[pulseaudio-discuss] [PATCH v2] call-state-tracker: New component.

[Colin Guthrie]

'Twas brillig, and Tanu Kaskinen at 18/04/11 10:31 did gyre and gimble:
> For publishing APIs:
> 
> /* Returns a negative error code if the extra api is already registered. */
> int pa_extra_api_register(const char *name, void *api);
> 
> void pa_extra_api_unregister(const_char *name);
> 
> For consuming APIs:
> 
> /* Returns the currently registered api object,
>  * or NULL if the api isn't registered right now. */
> void *pa_extra_api_get(const char *name);
> 
> Additionally, there would be a couple of hooks defined for getting
> notifications about APIs getting registered and unregistered.

That seems sensible.

> The "api object" would be a struct with function pointers. The API
> provider would create instances of that struct and provide the function
> implementation. The API consumer would talk to the provider using those
> function pointers. 

OK, that all seems fine IMO.

> The api object header could be located in
> src/extra_apis - that would make the api not directly dependent on a
> particular module. 

If the API is not dependant on a particular module, what code calls
pa_extra_api_register? I'd be happy enough defining this extra API as an
"IMC" (c.f. IPC) system and thus make it very much tied to modules.

You could even have a call tracker module that just provides the code
you posted earlier with nothing more than a .h file and pa__init and
pa__done implementations and make sure this is loaded before any modules
that happen to want to use it.

> I've been using the term "extra api" here. I don't think it's the
> greatest name in the world, but that's the best I could think of. I'd
> like "extension" more, but that word is already used for other purposes.

Yeah extension is already in use for protocol extensions I guess.

How about pa_imc_*? (for inter-module comms) or is that perhaps too
cryptic?

Col

-- 

Colin Guthrie
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http://colin.guthr.ie/

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