Re: [PATCH] Add persistent-https to contrib

On Thu, May 24, 2012 at 1:29 PM, Jeff King [off-list ref] wrote:

On Thu, May 24, 2012 at 12:33:08PM -0700, Shawn O. Pearce wrote:

quoted

$ (for i in {1..5}; do time git ls-remote
persistent-https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux

quoted

/dev/null;done) 2>&1 | grep real

real  0m0.208s
real  0m0.085s
real  0m0.079s
real  0m0.067s
real  0m0.059s

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?

I don't think that is grounds for rejecting this patch; obviously it is
working for you guys, and it is available right now, and it is only
going into contrib/ anyway. But a curl solution seems like a cleaner
long-term fix, and would benefit all curl users. It is even mentioned in
curl's doc/TODO file. :)

Well, this helper "solution" also has the benefit of HTTP keep-alive
working across Git command invocations. Its common for servers to use
a 5 minute keep-alive on an HTTP 1.1 connection. Git-over-HTTP
commonly uses Transfer-Encoding: chunked on replies, so keep-alive
will generally just work, even though a pack stream's length isn't
known in advance. Because the helper is an external process holding
that connection open, we also benefit from being able to reuse an
existing TCP connection to the server.

But sure, it would be nice if libcurl was able to share SSL sessions
across Git command invocations without this black magic proxy thing.