From 8917128bd6d10c1ea3b2ad229e4e21acfc656aa0 Mon Sep 17 00:00:00 2001
From: Mauricio Schneider <me@mauricioschneider.com>
Date: Wed, 4 Nov 2015 12:28:40 -0300
Subject: [PATCH] Change long-polling strategy to 5secs interval strategy on 5+
 instant responses.

---
 .../control-panel/long-polling/index.js       | 22 +++++++++++++++++--
 lib/agent/providers/network/index.js          |  5 ++++-
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/lib/agent/plugins/control-panel/long-polling/index.js b/lib/agent/plugins/control-panel/long-polling/index.js
index 697f2008b..360a08f90 100644
--- a/lib/agent/plugins/control-panel/long-polling/index.js
+++ b/lib/agent/plugins/control-panel/long-polling/index.js
@@ -12,7 +12,8 @@ var emitter,
     connection_status,
     connected,
     current_request,
-    loaded;
+    loaded,
+    instant_responses = 0;
 
 var request = function(re_schedule) {
   if (!connected || current_request) {
@@ -29,6 +30,10 @@ var request = function(re_schedule) {
       device_key = keys.get().device,
       api_key = keys.get().api;
 
+  // used for benchmarking and request interval setup
+  var request_start,
+      response_delay;
+
   if (!keys.get().device) return propagate_error(errors.get('NO_DEVICE_KEY'));
 
   var base  = protocol + '://' + host,
@@ -48,6 +53,7 @@ var request = function(re_schedule) {
   }
 
   logger.debug('Fetching instructions...');
+  request_start = new Date()
   current_request = needle.get(url, options);
   attach_listeners(current_request);
 
@@ -64,7 +70,7 @@ var request = function(re_schedule) {
 
     request.on('end', function() {
       var msg = options.proxy ? 'with proxy' : '';
-      logger.debug("Request " + msg + " ended.");
+      logger.debug('Request ' + msg + ' ended');
     });
 
     request.request.on('response', function(res) {
@@ -72,6 +78,18 @@ var request = function(re_schedule) {
         propagate_error('Invalid response received with status code ' + res.statusCode);
         clear_current_request();
       } else {
+        response_delay = (new Date() - request_start) / 1000;
+
+        if (response_delay < 1) {
+          instant_responses++
+        } else {
+          instant_responses = 0;
+        }
+
+        if (instant_responses > 5) {
+        logger.debug('It seems the server is not using long-polling. Adding delay.');
+          return setTimeout(check_for_reschedule, 5000);
+        }
         check_for_reschedule();
       }
     });
diff --git a/lib/agent/providers/network/index.js b/lib/agent/providers/network/index.js
index 43a0b8274..9cfeb4517 100644
--- a/lib/agent/providers/network/index.js
+++ b/lib/agent/providers/network/index.js
@@ -150,7 +150,10 @@ exp.get_connection_status = function(cb) {
     }
 
     if (res && res.statusCode) {
-      if (res.statusCode === 200) {
+      // 301 and 302 codes are in case the server redirects regular requests,
+      // but is still able to receive connections
+      var statusCodes = [200, 301, 302];
+      if (statusCodes.indexOf(res.statusCode) !== -1) {
         return cb('connected');
       } else {
         disconnected();