rankun203/index.html

## index.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Service Worker test</title>
    <script>
      navigator.serviceWorker.getRegistration().then(function (registration) {
        if (!registration || !navigator.serviceWorker.controller) {
          navigator.serviceWorker.register('./sw.js').then(function () {
            console.log('Service worker registered, reloading the page');
            window.location.reload();
          });
        } else {
          console.log('DEBUG: client is under the control of service worker');
        }
      });
    </script>
    <link rel='stylesheet' id='extra-fonts-css'
          href='https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800&#038;subset=latin,latin-ext'
          type='text/css' media='all'/>
</head>
<body>

<script src="https://lodestreams-com.disqus.com/count.js?check-china=true"></script>

</body>
</html>

## sw.js
/** Indicates that current user is browsing from China. */
ServiceWorkerGlobalScope.inChina = null;
var DEBUG                = true;
var EMPTY_RESPONSE       = '';
/** The patterns to be checked against the requesting URL. */
var CHECK_CHINA_PATTERNS = [
  'check-china=true',
  'disqus.com',
  'googleapis.com'
];

/**
 * Clear inChina global var.
 * User may request through a proxy sometime, so it's better to just
 * clear the inChina var in nearly future.
 *
 * @param sec {Number} Seconds later to take the action. Default is 2 minutes.
 */
function clearInChinaVarLater(sec) {
  clearTimeout(ServiceWorkerGlobalScope.clearInChinaVarLater_TIMER);

  ServiceWorkerGlobalScope.clearInChinaVarLater_TIMER = setTimeout(function () {
    console.log('ServiceWorkerGlobalScope.inChina = undefined');
    ServiceWorkerGlobalScope.inChina = undefined;
  }, sec || 2 * 60 * 1000);
}

/**
 * Fetch resource with China detection.
 * If in China, returns Empty response, otherwise returns a real request response.
 * This function will also cache the inChina as a service worker level global variable, and will clear it later.
 * @param theRequest {Request} The requesting Request, needed for firing another real request (event.request).
 * @returns {Response|Promise} response if it's a empty response, Promise if it's requesting the real URL.
 */
function fetchWithChinaDetection(theRequest) {
  clearInChinaVarLater();

  if (ServiceWorkerGlobalScope.inChina === false) {
    return fetch(theRequest);
  }

  if (ServiceWorkerGlobalScope.inChina === true) {
    return new Response(EMPTY_RESPONSE);
  }

  return fetch('https://freegeoip.net/json/')
    .then(function (resp) {
      return resp.json()
    })
    .then(function (json) {
      var country = json && json.country_code;

      if (country && country.indexOf('CN') >= 0) {
        if (DEBUG) console.log('ServiceWorkerGlobalScope.inChina === true');
        ServiceWorkerGlobalScope.inChina = true;
        return new Response(EMPTY_RESPONSE);
      }

      if (DEBUG) console.log('ServiceWorkerGlobalScope.inChina === false');
      ServiceWorkerGlobalScope.inChina = false;
      return fetch(theRequest);
    });
}

/**
 * Entrance event.
 * If current request is considered not accessible in China,
 * check current user location before make the decision.
 *
 * Otherwise, for normal requests, just return their originals.
 * @param event {Event} The request Event, event.request is a Request.
 */
self.onfetch = function (event) {
  var checkChina = false;
  CHECK_CHINA_PATTERNS.forEach(function (p) {
    checkChina = checkChina || event.request.url.indexOf(p) >= 0;
  });

  if (checkChina) {
    if (DEBUG) console.log('checkChina is true for ' + event.request.url);
    return event.respondWith(fetchWithChinaDetection(event.request));
  }

  return event.respondWith(fetch(event.request));
};
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<title>Service Worker test</title>
	<script>
	navigator.serviceWorker.getRegistration().then(function (registration) {
	if (!registration \|\| !navigator.serviceWorker.controller) {
	navigator.serviceWorker.register('./sw.js').then(function () {
	console.log('Service worker registered, reloading the page');
	window.location.reload();
	});
	} else {
	console.log('DEBUG: client is under the control of service worker');
	}
	});
	</script>
	<link rel='stylesheet' id='extra-fonts-css'
	href='https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800&subset=latin,latin-ext'
	type='text/css' media='all'/>
	</head>
	<body>

	<script src="https://lodestreams-com.disqus.com/count.js?check-china=true"></script>

	</body>
	</html>
	/** Indicates that current user is browsing from China. */
	ServiceWorkerGlobalScope.inChina = null;
	var DEBUG = true;
	var EMPTY_RESPONSE = '';
	/** The patterns to be checked against the requesting URL. */
	var CHECK_CHINA_PATTERNS = [
	'check-china=true',
	'disqus.com',
	'googleapis.com'
	];

	/**
	* Clear inChina global var.
	* User may request through a proxy sometime, so it's better to just
	* clear the inChina var in nearly future.
	*
	* @param sec {Number} Seconds later to take the action. Default is 2 minutes.
	*/
	function clearInChinaVarLater(sec) {
	clearTimeout(ServiceWorkerGlobalScope.clearInChinaVarLater_TIMER);

	ServiceWorkerGlobalScope.clearInChinaVarLater_TIMER = setTimeout(function () {
	console.log('ServiceWorkerGlobalScope.inChina = undefined');
	ServiceWorkerGlobalScope.inChina = undefined;
	}, sec \|\| 2 * 60 * 1000);
	}

	/**
	* Fetch resource with China detection.
	* If in China, returns Empty response, otherwise returns a real request response.
	* This function will also cache the inChina as a service worker level global variable, and will clear it later.
	* @param theRequest {Request} The requesting Request, needed for firing another real request (event.request).
	* @returns {Response\|Promise} response if it's a empty response, Promise if it's requesting the real URL.
	*/
	function fetchWithChinaDetection(theRequest) {
	clearInChinaVarLater();

	if (ServiceWorkerGlobalScope.inChina === false) {
	return fetch(theRequest);
	}

	if (ServiceWorkerGlobalScope.inChina === true) {
	return new Response(EMPTY_RESPONSE);
	}

	return fetch('https://freegeoip.net/json/')
	.then(function (resp) {
	return resp.json()
	})
	.then(function (json) {
	var country = json && json.country_code;

	if (country && country.indexOf('CN') >= 0) {
	if (DEBUG) console.log('ServiceWorkerGlobalScope.inChina === true');
	ServiceWorkerGlobalScope.inChina = true;
	return new Response(EMPTY_RESPONSE);
	}

	if (DEBUG) console.log('ServiceWorkerGlobalScope.inChina === false');
	ServiceWorkerGlobalScope.inChina = false;
	return fetch(theRequest);
	});
	}

	/**
	* Entrance event.
	* If current request is considered not accessible in China,
	* check current user location before make the decision.
	*
	* Otherwise, for normal requests, just return their originals.
	* @param event {Event} The request Event, event.request is a Request.
	*/
	self.onfetch = function (event) {
	var checkChina = false;
	CHECK_CHINA_PATTERNS.forEach(function (p) {
	checkChina = checkChina \|\| event.request.url.indexOf(p) >= 0;
	});

	if (checkChina) {
	if (DEBUG) console.log('checkChina is true for ' + event.request.url);
	return event.respondWith(fetchWithChinaDetection(event.request));
	}

	return event.respondWith(fetch(event.request));
	};