using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace NewLife.Caching
{
    /// <summary>缓存</summary>
    public abstract class Cache : ICache
    {
        #region 静态默认实现
        /// <summary>默认缓存</summary>
        public static ICache Default { get; set; } = new MyCache();
        #endregion

        #region 属性
        /// <summary>名称</summary>
        public String Name { get; protected set; }

        /// <summary>获取和设置缓存，永不过期</summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public virtual Object this[String key] { get { return Get(key); } set { Add(key, value); } }
        #endregion

        #region 方法
        /// <summary>是否包含缓存项</summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public abstract Boolean Contains(String key);

        /// <summary>添加缓存项</summary>
        /// <param name="key">键</param>
        /// <param name="value">值</param>
        /// <param name="expire">过期时间，秒</param>
        /// <returns></returns>
        public abstract Boolean Add(String key, Object value, Int32 expire = 0);

        /// <summary>添加获取缓存项</summary>
        /// <param name="key">键</param>
        /// <param name="value">值</param>
        /// <param name="expire">过期时间，秒</param>
        /// <returns></returns>
        public abstract Object AddOrGet(String key, Object value, Int32 expire = 0);

        /// <summary>获取缓存项</summary>
        /// <param name="key">键</param>
        /// <returns></returns>
        public abstract Object Get(String key);

        /// <summary>移除缓存项</summary>
        /// <param name="key">键</param>
        /// <returns></returns>
        public abstract Object Remove(String key);
        #endregion
    }
}