refactor: let the periodic work run more frequently and never fail from excessive retries preventing from re-running.

remove resume pending jobs from ApplicationContext onCreate and handle in home activity's onCreate instead.

prevent some illegal argument exceptions from Random.kt by returning null if empty

app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java

@@ -327,7 +327,6 @@ public class ApplicationContext extends MultiDexApplication implements Dependenc
                 .setJobStorage(new FastJobStorage(DatabaseFactory.getJobDatabase(this)))
                 .setDependencyInjector(this)
                 .build());
-        JobQueue.getShared().resumePendingJobs();
     }
 
     private void initializeDependencyInjection() {
@@ -455,7 +454,6 @@ public class ApplicationContext extends MultiDexApplication implements Dependenc
             poller.setUserPublicKey(userPublicKey);
             return;
         }
-        LokiAPIDatabase apiDB = DatabaseFactory.getLokiAPIDatabase(this);
         poller = new Poller();
         closedGroupPoller = new ClosedGroupPoller();
     }

app/src/main/java/org/thoughtcrime/securesms/loki/api/BackgroundPollWorker.kt

@@ -17,7 +17,6 @@ import org.session.libsession.snode.SnodeAPI
 import org.session.libsession.utilities.TextSecurePreferences
 import org.session.libsignal.utilities.logging.Log
 import org.thoughtcrime.securesms.database.DatabaseFactory
-import java.io.IOException
 import java.util.concurrent.TimeUnit
 
 class BackgroundPollWorker(val context: Context, params: WorkerParameters) : Worker(context, params) {
@@ -25,26 +24,10 @@ class BackgroundPollWorker(val context: Context, params: WorkerParameters) : Wor
     companion object {
         const val TAG = "BackgroundPollWorker"
 
-        private const val RETRY_ATTEMPTS = 3
-
-        @JvmStatic
-        fun scheduleInstant(context: Context) {
-            val workRequest = OneTimeWorkRequestBuilder<BackgroundPollWorker>()
-                    .setConstraints(Constraints.Builder()
-                            .setRequiredNetworkType(NetworkType.CONNECTED)
-                            .build()
-                    )
-                    .build()
-
-            WorkManager
-                    .getInstance(context)
-                    .enqueue(workRequest)
-        }
-
         @JvmStatic
         fun schedulePeriodic(context: Context) {
             Log.v(TAG, "Scheduling periodic work.")
-            val workRequest = PeriodicWorkRequestBuilder<BackgroundPollWorker>(15, TimeUnit.MINUTES)
+            val workRequest = PeriodicWorkRequestBuilder<BackgroundPollWorker>(5, TimeUnit.MINUTES)
                     .setConstraints(Constraints.Builder()
                             .setRequiredNetworkType(NetworkType.CONNECTED)
                             .build()
@@ -55,7 +38,7 @@ class BackgroundPollWorker(val context: Context, params: WorkerParameters) : Wor
                     .getInstance(context)
                     .enqueueUniquePeriodicWork(
                             TAG,
-                            ExistingPeriodicWorkPolicy.KEEP,
+                            ExistingPeriodicWorkPolicy.REPLACE,
                             workRequest
                     )
         }
@@ -105,9 +88,8 @@ class BackgroundPollWorker(val context: Context, params: WorkerParameters) : Wor
 
             return Result.success()
         } catch (exception: Exception) {
-            Log.v(TAG, "Background poll failed due to error: ${exception.message}.", exception)
-
-            return if (runAttemptCount < RETRY_ATTEMPTS) Result.retry() else Result.failure()
+            Log.e(TAG, "Background poll failed due to error: ${exception.message}.", exception)
+            return Result.retry()
         }
     }
 
@@ -116,8 +98,7 @@ class BackgroundPollWorker(val context: Context, params: WorkerParameters) : Wor
         override fun onReceive(context: Context, intent: Intent) {
             if (intent.action == Intent.ACTION_BOOT_COMPLETED) {
                 Log.v(TAG, "Boot broadcast caught.")
-                BackgroundPollWorker.scheduleInstant(context)
-                BackgroundPollWorker.schedulePeriodic(context)
+                schedulePeriodic(context)
             }
         }
     }

app/src/main/java/org/thoughtcrime/securesms/loki/api/PublicChatManager.kt

@@ -31,7 +31,7 @@ class PublicChatManager(private val context: Context) {
     refreshChatsAndPollers()
     for ((threadID, _) in chats) {
       val poller = pollers[threadID]
-      areAllCaughtUp = if (poller != null) areAllCaughtUp && poller.isCaughtUp else true
+      areAllCaughtUp = if (poller != null) areAllCaughtUp && poller.isCaughtUp else areAllCaughtUp
     }
     return areAllCaughtUp
   }
@@ -42,6 +42,9 @@ class PublicChatManager(private val context: Context) {
       val poller = pollers[threadID] ?: OpenGroupPoller(chat, executorService)
       poller.isCaughtUp = false
     }
+    for ((_,poller) in v2Pollers) {
+      poller.isCaughtUp = false
+    }
   }
 
   public fun startPollersIfNeeded() {

libsession/src/main/java/org/session/libsession/snode/utilities/Random.kt

@@ -6,6 +6,7 @@ import java.security.SecureRandom
  * Uses `SecureRandom` to pick an element from this collection.
  */
 fun <T> Collection<T>.getRandomElementOrNull(): T? {
+    if (isEmpty()) return null
     val index = SecureRandom().nextInt(size) // SecureRandom() should be cryptographically secure
     return elementAtOrNull(index)
 }

libsignal/src/main/java/org/session/libsignal/service/loki/Random.kt

@@ -6,6 +6,7 @@ import java.security.SecureRandom
  * Uses `SecureRandom` to pick an element from this collection.
  */
 fun <T> Collection<T>.getRandomElementOrNull(): T? {
+    if (isEmpty()) return null
     val index = SecureRandom().nextInt(size) // SecureRandom() should be cryptographically secure
     return elementAtOrNull(index)
 }