I'm sorting a large list (10.000+) items with use ...

# coroutines

[Remy Benza]

I'm sorting a large list (10.000+) items with use of the <http://Dispatcher.IO|Dispatcher.IO> from an Android room database. What pattern is recommended to use?

[Remy Benza]

A:

[Remy Benza]

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[Remy Benza]

or B:

[Remy Benza]

message has been deleted

[Remy Benza]

with A calling filterNotificationsOnDateRange() directly from the view (Fragment)

[Remy Benza]

with B I'm calling it inside lifecycleScope.launchWhenCreate { } in the Fragment

[Remy Benza]

would this change if I where to call another suspend function inside filterNotificationsOnDateRange() ? Let's say a call to get different data from the room db

[Dominaezzz]

B is better because it defers concurrency to the caller and uses the correct dispatcher.

[Dominaezzz]

Don't think it changes anything.

[Remy Benza]

But shouldn't the view be as 'dumb' as possible and the viewmodel handle all the logic?

[Remy Benza]

if you go for option A the scope will be canceled when the fragment lifecycle ends, aka on a config change. If you use the viewmodelscope the filter result would still be available

[Javier]

Why you are not using a query + flow in room?

[Remy Benza]

because I want to pull in the large data set once the sceens opens, then I let the user filter on various conditions

[Remy Benza]

I dont want this dataset to be updated automatically while the screen is open, with use of Flow

[Dominaezzz]

Ah, didn't notice it was in the view model. I guess A is fine then.

[wasyl]

As a side note, shouldn’t you use Dispatchers.Default for sorting a large list? Sorting is cpu-bound

[Remy Benza]

yes