IMemcachedClient.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using System.Collections.Generic;
using Enyim.Caching.Memcached;
using Enyim.Caching.Memcached.Results;

namespace Enyim.Caching
{
	public interface IMemcachedClient : IDisposable
	{
		event Action<IMemcachedNode> NodeFailed;

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <remarks>The item does not expire unless it is removed due memory pressure.</remarks>
		/// <returns>true if the item was successfully stored in the cache; false otherwise.</returns>
		bool Store(StoreMode mode, string key, object value);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <returns>true if the item was successfully stored in the cache; false otherwise.</returns>
		bool Store(StoreMode mode, string key, object value, TimeSpan validFor);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <returns>true if the item was successfully stored in the cache; false otherwise.</returns>
		bool Store(StoreMode mode, string key, object value, DateTime expiresAt);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <remarks>The item does not expire unless it is removed due memory pressure.</remarks>
		/// <returns>true if the item was successfully stored in the cache; false otherwise.</returns>
		Task<bool> StoreAsync(StoreMode mode, string key, object value, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <returns>true if the item was successfully stored in the cache; false otherwise.</returns>
		Task<bool> StoreAsync(StoreMode mode, string key, object value, TimeSpan validFor, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <returns>true if the item was successfully stored in the cache; false otherwise.</returns>
		Task<bool> StoreAsync(StoreMode mode, string key, object value, DateTime expiresAt, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <remarks>The item does not expire unless it is removed due memory pressure. The text protocol does not support this operation, you need to Store then GetWithCas.</remarks>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		CasResult<bool> Cas(StoreMode mode, string key, object value);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <remarks>The item does not expire unless it is removed due memory pressure.</remarks>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		CasResult<bool> Cas(StoreMode mode, string key, object value, ulong cas);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		CasResult<bool> Cas(StoreMode mode, string key, object value, DateTime expiresAt, ulong cas);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		CasResult<bool> Cas(StoreMode mode, string key, object value, TimeSpan validFor, ulong cas);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <remarks>The item does not expire unless it is removed due memory pressure. The text protocol does not support this operation, you need to Store then GetWithCas.</remarks>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		Task<CasResult<bool>> CasAsync(StoreMode mode, string key, object value, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		Task<CasResult<bool>> CasAsync(StoreMode mode, string key, object value, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		Task<CasResult<bool>> CasAsync(StoreMode mode, string key, object value, DateTime expiresAt, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location and returns its version.
		/// </summary>
		/// <param name="mode">Defines how the item is stored in the cache.</param>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="value">The object to be inserted into the cache.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>A CasResult object containing the version of the item and the result of the operation (true if the item was successfully stored in the cache; false otherwise).</returns>
		Task<CasResult<bool>> CasAsync(StoreMode mode, string key, object value, TimeSpan validFor, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <param name="cacheMinutes"></param>
		/// <returns>true if the item was successfully added in the cache; false otherwise.</returns>
		bool Set(string key, object value, int cacheMinutes);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <param name="cacheMinutes"></param>
		/// <returns>true if the item was successfully added in the cache; false otherwise.</returns>
		Task<bool> SetAsync(string key, object value, int cacheMinutes, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <param name="cacheMinutes"></param>
		/// <returns>true if the item was successfully added in the cache; false otherwise.</returns>
		bool Add(string key, object value, int cacheMinutes);

		/// <summary>
		/// Inserts an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <param name="cacheMinutes"></param>
		/// <returns>true if the item was successfully added in the cache; false otherwise.</returns>
		Task<bool> AddAsync(string key, object value, int cacheMinutes, CancellationToken cancellationToken = default);

		/// <summary>
		/// Replaces an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <param name="cacheMinutes"></param>
		/// <returns>true if the item was successfully replaced in the cache; false otherwise.</returns>
		bool Replace(string key, object value, int cacheMinutes);

		/// <summary>
		/// Replaces an item into the cache with a cache key to reference its location.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <param name="cacheMinutes"></param>
		/// <returns>true if the item was successfully replaced in the cache; false otherwise.</returns>
		Task<bool> ReplaceAsync(string key, object value, int cacheMinutes, CancellationToken cancellationToken = default);

		/// <summary>
		/// Increments the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		ulong Increment(string key, ulong defaultValue, ulong delta);

