// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;

namespace Microsoft.Extensions.Caching.Memory
{
    /// <summary>
    /// Represents a local in-memory cache whose values are not serialized.
    /// </summary>
    public interface IMemoryCache : IDisposable
    {
        /// <summary>
        /// Gets the item associated with this key if present.
        /// </summary>
        /// <param name="key">An object identifying the requested entry.</param>
        /// <param name="value">The located value or null.</param>
        /// <returns>True if the key was found.</returns>
        bool TryGetValue(object key, out object? value);

        /// <summary>
        /// Create or overwrite an entry in the cache.
        /// </summary>
        /// <param name="key">An object identifying the entry.</param>
        /// <returns>The newly created <see cref="ICacheEntry"/> instance.</returns>
        ICacheEntry CreateEntry(object key);

        /// <summary>
        /// Removes the object associated with the given key.
        /// </summary>
        /// <param name="key">An object identifying the entry.</param>
        void Remove(object key);

#if NET
        /// <summary>
        /// Gets a snapshot of the cache statistics if available.
        /// </summary>
        /// <returns>An instance of <see cref="MemoryCacheStatistics"/> containing a snapshot of the cache statistics.</returns>
        MemoryCacheStatistics? GetCurrentStatistics() => null;
#endif
    }
}