Bazaar dirstate locking (was: lock_* API change)

[Eli Zaretskii]

> Date: Tue, 18 May 2010 15:46:23 +1200
> From: Robert Collins <robertc at robertcollins.net>
> Cc: Eli Zaretskii <eliz at gnu.org>, bazaar at lists.canonical.com, monnier at iro.umontreal.ca, 
> 	Karl Fogel <kfogel at red-bean.com>
> 
> Data point: the main reason commits take minutes is because we're
> manipulating a non-trivial-size database using VFS operations, over
> high (> 1ms) latency, low bandwidth links.

Can you be more specific, please?  fencepost.gnu.org is also > 1ms
latency, and yet using bzr on it with savannah.gnu.org is lightning
fast.  Also, does the latency matter more than bandwidth?

IOW, where you expect the break-even point for these two parameters to
be, in your experience and according to your knowledge?

> Karl Fogel is working on Savannah to rectify this.

Sigh.  I'm grateful to Karl, but it's been almost 6 months since Emacs
switched to Bazaar, and bzr+ssh still looks like a pipe dream.  There
isn't even an ETA yet.  I'm starting to think that if this is so
difficult and needs so much labor, maybe it will never happen.  If you
read emacs-devel, you will see that Bazaar loses Emacs contributors
almost every day -- they switch to other VCSs.  If someone here feels
as bad about that as I do, perhaps you should do something about that.

> Until its fixed, I *totally expect* operations to be slow and take
> ages.

Btw, what would you expect to be a reasonable time for "update" and
"commit" with bzr+ssh, over a link with ~100ms latency and 3Mb
bandwidth?  Someone said on the Emacs list not to expect any panacea
from that, so I'm curious what do Bazaar developers think about that.

Thanks.