namespace NewLife.Caching;

/// <summary>轻量级生产者消费者接口</summary>
/// <remarks>
/// 不一定支持Ack机制；也不支持消息体与消息键分离
/// </remarks>
/// <typeparam name="T"></typeparam>
public interface IProducerConsumer<T>
{
    /// <summary>元素个数</summary>
    Int32 Count { get; }

    /// <summary>集合是否为空</summary>
    Boolean IsEmpty { get; }

    /// <summary>生产添加</summary>
    /// <param name="values"></param>
    /// <returns></returns>
    Int32 Add(params T[] values);

    /// <summary>消费获取一批</summary>
    /// <param name="count"></param>
    /// <returns></returns>
    IEnumerable<T> Take(Int32 count = 1);

    /// <summary>消费获取一个</summary>
    /// <param name="timeout">超时。默认0秒，永久等待</param>
    /// <returns></returns>
    T? TakeOne(Int32 timeout = 0);

    /// <summary>异步消费获取一个</summary>
    /// <param name="timeout">超时。单位秒，0秒表示永久等待</param>
    /// <returns></returns>
    Task<T?> TakeOneAsync(Int32 timeout = 0);

    /// <summary>异步消费获取一个</summary>
    /// <param name="timeout">超时。单位秒，0秒表示永久等待</param>
    /// <param name="cancellationToken">取消通知</param>
    /// <returns></returns>
    Task<T?> TakeOneAsync(Int32 timeout, CancellationToken cancellationToken);

    /// <summary>确认消费</summary>
    /// <param name="keys"></param>
    /// <returns></returns>
    Int32 Acknowledge(params String[] keys);
}