NHibernateHelper.cs

namespace Data
{
  using System;
	using System.Configuration;
	using System.IO;
	using System.Reflection;
	using System.Runtime.Serialization.Formatters.Binary;
	using FluentNHibernate.Cfg;
	using FluentNHibernate.Cfg.Db;
	using FluentNHibernate.Conventions.Helpers;
	using NHibernate;
	using NHibernate.Cache;
	using NHibernate.Context;
	using NHibernate.Event;
	using Configuration = NHibernate.Cfg.Configuration;

	public static class NHibernateHelper
	{
		private static readonly string SerializedConfig = string.Format("NHConfiguration.{0}.{1}.serialized", Assembly.GetExecutingAssembly().GetName().Version, ConnectionStringSettings.Name);
		private static readonly string ConfigPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, SerializedConfig);

		public static ConnectionStringSettings ConnectionStringSettings
		{
			get
			{
				return ConfigurationManager.ConnectionStrings[Environment.MachineName] ??
				       ConfigurationManager.ConnectionStrings["default"];
			}
		}

		public static ISessionFactory CreateSessionFactory()
		{
			return CreateSessionFactory(null);
		}

		public static ISessionFactory CreateSessionFactory(ConnectionStringSettings connectionStringSettings)
		{
			var con = connectionStringSettings == null ? ConnectionStringSettings.ConnectionString : connectionStringSettings.ConnectionString;
			var msSqlConfiguration = MsSqlConfiguration.MsSql2008.ConnectionString(con);
#if DEBUG
			msSqlConfiguration.ShowSql().FormatSql();
#endif

			return CreateNHConfig(msSqlConfiguration).BuildSessionFactory();
		}


		public static Configuration CreateNHConfig(MsSqlConfiguration msSqlConfiguration)
		{
			var serializer = new BinaryFormatter();
			Configuration returnConfig;

			if (File.Exists(ConfigPath)/* && IsConfigurationFileValid()*/)
			{
				using (Stream stream = File.OpenRead(ConfigPath))
				{
					returnConfig = serializer.Deserialize(stream) as Configuration;
				}
			}
			else
			{			
				returnConfig = Fluently.Configure()
					.Database(msSqlConfiguration)
					.Mappings(m => m.FluentMappings
					               	.AddFromAssembly(Assembly.Load("MyProject.Data"))
					               	.Conventions.Add(
					               		Table.Is(x => "tbl" + x.EntityType.Name),
					               		PrimaryKey.Name.Is(x => x.EntityType.Name + "Id"),
					               		ForeignKey.EndsWith("Id")
					               	)
					)
					.CurrentSessionContext<WebSessionContext>()
					.Cache(c => c.UseQueryCache().ProviderClass<HashtableCacheProvider>())				
#if DEBUG
					.ExposeConfiguration(cfg => cfg.SetProperty("generate_statistics", "true"))
#endif
					.BuildConfiguration();

				using (Stream stream = File.OpenWrite(ConfigPath))
				{
					serializer.Serialize(stream, returnConfig);
				}
			}
			return returnConfig;
		}


		private static bool IsConfigurationFileValid()
		{
			var assInfo = new FileInfo(ConfigPath);
			return assInfo.LastWriteTime >= File.GetCreationTime(Assembly.GetExecutingAssembly().Location);
		}
	}
}