Re: [Tracker] Prevent removed files from being removed from the db

[Martyn Russell <martyn lanedo com>]

On Mon, 2010-05-17 at 19:42 +0200, Philip Van Hoof wrote:
> On Mon, 2010-05-17 at 13:23 -0400, Nikolaus Rath wrote:
> > Philip Van Hoof <spam-+mS4aLmNmLKG5XvV6lv2jw public gmane org> writes:
> > > On Mon, 2010-05-17 at 10:07 -0400, Nikolaus Rath wrote:
> > > > Hello,
> > > >
> > > > I want to store lots of (valuable) additional metadata about my files in
> > > > the tracker database.
> > > >
> > > > However, I am a little bit concerned about the safety of this
> > > > information. Apparently, tracker deletes everything that is associated
> > > > with a given file if it can't find the file itself.
> > >
> > > > Is there a way to make tracker keep all the information in the database,
> > > > even if the file temporarily disappears?
> > >
> > > This is not possible, for file (system) resources
> > >
> > > > I'm worried about network failures, disconnected external drives,
> > > > accidental renames of the directory etc.
> > >
> > > Disconnected external drives are handled,
> >
> > How can Tracker (reliably) detect if a resource is on an external drive?
> > I can't believe that this works for anything but the trivial case where
> > /dev/sdX is directly mounted. But if the disk is e.g. LUKS encrypted,
> > then there's already a device mapper in between. It get's even worse
> > with all the possibilities that FUSE and bind mounts offer.
>
> HAL (or devicekit) has a unique ID for each removable device. We detect
> and use this unique ID for this purpose.
>
> If you can't believe this, why don't you try it?

We switched to GIO recently, but that too falls back to HAL/devicehit.
We do have to do some interesting things to make this work in a number
of cases (like for optical media), but generally it works. There might
be some corner cases that still need fixing, but no one has found them
yet.

Please report any bugs you find relating to this, we will be happy to
receive them, even happier to receive patches :)

-- 
Regards,
Martyn