Zeta .NET Base Libraries

namespace ZetaLib.Web.Caching
{
	#region Using directives.
	// ----------------------------------------------------------------------

	using System;
	using System.Collections;
	using System.Collections.Specialized;
	using System.Web;
	using System.Web.Caching;
	using System.Collections.Generic;
	using ZetaLib.Core.Caching;

	// ----------------------------------------------------------------------
	#endregion

	/////////////////////////////////////////////////////////////////////////

	/// <summary>
	/// Provide an extended version of System.Web.Caching.Cache.
	/// </summary>
	public class WebCacheManager :
		CacheManager
	{
		#region Public methods and properties.
		// ------------------------------------------------------------------

		/// <summary>
		/// Caching items on a per-request-basis.
		/// </summary>
		/// <value>The per request.</value>
		public PerRequestWebCache PerRequest
		{
			get
			{
				lock ( thisLock )
				{
					if ( perRequest == null )
					{
						perRequest = new PerRequestWebCache();
					}

					return perRequest;
				}
			}
		}

		/// <summary>
		/// Caching on a per-user-session-basis.
		/// </summary>
		/// <value>The per session.</value>
		public PerSessionWebCache PerSession
		{
			get
			{
				lock ( thisLock )
				{
					if ( perSession == null )
					{
						perSession = new PerSessionWebCache();
					}

					return perSession;
				}
			}
		}

		/// <summary>
		/// Caching on a per-application-basis, shared by all users.
		/// </summary>
		/// <value>The per application.</value>
		public PerApplicationWebCache PerApplication
		{
			get
			{
				lock ( thisLock )
				{
					if ( perApplication == null )
					{
						perApplication = new PerApplicationWebCache();
					}

					return perApplication;
				}
			}
		}

		/// <summary>
		/// Empties the complete cache.
		/// </summary>
		public override void RemoveAll()
		{
			base.RemoveAll();

			PerSession.RemoveAll();
			PerApplication.RemoveAll();
		}

		/// <summary>
		/// Removes all items from the cache with
		/// a certain prefix in the key.
		/// </summary>
		/// <param name="group">The group.</param>
		public override void RemoveAll(
			CacheItemGroup group )
		{
			base.RemoveAll( group );

			PerSession.RemoveAll( group );
			PerApplication.RemoveAll( group );
		}

		// ------------------------------------------------------------------
		#endregion

		#region Private helper.
		// ------------------------------------------------------------------

		/// <summary>
		/// Best practice, see C# MSDN documentation of the "lock" keyword.
		/// </summary>
		private object thisLock = new object();

		/// <summary>
		/// Storing the other cache references.
		/// </summary>
		private PerRequestWebCache perRequest = null;
		private PerSessionWebCache perSession = null;
		private PerApplicationWebCache perApplication = null;

		// ------------------------------------------------------------------
		#endregion
	}

	/////////////////////////////////////////////////////////////////////////
}