hal draft spec

[Dave Malcolm]

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