Fix memory leaks in rate limiter

node_modules/c9/ratelimit.js

@@ -6,26 +6,24 @@ var error = require("http-error");
 module.exports = ratelimit;
 
 function ratelimit(key, duration, max) {
-    var limit = {};
+    var counts = {};
     return function(req, res, next) {
         var handle = req.params[key];
 
-        var lim = limit[handle] || (limit[handle] = []);
-        var now = Date.now();
-        for (var i = 0; i < lim.length; i++) {
-            if (now - lim[i] > duration) {
-                lim.splice(i, 1);
-                i--;
-            }
-            else break;
-        }
-        if (lim.length > max) {
+        counts[handle] = counts[handle] || 0;
+        if (counts[handle] >= max) {
             var err = new error.TooManyRequests("Rate limit exceeded");
-            err.retryIn = duration - (Date.now() - lim[0]);
-            next(err);
-            return;
+            err.retryIn = Math.min(duration, 5000);
+            return next(err);
         }
-        lim.push(Date.now());
+        
+        counts[handle]++;
+        setTimeout(function () {
+            counts[handle]--;
+            if (counts[handle] == 0) {
+                delete counts[handle];
+            }
+        }, duration);
         
         return next();
     };