[Xapian-discuss] Bindings, snapshots, and automated tinderbox builds

[Olly Betts]

This mail is a bit of a potpourri, but there's a theme of sorts so it
seems better to collect these things together rather than sending N
separate small messages.

I added the bindings to the the automated tinderbox builds a few weeks
ago.  It's thrown up a few portability issues which I've fixed, but
there are still some build/test failures on the bindings which I've not
analysed yet.  Some could be problems in the autobuild framework rather
than the bindings though.

http://www.oligarchy.co.uk/tinderbox/xapian/status.html

There's one which I have analysed but not fixed is that bindings don't
work with Python 2.1 currently - "make check" segfaults while python is
cleaning up before exiting (at least judging from the backtrace).

Is anyone using Xapian with Python 2.1?  It's a bit of an old version
these days (the last 2.1 release was 2.1.3 just under 4 years ago), so
I'm tempted to declare it "currently unsupported" rather than spend a
lot of time trying to figure out what's going wrong (I think our support
has been broken for over 6 months without anyone reporting it).  I'd
leave the build machinery in place in case anyone wants to fix it in the
future (it requires separately generated SWIG wrappers).

I've also added the perl Search::Xapian bindings to the snapshot build
script so I can test that in the tinderbox too (but I still need to
tweak the autobuild scripts to cope with non-matching SVN revisions
because it comes from a different repo).

But a side benefit is that you can now download the very latest SVN
version of Search::Xapian which may have more features (and perhaps more
bugs) than the latest official release on CPAN:

http://www.oligarchy.co.uk/xapian/trunk/

And lastly after a bit of quick prototyping and some discussions with
Eric B. Ridge, I'm intending to try to move the Java bindings over to
use SWIG.  SWIG's Java support seems to have matured and the latest
release allows you to automatically rename methods to match Java's
conventions (like we now do for C#).

It's currently rather labour-intensive to add a new method to the JNI
wrappers, whereas with SWIG it's usually just a matter of
cut-and-pasting the method prototype into xapian.i, and that work
already gets done for the other languages.  As a result, the Java
wrappers don't wrap a number of newer API methods whereas the SWIG
wrappers are close to complete.

SWIG also generates a smaller .so glue library, and supports generating
GCJ's CNI wrappers as an alternative to Sun's JNI, which gives more
efficient wrappers if you're using GCJ:

http://gcc.gnu.org/java/faq.html#2_2
http://gcc.gnu.org/java/faq.html#2_3

It's probably not going to happen instantly though - this is really
just an FYI, and an opportunity for anyone who thinks it's a bad idea
to speak up (though if we don't do this, we need someone to volunteer
to write all the JNI code to wrap the missing classes and methods...)

Cheers,
    Olly