/// <summary>
/// 将 CacheOptionEntry 对象实例，转化为 MemoryCacheEntryOptions
/// </summary>
/// <param name="entry"></param>
/// <returns></returns>
public static MemoryCacheEntryOptions ConvertToMemoryCacheEntryOptions(this CacheOptionEntry entry)
{
return(new MemoryCacheEntryOptions
{
AbsoluteExpiration = entry.AbsoluteExpiration,
AbsoluteExpirationRelativeToNow = entry.AbsoluteExpirationRelativeToNow,
SlidingExpiration = entry.SlidingExpiration
});
}
/// <summary>
/// 将 CacheOptionEntry 对象实例，转化为 DistributedCacheEntryOptions
/// </summary>
/// <param name="entry"></param>
/// <returns></returns>
public static DistributedCacheEntryOptions ConvertToDistributedCacheEntry(this CacheOptionEntry entry)
{
return(new DistributedCacheEntryOptions
{
AbsoluteExpiration = entry.AbsoluteExpiration,
AbsoluteExpirationRelativeToNow = entry.AbsoluteExpirationRelativeToNow,
SlidingExpiration = entry.SlidingExpiration
});
}
/// <summary>
/// 将 CacheOptionEntry 对象实例，转化为相对与当前时间的 TimeSpan
/// </summary>
/// <param name="entry"></param>
/// <returns></returns>
/// <exception cref="NotSupportedException">当 CacheOptionEntry 对象的
/// <see cref="CacheOptionEntry.AbsoluteExpirationRelativeToNow"/>属性和<see cref="CacheOptionEntry.AbsoluteExpiration"/>都为null时</exception>
public static TimeSpan ConvertToTimeSpanRelativeToNow(this CacheOptionEntry entry)
{
if (entry.AbsoluteExpirationRelativeToNow.HasValue)
{
return(entry.AbsoluteExpirationRelativeToNow.Value);
}
if (entry.AbsoluteExpiration.HasValue)
{
return(entry.AbsoluteExpiration.Value - DateTimeOffset.UtcNow);
}
if (entry.SlidingExpiration.HasValue)
{
throw new NotSupportedException($"Unable to convert {nameof(CacheOptionEntry.SlidingExpiration)} to TimeSpan for relative to now. This operation is not supported.");
}
throw new NotSupportedException($"Unable to convert {nameof(CacheOptionEntry)} to TimeSpan for relative to now. This operation is not supported.");
}
/// <summary>
/// 获取缓存，若不存在则创建
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="cache"></param>
/// <param name="key"></param>
/// <param name="func"></param>
/// <param name="entry"></param>
/// <returns></returns>
public static T GetOrCreate <T>(this IMemoryCache cache, object key, Func <T> func, CacheOptionEntry entry)
{
return(cache.GetOrCreate(key, options =>
{
options.AbsoluteExpiration = entry.AbsoluteExpiration;
options.AbsoluteExpirationRelativeToNow = entry.AbsoluteExpirationRelativeToNow;
options.SlidingExpiration = entry.SlidingExpiration;
return func();
}));
}
/// <summary>
/// 设置滑动过期时间
/// </summary>
/// <param name="entry"></param>
/// <param name="offset"></param>
/// <returns></returns>
public static CacheOptionEntry SetSlidingExpiration(this CacheOptionEntry entry, TimeSpan offset)
{
entry.SlidingExpiration = new TimeSpan?(offset);
return(entry);
}
/// <summary>
/// 设置绝对过期时间
/// </summary>
/// <param name="entry"></param>
/// <param name="absolute"></param>
/// <returns></returns>
public static CacheOptionEntry SetAbsoluteExpiration(this CacheOptionEntry entry, DateTimeOffset absolute)
{
entry.AbsoluteExpiration = new DateTimeOffset?(absolute);
return(entry);
}
/// <summary>
/// 设置以对当前时间为基础时间的绝对过期时间
/// </summary>
/// <param name="entry"></param>
/// <param name="relative"></param>
/// <returns></returns>
public static CacheOptionEntry SetAbsoluteExpiration(this CacheOptionEntry entry, TimeSpan relative)
{
entry.AbsoluteExpirationRelativeToNow = new TimeSpan?(relative);
return(entry);
}