mirror of
https://github.com/permissionlesstech/bitchat-android.git
synced 2026-08-15 06:56:30 +00:00
fix: rate-limit peer availability alerts
This commit is contained in:
callebtc
parent
4fad876944
commit
2807a16d1e
@ -13,6 +13,7 @@ import android.util.Log
|
||||
import androidx.core.app.NotificationCompat
|
||||
import androidx.core.app.NotificationManagerCompat
|
||||
import androidx.core.content.ContextCompat
|
||||
import androidx.core.content.edit
|
||||
import com.bitchat.android.MainActivity
|
||||
import com.bitchat.android.R
|
||||
|
||||
@ -22,24 +23,108 @@ internal enum class PeerAvailabilityAction {
|
||||
CLEAR
|
||||
}
|
||||
|
||||
internal interface PeerAvailabilityAlertHistory {
|
||||
var lastAlertAtMillis: Long?
|
||||
}
|
||||
|
||||
internal class SharedPreferencesPeerAvailabilityAlertHistory(
|
||||
context: Context
|
||||
) : PeerAvailabilityAlertHistory {
|
||||
companion object {
|
||||
internal const val PREFERENCES_NAME = "peer_availability_notifications"
|
||||
private const val KEY_LAST_ALERT_AT_MILLIS = "last_alert_at_millis"
|
||||
}
|
||||
|
||||
private val preferences =
|
||||
context.getSharedPreferences(PREFERENCES_NAME, Context.MODE_PRIVATE)
|
||||
|
||||
override var lastAlertAtMillis: Long?
|
||||
get() = if (preferences.contains(KEY_LAST_ALERT_AT_MILLIS)) {
|
||||
preferences.getLong(KEY_LAST_ALERT_AT_MILLIS, 0L)
|
||||
} else {
|
||||
null
|
||||
}
|
||||
set(value) {
|
||||
preferences.edit {
|
||||
if (value == null) {
|
||||
remove(KEY_LAST_ALERT_AT_MILLIS)
|
||||
} else {
|
||||
putLong(KEY_LAST_ALERT_AT_MILLIS, value)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Tracks mesh availability epochs. A notification is eligible only for a background
|
||||
* transition from no peers to at least one peer. Returning to zero starts a new epoch.
|
||||
* Tracks mesh availability epochs with two anti-flapping gates:
|
||||
* - no more than one alert per persisted cooldown window;
|
||||
* - after an alert, the mesh must remain empty before another epoch can re-arm.
|
||||
*/
|
||||
internal class PeerAvailabilityTracker {
|
||||
internal class PeerAvailabilityTracker(
|
||||
private val alertHistory: PeerAvailabilityAlertHistory,
|
||||
private val nowMillis: () -> Long = System::currentTimeMillis,
|
||||
private val alertCooldownMs: Long = ALERT_COOLDOWN_MS,
|
||||
private val emptyRearmDelayMs: Long = EMPTY_REARM_DELAY_MS
|
||||
) {
|
||||
companion object {
|
||||
internal const val ALERT_COOLDOWN_MS = 5 * 60_000L
|
||||
internal const val EMPTY_REARM_DELAY_MS = 30_000L
|
||||
}
|
||||
|
||||
private var previousPeerCount = 0
|
||||
private var isArmed = true
|
||||
private var emptySinceMillis: Long? = null
|
||||
|
||||
init {
|
||||
require(alertCooldownMs >= 0) { "alertCooldownMs must not be negative" }
|
||||
require(emptyRearmDelayMs >= 0) { "emptyRearmDelayMs must not be negative" }
|
||||
}
|
||||
|
||||
fun update(peerCount: Int, isAppInBackground: Boolean): PeerAvailabilityAction {
|
||||
require(peerCount >= 0) { "peerCount must not be negative" }
|
||||
|
||||
val action = when {
|
||||
peerCount == 0 -> PeerAvailabilityAction.CLEAR
|
||||
previousPeerCount == 0 && isAppInBackground -> PeerAvailabilityAction.SHOW
|
||||
else -> PeerAvailabilityAction.NONE
|
||||
val now = nowMillis()
|
||||
if (peerCount == 0) {
|
||||
if (previousPeerCount > 0 || emptySinceMillis == null) {
|
||||
emptySinceMillis = now
|
||||
}
|
||||
previousPeerCount = 0
|
||||
return PeerAvailabilityAction.CLEAR
|
||||
}
|
||||
|
||||
val transitionedFromEmpty = previousPeerCount == 0
|
||||
previousPeerCount = peerCount
|
||||
return action
|
||||
if (!transitionedFromEmpty) return PeerAvailabilityAction.NONE
|
||||
|
||||
if (!isArmed) {
|
||||
val emptySince = emptySinceMillis
|
||||
val remainedEmptyLongEnough =
|
||||
emptySince != null && now - emptySince >= emptyRearmDelayMs
|
||||
if (!remainedEmptyLongEnough) {
|
||||
emptySinceMillis = null
|
||||
return PeerAvailabilityAction.NONE
|
||||
}
|
||||
isArmed = true
|
||||
}
|
||||
emptySinceMillis = null
|
||||
|
||||
val lastAlertAt = alertHistory.lastAlertAtMillis
|
||||
val cooldownElapsed =
|
||||
lastAlertAt == null || now - lastAlertAt >= alertCooldownMs
|
||||
return if (isAppInBackground && cooldownElapsed) {
|
||||
PeerAvailabilityAction.SHOW
|
||||
} else {
|
||||
PeerAvailabilityAction.NONE
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Called only after NotificationManager accepts the post. Failed or disabled posts
|
||||
* do not consume the cooldown or require the mesh to re-arm.
