base dir spec question.

[Sander Jansen]

On Thu, May 6, 2010 at 10:27 AM, Simon McVittie
<simon.mcvittie at collabora.co.uk> wrote:
> (Cc'ing the author of the specification in question: Waldo, could you clarify
> whether I'm interpreting it correctly?)
>
> At the beginning of this thread, Sander Jansen <s.jansen at gmail.com> wrote:
>> For my music manager I need to store a sqlite3 database file somewhere
>> on disk. Which directory would be the most appropriate to use, the
>> XDG_CONFIG_HOME or the XDG_DATA_HOME directory?
>
> On Thu, 06 May 2010 at 09:28:42 -0500, Sander Jansen wrote:
>> The database is really
>> a hybrid between config and data, so I think I agree that a local /var
>> would be the best fit. I think I'm going to stick with XDG_CONFIG_HOME
>> for now.
>
> I'm pretty sure this isn't configuration (preferences). Deleting preferences
> is meant to return the app to an unconfigured state, but not destroy
> user-entered data like this:
>
> On Thu, 06 May 2010 at 09:28:42 -0500, Sander Jansen wrote:
>> In addition, users
>> may change the data in the database without writing it back to the tag
>> as well.
>
> so I'd put it in XDG_DATA_HOME, as Julien Danjou suggested.
>
> There seems to be some disagreement over what XDG_DATA_xxx is for, and
> in particular whether it's "like /usr/share", "like /var/lib", or something
> else entirely.
>
> My personal impression is it's a combination of "like /usr/share" and
> "like /var/lib" - the system-wide part is in /usr/share because it isn't
> edited, even by the system administrator, but the part in a user-specific
> directory can be changed by that user.
>
> The basedir document itself describes XDG_DATA_HOME as "a single base directory
> relative to which user-specific data files should be written". I think
> that sounds like a suitable place for databases...
>
> GNOME's interpretation of the XDG_foo directories is at
> <http://live.gnome.org/GnomeGoals/XDGConfigFolders>. It references
> <http://ploum.frimouvy.org/?207-modify-your-application-to-use-xdg-folders>,
> which focuses on defining what preferences and cache are, then considers
> everything else that's not an explicitly-saved document to be "data".
>
> KDE's interpretation is
> <http://techbase.kde.org/KDE_System_Administration/XDG_Filesystem_Hierarchy>,
> which says
>> Data that applications store which are specific to a given user are
>> to be stored in the XDG_DATA_HOME directory
> [...]
>> Configuration information should be stored in the XDG_CONFIG_HOME directory
>
> The freedesktop.org trash specification (which sounds like a user-specific
> part of /var to me...) uses XDG_DATA_HOME, too.
>

Ok. Looking at the competition (exaile, rhythmbox), they seems to be
using XDG_DATA_HOME as well. So perhaps the XDG_DATA_HOME is a better
place, especially if people want to wipe their config files.

XDG_DATA_HOME seems more appropriate for things like games where you
can download customizations (example: openttd where you can download
new vehicles,scenery and scenarios).

The question is whether you still want to add a XDG_VAR_HOME as well
and tell all applications that use XDG_DATA_HOME they may need move
their databases to XDG_VAR_HOME.

Cheers,

Sander

-- 
"The sands of time were eroded by
The river of constant change."