Method attach

packages/engine.io/lib/server.ts:955–1005

* Captures upgrade requests for a http.Server. * * @param {http.Server} server * @param {Object} options

(server: HttpServer, options: AttachOptions = {})

   * @param {Object} options
   */
  public attach(server: HttpServer, options: AttachOptions = {}) {
    const path = this._computePath(options);
    const destroyUpgradeTimeout = options.destroyUpgradeTimeout || 1000;

    function check(req) {
      class="cm">// TODO use `path === new URL(...).pathname` in the next major release (ref: https://nodejs.org/api/url.html)
      return path === req.url.slice(0, path.length);
    }

    class="cm">// cache and clean up listeners
    const listeners = server.listeners(class="st">"request").slice(0);
    server.removeAllListeners(class="st">"request");
    server.on(class="st">"close", this.close.bind(this));
    server.on(class="st">"listening", this.init.bind(this));

    class="cm">// add request handler
    server.on(class="st">"request", (req, res) => {
      if (check(req)) {
        debug(class="st">'intercepting request for path "%s"', path);
        this.handleRequest(req, res);
      } else {
        let i = 0;
        const l = listeners.length;
        for (; i < l; i++) {
          listeners[i].call(server, req, res);
        }
      }
    });

    if (~this.opts.transports.indexOf(class="st">"websocket")) {
      server.on(class="st">"upgrade", (req, socket, head) => {
        if (check(req)) {
          this.handleUpgrade(req, socket, head);
        } else if (false !== options.destroyUpgrade) {
          class="cm">// default node behavior is to disconnect when no handlers
          class="cm">// but by adding a handler, we prevent that
          class="cm">// and if no eio thing handles the upgrade
          class="cm">// then the socket needs to die!
          setTimeout(function () {
            class="cm">// @ts-ignore
            if (socket.writable && socket.bytesWritten <= 0) {
              socket.on(class="st">"error", (e) => {
                debug(class="st">"error while destroying upgrade: %s", e.message);
              });
              return socket.end();
            }
          }, destroyUpgradeTimeout);
        }
      });
    }
  }
}

/**