Vert.x live chat feeds

chat-server.kt

fun main() {
  val rooms = mutableMapOf<String, MutableSet<ServerWebSocket>>()
  val vertx = Vertx.vertx()
  vertx.createHttpServer()
    .webSocketHandler {
      rooms.computeIfPresent(it.path()) { _, listOfConnections ->
        listOfConnections.add(it)
        listOfConnections
      }
      rooms.computeIfAbsent(it.path()) { _ -> mutableSetOf(it) }
      it.closeHandler { _ -> rooms[it.path()]?.remove(it) }
      it.textMessageHandler { event ->
        rooms[it.path()]?.filterNot { ws -> ws == it }?.forEach { ws -> ws.writeTextMessage(event) }
      }
    }
    .listen(9999)
    .onSuccess { println("server successfully started on port 9999") }
    .onFailure { println("failed to start server: " + it.stackTrace) }
}