Re: Emacs Bazaar repository

[Giorgos Keramidas]

On 2008-03-14 10:46, Jonathan Lange <address@hidden> wrote:
> On Thu, Mar 13, 2008 at 7:04 PM, dhruva <address@hidden> wrote:
> > Hi,
> >   I got bzr setup and running on my M$-XP box. I got the bzr repo of
> >  emacs (by downloading the emacs.tar.gz) and updated it to the latest.
> >   I wanted to make sure the recent changesets are pulled in. I typed
> >  "bzr log -l 10". It took ~24 seconds (elapsed time from perfmon)
> >  consistently. Whereas Mercurial (hg log -l 10) on the trunk to 2
> >  seconds (and the mercurial repo is on a CIFS mounted drive while bzr
> >  repo was on local disk). GIT was fastest though even on a CIFS mounted
> >  system.
> >
>
> I was a bit curious about this so I asked my friendly neighbourhood
> Bazaar hacker (CCd). He tells me that comparing 'bzr log' to 'hg log'
> is like comparing apples with ... umm, apple trees. Bazaar's log
> displays all merges and thus has to do calculations on the whole
> ancestry graph. Mercurial's log just displays the mainline history.
> 'bzr log --line' is a better comparison.

The `glog' extension of Mercurial displays an ancestry graph and it can
show the last 3 changesets in less than 1/3 of a second, on a system
that is currently building the CVS 'HEAD' of FreeBSD and the CVS 'HEAD'
of Emacs itself:

  address@hidden:/hg/emacs/gker$ /usr/bin/time hg glog -l3
  @    changeset:   1988:601be9d00890
  |\   branch:      keramida
  | |  tag:         tip
  | |  parent:      1724:25ffb390e254
  | |  parent:      1987:c2bdce21cc28
  | |  user:        Giorgos Keramidas <address@hidden>
  | |  date:        Fri Mar 14 16:48:24 2008 +0200
  | |  summary:     Merge from HEAD
  | |
  | o  changeset:   1987:c2bdce21cc28
  | |  branch:      HEAD
  | |  user:        bastien1
  | |  date:        Fri Mar 14 10:13:27 2008 +0000
  | |  summary:     * textmodes/flyspell.el (nxml-mode): Add the right.
  | |
  | o  changeset:   1986:414912c00a1f
  | |  branch:      HEAD
  | |  user:        miles
  | |  date:        Fri Mar 14 10:06:41 2008 +0000
  | |  summary:     Add arch tagline
  | |
          0.25 real         0.15 user         0.08 sys
  address@hidden:/hg/emacs/gker$

I'm not sure if `wait, because we are calculating the changeset
ancestry' is a valid reason for taking too long to show the last two or
three log entries...

> Definitely. I hate waiting for anything, computers most of all. I'll
> hassle Martin and try to get this fixed. Alternatively, the Bazaar
> project welcomes patches with open arms. :)

That's cool.  If Emacs converts to bzr, we need all the speed we can
get.  The CVS repository of Emacs is one of the CVS repositories with
the longest uninterrupted history I have ever seen :)