On Tue, Feb 24, 2015 at 2:50 PM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote: > Hi Jakub, > >>>>> Since we can't any more track multiple different discoveries within the >>>>> same application (D-Bus connection) the StopDiscovery behavior is now >>>>> quite broken. The simplest way around that would be to add a discovery >>>>> instance return parameter to StartServiceDiscovery and to have a new >>>>> StopServiceDiscovery D-Bus method that'd take this as an input >>>>> parameter. >>>> >>>> Right now each application can call StartDiscovery only once, I want >>>> each application to be able to call StartDiscovery OR >>>> StartFilteredDiscovery only once. This way we are completly fine with >>>> one StopDiscovery method. If some application needs to change filter, >>>> it can always stop and restart it's scan. >>> >>> Actually I remembered wrong how the current code works. I thought it was >>> allowing multiple StartDiscovery() per app, but there's indeed a >>> hard-coded limit of just one. Keeping this policy around would allow >>> StopDiscovery to be used for StartDiscovery and StartServiceDiscovery >>> alike, and each app would then only be allowed to call one of those at a >>> time. >>> >> >> So I want to keep the limit of one session per app, but I think that >> app should be able to call StartServiceDiscovery multiple times, in >> order to update it's filter without calling StopDiscovery to first >> stop it's discovery. That would simplify filter updating for apps that >> would have such need, and make their logic simpler. > > we have never done such an API design before. I am a bit reluctant to allow that now. The whole API design is falling into one simple approach that the name of method calls and properties is pretty self explanatory. That StartServiceDiscovery means also additionally UpdateServiceDiscovery is not something I would consider intuitive. > >> Example: App wants to update it's filter. If It can't call >> StartServiceDiscovery more than once, here are steps: >> 1. app call StopDiscovery. >> 2. Discovering property changed to false. >> 3. It calls StartFilteredDiscovery with updated filter. >> 4. Discovering property changed to true >> >> If calling StartFilteredDiscovery more than once is possible: >> 1. app call StartServiceDiscovery with updated filter, filter is >> updated internally and "Discovering" property is not updated at all. >> >> >> I think I argree with all other comments from other emails. I'll >> update documentation accordingly. >> I'll say in doc, that StartServiceDiscovery might be called multiple >> times, and keep only one session. If anyone doesn't argree with that >> I'll remove that, as that's only for convinience, and doesn't really >> affect functionality. > > While I just looked at this for only a few minutes, the double execution of StartServiceDiscovery is something that does not fell right. Why not introduce UpdateServiceDiscovery or ChangeServiceDiscovery. Ok, I'll make it so you can call StartFilteredDiscovery only once. If you want to change filter just stop and start the filtered scan again. > > Regards > > Marcel > -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
