TransactionFilter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / Common / AuthoringOM / Filters / TransactionFilter.cs / 1305376 / TransactionFilter.cs
                        
                        
                            // **************************************************************************** 
// Copyright (C) 2000-2001 Microsoft Corporation.  All rights reserved.
//
// CONTENTS
//     Scope like TransactionModel Interceptor/Filter Executor 
//
// DESCRIPTION 
// 
// ***************************************************************************
namespace System.Workflow.ComponentModel 
{
    using System;
    using System.Collections;
    using System.Diagnostics; 
    using System.ComponentModel;
    using System.Workflow.ComponentModel; 
    using System.Workflow.ComponentModel.Design; 
    using System.Workflow.Runtime;
    using System.Collections.Generic; 
    using System.Runtime.Serialization;
    using System.Security.Permissions;
    using System.Reflection;
 
    // TransactedFilter
    // 
    // This interceptor executor deals with the transaction aspects (as 
    // defined by the current scope activity) of an activity.
    // 
    // The activity must be attributed with SupportsTransactionAttribute.
    // The activity executor need not worry about any of the scope like
    // transaction behavior management.
    internal sealed class TransactedContextFilter : ActivityExecutionFilter, IActivityEventListener, IActivityEventListener 
    {
        #region ActivityExecutor Members 
 
        public override ActivityExecutionStatus Execute(Activity activity, ActivityExecutionContext executionContext)
        { 
            if (executionContext == null)
                throw new ArgumentNullException("executionContext");
            if (activity == null)
                throw new ArgumentNullException("activity"); 
            if (!activity.SupportsTransaction)
                throw new ArgumentException("activity"); 
 
            // subscribe to the main activity
            activity.RegisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this); 
            activity.HoldLockOnStatusChange(this);
            return TransactedContextFilter.ExecuteActivity(activity, executionContext, false);
        }
        #endregion 

        #region IActivityEventListener Members 
 
        void IActivityEventListener.OnEvent(object sender, ActivityExecutionStatusChangedEventArgs e)
        { 
            ActivityExecutionContext context = sender as ActivityExecutionContext;
            if (context == null)
                throw new ArgumentException("sender");
 
            if (context.Activity.HasPrimaryClosed && context.Activity.LockCountOnStatusChange == 1)
            { 
                // get exception 
                Exception exception = (Exception)context.Activity.GetValue(ActivityExecutionContext.CurrentExceptionProperty);
                if (exception != null) 
                {
                    WorkflowTransactionOptions transactionOptions = TransactedContextFilter.GetTransactionOptions(context.Activity);
                    if (transactionOptions != null)
                    { 
                        // request revert to checkpoint state
                        context.RequestRevertToCheckpointState(this.OnRevertInstanceState, new StateRevertedEventArgs(exception), false, null); 
                    } 
                    else
                    { 
                        // release locks
                        context.ReleaseLocks(false);
                        context.Activity.UnregisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this);
                        context.Activity.ReleaseLockOnStatusChange(this); 
                    }
                } 
                else 
                {
                    try 
                    {
                        // 1st param is for transactional, means if the release lock on status change will try to persist the workflow instace
                        // if that fails, then locks will be reacquired, otherwise they will be released.
                        context.ReleaseLocks(true); 
                        context.Activity.UnregisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this);
                        context.Activity.ReleaseLockOnStatusChange(this); 
                        context.DisposeCheckpointState(); 
                    }
                    catch 
                    {
                        // re-subscribe
                        context.Activity.RegisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this);
                        throw; 
                    }
                } 
            } 
        }
        #endregion 

        #region OnRevertInstanceData Member

        private void OnRevertInstanceState(object sender, EventArgs e) 
        {
            if (sender == null) 
                throw new ArgumentNullException("sender"); 
            if (e == null)
                throw new ArgumentNullException("e"); 

            ActivityExecutionContext context = sender as ActivityExecutionContext;
            StateRevertedEventArgs args = e as StateRevertedEventArgs;
 
            // stash exception
            context.Activity.SetValueCommon(ActivityExecutionContext.CurrentExceptionProperty, args.Exception, ActivityExecutionContext.CurrentExceptionProperty.DefaultMetadata, false); 
 
            // cancel the activity
            context.ReleaseLocks(false); 
            context.Activity.UnregisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this);
            context.Activity.ReleaseLockOnStatusChange(this);
        }
 
        #endregion
 
        #region IActivityEventListener Members 

        void IActivityEventListener.OnEvent(object sender, EventArgs e) 
        {
            ActivityExecutionContext context = (ActivityExecutionContext)sender;

            // only if activity is still executing, then run it 
 			if (context.Activity.ExecutionStatus == ActivityExecutionStatus.Executing)
            { 
				ActivityExecutionStatus newStatus = TransactedContextFilter.ExecuteActivity(context.Activity, context, true); 
				if (newStatus == ActivityExecutionStatus.Closed)
                    context.CloseActivity(); 
            }
        }
        #endregion
 
        #region Helper Methods
        private static ActivityExecutionStatus ExecuteActivity(Activity activity, ActivityExecutionContext context, bool locksAcquired) 
        { 
            // acquire needed synchronization
            TransactedContextFilter executor = (TransactedContextFilter)ActivityExecutors.GetActivityExecutorFromType(typeof(TransactedContextFilter)); 
            if (!locksAcquired && !context.AcquireLocks(executor))
				return activity.ExecutionStatus;

            // checkpoint for instance state 
            //
            WorkflowTransactionOptions transaction = TransactedContextFilter.GetTransactionOptions(activity); 
            if (transaction != null) 
                context.CheckpointInstanceState();
 
            // delegate to the next executor for the activity
            return executor.NextActivityExecutorInChain(activity).Execute(activity, context);
        }
 
        internal static WorkflowTransactionOptions GetTransactionOptions(Activity activity)
        { 
            return activity.GetValue(activity is TransactionScopeActivity ? TransactionScopeActivity.TransactionOptionsProperty : CompensatableTransactionScopeActivity.TransactionOptionsProperty) as WorkflowTransactionOptions; 
        }
        #endregion 
    }

    #region StateRevertedEventArgs Class
    [Serializable] 
    internal class StateRevertedEventArgs : EventArgs
    { 
        public Exception Exception; 
        public StateRevertedEventArgs(Exception exception)
        { 
            this.Exception = exception;
        }
    }
    #endregion 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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TransactionFilter.cs source code in C# .NET

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