fu.js

var getMap = {};

fu.get = function (path, handler) {
  getMap[path] = handler;
};

var server = createServer(function (req, res) {
  if (req.method === "GET" || req.method === "HEAD") {
    var handler = getMap[url.parse(req.url).pathname] || notFound;

    res.simpleText = function (code, body) {
      res.sendHeader(code, [ ["Content-Type", "text/plain"]
                           , ["Content-Length", body.length]
                           ]);
      res.write(body);
      res.close();
    };

    res.simpleJSON = function (code, obj) {
      var body = JSON.stringify(obj);
      res.sendHeader(code, [ ["Content-Type", "text/json"]
                           , ["Content-Length", body.length]
                           ]);
      res.write(body);
      res.close();
    };

    handler(req, res);
  }
});

fu.listen = function (port, host) {
  server.listen(port, host);
};

latest_message.js

fu.get("/latest_message", function (req, res) {
  var since = parseInt(qs.parse(url.parse(req.url).query).since);

  if(since < latestMessageReceived) // new message since client last requested
    sendLatestMessageToClient(res); // send it straight to them
  else
    messageRequests.push({ callback: sendLatestMessageToClient, res: res }); // queue up the requst
});

longPoll.js

var transmission_errors = 0;
var lastMessageReceived = 0; // a long time ago
function longPoll (data) {
  if (data && data.message) {
    updateMessage(data.message);
    lastMessageReceived = new Date().getTime();
  }

  $.ajax({ cache: false,
            type: "GET",
            url: "/latest_message",
            dataType: "json",
           data: { since: lastMessageReceived },
            error: function () {
             transmission_errors += 1;
             setTimeout(longPoll, 10*1000);
           },
            success: function (data) {
             setTimeout(function () {
               transmission_errors = 0;
               longPoll(data);
             }, 100);
           }
         });
}

send_message.js

var latestMessageReceived = new Date().getTime();
fu.get("/send_message", function (req, res) {
  var message = qs.parse(url.parse(req.url).query).message;
  storeMessage(message, function() {
    latestMessageReceived = new Date().getTime();
    res.simpleJSON(200, {});

    // respond to queued message requests from clients now that we have a new message to send out  
    while (messageRequests.length > 0)
    {
      var messageRequest = messageRequests.shift();
      messageRequest.callback(messageRequest.res);
    }
  });
});

sendLatestMessageToClient.js

function sendLatestMessageToClient(res) {
  var redisClient = new redis.createClient();
  redisClient.stream.addListener("connect", function () {
    redisClient.lindex('messages', 0, function (err, value) {
      res.simpleJSON(200, { message: value.toString(), timestamp: new Date().getTime() });
      redisClient.close();
    });
  });
}

storeMessage.js

function storeMessage(message, callback) {
  var redisClient = new redis.createClient();
  redisClient.stream.addListener("connect", function () {
    redisClient.lpush('messages', message, function (err, value) {
      redisClient.close();
      callback();
    });
  });
}

tryToSendMessage.js

function tryToSendMessage(message) {
  jQuery.get("/unique_chalk",
            { message: message },
            function (data) {
              if(data && data.message) {
                jQuery.get("/send_message", { message: message }, function (data) {} , "json");
                updateErrorMessage("");
                $("#message_field").attr("value", "");
              }
              else
                updateErrorMessage("said before");
              
            }, "json");
}