gistfile1.js

var sys = require('sys'), 
   http = require('http'),
    url = require('url');

var subscriptions = {}

function getSubscribers (did) {
  if (subscriptions[did]) {
    // log open already.
    return subscriptions[did];
  } else if (subscriptions[did] == false) {
    // log is closed.
    return false;
  } else {
    // create a new log.
    subscriptions[did] = [];
    return subscriptions[did];
  }
}

var logs = {};

http.createServer(function (req, res) {
  var requrl = url.parse(req, true);
  if (requrl.pathname == '/newlogmessage') {
    // We have an incoming message from the runner.
    var subscribers = getSubscribers(requrl.query.deployid);

    if (subscribers === false) {
      // this shouldn't happen. we're getting a new message for a closed log.
      res.sendHeader(400, {'Content-Type': 'text/plain'});
      res.sendBody('wtf dude, you closed the log, now new messages? screw off.');
      res.finish();
    }

    var subl = subscribers.length;

    var message = '';

    req.addListener('body', function(chunk) {
      if (!logs[requrl.query.deployid) {
        logs[requrl.query.deployid] = '';
      }

      logs[requrl.query.deployid] += chunk;

      for (var i = 0; i < subl; i++) {
        subscribers[i].sendBody(chunk);
      }
    });
  } else if (requrl.pathname == '/endlog') {

    // Close off the log.
    var subscribers = getSubscribers(requrl.query.deployid);
    
    // finish all the subscription requests.
    for (var i = 0, l = subscribers.length; i < l; i++) {
      subscribers[i].finish();
    }

    subscriptions[requrl.query.deployid] = false;

  } else if (requrl.pathname == '/listen') {

    // There's a user connecting to listen to the stream.
    var subscribers = getSubscribers(requrl.query.deployid);

    if (subscribers === false) {
      if (logs[requrl.query.deployid]) {
         res.sendHeader(200, {'Content-Type': 'text/plain'});
         res.sendBody(logs[requrl.query.deployid]);
         res.finish();
      } else {
         res.sendHeader(404, {'Content-Type': 'text/plaine'});
         res.sendBody('no record of that deploy');
         res.finish();
    } else {
      // There's an open log with that id. Start streaming.
      res.sendHeader(200, {'Content-Type': 'text/plain'});

      // Send any existing log.
      if (logs[requrl.query.deployid]) {
        res.sendBody(logs[requrl.query.deployid]);
      }

      // Add this client to the list of clients that should receive updates.
      subscribers.push(res);
    }
  }
}).listen(8000);

sys.puts('Server running at http://127.0.0.1:8000/');