Re: An answer to metadata, complete.

[James Michael Mastros <spare jennifer-unix dyn ml org>]

On Thu, Aug 13, 1998 at 07:44:48 PM +0200, Andreas Kostyrka wrote:
> Actually, I think that file metadata has many benefits:
> -) No central registry stuff like in Win95, each object (file) can design
>    at creation time how it likes to be opened, printed, etc.
>    (And centry registries/databases tend to throw up/become out of sync.)
> -) Not the broken ``extensions'' solution used in Win95, etc., but it
>    should used as a file ``class'' based fallback solution.

I think we really need two classes of metadata: "class" and per-file.
Really, I think it's more useful to know that all HTML files (that is to
say, all files matching the regex \.[Hh][Tt][Mm][Ll]\?$) you edit with emacs
and view with netscape and have the icon /usr/share/pixmaps/HTML.png.  Then,
if you want, you can specify a per-file default, or icon.

That way, only a few files need metadata at all.  Yes, this does mean a
centralized database, ala Win95.  But we can do a better job then they did:
1) Make it textual.
2) Make it well-documented.
3) Don't store information not about filetypes in it.
4) Make a big, bold statement in the style-guide, and the documentation of
   the database: "PROGRAMS SHALL NOT MODIFY THE FILETYPE DATABASE WITHOUT
   USER CONFIRMATION.  VIOLATORS WILL BE LOUDLY DENOUNCED."  And mean it.
   Realy, that's half the problem with win95's registry.

> -) In my opinion it can be done in a UNIX compatible way, but it is some
>    work.
>    *) By default store the metadata in filename.metadata
>    *) For ELF binaries store it in the binary directly.
>    *) For existing formats like TIFF, sh scripts, etc. that know
>       about comments, store it in a comment.
>    *) For new Gnome filetypes, store it in a standard way.
>    
>    I know this is NOT nice, but considering that metadata usually will be
>    small (<1KB) I'd say, this ``inline'' (better infile) storage method
>    should be acceptable for many formats.
No.  I repeat, no.  I do not like this idea AT ALL.  Changing the metadata
of a file shouldn't change the data.  That's the whole point of having a
metadata system.  Storing it externaly to the file somehow is the only
option.  Think of signed files, that know their own hash.

> -) On free systems, one actually could patch the GNU file utils to
>    ``cover'' the metadata files, and automatically take it into account.
Optionaly, of corse.

I think we just have to accept the fact that the metadata will get out of
sync somtimes, and deal with it gracefuly.  (IE have an automated system of
attempting to match orphaned metadata with it's file, and delete it if you
can't find the file.)

	-=- James Mastros
-- 
A basement-GNOME (http://www.gnome.org/) with PIP (IETF group) and WINE
(http://www.winehq.com/).  Not really as impressive as it might sound, or as
Tolkinen.