Hi,
On Mar 17, 2008, at 3:22 PM, Peter Saint-Andre wrote:
Pedro Melo wrote:
On Mar 11, 2008, at 12:06 AM, Dave Cridland wrote:
On Mon Mar 10 23:45:28 2008, Peter Saint-Andre wrote:
One potential problem: this is not a nice, small, incremental
change.
Now servers and clients must support:
1. The 'sequence' attribute.
2. Roster pushes via message, not IQ.
3. Multiple items in a roster push.
4. Multiple items in a roster set.
The more we change, the less likely it is that clients and
servers will
add this feature. Then we're back where we started.
"If it ain't broke, don't fix it."
So what's broken?
1. Huge roster gets every time you log in. The 'sequence' stuff
fixes
this.
What's not broken?
2. Roster pushes via IQ.
3. One item per roster push.
4. One item per roster set.
Why are we fixing 2, 3, and 4? Just because we can? Because it
is more
elegant? Or because it really solves a big problem on the network?
Unless there is a compelling need, I'd vote for changing as
little as
possible.
The problem is that if you go for Joe's concept - which is certainly
elegant - of having the roster "diff" simply sent as a bunch of
pushes, then these - being sent as <iq/> - need to be acknowledged.
Now, I appreciate that clients don't always do this, but the fact is
that they should be doing so. I'm unhappy with suggesting that
clients
quietly ignore RFC 3920 because nobody cares.
So we can fix that simply by using <message/> instead of <iq/> -
it's
a pretty trivial change, and it eliminates the type='result'
reply for
clients on all pushes, so it's inarguably a performance improvement.
Ok, I must have been missing something because if you want to fix
something, why not just do multiple items per roster push?
Because it's never been done that way.
The argument that diff is complex doesn't play well with me. Each
item
is a replacement item, so no diff required. The usual code for a
client
"foreach item update my model" will work with both.
But clients have never expected multiple items in a roster push.
However, that might be something clients could move to if they support
sequencing. My question is: will clients do that?
Yes. Basically if I'm a client and I'm telling the server that yes, I
support sequencing and I want to use it, the server is OK to change
previous rules if they are specified in the new XEP.
Best regards,
--
Pedro Melo
Blog: http://www.simplicidade.org/notes/
XMPP ID: [EMAIL PROTECTED]
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