Graphx - how to add vertices to a HashSet of vertices ?

[Ranjana Rajendran]

Hi,

sampledVertices is a HashSet of vertices

      var sampledVertices: HashSet[VertexId] = HashSet()

In each iteration, I am making a list of neighborVertexIds

      val neighborVertexIds = burnEdges.map((e:Edge[Int]) => e.dstId)

I want to add this neighborVertexIds to the sampledVertices Hashset.

What is the best way to do this ?

   Currently, I have

sampledVertices = sampledVertices ++ neighborVertexIds.toArray

I realize, toArray is making this a separate stage.

What will be the most efficient way to achieve this ?

Similarly, I need to add the neighborVertexIds to burnQueue where burnQueue
is is a queue of vertices

var burnQueue: Queue[VertexId] = Queue()

Thank you,

Ranjana