Nooooooo! -- John Panzer / Google [email protected] / abstractioneer.org <http://www.abstractioneer.org/> / @jpanzer
On Wed, Oct 21, 2009 at 3:28 PM, Matthew Terenzio <[email protected]>wrote: > > What is an update? > > On Wed, Oct 21, 2009 at 6:19 PM, Bob Wyman <[email protected]> wrote: > > Please.... Please.... Don't anyone restart the "What is an update?" > > discussion... Too many lives have been wasted on that one already. > > > > bob wyman > > > > On Wed, Oct 21, 2009 at 6:11 PM, Tim Bray <[email protected]> wrote: > >> > >> >> 3. High-level Protocol Flow, last bullet point. "The hub caches > >> >> minimal metadata..." I read this a few times and it seems to be > >> >> describing one particular implementation strategy. If so, why not > say > >> >> so? The current language makes it look like this is maybe a > normative > >> >> part of what you have to do to implement PuSH, which I'm pretty sure > >> >> it isn't. > >> > > >> > I think this is intended to be normative. A stateless hub can't > >> > function properly (doing feed diffs). The language here was chosen > >> > specifically to imply stateful handling of content without dictating > >> > the specific implementation. > >> > >> In fact, what you're specifying is that the hub MUST be able to detect > >> a delta so it can inform subscribers. Normative text should specify > >> policy not mechanism. > >> > >> This touches on a nasty subject that you probably don't want to go > >> near. If I were implementing, I think it might be perfectly OK to > >> stash just atom:feed/atom:updated and //atom:entry/atom:updated. > >> > >> I am quite sure there are others who would disagree & insist on > >> stashing enough to detect differences in the white space between > >> attribute values. Don't laugh, I speak from bitter experience. If > >> there's one thing we learned in the process of building 4287, it is > >> hopeless to expect consensus on what constitutes an "update". I have > >> a thousand emails to show you if you disagree. > >> > >> So I think it's probably inappropriate to specify "minimal" metadata. > >> Just say "The hub stores sufficient state information about each topic > >> to detect changes so that it can notify subscribers." -T > > > > >
