[RFC] One ioslave to rule them all...
ervin at ipsquad.net
Sat Jun 25 23:46:29 BST 2005
I'd need some opinions about the work I've done until now and about my current
plans about system:/. The basic idea behind this ioslave was to have one root
allowing desktop users to easily browse the relevant places in the system. I
want to push the idea further hence why I need to know if there are
suggestions or objections.
In order to have this possible I developed mainly three ioslaves:
- media:/ which allows to deal with your partitions, removable media, cdroms,
- remote:/ which allows to have "remote folders" and is possible to use thanks
- home:/ which displays home directories of the users being in the same groups
than the current user (because it's generally more relevant to share files
with them), and the current user home directory.
Currently system:/ points to media:/, trash:/, remote:/, settings:/ and home:/
(which was committed yesterday). home:/ being the last part of my great evil
plan : hiding the real file hierarchy!
I'm now almost able to do it, in fact if I could even do it now. Some of you
may wonder "why hiding the unixian file hierarchy??? and push use of
The answer is simply that for a desktop user this unix file hierarchy is an
So, the current status of what I've done is exactly this : if you start
browsing using system:/ you can stay in this virtual hierarchy and do all
your daily work using it (as a desktop user, not a sysadmin).
So the user could use only this, but some entry point to the unix filesystem
still remain, in particular the shortcuts to the home directory...
Where I'd like to go is the following : replace $HOME with home:/$USER
everywhere, this way the user will be "on the right track" by default (in the
Of course this would raise some issues on interoperability mainly because
there's no consensus about the available VFS protocols between desktops. I
currently see two problems in this area (I'll use media:/ as example since
it's older and more known, but everything I'll present is true with home:/ as
1) Opening a file in the system:/ (media:/) hierarchy.
When opening a file with an application, the application is launched thanks to
its desktop file, and %u is replaced with the file URL (a media:/ URL for
example). It'll work flawlessly with most KDE applications since they support
KIO. But, some of them don't really support KIO completely (Kaffeine for
example because it uses xine which only support some protocols like http and
file). Moreover, non-KDE applications know nothing about media:/ URLs!
Then two things have been introduced:
- KIO::NetAccess::mostLocalURL() which allows KDE applications to resolve an
URL to a file:/ URL if needed (and if possible).
- X-KDE-Protocols key in desktop files, which allows to restrict the set of
supported protocols for an applications. Anything not present in this set is
automatically resolved to file:/ URLs if possible before launching the
This way, we keep the compatibility with most applications, and KDE
applications are able to have more control on the process. I then consider
this issue as solved, the real solution would be of course to ensure that any
non-KDE application could deal with any KDE URL but that's definitely not
feasible currently, it would require a common VFS across all desktops,
something that we won't have before a long time IMO.
2) Drag and Dropping a file from the system:/ (media:/) hierarchy.
It's the same kind of issue than opening a file. The main difference being
that the application is already running, so the only counter-measure that can
apply is KIO::NetAccess::mostLocalURL(), then only KDE applications can
resolve the URLs to file:/ URLs... I've find no real way to make it work for
non-KDE applications. Suggestions are welcome!
Now I'm pondering on what to do :
a) Replacing $HOME with home:/$USER right now?
b) Replacing $HOME with home:/$USER for KDE 4 only?
c) Give up the whole idea?
d) Something else?
Of course I tend to think I should apply a), but I would consider b)
acceptable whereas I really dislike c). Of course, I'm open to any
interesting "d)" proposal.
Any opinions? advices?
Kévin 'ervin' Ottens, http://ervin.ipsquad.net
"Ni le maître sans disciple, Ni le disciple sans maître,
Ne font reculer l'ignorance."
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