frostfs-sdk-csharp/src/FrostFS.SDK.Client/Pool/InnerPool.cs

using FrostFS.SDK.Client;

internal sealed class InnerPool
{
    private readonly object _lock = new();

    internal InnerPool(Sampler sampler, ClientWrapper[] clients)
    {
        Clients = clients;
        Sampler = sampler;
    }

    internal Sampler Sampler { get; set; }

    internal ClientWrapper[] Clients { get; }

    internal ClientWrapper? Connection()
    {
        lock (_lock)
        {
            if (Clients.Length == 1)
            {
                var client = Clients[0];
                if (client.IsHealthy())
                {
                    return client;
                }
            }
            else
            {
                var attempts = 3 * Clients.Length;

                for (int i = 0; i < attempts; i++)
                {
                    int index = Sampler.Next();

                    if (Clients[index].IsHealthy())
                    {
                        return Clients[index];
                    }
                }
            }

            return null;
        }
    }
}