rolling-rate-limiter - npm Package Compare versions

Comparing version 0.0.0 to 0.0.1

index.js

@@ -11,4 +11,4 @@ var assert = require("assert");
       minDifference   = options.minDifference,
-      namespace       = options.namespace || ("rate-limiter-" + Math.random().toString(36).slice(2));
-  
+      namespace       = options.namespace || (options.redis ? ("rate-limiter-" + Math.random().toString(36).slice(2)) : "");
+
   redis = redis || fakeredis.createClient();
@@ -25,2 +25,7 @@
   return function (id, cb) {
+    if (!cb) {
+      cb = id;
+      id = "";
+    }
+    
     assert.equal(typeof cb, "function", "Callback must be a function.");
@@ -27,0 +32,0 @@

package.json

 {
   "name": "rolling-rate-limiter",
-  "version": "0.0.0",
+  "version": "0.0.1",
   "description": "Rate limiter that supports a rolling window, either in-memory or backed by redis",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

 # Rolling Rate Limiter
+[![Build Status](https://travis-ci.org/classdojo/rolling-rate-limiter.svg?branch=master)](https://travis-ci.org/classdojo/rolling-rate-limiter)
 
 ## Description
-This is an implementation of a rate limiter in node.js that allows for rate limiting with a rolling window.  This means that if a user is allowed 5 actions per 60 seconds, any action will be blocked if 5 actions have already occured in the preceeding 60 seconds, without any set points at which this interval resets.  This contrasts with many existing implementations, in which a user could make 5 requests at 0:59 and another 5 requests at 1:01.  The implementation uses what I believe to be a novel algorithm, using sorted sets.
+This is an implementation of a rate limiter in node.js that allows for rate limiting with a rolling window.  This means that if a user is allowed 5 actions per 60 seconds, any action will be blocked if 5 actions have already occured in the preceeding 60 seconds, without any set points at which this interval resets.  This contrasts with many existing implementations, in which a user could make 5 requests at 0:59 and another 5 requests at 1:01.  The implementation uses what I believe to be a novel algorithm, using sorted sets.  It can use either in-memory storage or Redis as a backend.
 
-## Method of operation
-  * Users are namespaced by an identifier, which is combined with a rate limiter namespace to form unique keys in redis.
-  * Each key corresponds to a sorted set.  The keys and values are both set to the (microsecond) times at which actions were attempted.
-  * When a new action comes in, all elements in the set with keys less than (now - rate limit window) are dropped.
-  * If there are still (limit) actions in the set, the current action is blocked.
-  * If the most recent previous key is too close to the current time, and a minimum difference has been set, the current action is blocked.
-  * The current action is added to the set.
-  * __Note__: if an action is blocked, it is still added to the set.
-  * All redis operations are performed as an atomic transaction.
-
 ## Examples
@@ -26,5 +17,7 @@
     maxInInterval: 10
-    minDifference: 100 // optional, in miliseconds
+    minDifference: 100 // optional: the minimum time (in miliseconds) between any two actions
   });
 
+  // First argument should be a unique identifier for a user.
+  // If the limiter does not differentiate between users, pass only a callback.
   limiter("user1234", function(err, success) {
@@ -43,4 +36,4 @@ // errors if redis connection failed, etc
 
