last ...

Providers/XApplicationProvider.cs

@@ -13,6 +13,7 @@ using System.Linq.Expressions;
 using IdentityServer4.Extensions;
 using xIdentityModels.Extensions;
 using Microsoft.EntityFrameworkCore.Query;
+using Microsoft.Extensions.Caching.Memory;
 
 namespace xIds.Providers
 {
@@ -21,6 +22,7 @@ namespace xIds.Providers
     /// </summary>
     public partial class XApplicationProvider : IXApplicationProvider
     {
+        private readonly IMemoryCache cache;
         private readonly string permittedRole;
         private readonly XIdentityDbContext dbContext;
         private readonly IXIdentityManager identityManager;
@@ -28,6 +30,7 @@ namespace xIds.Providers
         private readonly XApiKeyConfiguration apiKeyConfiguration;
 
         public XApplicationProvider(
+            IMemoryCache cache,
             XIdentityDbContext dbContext,
             IXIdentityManager identityManager,
             XDataServiceConfiguration configuration,
@@ -36,6 +39,7 @@ namespace xIds.Providers
         )
         {
             //
+            this.cache = cache;
             this.dbContext = dbContext;
             this.permittedRole = permittedRole;
             this.configuration = configuration;
@@ -190,7 +194,7 @@ namespace xIds.Providers
             // Return result ...
             return result;
         }
-        
+
         /// <summary>
         /// Prepare a Queryable of Items ...
         /// </summary>
@@ -233,7 +237,7 @@ namespace xIds.Providers
             // Return result ...
             return result;
         }
-        
+
         /// <summary>
         /// Prepare a Queryable of Items ...
         /// </summary>
@@ -249,7 +253,7 @@ namespace xIds.Providers
         {
             //
             // Global Result ...
-            var result = dbContext.ApiKeyUsage.AsQueryable();
+            var result = dbContext.ApiKeyUsages.AsQueryable();
 
             //
             // Handle Filtering ...
@@ -275,6 +279,45 @@ namespace xIds.Providers
             //
             // Return result ...
             return result;
-        }    
+        }
+
+        /// <summary>
+        /// Handle Rate Limit Checking ...
+        /// </summary>
+        /// <param name="apiKeyId"></param>
+        /// <param name="limitPerMinute"></param>
+        /// <returns></returns>
+        private bool CheckRateLimit(
+            Guid apiKeyId, 
+            int limitPerMinute
+        )
+        {
+            //
+            var cacheKey = $"ratelimit:{apiKeyId}";
+            var currentCount = cache.GetOrCreate(
+                cacheKey, 
+                entry =>
+                {
+                    //
+                    entry.SlidingExpiration = TimeSpan.FromMinutes(1);
+                    return 0;
+                }
+            );
+
+            //
+            if (currentCount >= limitPerMinute) {
+                return false;
+            }
+
+            //
+            cache.Set(
+                cacheKey, 
+                currentCount + 1, 
+                TimeSpan.FromMinutes(1)
+            );
+
+            //
+            return true;
+        }
     }
 }