		/// <summary>
		/// Increments the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		ulong Increment(string key, ulong defaultValue, ulong delta, DateTime expiresAt);

		/// <summary>
		/// Increments the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		ulong Increment(string key, ulong defaultValue, ulong delta, TimeSpan validFor);

		/// <summary>
		/// Increments the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<ulong> IncrementAsync(string key, ulong defaultValue, ulong delta, CancellationToken cancellationToken = default);

		/// <summary>
		/// Increments the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<ulong> IncrementAsync(string key, ulong defaultValue, ulong delta, DateTime expiresAt, CancellationToken cancellationToken = default);

		/// <summary>
		/// Increments the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<ulong> IncrementAsync(string key, ulong defaultValue, ulong delta, TimeSpan validFor, CancellationToken cancellationToken = default);

		/// <summary>
		/// Increments the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		CasResult<ulong> Increment(string key, ulong defaultValue, ulong delta, ulong cas);

		/// <summary>
		/// Increments the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		CasResult<ulong> Increment(string key, ulong defaultValue, ulong delta, DateTime expiresAt, ulong cas);

		/// <summary>
		/// Increments the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		CasResult<ulong> Increment(string key, ulong defaultValue, ulong delta, TimeSpan validFor, ulong cas);

		/// <summary>
		/// Increments the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<CasResult<ulong>> IncrementAsync(string key, ulong defaultValue, ulong delta, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Increments the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<CasResult<ulong>> IncrementAsync(string key, ulong defaultValue, ulong delta, DateTime expiresAt, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Increments the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to increase the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<CasResult<ulong>> IncrementAsync(string key, ulong defaultValue, ulong delta, TimeSpan validFor, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Decrements the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		ulong Decrement(string key, ulong defaultValue, ulong delta);

		/// <summary>
		/// Decrements the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		ulong Decrement(string key, ulong defaultValue, ulong delta, DateTime expiresAt);

		/// <summary>
		/// Decrements the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		ulong Decrement(string key, ulong defaultValue, ulong delta, TimeSpan validFor);

		/// <summary>
		/// Decrements the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<ulong> DecrementAsync(string key, ulong defaultValue, ulong delta, CancellationToken cancellationToken = default);

		/// <summary>
		/// Decrements the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<ulong> DecrementAsync(string key, ulong defaultValue, ulong delta, DateTime expiresAt, CancellationToken cancellationToken = default);

		/// <summary>
		/// Decrements the value of the specified key by the given amount. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<ulong> DecrementAsync(string key, ulong defaultValue, ulong delta, TimeSpan validFor, CancellationToken cancellationToken = default);

		/// <summary>
		/// Decrements the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		CasResult<ulong> Decrement(string key, ulong defaultValue, ulong delta, ulong cas);

		/// <summary>
		/// Decrements the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		CasResult<ulong> Decrement(string key, ulong defaultValue, ulong delta, DateTime expiresAt, ulong cas);

		/// <summary>
		/// Decrements the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		CasResult<ulong> Decrement(string key, ulong defaultValue, ulong delta, TimeSpan validFor, ulong cas);

		/// <summary>
		/// Decrements the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<CasResult<ulong>> DecrementAsync(string key, ulong defaultValue, ulong delta, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Decrements the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="expiresAt">The time when the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<CasResult<ulong>> DecrementAsync(string key, ulong defaultValue, ulong delta, DateTime expiresAt, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Decrements the value of the specified key by the given amount, but only if the item's version matches the CAS value provided. The operation is atomic and happens on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="defaultValue">The value which will be stored by the server if the specified item was not found.</param>
		/// <param name="delta">The amount by which the client wants to decrease the item.</param>
		/// <param name="validFor">The interval after the item is invalidated in the cache.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <returns>The new value of the item or defaultValue if the key was not found.</returns>
		/// <remarks>If the client uses the Text protocol, the item must be inserted into the cache before it can be changed. It must be inserted as a <see cref="System.String"/>. Moreover the Text protocol only works with <see cref="System.UInt32"/> values, so return value -1 always indicates that the item was not found.</remarks>
		Task<CasResult<ulong>> DecrementAsync(string key, ulong defaultValue, ulong delta, TimeSpan validFor, ulong cas, CancellationToken cancellationToken = default);

