Added rate limit update event

CryptoExchange.Net/RateLimiting/Guards/RateLimitGuard.cs

@@ -110,7 +110,7 @@ namespace CryptoExchange.Net.RateLimiting.Guards
 
             var delay = tracker.GetWaitTime(requestWeight);
             if (delay == default)
-                return LimitCheck.NotNeeded;
+                return LimitCheck.NotNeeded(Limit, TimeSpan, tracker.Current);
 
             return LimitCheck.Needed(delay, Limit, TimeSpan, tracker.Current);
         }

CryptoExchange.Net/RateLimiting/Guards/SingleLimitGuard.cs

@@ -64,7 +64,7 @@ namespace CryptoExchange.Net.RateLimiting.Guards
 
             var delay = tracker.GetWaitTime(requestWeight);
             if (delay == default)
-                return LimitCheck.NotNeeded;
+                return LimitCheck.NotNeeded(_limit, _period, tracker.Current);
 
             return LimitCheck.Needed(delay, _limit, _period, tracker.Current);
         }

CryptoExchange.Net/RateLimiting/Interfaces/IRateLimitGate.cs

@@ -16,6 +16,11 @@ namespace CryptoExchange.Net.RateLimiting.Interfaces
         /// </summary>
         event Action<RateLimitEvent> RateLimitTriggered;
 
+        /// <summary>
+        /// Event when the rate limit is updated. Note that it's only updated when a request is send, so there are no specific updates when the current usage is decaying.
+        /// </summary>
+        event Action<RateLimitUpdateEvent>? RateLimitUpdated;
+
         /// <summary>
         /// Add a rate limit guard
         /// </summary>

CryptoExchange.Net/RateLimiting/LimitCheck.cs

@@ -45,7 +45,7 @@ namespace CryptoExchange.Net.RateLimiting
         /// <summary>
         /// No wait needed
         /// </summary>
-        public static LimitCheck NotNeeded { get; } = new LimitCheck(true, default, default, default, default);
+        public static LimitCheck NotNeeded(int limit, TimeSpan period, int current) => new(true, default, limit, period, current);
 
         /// <summary>
         /// Wait needed

CryptoExchange.Net/RateLimiting/RateLimitEvent.cs

@@ -4,10 +4,14 @@ using System;
 namespace CryptoExchange.Net.RateLimiting
 {
     /// <summary>
-    /// Rate limit event
+    /// Rate limit triggered event
     /// </summary>
     public record RateLimitEvent
     {
+        /// <summary>
+        /// Id of the item the limit was checked for
+        /// </summary>
+        public int ItemId { get; set; }
         /// <summary>
         /// Name of the API limit that is reached
         /// </summary>
@@ -52,18 +56,9 @@ namespace CryptoExchange.Net.RateLimiting
         /// <summary>
         /// ctor
         /// </summary>
-        /// <param name="apiLimit"></param>
-        /// <param name="limitDescription"></param>
-        /// <param name="definition"></param>
-        /// <param name="host"></param>
-        /// <param name="current"></param>
-        /// <param name="requestWeight"></param>
-        /// <param name="limit"></param>
-        /// <param name="timePeriod"></param>
-        /// <param name="delayTime"></param>
-        /// <param name="behaviour"></param>
-        public RateLimitEvent(string apiLimit, string limitDescription, RequestDefinition definition, string host, int current, int requestWeight, int? limit, TimeSpan? timePeriod, TimeSpan? delayTime, RateLimitingBehaviour behaviour)
+        public RateLimitEvent(int itemId, string apiLimit, string limitDescription, RequestDefinition definition, string host, int current, int requestWeight, int? limit, TimeSpan? timePeriod, TimeSpan? delayTime, RateLimitingBehaviour behaviour)
         {
+            ItemId = itemId;
             ApiLimit = apiLimit;
             LimitDescription = limitDescription;
             RequestDefinition = definition;

CryptoExchange.Net/RateLimiting/RateLimitGate.cs

@@ -23,6 +23,8 @@ namespace CryptoExchange.Net.RateLimiting
 
         /// <inheritdoc />
         public event Action<RateLimitEvent>? RateLimitTriggered;
+        /// <inheritdoc />
+        public event Action<RateLimitUpdateEvent>? RateLimitUpdated;
 
