Code review comment for lp:~spiv/bzr/inventory-delta

On Thu, 2009-07-16 at 16:06 +0000, John A Meinel wrote:
>
> (3) is an issue I'd like to see addressed, but which Robert seems
> particularly unhappy having us try to do. (See other bug comments, etc
> about how other systems don't do it and he feels it isn't worth
> doing.)

I'd like to be clear about this. I'd be ecstatic *if* we can do it well
and robustly. However I don't think it is *at all* easy to that. If I'm
wrong - great.

I'm fine with keeping IDS for local fetches. But when networking is
involved IDS is massively slower than the streaming codepath.

> It was fairly straightforward to do with IDS, the argument I think
> from
> Robert is that the client would need to be computing whether it has a
> 'complete' set and thus can commit the current write group. (the
> *source* knows these sort of things, and can just say "and now you
> have
> it", but the client has to re-do all that work to figure it out from a
> stream.)

I think that aspect is simple - we have a stream subtype that says
'checkpoint'. Its the requirement to do all that work that is, I think
problematic - and thats *without* considering stacking, which makes it
hugely harder.

-Rob