		/// <summary>
		/// Appends the data to the end of the specified item's data on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="data">The data to be appended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		bool Append(string key, ArraySegment<byte> data);

		/// <summary>
		/// Appends the data to the end of the specified item's data on the server, but only if the item's version matches the CAS value provided.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <param name="data">The data to be prepended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		CasResult<bool> Append(string key, ulong cas, ArraySegment<byte> data);

		/// <summary>
		/// Appends the data to the end of the specified item's data on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="data">The data to be appended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		Task<bool> AppendAsync(string key, ArraySegment<byte> data, CancellationToken cancellationToken = default);

		/// <summary>
		/// Appends the data to the end of the specified item's data on the server, but only if the item's version matches the CAS value provided.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <param name="data">The data to be prepended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		Task<CasResult<bool>> AppendAsync(string key, ulong cas, ArraySegment<byte> data, CancellationToken cancellationToken = default);

		/// <summary>
		/// Inserts the data before the specified item's data on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="data">The data to be appended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		bool Prepend(string key, ArraySegment<byte> data);

		/// <summary>
		/// Appends the data to the end of the specified item's data on the server, but only if the item's version matches the CAS value provided.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <param name="data">The data to be prepended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		CasResult<bool> Prepend(string key, ulong cas, ArraySegment<byte> data);

		/// <summary>
		/// Inserts the data before the specified item's data on the server.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="data">The data to be appended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		Task<bool> PrependAsync(string key, ArraySegment<byte> data, CancellationToken cancellationToken = default);

		/// <summary>
		/// Appends the data to the end of the specified item's data on the server, but only if the item's version matches the CAS value provided.
		/// </summary>
		/// <param name="key">The key used to reference the item.</param>
		/// <param name="cas">The cas value which must match the item's version.</param>
		/// <param name="data">The data to be prepended to the item.</param>
		/// <returns>true if the data was successfully stored; false otherwise.</returns>
		Task<CasResult<bool>> PrependAsync(string key, ulong cas, ArraySegment<byte> data, CancellationToken cancellationToken = default);

		/// <summary>
		/// Tries to get an item from the cache.
		/// </summary>
		/// <param name="key">The identifier for the item to retrieve.</param>
		/// <param name="value">The retrieved item or null if not found.</param>
		/// <returns>The <value>true</value> if the item was successfully retrieved.</returns>
		bool TryGet(string key, out object value);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <param name="key">The identifier for the item to retrieve.</param>
		/// <returns>The retrieved item, or <value>null</value> if the key was not found.</returns>
		object Get(string key);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="key">The identifier for the item to retrieve.</param>
		/// <returns>The retrieved item, or <value>default(T)</value> if the key was not found.</returns>
		T Get<T>(string key);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <param name="key">The identifier for the item to retrieve.</param>
		/// <returns>The retrieved item, or <value>null</value> if the key was not found.</returns>
		Task<object> GetAsync(string key, CancellationToken cancellationToken = default);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="key">The identifier for the item to retrieve.</param>
		/// <returns>The retrieved item, or <value>default(T)</value> if the key was not found.</returns>
		Task<T> GetAsync<T>(string key, CancellationToken cancellationToken = default);

		/// <summary>
		/// Tries to get an item from the cache with CAS.
		/// </summary>
		/// <param name="key"></param>
		/// <param name="value"></param>
		/// <returns></returns>
		bool TryGetWithCas(string key, out CasResult<object> value);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <param name="key"></param>
		/// <returns></returns>
		CasResult<object> GetWithCas(string key);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="key"></param>
		/// <returns></returns>
		CasResult<T> GetWithCas<T>(string key);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <param name="key"></param>
		/// <returns></returns>
		Task<CasResult<object>> GetWithCasAsync(string key, CancellationToken cancellationToken = default);

		/// <summary>
		/// Retrieves the specified item from the cache.
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="key"></param>
		/// <returns></returns>
		Task<CasResult<T>> GetWithCasAsync<T>(string key, CancellationToken cancellationToken = default);

