Re: [RFC PATCH] Reduce the number of connects when fetching

[Johannes Sixt <j.sixt@viscovery.net>]

Junio C Hamano schrieb:
> Daniel Barkalow <barkalow@iabervon.org> writes:
>> ... In particular, I don't know if there's a way to have the 
>> connection end up in a state where objects for more refs can be requested 
>> after some refs have been requested and the resulting objects read.
> 
> The upload-pack protocol goes "S: here are what I have, C: I
> want these, C: I have these, S: ok, continue, C: I have these,
> S: ok, continue, C: I have these, S: ok, I've heard enough, C:
> done, S: packfile is here", so after packfile generation starts
> there is nothing further the downloader can say.
> 
> Otherwise you would be able to do the tag following using the
> same connection, but that is unfortunately not a case.

How about:

S: here are what I have
C: I want these
C: want tags   <-- new
C: I have these
S: ok, continue
C: I have these
S: ok, continue
C: I have these
S: ok, these are the tags  <-- new
S: I've heard enough
C: done
S: packfile is here

The tags that the server provides are those (and only those[*]) that 
reference objects in the packfile that it's going to send.

[*] This way the client doesn't have to figure out which tags it wants; as a 
side-effect it won't accidentally fetch tags for objects that it happens to 
have in the repository, but aren't reachable from any ref (like what used to 
happen).

-- Hannes