//------------------------------------------------------------------------------
// <copyright file="SqlTransaction.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// <owner current="true" primary="true">[....]</owner>
// <owner current="true" primary="false">[....]</owner>
//------------------------------------------------------------------------------

namespace System.Data.SqlClient {
    using System.Data;
    using System.Data.Common;
    using System.Data.ProviderBase;
    using System.Data.Sql;
    using System.Data.SqlTypes;
    using System.Diagnostics;
    using System.Runtime.CompilerServices;
    using System.Runtime.ConstrainedExecution;
    using System.Threading;

    public sealed class SqlTransaction : DbTransaction {
        private  static   int            _objectTypeCount; // Bid counter
        internal readonly int            _objectID = System.Threading.Interlocked.Increment(ref _objectTypeCount);
        internal readonly IsolationLevel _isolationLevel = IsolationLevel.ReadCommitted;

        private  SqlInternalTransaction  _internalTransaction;
        private  SqlConnection           _connection;

        private  bool                    _isFromAPI;

        internal SqlTransaction(SqlInternalConnection internalConnection, SqlConnection con, 
                                IsolationLevel iso, SqlInternalTransaction internalTransaction) {
            SqlConnection.VerifyExecutePermission();

            _isolationLevel = iso;
            _connection = con;

            if (internalTransaction == null) {
                _internalTransaction = new SqlInternalTransaction(internalConnection, TransactionType.LocalFromAPI, this);
            }
            else {
                Debug.Assert(internalConnection.CurrentTransaction == internalTransaction, "Unexpected Parser.CurrentTransaction state!");
                _internalTransaction = internalTransaction;
                _internalTransaction.InitParent(this);
            }
        }

        ////////////////////////////////////////////////////////////////////////////////////////
        // PROPERTIES
        ////////////////////////////////////////////////////////////////////////////////////////

        new public SqlConnection Connection { // MDAC 66655
            get {
                if (IsZombied) {
                    return null;
                }
                else {
                    return _connection;
                }
            }
        }

        override protected DbConnection DbConnection {
            get {
                return Connection;
            }
        }

        internal SqlInternalTransaction InternalTransaction {
            get {
                return _internalTransaction;
            }
        }

        override public IsolationLevel IsolationLevel {
            get {
                ZombieCheck();
                return _isolationLevel;
            }
        }

        private bool IsYukonPartialZombie {
            get {
                return (null != _internalTransaction && _internalTransaction.IsCompleted);
            }
        }

        internal bool IsZombied {
            get {
                return (null == _internalTransaction || _internalTransaction.IsCompleted);
            }
        }

        internal int ObjectID {
            get {
                return _objectID;
            }
        }

        internal SqlStatistics Statistics {
            get {
                if (null != _connection) {
                    if (_connection.StatisticsEnabled) {
                        return _connection.Statistics;
                    }
                }
                return null;
            }
        }

        ////////////////////////////////////////////////////////////////////////////////////////
        // PUBLIC METHODS
        ////////////////////////////////////////////////////////////////////////////////////////

        override public void Commit() {
            SqlConnection.ExecutePermission.Demand(); // MDAC 81476

            ZombieCheck();
            
            SqlStatistics statistics = null;
            IntPtr hscp;
            
            Bid.ScopeEnter(out hscp, "<sc.SqlTransaction.Commit|API> %d#", ObjectID);
            Bid.CorrelationTrace("<sc.SqlTransaction.Commit|API|Correlation> ObjectID%d#, ActivityID %ls", ObjectID);

            TdsParser bestEffortCleanupTarget = null;
            RuntimeHelpers.PrepareConstrainedRegions();
            try {
#if DEBUG
                TdsParser.ReliabilitySection tdsReliabilitySection = new TdsParser.ReliabilitySection();

                RuntimeHelpers.PrepareConstrainedRegions();
                try {
                    tdsReliabilitySection.Start();
#else
                {
#endif //DEBUG
                    bestEffortCleanupTarget = SqlInternalConnection.GetBestEffortCleanupTarget(_connection);
                    statistics = SqlStatistics.StartTimer(Statistics);

                    _isFromAPI = true;

