Duplicate location updates when I use multiple objects of ReactiveLocationProvider

[debugger22]

First of all thanks for the awesome work on this library!

I recently ran into a strange issue. I am using two objects of ReactiveLocationProvider namely mReactiveLocationProviderActive and mReactiveLocationProviderPassive. The active one sends location updates only when the device moves a specified distance with an interval of 5 seconds whereas the passive one sends location updates every minute with no restriction on the displacement.

It works in most cases except in some cases where it starts sending duplicate lat/lng. For example, look at the following table. The lat/lng pairs are same where as the accuracy is different.

Time	Latitude	Longitude	Accuracy
04 Jul 2018 06:24:33 PM IST	19.11526	72.85758	15.151
04 Jul 2018 06:15:58 PM IST	19.11526	72.85758	15.062
04 Jul 2018 06:13:11 PM IST	19.11526	72.85758	15.1
04 Jul 2018 06:12:26 PM IST	19.11526	72.85758	15.089
04 Jul 2018 06:11:00 PM IST	19.11526	72.85758	15.222
04 Jul 2018 06:02:30 PM IST	19.11526	72.85758	20.09
04 Jul 2018 05:46:29 PM IST	19.11526	72.85758	24.2

It works perfectly fine when there is only a single object of ReactiveLocationProvider.

Following is the code which I am using.

@Inject
ReactiveLocationProvider mReactiveLocationProviderActive;
@Inject
ReactiveLocationProvider mReactiveLocationProviderPassive;

private LocationRequest       mLocationRequestActive;
private LocationRequest       mLocationRequestPassive;

/**
 * Actively gets location update only when vehicle moves with a fixed time period
 */
private void requestLocationUpdatesActive() {
    mLocationRequestActive = LocationRequest.create();
    mLocationRequestActive.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequestActive.setFastestInterval(5000);
    mLocationRequestActive.setInterval(5*1000);
    mLocationRequestActive.setSmallestDisplacement(5.0f);

    mSubscriptions.add(mReactiveLocationProviderActive
                               .getUpdatedLocation(mLocationRequestActive)
                               .observeOn(AndroidSchedulers.mainThread())
                               .subscribe(this::onLocationChanged,
                                          throwable -> Timber.e(throwable,
                                                                "Location request error")));
}

/**
 * Passively gets location update irrespective of whether vehicle is moving or not
 */
private void requestLocationUpdatesPassive() {
    mLocationRequestPassive = LocationRequest.create();
    mLocationRequestPassive.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequestPassive.setFastestInterval(60000);
    mLocationRequestPassive.setInterval(60*1000);

    mSubscriptions.add(mReactiveLocationProviderPassive
                               .getUpdatedLocation(mLocationRequestPassive)
                               .observeOn(AndroidSchedulers.mainThread())
                               .subscribe(this::onLocationChanged,
                                          throwable -> Timber.w(throwable,
                                                                "Location request error")));
}

/**
* Sends location update to the server
*/
private void onLocationChanged(Location newLocation) {
  // Send location update to the server
}

Library versions that I am using:

• pl.charmas.android:android-reactive-location:0.9@aar
• io.reactivex:rxjava:1.3.0
• io.reactivex:rxandroid:1.2.1
• com.google.android.gms:play-services-location:11.0.4

Any help would be highly appreciated. TIA.

[debugger22]

@mcharmas Hey could you please take a look at this issue.

[mcharmas]

Hi @debugger22, to be honest I have no idea what can be the case here. Library is just a wrapper on play services and no state is shared between multiple instances of ReactiveLocationProvider object.

It should not even matter if you are using multiple instances of ReactiveLocationProvider vs one instance. For each locations subscription there is new connection to play services being made and data you get comes straight from location services.

If you want to get rid of duplicates you can merge these two observables and use distinct() operator on the observable but be aware of memory implications. Maybe distinctUntilChanged() will better for your use case? Having one subscription would be more elegant solution especially if you don't need a distinction where location is coming from.