Made requests object safer. Expire requests before sending error back

node_modules/c9/ratelimit.js

@@ -7,34 +7,42 @@ var _ = require("lodash");
 module.exports = ratelimit;
 
 function ratelimit(key, duration, max) {
-    var requests = {};
+    var requests = Object.create(null); // in case there handles like 'constructor'
     setInterval(function() {
-        _.forIn(requests, function (requestsForHandle, key) {
-            var totalToSplice = 0;
-            var expireTime = Date.now() - duration;  
-            /* Requests are already sorted by date as they are appended, so we just loop 
-                until we find one that shouldn't have expired and splice them from the list */
-            for (var i = 0; i < requestsForHandle.length; i++)  {
-                if (requestsForHandle[i] >= expireTime) break;
-                totalToSplice++;
-            }
-            requests[key].splice(0, totalToSplice);
-            if (requests[key].length == 0) {
-                delete requests[key];
-            }
-        });
-    }, 10);
-    return function(req, res, next) {
-        var handle = req.params[key];
-
-        requests[handle] = requests[handle] || [];
-        if (requests[handle].length >= max) {
-            var err = new error.TooManyRequests("Rate limit exceeded");
-            err.retryIn = Math.min(duration, 5000);
-            return next(err);
+        Object.keys(requests).forEach(expireRequests);
+    }, duration * 0.75);
+    
+    function expireRequests(value)  {
+        var requestsForHandle = requests[value]; 
+        var totalToSplice = 0;
+        var expireTime = Date.now() - duration;  
+        /* Requests are already sorted by date as they are appended, so we just loop 
+            until we find one that shouldn't have expired and splice them from the list */
+        for (var i = 0; i < requestsForHandle.length; i++)  {
+            if (requestsForHandle[i] >= expireTime) break;
+            totalToSplice++;
+        }
+        requests[value].splice(0, totalToSplice);
+        if (requests[value].length == 0) {
+            delete requests[value];
         }
         
-        requests[handle].push(Date.now());
+        return true;
+    }
+    
+    return function(req, res, next) {
+        var value = req.params[key];
+
+        requests[value] = requests[value] || [];
+        if (requests[value].length >= max) {
+            if (expireRequests(value) && requests[value].length >= max) {
+                var err = new error.TooManyRequests("Rate limit exceeded");
+                err.retryIn = Math.min(duration, 5000);
+                return next(err);
+            }
+        }
+        
+        requests[value].push(Date.now());
         return next();
     };
 }