Databasing framework with LINQ support

using System;

namespace Pfz.Databasing
{
	/// <summary>
	/// Class used to manage the "actual" connection of a thread.
	/// You must guarantee that the connection is opened.
	/// </summary>
	public sealed class ThreadConnection:
		IDisposable
	{
		[ThreadStatic]
		private static IDatabaseConnection fValue;
		
		/// <summary>
		/// Gets or sets the actual threadconnection, without expecting to
		/// "cancel" the modification.
		/// </summary>
		public static IDatabaseConnection Value
		{
			get
			{
				return fValue;
			}
			set
			{
				fValue = value;
			}
		}
		
		/// <summary>
		/// Gets the Value or throws an exception if it is null.
		/// </summary>
		public static IDatabaseConnection Get()
		{
			var result = Value;
			if (result == null)
				throw new DatabaseException("Pfz.Databasing.ThreadConnection.Value is null.");
			
			return result;
		}

		private IDatabaseConnection fOldConnection;
		private bool fOwnsConnection;
		
		/// <summary>
		/// Creates the ThreadConnection object setting the actual connection
		/// to the given one.
		/// </summary>
		public ThreadConnection(IDatabaseConnection connection, bool ownsConnection)
		{
			fOldConnection = fValue;
			fValue = connection;
			fOwnsConnection = ownsConnection;
		}
		
		/// <summary>
		/// Restores the oldconnection for the thread.
		/// </summary>
		public void Dispose()
		{
			var value = fValue;
			fValue = fOldConnection;
			
			if (fOwnsConnection && value != null)
				value.Dispose();
		}
	}
}