OpenQuery/Services/RateLimiter.cs

namespace OpenQuery.Services;

public sealed class RateLimiter : IAsyncDisposable
{
    private readonly SemaphoreSlim _semaphore;

    public RateLimiter(int maxConcurrentRequests)
    {
        _semaphore = new SemaphoreSlim(maxConcurrentRequests, maxConcurrentRequests);
    }

    public async Task<T> ExecuteAsync<T>(Func<Task<T>> action, CancellationToken cancellationToken = default)
    {
        await _semaphore.WaitAsync(cancellationToken);
        try
        {
            return await action();
        }
        finally
        {
            _semaphore.Release();
        }
    }

    public async Task ExecuteAsync(Func<Task> action, CancellationToken cancellationToken = default)
    {
        await _semaphore.WaitAsync(cancellationToken);
        try
        {
            await action();
        }
        finally
        {
            _semaphore.Release();
        }
    }

    public async ValueTask DisposeAsync()
    {
        _semaphore.Dispose();
    }
}