Re: [PATCH] Add persistent-https to contrib

[Jeff King <peff@peff.net>]

On Thu, May 24, 2012 at 01:46:36PM -0700, Shawn O. Pearce wrote:

> >> Nice numbers. And as clever as I find this helper-wrapping-a-helper
> >> solution, I wonder if the right layer for a fix isn't inside curl. It
> >> already keeps an ssl session-id cache in memory; how hard would it be to
> >> turn that into an on-disk cache?
> ...
> > Well, this helper "solution" also has the benefit of HTTP keep-alive
> > working across Git command invocations.

True. It also works even when the server does not support ssl id
caching.

> Here is plaintext HTTP, where the benefit is from HTTP keep-alive:
> 
>   (for i in {1..5}; do time git ls-remote
> http://android.googlesource.com/tools/repo >/dev/null;done) 2>&1  |
> grep real
>   real	0m0.098s
>   real	0m0.097s
>   real	0m0.106s
>   real	0m0.095s
>   real	0m0.105s
> 
>   (for i in {1..5}; do time git ls-remote
> persistent-http://android.googlesource.com/tools/repo >/dev/null;done)
> 2>&1  | grep real
>   real	0m0.134s
>   real	0m0.065s
>   real	0m0.063s
>   real	0m0.061s
>   real	0m0.067s
> 
> Notice we still save 30ms or so in this case. That is about the RTT
> for my workstation to that server. :-)

Nice. I assumed most of your speedup was coming from dropping the SSL
setup, but it seems that a good chunk of it is just the TCP setup.
Thanks for providing numbers.

-Peff