tw: wrap map ops in transaction

lib/Db/TimelineWriteMap.php

@@ -82,6 +82,8 @@ trait TimelineWriteMap
             return;
         }
 
+        $this->connection->beginTransaction();
+
         $query = $this->connection->getQueryBuilder();
         $query->update('memories_mapclusters')
             ->set('point_count', $query->createFunction('point_count + 1'))
@@ -92,6 +94,8 @@ trait TimelineWriteMap
         $query->executeStatement();
 
         $this->mapUpdateAggregates($clusterId);
+
+        $this->connection->commit();
     }
 
     /**
@@ -104,6 +108,8 @@ trait TimelineWriteMap
      */
     private function mapCreateCluster(float $lat, float $lon): int
     {
+        $this->connection->beginTransaction();
+
         $query = $this->connection->getQueryBuilder();
         $query->insert('memories_mapclusters')
             ->values([
@@ -117,6 +123,8 @@ trait TimelineWriteMap
         $clusterId = (int) $query->getLastInsertId();
         $this->mapUpdateAggregates($clusterId);
 
+        $this->connection->commit();
+
         return $clusterId;
     }
 
@@ -133,6 +141,8 @@ trait TimelineWriteMap
             return;
         }
 
+        $this->connection->beginTransaction();
+
         $query = $this->connection->getQueryBuilder();
         $query->update('memories_mapclusters')
             ->set('point_count', $query->createFunction('point_count - 1'))
@@ -143,6 +153,8 @@ trait TimelineWriteMap
         $query->executeStatement();
 
         $this->mapUpdateAggregates($clusterId);
+
+        $this->connection->commit();
     }
 
     /**