From: Eric S. Raymond <esr@thyrsus.com>
Date: Wed, 18 Dec 2013 00:21:22 GMT
Subject: Re: I have end-of-lifed cvsps
Message-ID: <20131218002122.GA20152@thyrsus.com>
In-Reply-To: <CANQwDwdQZGhR=hhFHe7wRAeNej_F5fHspN7+f-LiJu06utwC-w@mail.gmail.com>

Jakub Narębski <jnareb@gmail.com>:
> > No, cvs-fast-export does not have --export-marks. It doesn't generate the
> > SHA1s that would require. Even if it did, it's not clear how that would help.
> 
> I was thinking about how the following part of git-fast-export
> `--import-marks=<file>`
> 
>   Any commits that have already been marked will not be exported again.
>   If the backend uses a similar --import-marks file, this allows for incremental
>   bidirectional exporting of the repository by keeping the marks the same
>   across runs.

I understand that. But it's not relevant - cvs-fast-import doesn't know about
git SHA1s, and cannot.
 
> How cvs-fast-export know where to start exporting from in incremental mode?

You give it a cutoff date. This is the same way cvsps-2.x and 3.x worked,
and it's what the cvsimport wrapper expects to pass down.

> BTW. does cvs-fast-export support incremental *output*, or does it
> perform also incremental *work*?

As I tried to explain previously in my response to John Herland, it's
incremental output only.  There is *no* CVS exporter known to me, or
him, that supports incremental work.  That would be at best be impractically
difficult; given CVS's limitations it may be actually impossible. I wouldn't
bet against impossible.

> Anyway, that might mean that generic fast-import stream based incremental
> (i.e. supporting proper thin fetch) remote helper is out of question, perhaps
> writing one for cvs / cvs-fe would bring incremental import from CVS to
> git?

Sorry, I don't understand that.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>