Update rate limit

Author: adamelfstrom

FortnoxSDK.Tests/RateLimiterTests.cs

@@ -35,12 +35,15 @@ public async Task Test_RateLimiter_NoError()
         watch.Stop();
 
         /*
-         * Given the rate limiter of 4 requests per second,
-         * 200 requests should be executed in ~50 seconds.
-         * Note: time per request might be longer than 250ms, hence the longer maximum allowed elapsed time
+         * Given the rate limiter of 4.8 requests per second (24/5),
+         * 200 requests should be executed in ~41 seconds.
+         * 
+         * If we can increase the rate limiter to the advertised 25/5 (5 per second), 
+         * 200 requests should be executed in ~40 seconds.
          */
+
         Assert.AreEqual(200, counter);
-        Assert.IsTrue(watch.Elapsed.TotalSeconds is > 49 and < 65);
+        Assert.IsTrue(watch.Elapsed.TotalSeconds is > 40);
     }
 
     [Ignore("Can make other test fail due to exhausting rate limiter")]

FortnoxSDK/Connectors/Base/RateLimiter.cs

@@ -7,12 +7,12 @@
 namespace Fortnox.SDK.Connectors.Base;
 
 /// <summary>
-/// Rate limit - 4 requests per 1 seconds per token
+/// Rate limit - 25 requests per 5 seconds per token 
 /// </summary>
 internal class RateLimiter
 {
-    private const int MaxCount = 4;
-    private static readonly TimeSpan Period = TimeSpan.FromSeconds(1);
+    private const int MaxCount = 24; // Rate limit is 25 requests over 5 second sliding window, but using the max allowed still seems to trigger the limit. 24 req per 5 sec seems to work consistently.
+    private static readonly TimeSpan Period = TimeSpan.FromSeconds(5);
 
     private static readonly Dictionary<string, TimeLimiter> RateLimiters = new();