hal draft spec

Dave Malcolm david at davemalcolm.demon.co.uk
Fri Sep 12 20:13:35 EEST 2003

On Fri, 2003-09-12 at 06:57, David Zeuthen wrote:
> On Tue, 2003-09-09 at 23:47, David Zeuthen wrote:
> > I got a prototype implementation with some short cuts relative to my
> > draft spec below.. I'm prepared, at some point (e.g. when it conforms to
> > some specification), to release this under a free software license.
> First of all thanks for all the feedback, both on this list and
> privately. Sometimes source code speak better than wannabe draft specs,
> so I've put together a release 0.0.1-pre available with usage
> instructions at
> http://pdx.freedesktop.org/~hal/index.html
> This code is released only to provide more information than was provided
> in the initial post to the xdg-list, not to do anything useful. I take
> no responsibility if it breaks something for you. Through some cosmic
> events it may work for you though :-) . Let me know.
> I will update that site from time to time with the draft spec and
> perhaps a few new releases. The code will live in CVS on
> freedesktop.org.
> Well, enough disclaimers already. Any feedback is welcome. Note that I'm
> traveling from Saturday night until Tuesday night and I will probably
> not have access to e-mail.

A thought on the proposal:

Flat vs hierarchical
Currently there is a single list of all devices attached to the system. 
Perhaps devices should form a hierarchy: 
	- a connectivity hierarchy, with a "root" device representing the
motherboard, with CPU and memory attached, and buses coming off it etc
	- a category hierarchy: with "All devices" at the root, with
subcategories such as "Storage Devices", "Joysticks" etc

Rather than querying all devices and have device added/removed
messages,  you query for the root device, query the children of a
device, and get child added/removed messages for a particular node in
the hierarchy.

The category hierarchy could be generated from the physical hierarchy
inside libhal.

Or is this just an unnecessary complication?

Dave Malcolm

More information about the xdg mailing list