-### With a redis instance
-This allows multiple processes (e.g. multiple instances of a server application) to use a single redis to share rate limiter state.
+### With a redis backend
+This allows multiple processes (e.g. multiple instances of a server application) to use a single redis to share rate limiter state.  Make sure that the limiters have identical configurations in each instance.
 ```javascript
@@ -54,19 +47,20 @@
     redis: client,
-    namespace: "UserLoginLimiter" // optional, allows one redis instance to handle multiple rate limiters
-    interval: 1000 // in miliseconds
+    namespace: "UserLoginLimiter" // optional: allows one redis instance to handle multiple groups of rate limiters. defaults to "rate-limiter-{string of random characters}"
+    interval: 1000
     maxInInterval: 10
-    minDifference: 100 // optional, in miliseconds
+    minDifference: 100
   });
 
-  limiter("user1234", function(err, success) {
-    // errors if redis connection failed, etc
-    if (err) throw err;
+  // operation same as above.
 
-    if (success) {
-      // limit was not exceeded, action should be allowed
-    } else {
-      // limit was exceeded, action should not be allowed
-    }
-  });
+```
 
-```
+## Method of operation
+  * Each key corresponds to a sorted set.  The keys and values are both set to the (microsecond) times at which actions were attempted.
+  * When a new action comes in, all elements in the set with keys less than (now - rate limit window) are dropped.
+  * If there are still (limit) actions in the set, the current action is blocked.
+  * If the most recent previous key is too close to the current time, and a minimum difference has been set, the current action is blocked.
+  * The current action is added to the set.
+  * __Note__: if an action is blocked, it is still added to the set.  This means that if a user is continually attempting actions more quickly than the allowed rate, __all__ of their actions will be blocked until.
+  * If the limiter uses a redis instance, identifiers can be namespaced by an identifier, which is combined with a rate limiter namespace to form unique keys.
+  * All redis operations for a single rate-limit check are performed as an atomic transaction.

test/index.js

@@ -14,6 +14,11 @@ var sinon = require("sinon");
     increment: function(userId, cb) {
-      counts[userId] = counts[userId] || 0;
-      rateLimiter(userId, function(err, success) {
+      if (!cb) {
+        cb = userId;
+        userId = null;
+      }
+      counts[String(userId)] = counts[String(userId)] || 0;
+      var limit = userId ? rateLimiter.bind(null, userId) : rateLimiter
+      limit(function(err, success) {
         if (success) {
-          counts[userId]++;
+          counts[String(userId)]++;
         }
@@ -25,3 +30,3 @@ cb(err);
     getCount: function(userId) {
-      return counts[userId];
+      return counts[userId == null ? "null" : userId];
     }
@@ -84,3 +89,3 @@ };
       var counter = RateLimitedCounter({
-        interval: 1000,
+        interval: 300,
         maxInInterval: 30
@@ -90,6 +95,6 @@ });
       async.times(100, function(n, next) {
-        counter.increment(1, next);
+        counter.increment(next);
       }, function(err) {
         if (err) throw err;
-        expect(counter.getCount(1)).to.equal(30);
+        expect(counter.getCount()).to.equal(30);
         done();
@@ -101,3 +106,3 @@ });
       var counter = RateLimitedCounter({
-        interval: 1000,
+        interval: 300,
         maxInInterval: 30
@@ -120,3 +125,3 @@ });
       var counter = RateLimitedCounter({
-        interval: 1000,
+        interval: 300,
         maxInInterval: 30
@@ -139,3 +144,3 @@ });
           });
-        }, 1000);
+        }, 500);
       });
@@ -175,3 +180,3 @@ });
         redis: redis.createClient(),
-        interval: 1000,
+        interval: 300,
         maxInInterval: 30
@@ -181,6 +186,6 @@ });
       async.times(100, function(n, next) {
-        counter.increment(1, next);
+        counter.increment(next);
       }, function(err) {
         if (err) throw err;
-        expect(counter.getCount(1)).to.equal(30);
+        expect(counter.getCount()).to.equal(30);
         done();
@@ -193,3 +198,3 @@ });
         redis: redis.createClient(),
-        interval: 1000,
+        interval: 300,
         maxInInterval: 30
@@ -213,3 +218,3 @@ });
         redis: redis.createClient(),
-        interval: 1000,
+        interval: 300,
         maxInInterval: 30
@@ -232,3 +237,3 @@ });
           });
-        }, 1000);
+        }, 300);
       });
@@ -261,3 +266,3 @@ });
           redis: client,
-          interval: 500,
+          interval: 300,
           maxInInterval: 15,
@@ -267,3 +272,3 @@ }),
           redis: client,
-          interval: 500,
+          interval: 300,
           maxInInterval: 15,
@@ -294,3 +299,3 @@ })
           namespace: namespace,
-          interval: 500,
+          interval: 300,
           maxInInterval: 30,
@@ -301,3 +306,3 @@ }),
           namespace: namespace,
-          interval: 500,
+          interval: 300,
           maxInInterval: 30,
@@ -334,9 +339,2 @@ })
   });
-});
-
-
-
-
-
-
-
+});

No alert changes

Improved metrics

Total package byte prevSize

14994

increased by5.26%

Number of package files

6

increased by20%

Lines of code

316

increased by2.6%

Worsened metrics

Number of lines in readme file

64

decreased by-7.25%

No dependency changes