                    _internalTransaction.Commit();
                }
#if DEBUG
                finally {
                    tdsReliabilitySection.Stop();
                }
#endif //DEBUG
            }
            catch (System.OutOfMemoryException e) {
                _connection.Abort(e);
                throw;
            }
            catch (System.StackOverflowException e) {
                _connection.Abort(e);
                throw;
            }
            catch (System.Threading.ThreadAbortException e)  {
                _connection.Abort(e);
                SqlInternalConnection.BestEffortCleanup(bestEffortCleanupTarget);
                throw;
            }
            finally {
                _isFromAPI = false;
                
                SqlStatistics.StopTimer(statistics);
                Bid.ScopeLeave(ref hscp);
            }
        }

        protected override void Dispose(bool disposing) {
            if (disposing) {
                TdsParser bestEffortCleanupTarget = null;
                RuntimeHelpers.PrepareConstrainedRegions();
                try {
#if DEBUG
                    TdsParser.ReliabilitySection tdsReliabilitySection = new TdsParser.ReliabilitySection();

                    RuntimeHelpers.PrepareConstrainedRegions();
                    try {
                        tdsReliabilitySection.Start();
#else
                    {
#endif //DEBUG
                        bestEffortCleanupTarget = SqlInternalConnection.GetBestEffortCleanupTarget(_connection);
                        if (!IsZombied && !IsYukonPartialZombie) {
                            _internalTransaction.Dispose();
                        }
                    }
#if DEBUG
                    finally {
                        tdsReliabilitySection.Stop();
                    }
#endif //DEBUG
                }
                catch (System.OutOfMemoryException e) {
                    _connection.Abort(e);
                    throw;
                }
                catch (System.StackOverflowException e) {
                    _connection.Abort(e);
                    throw;
                }
                catch (System.Threading.ThreadAbortException e)  {
                    _connection.Abort(e);
                    SqlInternalConnection.BestEffortCleanup(bestEffortCleanupTarget);
                    throw;
                }
            }
            base.Dispose(disposing);
        }

        override public void Rollback() {
            if (IsYukonPartialZombie) {
                // Put something in the trace in case a customer has an issue
                if (Bid.AdvancedOn) {
                    Bid.Trace("<sc.SqlTransaction.Rollback|ADV> %d# partial zombie no rollback required\n", ObjectID);
                }
                _internalTransaction = null; // yukon zombification
            }
            else {
                ZombieCheck();

                SqlStatistics statistics = null;
                IntPtr hscp;
                Bid.ScopeEnter(out hscp, "<sc.SqlTransaction.Rollback|API> %d#", ObjectID);
                Bid.CorrelationTrace("<sc.SqlTransaction.Rollback|API|Correlation> ObjectID%d#, ActivityID %ls\n", ObjectID);

                TdsParser bestEffortCleanupTarget = null;
                RuntimeHelpers.PrepareConstrainedRegions();
                try {
#if DEBUG
                    TdsParser.ReliabilitySection tdsReliabilitySection = new TdsParser.ReliabilitySection();

                    RuntimeHelpers.PrepareConstrainedRegions();
                    try {
                        tdsReliabilitySection.Start();
#else
                    {
#endif //DEBUG
                        bestEffortCleanupTarget = SqlInternalConnection.GetBestEffortCleanupTarget(_connection);
                        statistics = SqlStatistics.StartTimer(Statistics);

                        _isFromAPI = true;
                        
                        _internalTransaction.Rollback();
                    }
#if DEBUG
                    finally {
                        tdsReliabilitySection.Stop();
                    }
#endif //DEBUG
                }
                catch (System.OutOfMemoryException e) {
                    _connection.Abort(e);
                    throw;
                }
                catch (System.StackOverflowException e) {
                    _connection.Abort(e);
                    throw;
                }
                catch (System.Threading.ThreadAbortException e)  {
                    _connection.Abort(e);
                    SqlInternalConnection.BestEffortCleanup(bestEffortCleanupTarget);
                    throw;
                }
                finally {
                    _isFromAPI = false;
                    
                    SqlStatistics.StopTimer(statistics);
                    Bid.ScopeLeave(ref hscp);
                }
            }
        }

        public void Rollback(string transactionName) {
            SqlConnection.ExecutePermission.Demand(); // MDAC 81476

            ZombieCheck();

            SqlStatistics statistics = null;
            IntPtr hscp;
            Bid.ScopeEnter(out hscp, "<sc.SqlTransaction.Rollback|API> %d# transactionName='%ls'", ObjectID, transactionName);

