[Monotone-devel] Re: nuskool & certs created after a revision

[Lapo Luchini]

Lapo Luchini wrote:
> This way I only have, on each sync, to double-check the certs created at 
> the time of the frontier, which as we well know is usually composed of 
> only a few heads (1, 2, rarely more).

Uh, not so, this does not work as well, seen in the daylight: *which* 
frontier? The very edge of the full DAG may well reside in private 
branches that never get synced, so that can't be used. The "creation 
time revision ID" could be selected within the same branch as the node 
the cert is referring to in the first place, except:
a. it may not have a branch and it's not nice to rely on one
b. as the inclusion/exclusion pattern changes, the frontier "moves" and 
may probably hide my "frontier time creation" certs.

Reading William's and Graydon's answers, I'm not sure I perfectly 
understood their proposal and why it doesn't have the same problem as 
mine. Graydon, what's the relation between your synthetic tree file and 
branches?

Of course one approach that works for sure is gsync-over-branches (and 
sending all of the certs with them as well) and then a merkle-refinement 
just to catch up with those few certs that are created later. I think 
that such a merkle-refinement would be very fast, as only differences in 
certificates created on the edge of previous gsync on the frontier nodes 
could really be different, so very little differences in average.

  Lapo