Add support for Twilight gateway queue

Myriad/Gateway/ShardIdentifyRatelimiter.cs

@@ -1,73 +0,0 @@
-using System;
-using System.Collections.Concurrent;
-using System.Threading.Tasks;
-
-using Serilog;
-
-namespace Myriad.Gateway
-{
-    public class ShardIdentifyRatelimiter
-    {
-        // 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);
-
-        private readonly ConcurrentDictionary<int, ConcurrentQueue<TaskCompletionSource>> _buckets = new();
-        private readonly int _maxConcurrency;
-
-        private Task? _refillTask;
-        private readonly ILogger _logger;
-
-        public ShardIdentifyRatelimiter(ILogger logger, int maxConcurrency)
-        {
-            _logger = logger.ForContext<ShardIdentifyRatelimiter>();
-            _maxConcurrency = maxConcurrency;
-        }
-
-        public Task Acquire(int shard)
-        {
-            var bucket = shard % _maxConcurrency;
-            var queue = _buckets.GetOrAdd(bucket, _ => new ConcurrentQueue<TaskCompletionSource>());
-            var tcs = new TaskCompletionSource();
-            queue.Enqueue(tcs);
-
-            ScheduleRefill();
-
-            return tcs.Task;
-        }
-
-        private void ScheduleRefill()
-        {
-            if (_refillTask != null && !_refillTask.IsCompleted)
-                return;
-
-            _refillTask?.Dispose();
-            _refillTask = RefillTask();
-        }
-
-        private async Task RefillTask()
-        {
-            await Task.Delay(TimeSpan.FromMilliseconds(250));
-
-            while (true)
-            {
-                var isClear = true;
-                foreach (var (bucket, queue) in _buckets)
-                {
-                    if (!queue.TryDequeue(out var tcs))
-                        continue;
-
-                    _logger.Information(
-                        "Allowing identify for bucket {BucketId} through ({QueueLength} left in bucket queue)",
-                        bucket, queue.Count);
-                    tcs.SetResult();
-                    isClear = false;
-                }
-
-                if (isClear)
-                    return;
-
-                await Task.Delay(BucketLength);
-            }
-        }
-    }
-}