Re: Erase cache, clean registry in Linux

[lee <lee@yun.yagibdah.de>]

On Wed, Nov 26, 2008 at 05:46:29PM -0800, Kelly Clowers wrote:
> On Wed, Nov 26, 2008 at 16:25, lee <lee@yun.yagibdah.de> wrote:
> 
> >You probably have been using applications that create thumbnails more
> >than I did. I'm using some gnome applications, but I'm not using
> >gnome ...
> 
> I probably just have more pics than you.

Or that, yes :)

> gthumb is probably the only app I use regularly that uses thumbnails
> (I use Awesome and a lot of CLI apps).

Hm, I never used gthumb --- and I'm not using thumbnails anyway, other
than eventually displaying directory contents with nautilus. If that
needs thumbnails, what do they do on windoze? Are they saving
thumbnails there, or are they created as needed, and if so, how did
they get that fast enough?

> > So how do I find out which programs create these thumbnails?
> 
> strace can monitor every file a program opens, so:
> 
> strace -e trace=open app_to_test 2> trace.txt
> 
> then search trace.txt for thumbnails

Yeah, but I'd need it the other way round: Monitor .thumbnails to see
which programs access it.

> Also, i just found an interesting bug report for gnome
> http://bugzilla.gnome.org/show_bug.cgi?id=150483
> 
> It is now fixed, and gnome-settings-daemon >= 2.24 now prunes the
> thumbnails dir if it is greater than 64 MB at login. I know I don't
> really want to g-s-d just to trim thumbnails..

Hm, that is not a fix, it's a poor workaround. And when I start
nautilus and look at the preferences dialog, there is no mentioning of
caching thumbnails whatsoever.

The cache won't probably be cleaned anyway because I'm already logged
in on the console from which I used startx before eventually starting
nautilus. Purging the cache only on login is silly anyway: I can stay
logged in for months.

> I have thought for a while that some sort of lightweight CLI-level
> session management (beyond simple shell login and logout scripts)
> would be nice for a number of things, including things like this.

What is session management?

To maintain a thumbnail cache, you either have to have the program
creating and using the cache constantly maintaining it, or you need a
daemon (like squid) that maintains it and provides an API for programs
that want to make use of the cache (which opens possibilities for
implementing security holes ...). One problem with gnome is that it
tries hard to hide its configuration and information about how it
works from the user, so they won't tell you how to configure this
daemon, and they won't even tell you that it's there :(

For example:


lee@cat:~$ nautilus
Initializing gnome-mount extension

** (nautilus:14999): WARNING **: No description found for mime type
"x-special/device-char" (file is ".recently-used"), please tell the
gnome-vfs mailing list.
^C
lee@cat:~$ ps xca |grep gno
14910 ?        S      0:00 gnome-vfs-daemo
lee@cat:~$ kill 14910
lee@cat:~$ ps xca |grep gno
lee@cat:~$ man gnome-vfs-daemon
No manual entry for gnome-vfs-daemon
lee@cat:~$ 


What the hell is "gnome-mount extension"? What is "gnome-vfs-daemon"?
Why is there no man page about it? What is "bonobo"-something that
sometimes starts running when using gnome programs? And so on ...

Hm, and it doesn't seem to create thumbnails. It didn't give me a
message that it can't write to .thumbnails, so something else must be
creating them.


-- 
"Don't let them, daddy. Don't let the stars run down."
http://adin.dyndns.org/adin/TheLastQ.htm