|
||||
*/
|
||||
fun markAlertShown() {
|
||||
alertHistory.lastAlertAtMillis = nowMillis()
|
||||
isArmed = false
|
||||
}
|
||||
}
|
||||
|
||||
@ -71,7 +156,9 @@ internal class PeerAvailabilityNotifier(
|
||||
private val context: Context,
|
||||
private val notificationManager: NotificationManagerCompat =
|
||||
NotificationManagerCompat.from(context),
|
||||
private val tracker: PeerAvailabilityTracker = PeerAvailabilityTracker(),
|
||||
private val tracker: PeerAvailabilityTracker = PeerAvailabilityTracker(
|
||||
SharedPreferencesPeerAvailabilityAlertHistory(context)
|
||||
),
|
||||
private val textProvider: PeerAvailabilityTextProvider =
|
||||
AndroidPeerAvailabilityTextProvider(context),
|
||||
private val canPostNotifications: () -> Boolean = {
|
||||
@ -140,6 +227,7 @@ internal class PeerAvailabilityNotifier(
|
||||
.setContentText(textProvider.body(peerCount))
|
||||
.setContentIntent(pendingIntent)
|
||||
.setAutoCancel(true)
|
||||
.setOnlyAlertOnce(true)
|
||||
.setPriority(NotificationCompat.PRIORITY_HIGH)
|
||||
.setCategory(NotificationCompat.CATEGORY_SOCIAL)
|
||||
.setShowWhen(true)
|
||||
@ -148,6 +236,7 @@ internal class PeerAvailabilityNotifier(
|
||||
|
||||
try {
|
||||
notificationManager.notify(NOTIFICATION_ID, notification)
|
||||
tracker.markAlertShown()
|
||||
Log.i(TAG, "Posted peer availability notification for $peerCount peer(s)")
|
||||
} catch (error: SecurityException) {
|
||||
Log.w(TAG, "Notification permission changed before peer alert was posted", error)
|
||||
|
||||
@ -1,11 +1,13 @@
|
||||
package com.bitchat.android.service
|
||||
|
||||
import android.app.Notification
|
||||
import android.app.NotificationManager
|
||||
import android.content.Context
|
||||
import androidx.test.core.app.ApplicationProvider
|
||||
import org.junit.Assert.assertEquals
|
||||
import org.junit.Assert.assertNotNull
|
||||
import org.junit.Assert.assertNull
|
||||
import org.junit.Assert.assertTrue
|
||||
import org.junit.Before
|
||||
import org.junit.Test
|
||||
import org.junit.runner.RunWith
|
||||
@ -16,19 +18,82 @@ import org.robolectric.annotation.Config
|
||||
class PeerAvailabilityTrackerTest {
|
||||
|
||||
@Test
|
||||
fun `background zero to nonzero transition shows once per availability epoch`() {
|
||||
val tracker = PeerAvailabilityTracker()
|
||||
fun `repeated flapping produces only one alert during cooldown`() {
|
||||
val clock = MutableClock()
|
||||
val tracker = tracker(clock = clock)
|
||||
var showCount = 0
|
||||
|
||||
if (tracker.update(1, isAppInBackground = true) == PeerAvailabilityAction.SHOW) {
|
||||
showCount++
|
||||
tracker.markAlertShown()
|
||||
}
|
||||
|
||||
repeat(5) {
|
||||
clock.advance(1_000L)
|
||||
assertEquals(
|
||||
PeerAvailabilityAction.CLEAR,
|
||||
tracker.update(0, isAppInBackground = true)
|
||||
)
|
||||
clock.advance(PeerAvailabilityTracker.EMPTY_REARM_DELAY_MS)
|
||||
if (tracker.update(1, isAppInBackground = true) == PeerAvailabilityAction.SHOW) {
|
||||
showCount++
|
||||
tracker.markAlertShown()
|
||||
}
|
||||
}
|
||||
|
||||
assertEquals(1, showCount)
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `mesh must remain empty before notification re-arms`() {
|
||||
val clock = MutableClock()
|
||||
val tracker = tracker(
|
||||
clock = clock,
|
||||
alertCooldownMs = 0L
|
||||
)
|
||||
|
||||
assertEquals(PeerAvailabilityAction.SHOW, tracker.update(1, isAppInBackground = true))
|
||||
tracker.markAlertShown()
|
||||
|
||||