		/// <summary>
		/// Retrieves multiple items from the cache.
		/// </summary>
		/// <param name="keys">The list of identifiers for the items to retrieve.</param>
		/// <returns>a Dictionary holding all items indexed by their key.</returns>
		IDictionary<string, object> Get(IEnumerable<string> keys);

		/// <summary>
		/// Retrieves multiple items from the cache.
		/// </summary>
		/// <param name="keys">The list of identifiers for the items to retrieve.</param>
		/// <returns>a Dictionary holding all items indexed by their key.</returns>
		Task<IDictionary<string, object>> GetAsync(IEnumerable<string> keys, CancellationToken cancellationToken = default);

		/// <summary>
		/// Retrieves multiple items from the cache.
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="keys">The list of identifiers for the items to retrieve.</param>
		/// <returns>a Dictionary holding all items indexed by their key.</returns>
		IDictionary<string, T> Get<T>(IEnumerable<string> keys);

		/// <summary>
		/// Retrieves multiple items from the cache.
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="keys">The list of identifiers for the items to retrieve.</param>
		/// <returns>a Dictionary holding all items indexed by their key.</returns>
		Task<IDictionary<string, T>> GetAsync<T>(IEnumerable<string> keys, CancellationToken cancellationToken = default);

		/// <summary>
		/// Retrieves multiple items from the cache with CAS.
		/// </summary>
		/// <param name="keys"></param>
		/// <returns></returns>
		IDictionary<string, CasResult<object>> GetWithCas(IEnumerable<string> keys);

		/// <summary>
		/// Retrieves multiple items from the cache with CAS.
		/// </summary>
		/// <param name="keys"></param>
		/// <returns></returns>
		Task<IDictionary<string, CasResult<object>>> GetWithCasAsync(IEnumerable<string> keys, CancellationToken cancellationToken = default);

		/// <summary>
		/// Removes the specified item from the cache.
		/// </summary>
		/// <param name="key">The identifier for the item to delete.</param>
		/// <returns>true if the item was successfully removed from the cache; false otherwise.</returns>
		bool Remove(string key);

		/// <summary>
		/// Removes the specified item from the cache.
		/// </summary>
		/// <param name="key">The identifier for the item to delete.</param>
		/// <returns>true if the item was successfully removed from the cache; false otherwise.</returns>
		Task<bool> RemoveAsync(string key, CancellationToken cancellationToken = default);

		/// <summary>
		/// Determines whether an item that associated with the key is exists or not
		/// </summary>
		/// <param name="key">The key</param>
		/// <returns>Returns a boolean value indicating if the object that associates with the key is cached or not</returns>
		bool Exists(string key);

		/// <summary>
		/// Determines whether an item that associated with the key is exists or not
		/// </summary>
		/// <param name="key">The key</param>
		/// <returns>Returns a boolean value indicating if the object that associates with the key is cached or not</returns>
		Task<bool> ExistsAsync(string key, CancellationToken cancellationToken = default);

		/// <summary>
		/// Removes all data from the cache. Note: this will invalidate all data on all servers in the pool.
		/// </summary>
		void FlushAll();

		/// <summary>
		/// Removes all data from the cache. Note: this will invalidate all data on all servers in the pool.
		/// </summary>
		Task FlushAllAsync(CancellationToken cancellationToken = default);

		/// <summary>
		/// Gets statistics about the servers.
		/// </summary>
		/// <returns></returns>
		ServerStats Stats();

		/// <summary>
		/// Gets statistics about the servers.
		/// </summary>
		/// <param name="type"></param>
		/// <returns></returns>
		ServerStats Stats(string type);

		/// <summary>
		/// Gets statistics about the servers.
		/// </summary>
		/// <returns></returns>
		Task<ServerStats> StatsAsync(CancellationToken cancellationToken = default);

		/// <summary>
		/// Gets statistics about the servers.
		/// </summary>
		/// <param name="type"></param>
		/// <returns></returns>
		Task<ServerStats> StatsAsync(string type, CancellationToken cancellationToken = default);
	}
}

#region [ License information          ]
/* ************************************************************
 * 
 *    © 2010 Attila Kiskó (aka Enyim), © 2016 CNBlogs, © 2020 VIEApps.net
 *    
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *    
 *        http://www.apache.org/licenses/LICENSE-2.0
 *    
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 *    
 * ************************************************************/
#endregion