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Inefficient use of MapboxRouteLineApi cache for restricted sections

Open LukasPaczos opened this issue 3 years ago • 1 comments

Whenever the MapboxRouteLineApi needs to update the vanishing point (MapboxRouteLineApi#updateTraveledRouteLine), MapboxRouteLineOptions#styleInactiveRouteLegsIndependently is enabled, and the route goes through a visualized restricted section, the API needs to extract the full parsed route object to create the gradient expression for the restricted sections: https://github.com/mapbox/mapbox-navigation-android/blob/d8d04fe75e53063f5e185c3779c04c7b0914f77d/libnavui-maps/src/main/java/com/mapbox/navigation/ui/maps/route/line/api/MapboxRouteLineApi.kt#L463-L470

This parsed data is already cached in https://github.com/mapbox/mapbox-navigation-android/blob/d8d04fe75e53063f5e185c3779c04c7b0914f77d/libnavui-maps/src/main/java/com/mapbox/navigation/ui/maps/internal/route/line/MapboxRouteLineUtils.kt#L67-L72 however, the key of this cache is based on the hash of the full DirectionsRoute, which makes computing the key very expensive for long routes.

While this is not as problematic when routes are re-drawn (for each MapboxRouteLineApi#setNavigationRoutes), it is extremely unsuitable for very frequent updates of the vanishing point with MapboxRouteLineApi#updateTraveledRouteLine. This cache lookup on a route from Munich to Madrid can take more than 20% of the main thread's time on a rather powerful Samsung S22+, and on other hardware can even occasionally lead to ANRs if the frequency of the location indicator updates is high enough to flood the main thread. Screenshot from 2022-08-15 12-47-47

During the vanishing updates, they cache element is not possible to be changed, so instead of extracting the value from the cache on each update, we should store the List<ExtractedRouteData> locally in MapboxRouteLineApi and refresh it whenever routes are re-drawn. We already follow the same practice with the List<RouteLineExpressionData>: https://github.com/mapbox/mapbox-navigation-android/blob/d8d04fe75e53063f5e185c3779c04c7b0914f77d/libnavui-maps/src/main/java/com/mapbox/navigation/ui/maps/route/line/api/MapboxRouteLineApi.kt#L199

cc @cafesilencio @abhishek1508

LukasPaczos avatar Aug 15 '22 11:08 LukasPaczos

https://github.com/mapbox/mapbox-navigation-android/pull/6169 addresses the issue when the legs are not styled independently. This ticket keeps tracking the need for changes when they are.

LukasPaczos avatar Aug 15 '22 11:08 LukasPaczos