assertEquals(PeerAvailabilityAction.CLEAR, tracker.update(0, isAppInBackground = true))
|
||||
assertEquals(PeerAvailabilityAction.SHOW, tracker.update(1, isAppInBackground = true))
|
||||
assertEquals(PeerAvailabilityAction.NONE, tracker.update(2, isAppInBackground = true))
|
||||
clock.advance(PeerAvailabilityTracker.EMPTY_REARM_DELAY_MS - 1)
|
||||
assertEquals(PeerAvailabilityAction.NONE, tracker.update(1, isAppInBackground = true))
|
||||
|
||||
assertEquals(PeerAvailabilityAction.CLEAR, tracker.update(0, isAppInBackground = true))
|
||||
clock.advance(PeerAvailabilityTracker.EMPTY_REARM_DELAY_MS)
|
||||
assertEquals(PeerAvailabilityAction.SHOW, tracker.update(1, isAppInBackground = true))
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `cooldown survives tracker recreation`() {
|
||||
val clock = MutableClock()
|
||||
val history = InMemoryAlertHistory()
|
||||
val originalTracker = tracker(clock = clock, history = history)
|
||||
|
||||
assertEquals(
|
||||
PeerAvailabilityAction.SHOW,
|
||||
originalTracker.update(1, isAppInBackground = true)
|
||||
)
|
||||
originalTracker.markAlertShown()
|
||||
|
||||
clock.advance(PeerAvailabilityTracker.ALERT_COOLDOWN_MS - 1)
|
||||
val restartedDuringCooldown = tracker(clock = clock, history = history)
|
||||
assertEquals(
|
||||
PeerAvailabilityAction.NONE,
|
||||
restartedDuringCooldown.update(1, isAppInBackground = true)
|
||||
)
|
||||
|
||||
clock.advance(1)
|
||||
val restartedAfterCooldown = tracker(clock = clock, history = history)
|
||||
assertEquals(
|
||||
PeerAvailabilityAction.SHOW,
|
||||
restartedAfterCooldown.update(1, isAppInBackground = true)
|
||||
)
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `foreground discovery is not replayed after app enters background`() {
|
||||
val tracker = PeerAvailabilityTracker()
|
||||
val tracker = tracker()
|
||||
|
||||
assertEquals(PeerAvailabilityAction.NONE, tracker.update(1, isAppInBackground = false))
|
||||
assertEquals(PeerAvailabilityAction.NONE, tracker.update(1, isAppInBackground = true))
|
||||
@ -38,7 +103,19 @@ class PeerAvailabilityTrackerTest {
|
||||
|
||||
@Test(expected = IllegalArgumentException::class)
|
||||
fun `negative peer count is rejected`() {
|
||||
PeerAvailabilityTracker().update(-1, isAppInBackground = true)
|
||||
tracker().update(-1, isAppInBackground = true)
|
||||
}
|
||||
|
||||
private fun tracker(
|
||||
clock: MutableClock = MutableClock(),
|
||||
history: InMemoryAlertHistory = InMemoryAlertHistory(),
|
||||
alertCooldownMs: Long = PeerAvailabilityTracker.ALERT_COOLDOWN_MS
|
||||
): PeerAvailabilityTracker {
|
||||
return PeerAvailabilityTracker(
|
||||
alertHistory = history,
|
||||
nowMillis = clock::now,
|
||||
alertCooldownMs = alertCooldownMs
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
@ -54,6 +131,10 @@ class PeerAvailabilityNotifierTest {
|
||||
systemNotificationManager =
|
||||
context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
|
||||
systemNotificationManager.cancelAll()
|
||||
context.getSharedPreferences(
|
||||
SharedPreferencesPeerAvailabilityAlertHistory.PREFERENCES_NAME,
|
||||
Context.MODE_PRIVATE
|
||||
).edit().clear().commit()
|
||||
}
|
||||
|
||||
@Test
|
||||
@ -61,6 +142,7 @@ class PeerAvailabilityNotifierTest {
|
||||
val textProvider = testTextProvider()
|
||||
val notifier = PeerAvailabilityNotifier(
|
||||
context = context,
|
||||
tracker = tracker(),
|
||||
textProvider = textProvider,
|
||||
canPostNotifications = { true }
