[gcs-pcs-list] more comments (plain text)

[Xiaoming Liu]

On Mon, 6 Mar 2006, Eric Hellman wrote:

> basically, we're having this discussion because the relevant section of the 
> spec falls on the short side of "as short as possible, but not too short"
>
> What I'm observing is that there are two types of requests made to an unAPI 
> service
> 1. request for availability info
> 2. request for metadata object
>

I was thinking there is perhaps a proper model to describe unAPI, it's 
intriguing to me because it's recursive, and it may be useful to clarify 
error processing and perhaps other issues.

The model might be described as:
(a) a URI
(b) the URI can be disseminated in several formats.
(c) The format response itself (introspect document) is one of these 
disseminations.

give a concrete example, a request to UNAPI?uri=data:abc&format=fmt may 
return a result set including itself.
"<formats><format><name>fmt</name></format></formats>

I think this model is beautiful because it integrates your two types of 
requests. There is only one type of request which asks some kind of 
dissemination of an URI, and therefore we have a consistent way of error 
handling or other issues.

Notice I am not proposing changes to unapi spec, but just gives 
another view of the error handling problem raised by Eric.

xiaoming