Room list : debounce subscribe to visible rooms.

features/roomlist/impl/src/main/kotlin/io/element/android/features/roomlist/impl/RoomListPresenter.kt

@@ -61,7 +61,7 @@ import kotlinx.collections.immutable.toPersistentList
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.Job
-import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.first
@@ -73,6 +73,7 @@ import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 private const val EXTENDED_RANGE_SIZE = 40
+private const val SUBSCRIBE_TO_VISIBLE_ROOMS_DEBOUNCE_IN_MILLIS = 300L
 
 class RoomListPresenter @Inject constructor(
     private val client: MatrixClient,
@@ -301,7 +302,10 @@ class RoomListPresenter @Inject constructor(
     private var currentUpdateVisibleRangeJob: Job? = null
     private fun CoroutineScope.updateVisibleRange(range: IntRange) {
         currentUpdateVisibleRangeJob?.cancel()
-        currentUpdateVisibleRangeJob = launch(SupervisorJob()) {
+        currentUpdateVisibleRangeJob = launch {
+            // Debounce the subscription to avoid subscribing to too many rooms
+            delay(SUBSCRIBE_TO_VISIBLE_ROOMS_DEBOUNCE_IN_MILLIS)
+
             if (range.isEmpty()) return@launch
             val currentRoomList = roomListDataSource.allRooms.first()
             // Use extended range to 'prefetch' the next rooms info

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/roomlist/RustRoomListService.kt

@@ -53,11 +53,7 @@ internal class RustRoomListService(
     }
 
     override suspend fun subscribeToVisibleRooms(roomIds: List<RoomId>) {
-        val toSubscribe = roomIds.filterNot { roomSyncSubscriber.isSubscribedTo(it) }
-        if (toSubscribe.isNotEmpty()) {
-            Timber.d("Subscribe to ${toSubscribe.size} rooms: $toSubscribe")
-            roomSyncSubscriber.batchSubscribe(toSubscribe)
-        }
+        roomSyncSubscriber.batchSubscribe(roomIds)
     }
 
     override val allRooms: DynamicRoomList = roomListFactory.createRoomList(