On Wed, 2009-02-11 at 15:09 +0100, Carlos Garnacho wrote:

> Overall, great patch :), makes things quite more generic. A few comments
> about it:
> 
> * What about using GTypeModule and GInterfaces for the modules? you
> could have a single module that implements one interface for the indexer
> and other interface for trackerd.

I tried this, I found it too complicated and more difficult for higher
languages to integrate with. For example this way it's relatively easy
to write a push module in Vala.

There were also a few things that were not possible, or quite difficult
at least. I had started the refactor to make them similar to how your
module-sys works. But that was not possible for a couple of reasons.

I decided to just use GModule (it's only about a few methods anyway).

> * Do we really have to expose TrackerIndexer? I'd rather keep that as an
> internal detail, and this wouldn't work as is for external modules, we'd
> have to install a bunch of headers first... If we went through
> GTypeModule, modules could trigger signals that the indexer would
> listen, without any need to expose it to modules.

I think TrackerIndexer can be left out for the current modules. I added
it because for future ones it might be necessary to have it (for example
to pause and continue it).

Pausing, pre-committing and continuing it something I think will
eventually be necessary to add (for example a AddMany that adds really a
lot of triples, should pause+pre-commit, import, and then continue the
indexer.

Kinda like freeze/thaw.

> * in src/tracker-indexer/tracker-push.c (load_modules): there's no good
> reason for gotos if it's just used in a single place, just make that
> return immediately if the directory couldn't be opened.

Ok, I'll replace that.

> * in src/tracker-indexer/tracker-push.h: the .c file doesn't implement
> tracker_push_module_[create|shutdown]

Ah, oeps.

> * in src/tracker-indexer/Makefile.am and src/trackerd/Makefile.am: No
> need to discern between "pushi" and "pushd", since there's no naming
> collision.

Okay, I'll just use "push" everywhere then.

Thanks!

> On mar, 2009-02-03 at 11:52 +0100, Philip Van Hoof wrote: 
> > This is a new patch but with the indentation right for the two new files
> > this time
> > 
> > On Tue, 2009-02-03 at 00:40 +0100, Philip Van Hoof wrote:
> > > Hi there,
> > > 
> > > This long E-mail is also a request for a review of the attached patch,
> > > Martyn.
> > > 
> > > You can call me crazy for working on this until 24 'O clock, but I guess
> > > I wanted to have it done today.
> > > 
> > > Because Ivan Frade told me he likes the concept of letting applications
> > > push in data into Tracker for many situations, we decided to refactor
> > > the basis of the Evolution support that I recently finished [1].
> > > 
> > > [1] http://live.gnome.org/Evolution/Metadata (note that this is now a
> > > desktop neutral standard)
> > > 
> > > I made this part GModule based. Meaning that you can add more such
> > > "Evolution like" modules. That is also the plan. For example one module
> > > for KMail and very different one for an RSS web grabber will be made
> > > very soon. Perhaps we'll make other ones for other kinds of apps too.
> > > 
> > > How it works is simple, but can get a little bit confusing to read in C.
> > > I recommend reading this Vala example, as it does the same thing [2].
> > > 
> > > [2] http://live.gnome.org/Vala/DBusClientSamples/Waiting
> > > 
> > > In Tracker a few more things got added, like the GModule support.
> > > 
> > > tracker-push.c in trackerd is more or less a GModule loader and at the
> > > same time what the Vala example does [2] (go read it, in code it's much
> > > more easy to grasp than reading this gibberish explanation!):
> > > 
> > > -> Do a ListNames on DBus initially and if our service is among the ones
> > >    we want to consume, we more or less launch the GModule's
> > >    capabilities.
> > > 
> > > -> Then we start listening for NameOwnerChanged to know when we either
> > >    need to shutdown the GModule's capabilities, or when we need to
> > >    launch it.
> > > 
> > > Use-cases:
> > > 
> > > o. Evolution is not running, trackerd starts. User now starts Evolution.
> > >    The NameOwnerChanged will detect this event and will launch the
> > >    GModule for Evolution.
> > > 
> > > o. Evolution is running, trackerd starts. ListNames will find the
> > >    service for us and our handler will therefore launch the GModule.
> > > 
> > > o. We were once registered with Evolution, we're still running. But now
> > >    Evolution shuts down. The NameOwnerChanged will detect this event and
> > >    will disable the capabilities of the GModule for Evolution.
> > > 
> > > Now replace Evolution with KMail if you prefer the KDE desktop. Same
> > > story.
> > > 
> > > We decided to refactor this because we want to enable Vala, Python, C#,
> > > Perl, D, C++, YodaYodi++#1^^ developers to develop modules.
> > > 
> > > This means that it's all GObject & GModule based now.
> > > 
> > > You install a GModule that has a function that returns a GObject that
> > > implements some methods in a directory A, and one in a directory B.
> > > 
> > > Why two? Well one for the indexer and one for the daemon. The deamon is
> > > for your 'things' that need to be kept alive for a long time. The
> > > indexer is for your 'things' that will do a lot of DB transactions and
> > > insertions.
> > > 
> > > For for example the Evolution one the deamon one proxies RDF triples to
> > > the indexer one for this reason.
> > > 
> > > You can take a look at the existing Evolution one's Makefile.am to see
> > > how to deal with that, where to install it, etc.
> > > 
> > > Anyway, here's the patch. Please review asap as we'll need this for
> > > followup tasks soon (like the RSS and the KMail support).
> > > 
> > > 
> > > Thanks!
> > > 
> > _______________________________________________
> > tracker-list mailing list
> > [email protected]
> > http://mail.gnome.org/mailman/listinfo/tracker-list
> 
> _______________________________________________
> tracker-list mailing list
> [email protected]
> http://mail.gnome.org/mailman/listinfo/tracker-list

-- 
Philip Van Hoof, freelance software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://pvanhoof.be/blog
http://codeminded.be

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