Class SocketServer

src/back/SocketServer.ts:42–382

const MAX_RETRIES = 5;

export class SocketServer {
  api: BackAPI = create_api();
  clients: BackClients = create_server();

  retryCounter = 0;

  /** Underlying WebSocket server. */
  server?: ws.Server;
  /** Chosen host */
  host: string | undefined = undefined;
  /** Port the server is listening on (-1 if not listening). */
  port = -1;
  /** Secret value used for authentication. */
  secret: any;

  /** Middleware for BackOut responses */
  middlewareRes: PipelineRes = genPipelineBackOut();

  /** Queues for incoming requests. */
  queues: RequestQueue[] = [];

  lastClient?: BackClient;

  /**
   * Try to listen on one of the ports in the given range (starting from the lowest).
   * If it succeeds it will set the "server" and "port" properties of this object.
   * If it fails it will reject with the error.
   *
   * @param minPort Minimum port number (tried first).
   * @param maxPort Maximum port number (tried last).
   * @param host Server host (determines what clients can connect).
   */
  public async listen(minPort: number, maxPort: number, host: string | undefined): Promise<void> {
    this.host = host;
    const result = await startServer(this.port !== -1 ? this.port : minPort, this.port !== -1 ? this.port : maxPort, host);
    result.server.on('connection', this.onConnect.bind(this));
    this.server = result.server;
    this.port = result.port;
    this.retryCounter = 0; // Reset retries on a good connection
    this.server.on('error', this.onError);
  }

  onError(err: Error) {
    if (this.retryCounter < MAX_RETRIES) {
      if (this.server) { // Try and close / remove server first
        try {
          this.server.close();
        } catch {/** Ignore closure errors */} finally {
          this.server = undefined;
        }
      }
      this.retryCounter++;
      setTimeout(() => { // Sleep then try and connect again
        this.listen(0,0, this.host)
        .catch(this.onError); // If failed to open, keep trying until we get there!
      }, 1500);
    }
  }