TransactionMessage.cs :  » Persistence-Frameworks » Persist.NET » Persist » Attributes » C# / CSharp Open Source

// Persist library : Persistence layer
// Copyright (C) 2003 Vincent Daron
// 
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

using System;
using System.Runtime.Remoting.Contexts;
using System.Runtime.Remoting.Activation;
using System.Runtime.Remoting.Messaging;

namespace Persist.Attributes{
   /// <summary>
   /// This is the IMessage sink implementation used in the transaction mechanism
   /// </summary>
   public class TransactionMessage : IMessageSink
  {
      private IMessageSink theNextSink;

      /// <summary>
      /// Constructor
      /// </summary>
      /// <param name="nextSink"></param>
    public TransactionMessage(IMessageSink nextSink)
    {
      theNextSink = nextSink;
      }

      #region IMessageSink Members

      /// <summary>
      /// 
      /// </summary>
      /// <param name="msg"></param>
      /// <returns></returns>
      public IMessage SyncProcessMessage(IMessage msg)
      {
         Preprocess(msg);

         IMessage returnMethod = theNextSink.SyncProcessMessage(msg);

         PostProcess(msg, returnMethod);
         
         return returnMethod;
      }

      /// <summary>
      /// 
      /// </summary>
      public IMessageSink NextSink
      {
         get
         {
            return theNextSink;
         }
      }

      /// <summary>
      /// 
      /// </summary>
      /// <param name="msg"></param>
      /// <param name="replySink"></param>
      /// <returns></returns>
      public IMessageCtrl AsyncProcessMessage(IMessage msg, IMessageSink replySink)
      {
         throw new InvalidOperationException() ;
      }

      #endregion

      private void Preprocess(IMessage msg) 
      {
         Persist.PersistenceManagerFactory.Instance.BeginTransaction();
      }
      private void PostProcess(IMessage msg, IMessage msgReturn)
      {
         // We only want to process method return calls
         if (!(msg is IMethodMessage) ||
            !(msgReturn is IMethodReturnMessage)) return;

         if (((IMethodReturnMessage)msgReturn).Exception != null) 
         {
            Persist.PersistenceManagerFactory.Instance.Rollback();
         }
         else
         {
            Persist.PersistenceManagerFactory.Instance.Commit();
         }
      }
   }
}