Re: Question about gmc

[Owen Taylor <otaylor redhat com>]

Federico Mena Quintero <federico@redhat.com> writes:

> >  When I see files in the gnome desktop, for example the symbolic link to
> >  the partition /dev/hda1, or the direct access to the URL
> >  http://www.redhat.com they show the correct icon on them.
> >  However, when I use gmc to see this files - that reside in
> >  $HOME/.gnome-desktop - I don't see the correct icons on them.
> 
> If you go to Settings/Preferences and turn on "Caching/Allow
> customization of icons...", then you will see the appropriate icons,
> but not the names you gave to the URL links.  What this option does is
> it tell GMC to read the icon metadata information for files in the
> directory windows; normally it is not read because it can be very slow
> when your home directory is mounted over NFS.
> 
> This is a known problem/inconsistency in GMC.  It will be addressed in
> the new file manager, which will be able to do lazy reading of
> metadata.

Again ;-), while lazy reading of metadata may help with this problem a
bit, it isn't really addressing the problem of slow metadata,
and I bet it will _still_ be slow over NFS.

The problem is that gnome-metadata is creating and destroying
a lock directory each time it needs to read a metadata item.
This is intentionally meant to defeat all caching in NFS
and guarantee atomic operation, so it is definitely going to
be slow.

So, I think we need one or more of the following:

 - A batching interface to gnome-metadata
 - Something smarter for locks ... perhaps a split into reader/writer
   locks could be helpful. (Random, probably useless, idea)
 - A metadata server that avoids NFS and implements its own
   semantics which are appropriate to the situation.
   (GConf is actually about 90% of the way there.)

Regards,
                                        Owen