Dulwich C extensions and stand-alone Windows installation of bzr

[Jelmer Vernooij]

On Thu, Sep 15, 2011 at 08:27:46PM +0300, Eli Zaretskii wrote:
> > From: Martin Pool <mbp at canonical.com>
> > Date: Wed, 14 Sep 2011 15:04:44 +1000
> > Cc: Alexander Belchenko <bialix at ukr.net>, bazaar at lists.canonical.com

> > > Jelmer suggested (off-list) to use this:

> > >  python -c "import dulwich._pack"

> > > and it does not error out.

> > That's great.  So then if you install those .pyd(?) files inside the
> > selfcontained bzr install, you should be in business.  (There is some
> > chance the compiler or Python is ABI-incompatible but it's worth a
> > go.)

> Well, it does work.  I've been using it for a couple of days with
> several git repositories, and didn't see any problems.  The speedup is
> moderate (around 30% to 40%), which is less than what I hoped for;
> e.g., the initial branch from gnulib still takes around 1 hour.  But
> it's better than 2 ;-)

> I made sure that the *.pyd files are indeed loaded by bzr: first, with
> a 3-line "plugin" that just imported all three of them, and then by
> using the "Find handle" feature of the Process Explorer utility that
> clearly shows that bzr.exe has them open when bzr-git is being used.

> If there's a good place where I can upload these *.pyd files, perhaps
> to the bzr-git page on Launchpad, where others could download them,
> please tell me what to do.

> Finally, for the record, I'm going to describe here how to build and
> install these extensions using MinGW.  Most of the info came from the
> advice I got here and from Python docs, but not all of it was correct
> or optimal.  I would highly recommend to add what's below to the
> dulwich distro, in some README.mingw file or something.

Glad to hear you got it working, and thanks for writing this down.

I'll have a look at adding this as README.mingw to bzr-git, though I
wonder if the instructions could be simplified:

> Here's the final recipe I came up with:

>  1) Install Python.  It should be the precise version displayed by
>     "bzr version", which is currently 2.6.6.  (I tried Python 2.7 at
>     first, but bzr would not load the *.pyd files produced by that.)
>     There's no link on the Python download page to version 2.6.6, but
>     by looking around I found its installer here:

>       http://www.python.org/ftp/python/2.6.6/python-2.6.6.msi

>  2) Customize Python's distutils to use MinGW.  There are several ways
>     of doing that, all of them documented on this page:

>       http://docs.python.org/install/index.html#install-index

>     The method which was suggested on this list, i.e. to use the
>     "-c mingw32" switch to the setup.py script's "build" commands, is
>     not the best one, because (a) you need to remember to type it
>     every time, and (b) because only the "build" commands accept that
>     switch, "install" does not.

>     A better way is to add this to the distutils configuration file:

>       [build]
>       compiler = mingw32

>     This can be added either to %HOME%\pydistutils.cfg file (assuming
>     you have HOME defined) or to the Lib\distutils\distitils.cfg file
>     under the main Python installation directory.  I did the former.
>     If the configuration file does not exist, create it.

Is there a reason you can't just run "python setup.py install" after this, as
the final step, perhaps specifying a different --root ?

Cheers,

Jelmer