PS Activity objects: replace GetChannels() with something more useful

[smcv]

The code added in #4503 really wants to get the type, handle type and handle for each channel, without additional round trips. The ListChannels() method in Telepathy returns this information, but GetChannels() in the PS doesn't.

We should add a method (perhaps call it ListChannels() too?) that returns the connection object path, and an array of structs containing channel object paths, types, handle types and handles. The service name isn't strictly necessary, since Telepathy guarantees that you can derive it from the connection object path, but perhaps we should include that too for clarity.

Once this is implemented, we can remove numerous round trips in sugar.presence.

[jg]

hmmm. Estimates on consequences? Urgency? Particularly on scaling?

[smcv]

This is a refactoring task; low impact, low risk, low-urgency-but-would-be-nice. There is no effect on scalability.

I expect it to add around 10 lines of code to Presence Service and save between one and three D-Bus round trips per activity shared.

[gdesmott]

See #5079 for the sugar patch using this new API.

[smcv]

Reassigning to gdesmott, Cc the Collabora OLPC team, since I'm not currently working on OLPC.

[gdesmott]

I updated the patch and pushed it to a git branch: https://dev.laptop.org/git?p=users/guillaume/presence-service;a=shortlog;h=4757

[morgs]

Still review+ from me.

[marco]

Is this in?

[gdesmott]

It's not. I'll upgrade the branch and merge it soon.

[gdesmott]

I rebase my branch to master: https://dev.laptop.org/git?p=users/guillaume/presence-service;a=shortlog;h=4757-rebased

If no objection, I'll merge it tomorrow.

[gdesmott]

(In #5079) I rebased my branch to master: https://dev.laptop.org/git?p=users/guillaume/sugar-toolkit;a=shortlog;h=5079-rebased

Will consider merging once #4757 is fixed.

[morgs]

Looks like the keyword should be 8.2.0:+ not 8.0.2:+

[gdesmott]

Patch merged to PS HEAD. Will be included in the next release.

[daf]

Can you document the new method on on the wiki?

http://wiki.laptop.org/go/Presence_Service_DBus_API

[morgs]

Included in release 0.81.3

[gdesmott]

Replying to daf:

Can you document the new method on on the wiki? http://wiki.laptop.org/go/Presence_Service_DBus_API

Oh, forgot about that. Good catch.

Updated.