A push shouldn't lock NodeJS - added nextTick()

A pollbuffer with very many or heavy listeners can keep NodeJS quite busy on a push - especially if many pushes are made at once.

By putting the notification of all listeners on nextTick() we avoid that multiple pushes always results in multiple notifications. If a notification is already due to happen it will wait for that.

By putting each individual notification on nextTick() we ensure that very many listeners or a few heavy ones wont lock NodeJS for too long.

lib/longpollingbuffer.js

@@ -6,6 +6,7 @@ var LongPollingBuffer = function (buffersize) {
 
     var data = new Array();
     var listeners = {};
+    var dirty = false;
     this.size = buffersize;
     this.offset = 0;
     this.uid = 0;
@@ -19,8 +20,9 @@ var LongPollingBuffer = function (buffersize) {
     }
 
     var notifyAll = function (){
+        dirty = false;
         for(var key in listeners){
-            listeners[key]();
+            process.nextTick(listeners[key]);
         }
     }
 
@@ -38,7 +40,10 @@ var LongPollingBuffer = function (buffersize) {
         while(data.length > this.size){
             data.pop([]);
         }
-        notifyAll();
+        if (!dirty) {
+            process.nextTick(notifyAll);
+            dirty = true;
+        }
     }
 
     this.addListenerForUpdateSince = function(since, callback) {