Add notification throttling

1 files changed, 13 insertions, 1 deletions

diff --git a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/NotificationManager.kt b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/NotificationManager.kt
index 3d58e571fd..ed2d2f053a 100644
--- a/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/NotificationManager.kt
+++ b/android/service/src/main/kotlin/net/mullvad/mullvadvpn/service/notifications/NotificationManager.kt
@@ -5,7 +5,10 @@ import android.content.Context
 import android.content.pm.PackageManager
 import androidx.core.app.ActivityCompat
 import androidx.core.app.NotificationManagerCompat
+import kotlin.time.Duration.Companion.milliseconds
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.flow.debounce
 import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.launch
 import net.mullvad.mullvadvpn.lib.model.Notification
@@ -13,6 +16,7 @@ import net.mullvad.mullvadvpn.lib.model.NotificationUpdate
 import net.mullvad.mullvadvpn.service.notifications.accountexpiry.toNotification
 import net.mullvad.mullvadvpn.service.notifications.tunnelstate.toNotification
 
+@OptIn(FlowPreview::class)
 class NotificationManager(
     private val notificationManagerCompat: NotificationManagerCompat,
     notificationProviders: List<NotificationProvider<Notification>>,
@@ -23,7 +27,7 @@ class NotificationManager(
     init {
         scope.launch {
             notificationProviders
-                .map { it.notifications }
+                .map { it.notifications.debounce(NOTIFICATION_DEBOUNCE) }
                 .merge()
                 .collect { notificationUpdate ->
                     when (notificationUpdate) {
@@ -31,6 +35,7 @@ class NotificationManager(
                             notificationManagerCompat.cancel(
                                 notificationUpdate.notificationId.value
                             )
+
                         is NotificationUpdate.Notify -> {
                             val notification = notificationUpdate.value
                             val androidNotification = notification.toAndroidNotification(context)
@@ -56,4 +61,11 @@ class NotificationManager(
             is Notification.Tunnel -> toNotification(context)
             is Notification.AccountExpiry -> toNotification(context)
         }
+
+    companion object {
+        // According to testing we are only allowed to send 5 notifications per second at most,
+        // otherwise the system will start dropping them. To ensure we don't drop the latest
+        // notification debounce if we spam too much.
+        val NOTIFICATION_DEBOUNCE = 200.milliseconds
+    }
 }