CODE EXAMPLE FOR CSHARP

ASP.NET Core set update clear cache from IMemoryCache (set by Set method of CacheExtensions class)

Internally it uses IMemoryCache.
Use case is exactly the same with 2 additional features:

Clear all items from memory cache
Iterate through all key/value pairs
You have to register singleton:

serviceCollection.AddSingleton<IMyCache, MyMemoryCache>();
Use case:

public MyController(IMyCache cache)
{
    this._cache = cache;
}

[HttpPut]
public IActionResult ClearCache()
{
    this._cache.Clear();
    return new JsonResult(true);
}

[HttpGet]
public IActionResult ListCache()
{
    var result = this._cache.Select(t => new
    {
        Key = t.Key,
        Value = t.Value
    }).ToArray();
    return new JsonResult(result);
}