            TdsParser bestEffortCleanupTarget = null;
            RuntimeHelpers.PrepareConstrainedRegions();
            try {
#if DEBUG
                TdsParser.ReliabilitySection tdsReliabilitySection = new TdsParser.ReliabilitySection();

                RuntimeHelpers.PrepareConstrainedRegions();
                try {
                    tdsReliabilitySection.Start();
#else
                {
#endif //DEBUG
                    bestEffortCleanupTarget = SqlInternalConnection.GetBestEffortCleanupTarget(_connection);
                    statistics = SqlStatistics.StartTimer(Statistics);

                    _isFromAPI = true;
                    
                    _internalTransaction.Rollback(transactionName);
                }
#if DEBUG
                finally {
                    tdsReliabilitySection.Stop();
                }
#endif //DEBUG
            }
            catch (System.OutOfMemoryException e) {
                _connection.Abort(e);
                throw;
            }
            catch (System.StackOverflowException e) {
                _connection.Abort(e);
                throw;
            }
            catch (System.Threading.ThreadAbortException e)  {
                _connection.Abort(e);
                SqlInternalConnection.BestEffortCleanup(bestEffortCleanupTarget);
                throw;
            }
            finally {
                _isFromAPI = false;
                
                SqlStatistics.StopTimer(statistics);
                Bid.ScopeLeave(ref hscp);
            }
        }

        public void Save(string savePointName) {
            SqlConnection.ExecutePermission.Demand(); // MDAC 81476

            ZombieCheck();
            
            SqlStatistics statistics = null;
            IntPtr hscp;
            Bid.ScopeEnter(out hscp, "<sc.SqlTransaction.Save|API> %d# savePointName='%ls'", ObjectID, savePointName);

            TdsParser bestEffortCleanupTarget = null;
            RuntimeHelpers.PrepareConstrainedRegions();
            try {
#if DEBUG
                TdsParser.ReliabilitySection tdsReliabilitySection = new TdsParser.ReliabilitySection();

                RuntimeHelpers.PrepareConstrainedRegions();
                try {
                    tdsReliabilitySection.Start();
#else
                {
#endif //DEBUG
                    bestEffortCleanupTarget = SqlInternalConnection.GetBestEffortCleanupTarget(_connection);
                    statistics = SqlStatistics.StartTimer(Statistics);
                    
                    _internalTransaction.Save(savePointName);
                }
#if DEBUG
                finally {
                    tdsReliabilitySection.Stop();
                }
#endif //DEBUG
            }
            catch (System.OutOfMemoryException e) {
                _connection.Abort(e);
                throw;
            }
            catch (System.StackOverflowException e) {
                _connection.Abort(e);
                throw;
            }
            catch (System.Threading.ThreadAbortException e)  {
                _connection.Abort(e);
                SqlInternalConnection.BestEffortCleanup(bestEffortCleanupTarget);
                throw;
            }
            finally {
                SqlStatistics.StopTimer(statistics);
                Bid.ScopeLeave(ref hscp);
            }
        }

        ////////////////////////////////////////////////////////////////////////////////////////
        // INTERNAL METHODS
        ////////////////////////////////////////////////////////////////////////////////////////

        internal void Zombie() {
            // SQLBUDT #402544 For Yukon, we have to defer "zombification" until
            //                 we get past the users' next rollback, else we'll
            //                 throw an exception there that is a breaking change.
            //                 Of course, if the connection is aready closed, 
            //                 then we're free to zombify...
            SqlInternalConnection internalConnection = (_connection.InnerConnection as SqlInternalConnection);
            if (null != internalConnection && internalConnection.IsYukonOrNewer && !_isFromAPI) {
                if (Bid.AdvancedOn) {
                    Bid.Trace("<sc.SqlTransaction.Zombie|ADV> %d# yukon deferred zombie\n", ObjectID);
                }
            }
            else {
                _internalTransaction = null; // pre-yukon zombification
            }
            
        }

        ////////////////////////////////////////////////////////////////////////////////////////
        // PRIVATE METHODS
        ////////////////////////////////////////////////////////////////////////////////////////

        private void ZombieCheck() {
            // If this transaction has been completed, throw exception since it is unusable.
            if (IsZombied) {

                if (IsYukonPartialZombie) {
                    _internalTransaction = null; // yukon zombification
                }
                
                throw ADP.TransactionZombied(this);
            }
        }
    }
}