darcs performance

[Neil Mitchell]

Hi Sven,

> When getting a repo via HTTP, darcs seems to be *much* faster than via SSH.
> Here as an example the cpphs repo, 3.7 patches per second vs. 0.7 patches per
> second (almost unusable for large/old repos):

The difference is massive, I almost think that 5 times faster is an
understatement. If there are no patches to pull, I think the factor is
higher.

The Yhc people all check out over HTTP, and we have a "scons push"
target, which runs darcs with the ssh url and --no-set-default.

Thanks

Neil