From aa3eb3a3c6f8646f8cf166d437c5e9ed85172a3b Mon Sep 17 00:00:00 2001
From: Rashik Hasnat <rhasnat93@gmail.com>
Date: Thu, 30 Mar 2023 22:54:21 +0600
Subject: [PATCH] - Added Redis Rate Limit Configuration. - Added Connection
 multiplexer Factory Property in Redis Rate Limit COnfiguration. - Added a
 paramter to AddRedisRateLimiting method so that RedisRateLimitConfiguration
 Can be supplied. - Using the connection multiplexer from the factory if
 configured.

---
 .../RedisProcessingStrategy.cs                | 16 ++++++++++++---
 .../RedisRateLimitConfiguration.cs            | 20 +++++++++++++++++++
 .../StartupExtensions.cs                      | 10 ++++++++--
 3 files changed, 41 insertions(+), 5 deletions(-)
 create mode 100644 src/AspNetCoreRateLimit.Redis/RedisRateLimitConfiguration.cs

diff --git a/src/AspNetCoreRateLimit.Redis/RedisProcessingStrategy.cs b/src/AspNetCoreRateLimit.Redis/RedisProcessingStrategy.cs
index ff97be59..9ee54a25 100644
--- a/src/AspNetCoreRateLimit.Redis/RedisProcessingStrategy.cs
+++ b/src/AspNetCoreRateLimit.Redis/RedisProcessingStrategy.cs
@@ -3,6 +3,7 @@
 using System;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
 
 namespace AspNetCoreRateLimit.Redis
 {
@@ -12,15 +13,24 @@ public class RedisProcessingStrategy : ProcessingStrategy
         private readonly IRateLimitConfiguration _config;
         private readonly ILogger<RedisProcessingStrategy> _logger;
 
-        public RedisProcessingStrategy(IConnectionMultiplexer connectionMultiplexer, IRateLimitConfiguration config, ILogger<RedisProcessingStrategy> logger)
+        public RedisProcessingStrategy(IConnectionMultiplexer connectionMultiplexer, 
+                                       IRateLimitConfiguration config, 
+                                       ILogger<RedisProcessingStrategy> logger, 
+                                       IOptions<RedisRateLimitConfiguration> optionAccessor
+            )
             : base(config)
         {
-            _connectionMultiplexer = connectionMultiplexer ?? throw new ArgumentException("IConnectionMultiplexer was null. Ensure StackExchange.Redis was successfully registered");
             _config = config;
             _logger = logger;
+            var options = optionAccessor?.Value;
+            _connectionMultiplexer = options?.ConnectionMultiplexerFactory == null
+                ? connectionMultiplexer ?? throw new ArgumentException(
+                    "IConnectionMultiplexer was null. Ensure StackExchange.Redis was successfully registered")
+                : options.ConnectionMultiplexerFactory().GetAwaiter().GetResult();
+
         }
 
-        static private readonly LuaScript _atomicIncrement = LuaScript.Prepare("local count = redis.call(\"INCRBYFLOAT\", @key, tonumber(@delta)) local ttl = redis.call(\"TTL\", @key) if ttl == -1 then redis.call(\"EXPIRE\", @key, @timeout) end return count");
+        private static readonly LuaScript _atomicIncrement = LuaScript.Prepare("local count = redis.call(\"INCRBYFLOAT\", @key, tonumber(@delta)) local ttl = redis.call(\"TTL\", @key) if ttl == -1 then redis.call(\"EXPIRE\", @key, @timeout) end return count");
 
         public override async Task<RateLimitCounter> ProcessRequestAsync(ClientRequestIdentity requestIdentity, RateLimitRule rule, ICounterKeyBuilder counterKeyBuilder, RateLimitOptions rateLimitOptions, CancellationToken cancellationToken = default)
         {
diff --git a/src/AspNetCoreRateLimit.Redis/RedisRateLimitConfiguration.cs b/src/AspNetCoreRateLimit.Redis/RedisRateLimitConfiguration.cs
new file mode 100644
index 00000000..4977aafe
--- /dev/null
+++ b/src/AspNetCoreRateLimit.Redis/RedisRateLimitConfiguration.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
+using StackExchange.Redis;
+
+namespace AspNetCoreRateLimit.Redis
+{
+    /// <summary>
+    /// Configuration options for <see cref="RedisProcessingStrategy"/>.
+    /// </summary>
+    public class RedisRateLimitConfiguration : IOptions<RedisRateLimitConfiguration>
+    {
+        /// <summary>
+        /// Gets or sets a delegate to create the ConnectionMultiplexer instance.
+        /// </summary>
+        public Func<Task<IConnectionMultiplexer>> ConnectionMultiplexerFactory { get; set; }
+
+        public RedisRateLimitConfiguration Value => this;
+    }
+}
diff --git a/src/AspNetCoreRateLimit.Redis/StartupExtensions.cs b/src/AspNetCoreRateLimit.Redis/StartupExtensions.cs
index 65d0e464..e5136b24 100644
--- a/src/AspNetCoreRateLimit.Redis/StartupExtensions.cs
+++ b/src/AspNetCoreRateLimit.Redis/StartupExtensions.cs
@@ -1,11 +1,17 @@
-using Microsoft.Extensions.DependencyInjection;
+using System;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace AspNetCoreRateLimit.Redis
 {
     public static class StartupExtensions
     {
-        public static IServiceCollection AddRedisRateLimiting(this IServiceCollection services)
+        public static IServiceCollection AddRedisRateLimiting(this IServiceCollection services, Action<RedisRateLimitConfiguration> setupAction = null)
         {
+            services.AddOptions();
+            if (setupAction != null)
+            {
+                services.Configure(setupAction);
+            }
             services.AddDistributedRateLimiting<RedisProcessingStrategy>();
             return services;
         }