Re: Proposing couchdb-glib and evolution-couchdb for GNOME 2.30

[Mikkel Kamstrup Erlandsen <mikkel kamstrup gmail com>]

2009/10/1 Rodrigo Moya <rodrigo gnome-db org>:
> On Thu, 2009-10-01 at 16:02 +0200, Rodrigo Moya wrote:
>> On Thu, 2009-10-01 at 13:41 +0100, John Carr wrote:
>> > >>
>> > > it is not required for evo-couchdb to work, so I don't think it needs
>> > > any mention, apart from saying that if you want to run a local CouchDB,
>> > > you need to install CouchDB and all its dependencies.
>> >
>> > I only brought it up because of the ongoing mozilla vs webkit
>> > discussions (and mozilla js vs seed/jscore) and i think the most
>> > useful configuration of evo-couchdb does depend on couchdb and hence
>> > mozilla js.
>> >
>> > I'm only so bothered in as much as i really don't want a desktop in
>> > the future to need 2 javascript engines and each application depending
>> > on 2 or 3 different database engines and so on :]
>> >
>> you are indeed right, but I see couchdb can use different javascript
>> libraries (it has a configure option to tell it where to find libjs) so
>> I guess we could ask the couchdb guys to support our JS engine (when we
>> decide which one to use :)
>>
> ok, just asked the couchdb devels about this, and it seems to be much
> easier than I thought, so this should be easy to fix when we decide
> which JS engine to use.

Indeed, one can use any language as a CouchDB indexer. Indexer -
because that is really what the Javascript is used for. The (very)
simplified explanation is that you can't do custom queries against
Couch only index lookups, but you can create some very funky indexes.
These indexes are generated by calling out to an outside process over
a socket using some protocol defined in the Couch docs (which is also
why Couch is still very fast, the script engine is only used on
indexing time).

This external indexer process use libmozjs by default but you can
create your custom indexer in what ever language you want; Python,
Perl, even C if you are adventurous. It should not be a big task to
write an indexer based on libseed I think - although I haven't checked
the details.

-- 
Cheers,
Mikkel