Re: Listing branches with bzr

["Stephen J. Turnbull" <stephen@xemacs.org>]

Lennart Borgman writes:

 > Isn't it doing the same work as on the server?

Yes.

 > Is it the network traffic that makes it so incredibly slow?

Yes.  What you are seeing is bzr using algorithms designed on the
assumption that files are local on each individual file via HTTP.

 > I am thinking about Stephens reply (which I have not had time to
 > respond to). He mentioned that git uses SHA to identify files why bzr
 > does not do that? Is that the cause of the time trouble we are seeing?

As I wrote before, bzr uses a way to identify files that makes
tracking file and directory renames precise and efficient (in git
there is some imprecision and much slower).  For most other purposes,
the bzr file-tracking method and the git content-tracking method lead
to equivalent results with varying degrees of efficiency.  For a few
things git is quite a bit faster, but bzr is not unusable.

In any case it is not the cause of this slowdown.  The cause here
slowdown is that many files are being downloaded by HTTP, and this
would be also be true to some extent for git.  The big difference is
that for some reason Savannah admins think that use of git's smart
server is acceptable, security-wise, but they don't like bzr's.
Hopefully that can be changed soon, but to get things done in time for
the Emacs VCS switch probably only a request from Richard will do.
The Savannah admins don't currently consider installation of the smart
server a high priority (there's an open SR, and they've explicitly
said, "not now, and not soon").

 > I would consider that just as serious as a bug. But maybe there is
 > something I do not understand there.

There is.  Don't worry about it.  This is an administrative problem,
not a technical deficiency in bzr.[1]  Stefan and Karl are on this,
and they're getting help on the technical details that the Savannah
hackers need to know from senior bzr developers.  And you'll soak up
the technical knowledge as you use bzr; it's not something you need to
know to get started.



Footnotes: 
[1]  Unless you consider having *both* a smart, efficient server and a
very easy way for any Joe Hacker with a home page to give others
access to his bzr branch a bad thing. :-)