Greg Stein <gstein@lyra.org> writes:
> Subversion has always intended to use the "linking" model for copies. The
> question is whether we create a new revision to remember the operation.
I think JimB will best be able to follow up further on this thread.
-K
> On Wed, Jan 03, 2001 at 12:38:39AM -0800, Peter Vogel wrote:
> > My personal opinion is that *copying* implies no need
> > to maintain prior history, but *linking* implies that
> > the two files share a common history and future (though
> > the futures may be divergent (branches, etc)).
> >
> > Again, personal opinion, but based on 12 years
> > experience with this sort of thing...
> >
> > -Peter
> > --
> > Peter A. Vogel
> > Manager, Configuration Management
> > Arsin Corporation
> > 4800 Great America Parkway Suite 425, Santa Clara, CA 95054
> >
> >
> >
> >
> > > -----Original Message-----
> > > From: Greg Stein [mailto:gstein@lyra.org]
> > > Sent: Tuesday, January 02, 2001 8:47 PM
> > > To: dev@subversion.tigris.org
> > > Subject: FS copy model
> > >
> > >
> > > Okay... this isn't related to the network layer. Honest!
> > >
> > > :-)
> > >
> > >
> > > Let's say that I have the following items of interest in the FS:
> > >
> > > PATH ID
> > > / 1.37
> > > /A 50.7
> > > /A/foo 73.4
> > > /B 61.8
> > >
> > > Now I make a copy of /A/foo to /B/foo. The IDs are now:
> > >
> > > / 1.38
> > > /A 50.7
> > > /A/foo 73.4
> > > /B 61.9
> > > /B/foo 73.4
> > >
> > > And one more copy to /B/bar:
> > >
> > > / 1.39
> > > /A 50.7
> > > /A/foo 73.4
> > > /B 61.10
> > > /B/foo 73.4
> > > /B/bar 73.4
> > >
> > > In each copy, you'll note that only the directory's ID
> > > changes because I'm
> > > not actually making any change to 73.4. We see /B change and
> > > the resulting
> > > bubble-up to /.
> > >
> > >
> > > Question: should /B/foo and /B/bar know that they came from
> > > /A/foo? To put
> > > it another way, when somebody pulls up a change log for /B/foo:
> > >
> > > 1) they will see the changes from 73.1 thru 73.4
> > > 2) will they *also* see that /B/foo was copied from /A/foo?
> > >
> > > In the above handling of node IDs and copying, the answer is
> > > "No, they have
> > > no way of knowing whether /B/foo was copied from /A/foo or
> > > from /B/bar. The
> > > user *might* have a way to see that they are related, but only the
> > > inspection of parent directory changes will show the actual
> > > ordering of
> > > copies. Even then, the comment for the revision may not
> > > specify what was
> > > copied from where."
> > >
> > > Another alternative is to spin a new revision of 73.4 and insert some
> > > property / comment / marker saying that it was copied from
> > > /A/foo. The final
> > > ID table would look like:
> > >
> > > / 1.39
> > > /A 50.7
> > > /A/foo 73.4
> > > /B 61.10
> > > /B/foo 73.4.1.1
> > > /B/bar 73.4.2.1
> > >
> > >
> > > Which approach are we using today? (has it been considered?)
> > > Is that the
> > > preferred approach?
> > >
> > > I think another way to phrase the question is:
> > >
> > > Do we record a copy from one location to another in the FS?
> > > If so, then
> > > how is it recorded? Is there a machine-readable marker? (the checkin
> > > comment is not machine-readable)
> > >
> > > Cheers,
> > > -g
> > >
> > > --
> > > Greg Stein, http://www.lyra.org/
> > >
>
> --
> Greg Stein, http://www.lyra.org/
Received on Sat Oct 21 14:36:19 2006