Add support for Twilight gateway queue

Myriad/Gateway/Cluster.cs

@@ -4,6 +4,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 
+using Myriad.Gateway.Limit;
 using Myriad.Types;
 
 using Serilog;
@@ -15,7 +16,7 @@ namespace Myriad.Gateway
         private readonly GatewaySettings _gatewaySettings;
         private readonly ILogger _logger;
         private readonly ConcurrentDictionary<int, Shard> _shards = new();
-        private ShardIdentifyRatelimiter? _ratelimiter;
+        private IGatewayRatelimiter? _ratelimiter;
 
         public Cluster(GatewaySettings gatewaySettings, ILogger logger)
         {
@@ -35,10 +36,9 @@ namespace Myriad.Gateway
             await Start(info.Url, 0, info.Shards - 1, info.Shards, info.SessionStartLimit.MaxConcurrency);
         }
 
-        public async Task Start(string url, int shardMin, int shardMax, int shardTotal, int concurrency)
+        public async Task Start(string url, int shardMin, int shardMax, int shardTotal, int recommendedConcurrency)
         {
-            concurrency = GetActualShardConcurrency(concurrency);
+            _ratelimiter = GetRateLimiter(recommendedConcurrency);
-            _ratelimiter = new(_logger, concurrency);
             
             var shardCount = shardMax - shardMin + 1;
             _logger.Information("Starting {ShardCount} of {ShardTotal} shards (#{ShardMin}-#{ShardMax}) at {Url}",
@@ -77,5 +77,16 @@ namespace Myriad.Gateway
             
             return Math.Min(_gatewaySettings.MaxShardConcurrency.Value, recommendedConcurrency);
         }
+
+        private IGatewayRatelimiter GetRateLimiter(int recommendedConcurrency)
+        {
+            if (_gatewaySettings.GatewayQueueUrl != null)
+            {
+                return new TwilightGatewayRatelimiter(_logger, _gatewaySettings.GatewayQueueUrl);
+            }
+            
+            var concurrency = GetActualShardConcurrency(recommendedConcurrency);
+            return new LocalGatewayRatelimiter(_logger, concurrency);
+        }
     }
 }

Myriad/Gateway/GatewaySettings.cs

@@ -5,5 +5,6 @@
         public string Token { get; init; }
         public GatewayIntent Intents { get; init; }
         public int? MaxShardConcurrency { get; init; }
+        public string? GatewayQueueUrl { get; init; }
     }
 }

Myriad/Gateway/Limit/IGatewayRatelimiter.cs

@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+
+namespace Myriad.Gateway.Limit
+{
+    public interface IGatewayRatelimiter
+    {
+        public Task Identify(int shard);
+    }
+}

Myriad/Gateway/Limit/LocalGatewayRatelimiter.cs

@@ -4,9 +4,9 @@ using System.Threading.Tasks;
 
 using Serilog;
 
-namespace Myriad.Gateway
+namespace Myriad.Gateway.Limit
 {
-    public class ShardIdentifyRatelimiter
+    public class LocalGatewayRatelimiter: IGatewayRatelimiter
     {
         // docs specify 5 seconds, but we're actually throttling connections, not identify, so we need a bit of leeway
         private static readonly TimeSpan BucketLength = TimeSpan.FromSeconds(6);
@@ -17,13 +17,13 @@ namespace Myriad.Gateway
         private Task? _refillTask;
         private readonly ILogger _logger;
 
-        public ShardIdentifyRatelimiter(ILogger logger, int maxConcurrency)
+        public LocalGatewayRatelimiter(ILogger logger, int maxConcurrency)
         {
-            _logger = logger.ForContext<ShardIdentifyRatelimiter>();
+            _logger = logger.ForContext<LocalGatewayRatelimiter>();
             _maxConcurrency = maxConcurrency;
         }
 
