[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Re: [xri] Backtracking
On 26-Oct-07, at 11:35 AM, Victor Grey wrote: > Tan, William wrote: >> 1. Authority resolution and service selection are distinct phases. >> When authority resolution completes, it is done and returns the >> result to the calling function. It might be at the 3rd Ref out of >> 5 possible Refs, and there is no way to continue where it left off. >> 2. During service selection, if you see a Ref, you will spawn a >> different authority resolution phase, but that has nothing to do >> with the original authority resolution. This child authority >> resolution phase also knows nothing about service selection. It >> completes, and returns (if successful) the results back to the >> caller, which is the service selection function. If this child >> authority resolution phase fails and there are more Refs, the >> service selection function will spawn another authority resolution >> phase on the next Ref. > > Yes, well said, and that matches my understanding. > > John Bradley wrote: >> This is the tricky bit. I am informed that the current spec sec >> 11.5 intends that if the final XRD is returned and you do service >> selection on it, and if that "does not" find the required SEP >> then you must unwind back to the same point that you would have if >> the XRD was not returned. > > So, are you saying that if I resolve @a*b*c and the XRD for *c does > not contain the SEP I'm looking for, nor any REFs, I should go back > and look in *b for that SEP? That would not make any sense to me. My point exactly but in the spec says go back to *b and continue with the next ref in priority order. > > If however I follow an XRD level REF that I found in *c, and do not > find the SEP I'm looking for in the last XRD for -that- resolution > chain, I can go and examine any other REFs that I might have found > in *c. But once I start following REFs, I cannot backtrack to > before the XRD where I started following REFs. > Another issue I have raised is that if a XRD has a ref at the XRD level no SEPS are processed in that XRD. So if by other refs in *c you mean a ref in the default service then yes. =ve7jtb > =vg > > >
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]