Method flush

packages/engine.io/lib/socket.ts:509–532

* Attempts to flush the packets buffer. * * @private

()

   * @private
   */
  private flush() {
    if (
      "closed" !== this.readyState &&
      this.transport.writable &&
      this.writeBuffer.length
    ) {
      debug("flushing buffer to transport");
      this.emit("flush", this.writeBuffer);
      this.server.emit("flush", this, this.writeBuffer);
      const wbuf = this.writeBuffer;
      this.writeBuffer = [];

      if (this.packetsFn.length) {
        this.sentCallbackFn.push(this.packetsFn);
        this.packetsFn = [];
      } else {
        this.sentCallbackFn.push(null);
      }

      this.transport.send(wbuf);
      this.emit("drain");
      this.server.emit("drain", this);
    }
  }

  /**
   * Get available upgrades for this socket.