Re: Abolishing ChangeLog files

[Dmitry Gutov]

On 29.03.2013 19:36, Eli Zaretskii wrote:
> It's ~/.bzr.log, not ~/bazaar/.bzr.log.

Ah, it works fine, then. Thanks.

> > Thank you. It inspired me to run the same non-interactive tests you did,
> > and indeed the full 'git log lisp\progmodes\ruby-mode.el > NUL'
> > invocation is non-instantaneous every time, and it's on the same order
> > of magnitude as 'bzr log', although the latter takes twice as long:
> >
> > emacs-git-savannah>timep git log lisp\progmodes\ruby-mode.el > NUL
> >
> > real    00h00m04.652s
> > user    00h00m00.000s
> > sys     00h00m00.015s
> >
> > emacs-bzr\trunk>timep bzr log lisp\progmodes\ruby-mode.el > NUL
> >
> > real    00h00m08.269s
> > user    00h00m07.878s
> > sys     00h00m00.280s
> >
> > But! Git starts streaming output just as soon as it can, hence my
> > earlier impression that the command is instantaneous.
>
> That only matters if you want the first few revisions.  What if you
> want the last?

The most recent revisions are streamed first (they're at the top), and 
they are usually the ones I need. If I want the last, I can at least do 
some reading and scrolling while they're being retrieved.

And you shouldn't underestimate the perception of being instantaneous. 
If you were looking for a reason why people think that Bazaar is too 
slow, this one's a very plausible culprit.

> >   > I did, just now: (...)
> >
> > I tried it, too, and here Git wins hands-down.
> >
> > Here's how long it takes to update both when they are already up-to-date
> > (staging a situation when they're the same number of revisions
> > out-of-date is harder):
> >
> > emacs-git-savannah>timep git pull
> > Already up-to-date.
> >
> > real    00h00m02.139s
> > user    00h00m00.000s
> > sys     00h00m00.031s
> >
> > emacs-bzr\trunk>timep bzr update
> > Дерево в актуальной ревизии 112180 ветви
> > bzr+ssh://address@hidden/emacs/trunk
> >
> >
> > real    00h00m09.963s
> > user    00h00m00.343s
> > sys     00h00m00.202s
>
> So you wasted the whole of 7 sec to know that your tree is up to
> date.  Big deal!

You can reply "big deal" to almost any speed comparison. But yes, Bazaar 
took 7 seconds longer and, measuring relatively, was 4 times slower. 
It's annoying, and it gives a bad impression.

And it's even slower when there's actually stuff to update.

> > Before that, I updated this Bazaar clone from a several-days-old
> > revision, and it took 4 minutes.
>
> Your network needs an urgent upgrade.

My bandwidth definitely exceeds the connection speeds reported by Bazaar 
when it's doing its thing.

> > I don't have a similar result for Git
> > to compare, but considering it cloned the whole history in 30 minutes
> > (same as on your machine)
>
> You are mistaken, a full clone took me 3 hours, not 30 min.

I misremembered, then. But it definitely took me 30 minutes today to 
make a new clone of git://git.savannah.gnu.org/emacs.

I guess that means that my network is fine. You, on the other hand, may 
be hitting a bottleneck there. This could explain why network operations 
of Git and Bazaar take the same time on your machine.