[RFC] speech dispatcher client/server data types

[Andrei Kholodnyi]

On Mon, Oct 4, 2010 at 4:02 PM, William Hubbs <w.d.hubbs at gmail.com> wrote:
> Hi Andrei,
>
> On Mon, Oct 04, 2010 at 08:43:09AM -0500, Christopher Brannon wrote:
>> Andrei Kholodnyi <andrei.kholodnyi at gmail.com> writes:
>>
>> > My proposal would be to align these data types
>> > and use the data types definitions from the libspeechd across all
>> > project modules
>> > with a clear advantage of consistency in data types between client and 
>> > server.
>>
>> We have a trade-off.
>> I can see the advantage: consistency.
>> The disadvantage is coupling. ?If someone ever needs to change one of
>> those shared types, it must change in both the client and server, even
>> if there's a good reason for changing it in only one component.
>
> Also, when you change a type in the client, you have to bump the shared
> library revision number.

Yes, and what is bad about it? We are talking about server core data types.
E.g. if I decide to modify a priority and introduce "Emergency"
priority on the server side.
It is clear that I need to support it on the client side as well,
hence modify a lib revision number.

>
>> Also, sharing declarations means that components of Speech Dispatcher
>> could not be separated into subprojects, if the need ever arises.
>
> The way to do this, imho, would be to copy the types from libspeechd.h
> to some place in the include directory, but also leave them in
> libspeechd.h so the API and server sides are not forced to share
> the type declarations. ?Sharing these type declarations is the thing I
> am uncomfortable with about your proposal, not the actual data types.

ok, could you please then suggest how it should look like? the same
data types in two different headers?
My concern is also that we need to export two headers now,
one for the clients (libspeechd.h), another for the modules
(speechd_types.h) with the similar data types.
With my proposal these two will be merged in one.

Thanks,
Andrei.