Inform clients to reload via a 'restart' event sent on Tornado start up

(imported from commit 10bb45547ea0bf34e56fc620ecd7415bb8a825c5)

zephyr/lib/event_queue.py

@@ -135,10 +135,9 @@ def dump_event_queues():
     logging.info('Tornado dumped %d event queues in %.3fs'
                  % (len(clients), time.time() - start))
 
-def setup_event_queue(io_loop):
+def load_event_queues():
     global clients
     start = time.time()
-    # Read in existing event queues
     try:
         with file(PERSISTENT_QUEUE_FILENAME, "r") as stored_queues:
             clients = pickle.load(stored_queues)
@@ -151,6 +150,13 @@ def setup_event_queue(io_loop):
     logging.info('Tornado loaded %d event queues in %.3fs'
                  % (len(clients), time.time() - start))
 
+def send_restart_events():
+    for client in clients.itervalues():
+        event = dict(type='restart', server_generation=settings.SERVER_GENERATION)
+        client.add_event(event)
+
+def setup_event_queue(io_loop):
+    load_event_queues()
     atexit.register(dump_event_queues)
     # Make sure we dump event queues even if we exit via signal
     signal.signal(signal.SIGTERM, lambda signum, stack: sys.exit(1))
@@ -164,6 +170,8 @@ def setup_event_queue(io_loop):
     pc = PeriodicCallback(gc_event_queues, EVENT_QUEUE_GC_FREQ_MSECS, io_loop)
     pc.start()
 
+    send_restart_events()
+
 # Called from Django
 def request_event_queue(user_profile, apply_markdown):
     if settings.TORNADO_SERVER:

zephyr/static/js/zephyr.js

@@ -12,7 +12,6 @@ var viewport = $(window);
 
 var get_updates_params = {
     pointer: -1,
-    server_generation: -1, /* to be filled in on document.ready */
     last_event_id: 0
 };
 var get_updates_failures = 0;
@@ -606,14 +605,6 @@ function get_updates(options) {
     get_updates_params.pointer = furthest_read;
     get_updates_params.dont_block = options.dont_block || get_updates_failures > 0;
     get_updates_params.queue_id = page_params.event_queue_id;
-    if (reload.is_pending()) {
-        // We only send a server_generation to the server if we're
-        // interested in an immediate reply to tell us if we need to
-        // reload.  Once we're already reloading, we need to not
-        // submit the parameter, so that the server will process our
-        // future requests in longpolling mode.
-        delete get_updates_params.server_generation;
-    }
 
     get_updates_xhr = $.ajax({
         type:     'POST',
@@ -633,12 +624,6 @@ function get_updates(options) {
             get_updates_failures = 0;
             $('#connection-error').hide();
 
-            if (get_updates_params.server_generation === -1) {
-                get_updates_params.server_generation = data.server_generation;
-            } else if (data.server_generation !== get_updates_params.server_generation) {
-                reload.initiate();
-            }
-
             var messages = [];
             var new_pointer;
 
@@ -655,7 +640,10 @@ function get_updates(options) {
                     messages.push(event.message);
                     break;
                 case 'pointer':
-                    new_pointer = event.new_pointer;
+                    new_pointer = event.pointer;
+                    break;
+                case 'restart':
+                    reload.initiate();
                     break;
                 }
             });