|
||||
)
|
||||
@ -69,7 +151,9 @@ class PeerAvailabilityNotifierTest {
|
||||
notifier.onPeerCountChanged(2, isAppInBackground = true)
|
||||
|
||||
val notification =
|
||||
shadowOf(systemNotificationManager).getNotification(PeerAvailabilityNotifier.NOTIFICATION_ID)
|
||||
shadowOf(systemNotificationManager).getNotification(
|
||||
PeerAvailabilityNotifier.NOTIFICATION_ID
|
||||
)
|
||||
assertNotNull(notification)
|
||||
assertEquals(PeerAvailabilityNotifier.CHANNEL_ID, notification.channelId)
|
||||
assertEquals(
|
||||
@ -80,6 +164,7 @@ class PeerAvailabilityNotifierTest {
|
||||
textProvider.body(2),
|
||||
notification.extras.getString("android.text")
|
||||
)
|
||||
assertTrue(notification.flags and Notification.FLAG_ONLY_ALERT_ONCE != 0)
|
||||
assertNotNull(
|
||||
systemNotificationManager.getNotificationChannel(PeerAvailabilityNotifier.CHANNEL_ID)
|
||||
)
|
||||
@ -89,6 +174,7 @@ class PeerAvailabilityNotifierTest {
|
||||
fun `returning to zero cancels availability notification`() {
|
||||
val notifier = PeerAvailabilityNotifier(
|
||||
context = context,
|
||||
tracker = tracker(),
|
||||
textProvider = testTextProvider(),
|
||||
canPostNotifications = { true }
|
||||
)
|
||||
@ -97,14 +183,18 @@ class PeerAvailabilityNotifierTest {
|
||||
notifier.onPeerCountChanged(0, isAppInBackground = true)
|
||||
|
||||
assertNull(
|
||||
shadowOf(systemNotificationManager).getNotification(PeerAvailabilityNotifier.NOTIFICATION_ID)
|
||||
shadowOf(systemNotificationManager).getNotification(
|
||||
PeerAvailabilityNotifier.NOTIFICATION_ID
|
||||
)
|
||||
)
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `disabled notifications do not post`() {
|
||||
val history = InMemoryAlertHistory()
|
||||
val notifier = PeerAvailabilityNotifier(
|
||||
context = context,
|
||||
tracker = PeerAvailabilityTracker(history),
|
||||
textProvider = testTextProvider(),
|
||||
canPostNotifications = { false }
|
||||
)
|
||||
@ -112,8 +202,26 @@ class PeerAvailabilityNotifierTest {
|
||||
notifier.onPeerCountChanged(1, isAppInBackground = true)
|
||||
|
||||
assertNull(
|
||||
shadowOf(systemNotificationManager).getNotification(PeerAvailabilityNotifier.NOTIFICATION_ID)
|
||||
shadowOf(systemNotificationManager).getNotification(
|
||||
PeerAvailabilityNotifier.NOTIFICATION_ID
|
||||
)
|
||||
)
|
||||
assertNull(history.lastAlertAtMillis)
|
||||
}
|
||||
|
||||
@Test
|
||||
fun `shared preferences history persists last alert time`() {
|
||||
val history = SharedPreferencesPeerAvailabilityAlertHistory(context)
|
||||
history.lastAlertAtMillis = 42L
|
||||
|
||||
assertEquals(
|
||||
42L,
|
||||
SharedPreferencesPeerAvailabilityAlertHistory(context).lastAlertAtMillis ?: -1L
|
||||
)
|
||||
}
|
||||
|
||||
private fun tracker(): PeerAvailabilityTracker {
|
||||
return PeerAvailabilityTracker(InMemoryAlertHistory())
|
||||
}
|
||||
|
||||
private fun testTextProvider(): PeerAvailabilityTextProvider {
|
||||
@ -124,3 +232,17 @@ class PeerAvailabilityNotifierTest {
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private class InMemoryAlertHistory(
|
||||
override var lastAlertAtMillis: Long? = null
|
||||
) : PeerAvailabilityAlertHistory
|
||||
|
||||
private class MutableClock(
|
||||
private var currentMillis: Long = 1_000L
|
||||
) {
|
||||
fun now(): Long = currentMillis
|
||||
|
||||
fun advance(durationMillis: Long) {
|
||||
currentMillis += durationMillis
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user