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

On Mon, 5 Nov 2007, Junio C Hamano wrote:

Daniel Barkalow [off-list ref] writes:

quoted

The idea is to keep the open connection in the data for the transport in 
between getting the list of refs and doing anything further. This 
therefore moves the connection-handling aspects outside of fetch-pack() 
and handles them primarily in transport.c.

The idea is very sound.  The scripted version of git-fetch used
a separate ls-remote only because peek-remote and fetch-pack
were separate programs.

I figured that had to be the case, due to the way the protocol acts at the 
beginning.

quoted

... 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.

It would be nice if this could continue: "C: I also want these, S: ok, 
heard enough, C: done, S: another packfile is here"; we should be able to 
identify the end of the packfile on both ends to resume doing other 
things.

Or, maybe, "C: I also want these single objects, S: here's a thin pack of 
them", since it's exclusively tags pointing to objects we have just 
gotten.

	-Daniel
*This .sig left intentionally blank*