Emacs repository benchmark: bzr and git

[Stefan Monnier]

> I've tried to get a list of things that Bazaar needs to improve from
> trawling through this list and bugs on the Bazaar tracker.

> So far I have:
>   * bzr log needs to be much faster for single files[1] and for
> subsets of history.
>   * bzr diff -r <something> needs to take at most a couple of seconds
>   * bzr st <single file> needs to be instantaneous.
>   * Must be able to get the diff between the current branch and its
> parent very quickly.

Actually, this last point is the same as the second.  As for the
remaining three they come in this order:

   * bzr st <single file> needs to be instantaneous.
   * bzr diff -r <something> needs to take at most a couple of seconds
   * bzr log needs to be much faster for single files[1] and for
     subsets of history.

The first is very serious since it make vc-bzr unusable.  Also it's very
easy to fix by providing a new option that prevents outputting the list
of pending changes (which is the operation that takes a long time, and
we don't need that info anyway).

> These are all performance related. I can't recall coming across any
> other blockers, but then I haven't been following every email on this
> & related threads.

Also, given the current performance problems, we haven't tried
much more.  E.g. I have no idea how easy it will be to keep Bzr-Emacs in
sync with Gnus's repository.

> [1] Bazaar tends to assume you want to work with the whole tree for
> every operation.  I think this might be the root cause of a lot of the
> disappointment in Bazaar's performance.

Actually, as far as I can tell, most of the above problems are unrelated
to "single file vs whole tree": it takes about the same time to do it on
a single file than on the whole tree.


        Stefan