Re: [Monotone-devel] Re: netsync question

[Markus Schiltknecht]

On Sat, 2006-04-29 at 12:15 +0100, Bruce Stephens wrote:
> Well, you couldn't use *only* backward deltas.  If you've got
> A->B->C->D and you want to send that to someone who's got A, it's no
> good just sending the backward deltas D->C, C->B, B->A.  

Uhm.. why not? Couldn't this 'someone' just apply the backward deltas
with a 'patch -R' sort of? I begin to question my understanding of a
'delta'...

> You could send the full text of D, and the backward deltas.  Or, I
> guess, send the constructed A->D and the backward deltas.
> 
> That would have the disadvantage that it would be an all-or-nothing
> operation: if the connection died, or there was some verification
> error, then you'd end up with nothing.

...except if you send the fulltext of D. Which is acceptable for initial
pulls. In case of a subsequent pull, I guess 'all-or-nothing' is
acceptable.

Plus it would allow to fetch only the most recent history. Often people
don't care about all the history and only want the most recent revision.
Monotone should then be able to gracefully handle missing revisions and
offer to fetch them when needed.

But I'm sure this has been discussed before... care to give me some
hints?

Regards

Markus