[Telepathy] Telepathy and XPMN

[Jon Kristensen]

Here is a suggestion of what I imagine the "core" Telepathy channel API 
would look like (Channel.XPMNServiceProviderConnection). The 
"higher-level" profile channel would use the functionality of this 
channel to provide a simple API.

Is it reasonable that the signals use the exact data provided to the 
methods (such as 's: Value' and 'xml: Value'), or should I let the 
methods return an ID or something and track the reply using that?

    A channel type for managing communication between two XPMN devices.
    Due to the nature of XPMN, this channel can only be used with XMPP
    connections.

    While it is technically possible for XPMN application developers to
    use this channel directly, application developers SHOULD implement a
    higher-level and profile-specific channel instead (which internally
    creates an instance of this class).

    Rationale: Using this channel directly will force the application
    developer to deal with low-level XMPP technicalities. Additionally,
    a profile-specific middle-layer would allow an abstracted and usable
    API.

    You can use this channel to execute commands, get and set simple and
    complex variables as well as subscribe and unsubscribe to events
    (variable updates) on the service.

    *Methods*

    ExecuteCommand (xml: Command)

    GetAllVariables (s: EventName)
    GetLatestVariable (s: EventName)

    SetSimpleVariable (s: EventName, s: Value)
    SetComplexVariable (s: EventName, xml: Value)

    Subscribe (s: EventName)
    Unsubscribe (s: EventName)

    *Signals*

    Subscribed (s: EventName)
    Unsubscribed (s: EventName)

    CommandExecuted (xml: Command, xml: Result)

    SimpleVariableReceived (s: EventName, s: Value)
    ComplexVariableReceived (s: EventName, xml: Value)

    SimpleVariableSet (s: EventName, s: Value)
    ComplexVariableSet (s: EventName, xml: Value)

    *Telepathy Properties*

    auto_subscribe_features : <list of string> - read only


I appreciate any feedback, of course! :-)

Thanks!

Best,
Jon Kristensen

On 01/03/2011 03:17 PM, Jon Kristensen wrote:
> Hello Telepathy people!
>
> I'm developing an XPMN media server called Pontarius. I'm currently 
> looking into how XPMN could be integrated with Telepathy. You can read 
> about Pontarius at http://www.pontarius.org/.
>
> First off, let me clarify some XPMN terms:
>
> *XPMN:* Stands for Extended Personal Media Network and is a 
> decentralized media network software architecture. It allows extended 
> media networks to communicate seamlessly and addresses service 
> discovery (allowing devices to find and identify each other and their 
> capabilities), security (access control, encryption) and extensibility 
> (making it easy to extend for future use cases), all while being easy 
> to set up and use. All-in-all, it's an extremely powerful way to 
> arrange your media networks.
>
> *Extended media network:* An overlay network consisting (XPMN) devices 
> from one or more networks, such as home networks. One problem that 
> XPMN solves is that devices are able to communicate (over for example 
> Internet) even though they belong to different subnetworks.
>
> *Service:* A specific task or set of tasks that devices may be capable 
> of fulfilling. One example could be a TV playback and recording service.
>
> *Device:* A logical entity in the extended media network. It does not 
> have to be a physical device; one physical device can contain multiple 
> (XPMN) devices. Devices are often bound to a specific action (such as 
> controlling media playback). A device may be a controller, a service 
> provider, or both.
>
> *Controller:* A device controlling one or more services. Controllers 
> can also be service providers. An example of a controller could be a 
> smartphone application that can act as a remote control for a media 
> player service, allowing the user to play/pause, change the volume, etc.
>
> *Service provider:* A device providing one or more services. Service 
> providers can also be controllers.
>
> *Profile:* A profile is an extension on top of the XPMN architecture. 
> It is a specification that describes a service and includes the 
> communication protocol used between controllers and service providers. 
> There can be many implementations of any given profile, and they 
> should be seamlessly inter-operable.
>
> A XPMN device is basically a connected XMPP account. A directory 
> service could be using the full Jabber ID 
> sprint3 at test.pontarius.org/pontarius-directory. XPMN devices 
> communicate by exchanging general IQ get/set/result messages as well 
> as a small subset of the pubsub spec (like subscriptions, events and 
> items requests). Service discovery capabilities also play a part. The 
> mechanics for this is the same for every profile. See The Status and 
> Variable Event Mechanism at http://www.pontarius.org/test/0-1-alpha-2/ 
> for a brief (and incomplete) example of what it could look like.
>
> Every XPMN profile has a specialized API for the job that it's doing, 
> and they all use the above mentioned methods to do their job. One 
> simple profile could talk to a media player service to do things like 
> start and stop playback (think remote control), while another profile 
> can negotiate and download some data over a Jingle and SOCKS5 
> connection from some kind of transfer service. The external API for 
> these profiles should be made as simple as possible, and the profile 
> should hide the "core" XPMN module (from the previous paragraph) from 
> the third party developer. He should probably only know about the 
> TpAccount he want to connect with, and the full JID of the service he 
> wants to talk to. He would most likely be developing a Telepathy client.
>
> I don't really know where the "core" XPMN code and the 
> profile-specific (remote control, data transfer) code should go, what 
> it should be (Telepathy channels?) and how they should communicate. 
> What role could Gabble sidecars play here?
>
> Any ideas, comments or suggestions would be very appreciated!
>
> You can read more in-depth details about XPMN in Dirk Meyer's thesis 
> at http://elib.suub.uni-bremen.de/diss/docs/00011878.pdf. Also feel 
> free to ask questions to this mailing-list or to me directly. :-)
>
> Thanks!
>
> Warm regards,
> Jon Kristensen
>
>
> _______________________________________________
> telepathy mailing list
> telepathy at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/telepathy

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/telepathy/attachments/20110103/aeea5e0f/attachment-0001.htm>