         /// <summary>
         /// ctor
@@ -105,7 +107,7 @@ namespace CryptoExchange.Net.RateLimiting
                     else
                         logger.RateLimitRequestFailed(itemId, definition.Path, guard.Name, guard.Description);
                     
-                    RateLimitTriggered?.Invoke(new RateLimitEvent(_name, guard.Description, definition, host, result.Current, requestWeight, result.Limit, result.Period, result.Delay, rateLimitingBehaviour));
+                    RateLimitTriggered?.Invoke(new RateLimitEvent(itemId, _name, guard.Description, definition, host, result.Current, requestWeight, result.Limit, result.Period, result.Delay, rateLimitingBehaviour));
                     return new CallResult(new ClientRateLimitError($"Rate limit check failed on guard {guard.Name}; {guard.Description}"));
                 }
 
@@ -120,7 +122,7 @@ namespace CryptoExchange.Net.RateLimiting
                     else
                         logger.RateLimitDelayingRequest(itemId, definition.Path, result.Delay, guard.Name, description);
 
-                    RateLimitTriggered?.Invoke(new RateLimitEvent(_name, guard.Description, definition, host, result.Current, requestWeight, result.Limit, result.Period, result.Delay, rateLimitingBehaviour));
+                    RateLimitTriggered?.Invoke(new RateLimitEvent(itemId, _name, guard.Description, definition, host, result.Current, requestWeight, result.Limit, result.Period, result.Delay, rateLimitingBehaviour));
                     await Task.Delay((int)result.Delay.TotalMilliseconds + 1, ct).ConfigureAwait(false);
                     await _semaphore.WaitAsync(ct).ConfigureAwait(false);
                     return await CheckGuardsAsync(guards, logger, itemId, type, definition, host, apiKey, requestWeight, rateLimitingBehaviour, ct).ConfigureAwait(false);
@@ -133,6 +135,8 @@ namespace CryptoExchange.Net.RateLimiting
                 var result = guard.ApplyWeight(type, definition, host, apiKey, requestWeight);
                 if (result.IsApplied)
                 {
+                    RateLimitUpdated?.Invoke(new RateLimitUpdateEvent(itemId, _name, guard.Description, result.Current, result.Limit, result.Period));
+
                     if (type == RateLimitItemType.Connection)
                         logger.RateLimitAppliedConnection(itemId, guard.Name, guard.Description, result.Current);
                     else

CryptoExchange.Net/RateLimiting/RateLimitUpdateEvent.cs

@@ -0,0 +1,50 @@
+using CryptoExchange.Net.Objects;
+using System;
+
+namespace CryptoExchange.Net.RateLimiting
+{
+    /// <summary>
+    /// Rate limit update event
+    /// </summary>
+    public record RateLimitUpdateEvent
+    {
+        /// <summary>
+        /// Id of the item the limit was checked for
+        /// </summary>
+        public int ItemId { get; set; }
+        /// <summary>
+        /// Name of the API limit that is reached
+        /// </summary>
+        public string ApiLimit { get; set; } = string.Empty;
+        /// <summary>
+        /// Description of the limit that is reached
+        /// </summary>
+        public string LimitDescription { get; set; } = string.Empty;
+        /// <summary>
+        /// The current counter value
+        /// </summary>
+        public int Current { get; set; }
+        /// <summary>
+        /// The limit per time period
+        /// </summary>
+        public int? Limit { get; set; }
+        /// <summary>
+        /// The time period the limit is for
+        /// </summary>
+        public TimeSpan? TimePeriod { get; set; }
+
+        /// <summary>
+        /// ctor
+        /// </summary>
+        public RateLimitUpdateEvent(int itemId, string apiLimit, string limitDescription, int current, int? limit, TimeSpan? timePeriod)
+        {
+            ItemId = itemId;
+            ApiLimit = apiLimit;
+            LimitDescription = limitDescription;
+            Current = current;
+            Limit = limit;
+            TimePeriod = timePeriod;
+        }
+
+    }
+}