transactionmanager.cs

该文件是多层体系结构的数据访问层

#region Copyright & License
//
// $Copyright:$
//
#endregion
#region Document Information
// $Author: Bai.shijun $
// $Rev: $ 
// $Date: 05-10-08 16:13 $
#endregion

using System;
using System.Collections;
using System.EnterpriseServices;

namespace Eai.Data.Transaction
{
#if DEBUG
    public
#else
    internal
#endif
    class TransactionManager
    {
        /// <summary>
        /// transaction stack
        /// </summary>
        private Stack transStack = new Stack();

        private static object syncObj = new object();
        [ThreadStatic]
        private static TransactionManager instance;
        public static TransactionManager Instance
        {
            get
            {
                if (instance == null)
                {
                    lock (syncObj)
                    {
                        if (instance == null) instance = new TransactionManager();
                    }
                }
                return instance;
            }
        }

        public IMixTransaction CurrentTransaction
        {
            get
            {
                if (transStack.Count == 0) return null;
                return transStack.Peek() as IMixTransaction;
            }
        }

        public bool IsInTransaction
        {
            get
            {
                return transStack.Count > 0;
            }
        }

        public void Push(IMixTransaction trans)
        {
            transStack.Push(trans);
        }

        public IMixTransaction Pop()
        {
            return transStack.Pop() as IMixTransaction;
        }

        public static IMixTransaction CreateTransaction(MixTransactionOption mixTransOption, TransactionAttribute transAttr)
        {
            if (mixTransOption == MixTransactionOption.NotSupported) throw new InvalidOperationException("invalid mix transaction option");
            switch (mixTransOption)
            {
                case MixTransactionOption.Native:
                    {
                        return new NhNativeTransaction();
                    }
                case MixTransactionOption.COMPlus:
                    {
                        return new COMPlusTransaction(transAttr);
                    }
                case MixTransactionOption.PromotableTx:
                    {
                        return new PromotableTransaction();
                    }
            }

            throw new InvalidOperationException(String.Format("not supported mix transaction option {0}.", mixTransOption));
        }
    }
}