hiding queues inside CallbackFiller

lib/caching.js

@@ -44,12 +44,9 @@ var caching = function(args) {
             options = undefined;
         }
 
-        if (callbackFiller.queues[key]) {
-            callbackFiller.queues[key].push({cb: cb, domain: process.domain});
-            return;
-        }
-
-        callbackFiller.queues[key] = [{cb: cb, domain: process.domain}];
+        var hasKey = callbackFiller.has(key);
+        callbackFiller.add(key, {cb: cb, domain: process.domain});
+        if (hasKey) { return; }
 
         self.store.get(key, options, function(err, result) {
             if (err && (!self.ignoreCacheErrors)) {

lib/callback_filler.js

@@ -16,4 +16,16 @@ CallbackFiller.prototype.fill = function(key, err, data) {
     });
 };
 
+CallbackFiller.prototype.has = function(key) {
+    return this.queues[key];
+};
+
+CallbackFiller.prototype.add = function(key, funcObj) {
+    if (this.queues[key]) {
+        this.queues[key].push(funcObj);
+    } else {
+        this.queues[key] = [funcObj];
+    }
+};
+
 module.exports = CallbackFiller;

lib/multi_caching.js

@@ -96,12 +96,9 @@ var multiCaching = function(caches) {
             options = undefined;
         }
 
-        if (callbackFiller.queues[key]) {
-            callbackFiller.queues[key].push({cb: cb, domain: process.domain});
-            return;
-        }
-
-        callbackFiller.queues[key] = [{cb: cb, domain: process.domain}];
+        var hasKey = callbackFiller.has(key);
+        callbackFiller.add(key, {cb: cb, domain: process.domain});
+        if (hasKey) { return; }
 
         getFromHighestPriorityCache(key, function(err, result, index) {
             if (err) {