in the meantime I've also got closer to sanitize CVS repositories.
All of this process helped me a lot in understanding that process. And
I'm still happy to discuss some technical issues with you. IIRC that's
how we decided to work together, back then. Share algorithms and
experience but not code. Okay, maybe it was rather me deciding that way...

You seems to only look at this as a waste of effort. I think it very 
well paid off for me and for getting new inputs.

> cvs2svn is a mature project that is very good at understanding almost
> all of CVS's many perversities.  See [3] for a list of cvs2svn's main
> features, most of which would be helpful when converting to monotone.
> The emphasis is on robust conversions with no data loss, and sensible
> translation of CVS idioms.  Its test suite contains an extensive
> collection of strange CVS repositories that we have collected over the
> years, and cvs2svn can convert all of them.  It includes lots of options
> for customizing the conversion.

These are all good reasons to use cvs2svn.

> I'm not a monotone user, but if anybody wants to supply the monotone
> expertise, I'd be happy to work together to write a monotone backend for
> cvs2svn.  (I've already made this offer to Markus Schiltknecht but he
> doesn't seem interested.)  I think it should be easy to get the backend
> running in just a day or two.

Maybe that's possible, yes. None the less, I don't think it will make my
code obsolete.

I'll get back to you with technical aspects on the cvs2svn mailing list 
as soon as I've caught.

Regards

Markus