WorkflowStateRollbackService.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / RunTime / WorkflowStateRollbackService.cs / 1305376 / WorkflowStateRollbackService.cs
                        

                        
                            using System; 
using System.Collections.Generic;
using System.Collections;
using System.Diagnostics;
using System.Reflection; 
using System.Text;
using System.IO; 
using System.IO.Compression; 
using System.Transactions;
using System.Workflow.ComponentModel; 

namespace System.Workflow.Runtime
{
    internal sealed class WorkflowStateRollbackService 
    {
        WorkflowExecutor workflowExecutor; 
 
 		// cache the revert back data
        MemoryStream	clonedInstanceStateStream; 
        Activity workflowDefinition = null;
        bool			isInstanceStateRevertRequested = false;

		// revert back notification info 
		string		activityQualifiedName;
		int			activityContextId; 
 		EventArgs				callbackData; 
		EventHandler	callbackHandler;
 		bool		suspendOnRevert; 
 		string		suspendOnRevertInfo;

        Hashtable completedContextActivities = new Hashtable();
 
        public WorkflowStateRollbackService(WorkflowExecutor workflowExecutor)
        { 
            this.workflowExecutor = workflowExecutor; 
        }
 
        internal bool IsInstanceStateRevertRequested
        {
            get { return this.isInstanceStateRevertRequested; }
        } 

        internal void CheckpointInstanceState() 
        { 
            Debug.Assert(this.workflowExecutor.InstanceId != null, "instance id null at checkpoint time");
 
            // serialize the instance state
            this.clonedInstanceStateStream = new MemoryStream(10240);
            this.workflowExecutor.RootActivity.Save(this.clonedInstanceStateStream);
			this.workflowDefinition = this.workflowExecutor.WorkflowDefinition; 
            this.completedContextActivities = (Hashtable)this.workflowExecutor.CompletedContextActivities.Clone();
            this.clonedInstanceStateStream.Position = 0; 
        } 

 		internal void RequestRevertToCheckpointState(Activity currentActivity, EventHandler callbackHandler, EventArgs callbackData, bool suspendOnRevert, string suspendInfo) 
        {
            if (this.clonedInstanceStateStream == null)
                throw new InvalidOperationException(ExecutionStringManager.InvalidRevertRequest);
 
			// cache the after revert information
			this.activityContextId = ContextActivityUtils.ContextId(ContextActivityUtils.ContextActivity(currentActivity)); 
			this.activityQualifiedName = currentActivity.QualifiedName; 
 			this.callbackData = callbackData;
			this.callbackHandler = callbackHandler; 
 			this.suspendOnRevert = suspendOnRevert;
 			this.suspendOnRevertInfo = suspendInfo;

			// ask scheduler to stop 
            this.isInstanceStateRevertRequested = true;
            this.workflowExecutor.Scheduler.CanRun = false; 
        } 

        internal void DisposeCheckpointState() 
        {
            this.clonedInstanceStateStream = null;
        }
 
        internal void RevertToCheckpointState()
        { 
            Debug.Assert(this.clonedInstanceStateStream != null, "cloned instance-state stream null at restore time"); 

            // deserialize only on first access 
 			Activity clonedRootActivity = null;
            this.clonedInstanceStateStream.Position = 0;
            using (RuntimeEnvironment runtimeEnv = new RuntimeEnvironment(this.workflowExecutor.WorkflowRuntime))
            { 
                clonedRootActivity = Activity.Load(this.clonedInstanceStateStream, (Activity)this.workflowDefinition);
            } 
			Debug.Assert(clonedRootActivity != null); 
            //
            // Set the trackingListenerBroker before initializing the executor so the tracking 
            // runtime gets a reference to the correct object
            clonedRootActivity.SetValue(WorkflowExecutor.TrackingListenerBrokerProperty, workflowExecutor.RootActivity.GetValue(WorkflowExecutor.TrackingListenerBrokerProperty));

            // create the new workflowExecutor 
            WorkflowExecutor newWorkflowExecutor = new WorkflowExecutor(Guid.Empty);    // use a dummy guid while swapping executors
			newWorkflowExecutor.Initialize(clonedRootActivity, this.workflowExecutor.WorkflowRuntime, this.workflowExecutor); 
 
			// enqueue the activity notifier
 			Activity activityContext = newWorkflowExecutor.GetContextActivityForId(this.activityContextId); 
			Activity activity = activityContext.GetActivityByName(this.activityQualifiedName);
 			using (new ServiceEnvironment(activity))
 			{
				using (newWorkflowExecutor.SetCurrentActivity(activity)) 
 				{
                  using (ActivityExecutionContext executionContext = new ActivityExecutionContext(activity)) 
                        executionContext.Invoke(this.callbackHandler, this.callbackData); 
				}
			} 
            //
            // Push the batch item ordering id to the new instance
            newWorkflowExecutor.BatchCollection.WorkItemOrderId = this.workflowExecutor.BatchCollection.WorkItemOrderId;
            // replace pending batch items 
            foreach (KeyValuePair batch in this.workflowExecutor.BatchCollection)
            { 
                batch.Value.SetWorkBatchCollection(newWorkflowExecutor.BatchCollection); 
                Activity oldActivity = batch.Key as Activity;
                // no need to add the transient state batch 
                if (oldActivity != null)
                {
                    Activity newactivity = activityContext.GetActivityByName(oldActivity.QualifiedName);
                    newWorkflowExecutor.BatchCollection.Add(newactivity, batch.Value); 
                }
            } 
            this.workflowExecutor.BatchCollection.Clear(); 

            Debug.Assert(this.completedContextActivities != null); 
            newWorkflowExecutor.CompletedContextActivities = this.completedContextActivities;

			// replace with the WorkflowRuntime
 			Debug.Assert(this.workflowExecutor.IsInstanceValid); 
			this.workflowExecutor.WorkflowRuntime.ReplaceWorkflowExecutor(this.workflowExecutor.InstanceId, this.workflowExecutor, newWorkflowExecutor);
 
 			// now resume or suspend the scheduler as needed 
 			if (!this.suspendOnRevert)
			{ 
 				// get the new one going
				newWorkflowExecutor.Scheduler.Resume();
			}
			else 
 			{
				// this call will be old scheduler's thread 
 				newWorkflowExecutor.SuspendOnIdle(this.suspendOnRevertInfo); 
 			}
            DisposeCheckpointState(); 
        }
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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