Excerpts from Kevin Smith's message of 2015-09-14 09:58:56 +0100: > On 7 Sep 2015, at 23:15, Matthieu Rakotojaona > <[email protected]> wrote: > > > > Excerpts from Kim Alvefur's message of 2015-09-07 14:49:59 +0200: > >> Hi! > >> > >> On 2015-09-05 16:22, Matthieu Rakotojaona wrote: > >>> - MAM only allows something like "give me everything since this moment", > >>> however using dates is always problematic (clocks are not > >>> synchronized, time can drift, ...) > >> > >> FYI: MAM lets you request by archive id. There doesn't seem to be an > >> example describing that, but it's essentially the same as paging: > >> http://xmpp.org/extensions/xep-0313.html#query-paging > > > > Hey ! > > > > Yes, you can page with MAM. The problem is that there is no interaction > > between MAM's archive ids and actual items, so whenever you receive a > > notification you know that the latest archive id must have changed but > > you don't know the new value. So you'll have to retrieve back from the > > last event you retrieved. > > > > My idea was to make this id central in the Pubsub XEP, and then have > > references to other XEPs like "You can use RSM with those ids". > > > > XEP-0312 does feel more lightweight and more importantly more generic > > (it doesn't apply to only pubsub, but to everything that is based on > > presence) but still has the issue of clocks. > > Including the archive IDs in the delivered stanzas seems to be the most > sensible way to do this, such that you can then do a MAM sync on your > last-seen ID. > > Yes/no? > > /K
Yes, that would allow an implementor to make only the calls that are really needed for staying in sync. However I don't see why it should be a MAM sync; MAM in itself only allows you to query by date, in order to filter by IDs you use RSM which is already usable directly with pubsub (instead of doing MAM+RSM). The only difference will be the response: either you get a list of relevant items through pubsub, or you get a stream of messages through MAM. I can imagine the latter is better for huge responses because messages don't "clog" the pipe (they can be interleaved with other stanzas); is it really the preferred way to do it ?
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