Improve mass notification processing

lib/App.php

@@ -54,8 +54,7 @@ public function notify(INotification $notification): void {
 		$notificationId = $this->handler->add($notification);
 
 		try {
-			$notificationToPush = $this->handler->getById($notificationId, $notification->getUser());
-			$this->push->pushToDevice($notificationId, $notificationToPush);
+			$this->push->pushToDevice($notificationId, $notification);
 		} catch (NotificationNotFoundException $e) {
 			throw new \InvalidArgumentException('Error while preparing push notification');
 		}

lib/Handler.php

@@ -108,11 +108,27 @@ public function delete(INotification $notification): array {
 		}
 		$statement->closeCursor();
 
-		foreach ($deleted as $user => $entries) {
-			foreach ($entries as $entry) {
-				$this->deleteById($entry['id'], (string) $user, $notifications[$entry['id']]);
+		$this->connection->beginTransaction();
+		try {
+			$shouldFlush = $this->manager->defer();
+
+			foreach ($notifications as $n) {
+				$this->manager->dismissNotification($n);
+			}
+
+			$notificationIds = array_keys($notifications);
+			foreach (array_chunk($notificationIds, 1000) as $chunk) {
+				$this->deleteIds($chunk);
 			}
+
+			if ($shouldFlush) {
+				$this->manager->flush();
+			}
+		} catch (\Throwable $e) {
+			$this->connection->rollBack();
+			throw $e;
 		}
+		$this->connection->commit();
 
 		return $deleted;
 	}
@@ -156,6 +172,18 @@ public function deleteById(int $id, string $user, ?INotification $notification =
 		return (bool) $sql->executeStatement();
 	}
 
+	/**
+	 * Delete the notification matching the given ids
+	 *
+	 * @param int[] $ids
+	 */
+	public function deleteIds(array $ids): void {
+		$sql = $this->connection->getQueryBuilder();
+		$sql->delete('notifications')
+			->where($sql->expr()->in('notification_id', $sql->createNamedParameter($ids, IQueryBuilder::PARAM_INT_ARRAY)));
+		$sql->executeStatement();
+	}
+
 	/**
 	 * Get the notification matching the given id
 	 *

tests/Unit/AppTest.php

@@ -53,30 +53,21 @@ protected function setUp(): void {
 
 	public function dataNotify() {
 		return [
-			[23, 'user1'],
-			[42, 'user2'],
+			[23],
+			[42],
 		];
 	}
 
 	/**
 	 * @dataProvider dataNotify
 	 *
 	 * @param int $id
-	 * @param string $user
 	 */
-	public function testNotify($id, $user) {
-		$this->notification->expects($this->once())
-			->method('getUser')
-			->willReturn($user);
-
+	public function testNotify($id) {
 		$this->handler->expects($this->once())
 			->method('add')
 			->with($this->notification)
 			->willReturn($id);
-		$this->handler->expects($this->once())
-			->method('getById')
-			->with($id, $user)
-			->willReturn($this->notification);
 		$this->push->expects($this->once())
 			->method('pushToDevice')
 			->with($id, $this->notification);