[AUCTeX] How to speed up inserting \documentclass?

[Marcin Borkowski]

Hi all,

when I press C-c C-e in an empty LaTeX-mode buffer, I have to wait
quite a long time for Emacs to search for available classes.  Ditto for
\usepackage.

Is there an easy way of putting the relevant code in my init.el, so that
after Emacs finishes loading, LaTeX-global-class-files and
TeX-global-input-files are already initialized?

When I run e.g.

(setq TeX-global-input-files
      (mapcar 'list (TeX-search-files-by-type 'texinputs 'global t t)))

in mode other than LaTeX-mode, it won't work.  (It seems to find just
a few filenames, some belonging to the current directory, and `preview',
which might be part of AUCTeX.)

Also, both LaTeX-global-class-files and TeX-global-input-files seem to
contain each file twice on my system, even though the said file exists
only in one place in the filesystem.  What might be the reason for that?

AUCTeX v11.88.

TIA,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University