React to API change

Author: John Luo

src/Middleware/RequestLimiter/src/IPAggregatedRateLimiter.cs

@@ -40,17 +40,16 @@ public override long EstimatedCount(HttpContext resourceId)
             return _cache.TryGetValue(resourceId.Connection.RemoteIpAddress, out var count) ? count : 0;
         }
 
-        public override bool TryAcquire(HttpContext resourceId, long requestedCount, [NotNullWhen(true)] out Resource? resource)
+        public override Resource Acquire(HttpContext resourceId, long requestedCount)
         {
-            resource = Resource.NoopResource;
             if (requestedCount > _maxResourceCount)
             {
-                return false;
+                return Resource.FailNoopResource;
             }
 
             if (resourceId.Connection.RemoteIpAddress == null)
             {
-                return true;
+                return Resource.SuccessNoopResource;
             }
 
             var key = resourceId.Connection.RemoteIpAddress;
@@ -59,7 +58,7 @@ public override bool TryAcquire(HttpContext resourceId, long requestedCount, [No
             {
                 if (_cache.TryAdd(key, requestedCount))
                 {
-                    return true;
+                    return Resource.SuccessNoopResource;
                 }
             }
 
@@ -70,16 +69,16 @@ public override bool TryAcquire(HttpContext resourceId, long requestedCount, [No
                 {
                     if (newCount > _maxResourceCount)
                     {
-                        return false;
+                        return Resource.FailNoopResource;
                     }
 
-                    return true;
+                    return Resource.SuccessNoopResource;
                 }
                 if (!_cache.TryGetValue(key, out count))
                 {
                     if (_cache.TryAdd(key, requestedCount))
                     {
-                        return true;
+                        return Resource.SuccessNoopResource;
                     }
                 }
             }

src/Middleware/RequestLimiter/src/RateLimiter.cs

@@ -27,23 +27,22 @@ public RateLimiter(long resourceCount, long newResourcePerSecond)
             _renewTimer = new Timer(Replenish, this, TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(5));
         }
 
-        public override bool TryAcquire(long requestedCount, [NotNullWhen(true)] out Resource? resource)
+        public override Resource Acquire(long requestedCount)
         {
-            resource = Resource.NoopResource;
             if (Interlocked.Add(ref _resourceCount, requestedCount) <= _maxResourceCount)
             {
-                return true;
+                return Resource.SuccessNoopResource;
             }
 
             Interlocked.Add(ref _resourceCount, -requestedCount);
-            return false;
+            return Resource.FailNoopResource;
         }
 
         public override ValueTask<Resource> AcquireAsync(long requestedCount, CancellationToken cancellationToken = default)
         {
             if (Interlocked.Add(ref _resourceCount, requestedCount) <= _maxResourceCount)
             {
-                return ValueTask.FromResult(Resource.NoopResource);
+                return ValueTask.FromResult(Resource.SuccessNoopResource);
             }
 
             Interlocked.Add(ref _resourceCount, -requestedCount);
@@ -83,7 +82,7 @@ private static void Replenish(object? state)
                     if (requestToFulfill == request)
                     {
                         // If requestToFulfill == request, the fulfillment is successful.
-                        requestToFulfill.TCS.SetResult(Resource.NoopResource);
+                        requestToFulfill.TCS.SetResult(Resource.SuccessNoopResource);
                     }
                     else
                     {

src/Middleware/RequestLimiter/src/RequestLimiterMiddleware.cs

@@ -95,30 +95,34 @@ private bool ApplyLimit(RequestLimitRegistration registration, HttpContext conte
             {
                 var limiter = registration.ResolveLimiter(context.RequestServices);
                 _logger.LogInformation("Resource count: " + limiter.EstimatedCount);
-                if (!limiter.TryAcquire(out var resource))
+                // TODO use AcquireAsync to enable queuing
+                var resource = limiter.Acquire();
+                if (!resource.IsAcquired)
                 {
                     _logger.LogInformation("Resource exhausted");
                     context.Response.StatusCode = StatusCodes.Status429TooManyRequests;
                     return false;
                 }
 
                 _logger.LogInformation("Resource obtained");
-                obtainedResources.Push(resource.Value);
+                obtainedResources.Push(resource);
                 return true;
             }
             if (registration.ResolveAggregatedLimiter != null)
             {
                 var limiter = registration.ResolveAggregatedLimiter(context.RequestServices);
                 _logger.LogInformation("Resource count: " + limiter.EstimatedCount(context));
-                if (!limiter.TryAcquire(context, out var resource))
+                // TODO use AcquireAsync to enable queuing
+                var resource = limiter.Acquire(context);
+                if (!resource.IsAcquired)
                 {
                     _logger.LogInformation("Resource exhausted");
                     context.Response.StatusCode = StatusCodes.Status429TooManyRequests;
                     return false;
                 }
 
                 _logger.LogInformation("Resource obtained");
-                obtainedResources.Push(resource.Value);
+                obtainedResources.Push(resource);
                 return true;
             }
             throw new InvalidOperationException("Registration couldn't resolve limiter");