From 6c0737c3c08201453b2fe4e48e9d5b4a064ceb30 Mon Sep 17 00:00:00 2001
From: Tim Robinson <tim@timjrobinson.com>
Date: Thu, 12 May 2016 17:19:31 +0000
Subject: [PATCH] Switch rate limited to use one setInterval instead of many
 setTimeouts to clean itself up.

---
 node_modules/c9/ratelimit.js      | 32 ++++++++++++++++---------
 node_modules/c9/ratelimit_test.js | 40 ++++++++++++++++++++++++-------
 2 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/node_modules/c9/ratelimit.js b/node_modules/c9/ratelimit.js
index 01c5cd65..0efc15ef 100644
--- a/node_modules/c9/ratelimit.js
+++ b/node_modules/c9/ratelimit.js
@@ -1,4 +1,5 @@
 var error = require("http-error");
+var _ = require("lodash");
 
 /**
  * In memory rate limiter as connect middleware
@@ -6,25 +7,34 @@ var error = require("http-error");
 module.exports = ratelimit;
 
 function ratelimit(key, duration, max) {
-    var counts = {};
+    var requests = {};
+    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];
 
-        counts[handle] = counts[handle] || 0;
-        if (counts[handle] >= max) {
+        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);
         }
         
-        counts[handle]++;
-        setTimeout(function () {
-            counts[handle]--;
-            if (counts[handle] == 0) {
-                delete counts[handle];
-            }
-        }, duration);
-        
+        requests[handle].push(Date.now());
         return next();
     };
 }
diff --git a/node_modules/c9/ratelimit_test.js b/node_modules/c9/ratelimit_test.js
index aaa2b2bc..6277de4f 100644
--- a/node_modules/c9/ratelimit_test.js
+++ b/node_modules/c9/ratelimit_test.js
@@ -4,13 +4,14 @@ require("c9/inline-mocha")(module);
 
 var ratelimit = require("./ratelimit");
 var assert = require("assert");
+var async = require("async");
 
 describe("ratelimit", function() {
     it("Should limit based on key", function (done) {
-        var limiter = ratelimit("test", 10, 1);
-        limiter({params: {test: 1}}, null, function (err) {
+        var limiter = ratelimit("username", 10, 1);
+        limiter({params: {username: "super"}}, null, function (err) {
             assert(!err, err);
-            limiter({params: {test: 1}}, null, function (err) {
+            limiter({params: {username: "super"}}, null, function (err) {
                 assert(err);
                 assert.equal(err.code, 429);
                 done();
@@ -18,16 +19,39 @@ describe("ratelimit", function() {
         });
     });
     
-     it("Should work again after a delay", function (done) {
-        var limiter = ratelimit("test", 10, 1);
-        limiter({params: {test: 1}}, null, function (err) {
+    it("Should work again after a delay", function (done) {
+        var limiter = ratelimit("username", 10, 1);
+        limiter({params: {username: "super"}}, null, function (err) {
             assert(!err, err);
             setTimeout(function() {
-                limiter({params: {test: 1}}, null, function (err) {
+                limiter({params: {username: "super"}}, null, function (err) {
                     assert(!err, err);
                     done();
                 });
-            }, 15);
+            }, 25);
         });
     });
+    
+    it("Should work with many requests", function (done) {
+        var MAX_REQUESTS = 5;
+        var limiter = ratelimit("username", 10, MAX_REQUESTS);
+        var successfulRequests = 0;
+        async.times(10, function(n, next) {
+            limiter({params: {username: "super"}}, null, function (err) {
+                if (err) return next(err);
+                successfulRequests++;
+                next();
+            });
+        }, function (err) {
+            assert.equal(successfulRequests, MAX_REQUESTS);
+            setTimeout(function() {
+                limiter({params: {username: "super"}}, null, function (err) {
+                    assert(!err, err);
+                    done();
+                });
+            }, 25);
+        });
+    });
+    
+    
 });
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