-        public Task Acquire(int shard)
+        public Task Identify(int shard)
         {
             var bucket = shard % _maxConcurrency;
             var queue = _buckets.GetOrAdd(bucket, _ => new ConcurrentQueue<TaskCompletionSource>());

Myriad/Gateway/Limit/TwilightGatewayRatelimiter.cs

@@ -0,0 +1,27 @@
+using System.Net.Http;
+using System.Threading.Tasks;
+
+using Serilog;
+
+namespace Myriad.Gateway.Limit
+{
+    public class TwilightGatewayRatelimiter: IGatewayRatelimiter
+    {
+        private readonly string _url;
+        private readonly ILogger _logger;
+        private readonly HttpClient _httpClient = new();
+        
+        public TwilightGatewayRatelimiter(ILogger logger, string url)
+        {
+            _url = url;
+            _logger = logger;
+        }
+
+        public async Task Identify(int shard)
+        {
+            // Literally just request and wait :p
+            _logger.Information("Shard {ShardId}: Requesting identify at gateway queue {GatewayQueueUrl}", shard, _url);
+            await _httpClient.GetAsync(_url);
+        }
+    }
+}

Myriad/Gateway/Shard.cs

@@ -3,6 +3,7 @@ using System.Net.WebSockets;
 using System.Text.Json;
 using System.Threading.Tasks;
 
+using Myriad.Gateway.Limit;
 using Myriad.Gateway.State;
 using Myriad.Serialization;
 using Myriad.Types;
@@ -17,7 +18,7 @@ namespace Myriad.Gateway
 
         private readonly GatewaySettings _settings;
         private readonly ShardInfo _info;
-        private readonly ShardIdentifyRatelimiter _ratelimiter;
+        private readonly IGatewayRatelimiter _ratelimiter;
         private readonly string _url;
         private readonly ILogger _logger;
         private readonly ShardStateManager _stateManager;
@@ -41,7 +42,7 @@ namespace Myriad.Gateway
         private TimeSpan _reconnectDelay = TimeSpan.Zero;
         private Task? _worker;
 
-        public Shard(GatewaySettings settings, ShardInfo info, ShardIdentifyRatelimiter ratelimiter, string url, ILogger logger)
+        public Shard(GatewaySettings settings, ShardInfo info, IGatewayRatelimiter ratelimiter, string url, ILogger logger)
         {
             _jsonSerializerOptions = new JsonSerializerOptions().ConfigureForMyriad();
 
@@ -105,11 +106,14 @@ namespace Myriad.Gateway
             }
         }
         
-        public Task Start()
+        public async Task Start()
         {
             if (_worker == null)
                 _worker = ShardLoop();
-            return Task.CompletedTask;
+
+            // we can probably TCS this instead of spin loop but w/e
+            while (State != ShardState.Connected) 
+                await Task.Delay(100);
         }
 
         public async Task UpdateStatus(GatewayStatusUpdate payload)
@@ -125,7 +129,7 @@ namespace Myriad.Gateway
         {
             while (true)
             {
-                await _ratelimiter.Acquire(_info.ShardId);
+                await _ratelimiter.Identify(_info.ShardId);
 
                 _logger.Information("Shard {ShardId}: Connecting to WebSocket", _info.ShardId);
                 try

PluralKit.Bot/BotConfig.cs

@@ -18,6 +18,8 @@ namespace PluralKit.Bot
         
         public ClusterSettings? Cluster { get; set; }
         
+        public string? GatewayQueueUrl { get; set; }
+
         public record ClusterSettings
         {
             public string NodeName { get; set; }

PluralKit.Bot/Modules.cs

@@ -28,6 +28,7 @@ namespace PluralKit.Bot
                 {
                     Token = botConfig.Token,
                     MaxShardConcurrency = botConfig.MaxShardConcurrency,
+                    GatewayQueueUrl = botConfig.GatewayQueueUrl,
                     Intents = GatewayIntent.Guilds |
                               GatewayIntent.DirectMessages |
                               GatewayIntent.DirectMessageReactions |