/// <summary>
/// Constructor for the workflow event processor.
/// </summary>
/// <param name="decisionTask">Decision task passed in from SWF as decision task response.</param>
/// <param name="workflows">IEnumerable set of string for workflow name and Type for workflow class.</param>
/// <param name="request">The request used to retrieve <paramref name="decisionTask"/>, which will be used to retrieve subsequent history event pages.</param>
/// <param name="swfClient">An SWF client.</param>
public WorkflowEventsProcessor(DecisionTask decisionTask, IEnumerable<KeyValuePair<string, Type>> workflows, PollForDecisionTaskRequest request, IAmazonSimpleWorkflow swfClient)
{
// Decision task can't be null.
if (decisionTask == null)
{
throw new ArgumentNullException("decisionTask");
}
if (request == null)
{
throw new ArgumentNullException("request");
}
// Store the decision task and allocate a new decision context and event dictionary which
// we will use as we walk through the chain of events
_decisionTask = decisionTask;
_request = request;
_decisionContext = new WorkflowDecisionContext();
_swfClient = swfClient;
// Set up our events data structure
_events = new WorkflowEventsIterator(ref decisionTask, _request, _swfClient);
_workflows = (Dictionary<string, Type>) workflows;
}
public override List<Decision> Decide(DecisionTask task)
{
var decisions = new List<Decision>();
List<ActivityState> activityStates;
string startingInput;
//ProcessHistory(task, out startingInput, out activityStates);
HistoryIterator iterator = new HistoryIterator(this.Client, task);
foreach (var evnt in iterator)
{
if (evnt.EventType == EventType.WorkflowExecutionStarted)
{
//startingInput = evnt.WorkflowExecutionStartedEventAttributes.Input; //this.Deserialize<WorkFlowExecutionInput>(evnt.WorkflowExecutionStartedEventAttributes.Input);
decisions.Add(new Decision()
{
DecisionType = DecisionType.ScheduleActivityTask,
ScheduleActivityTaskDecisionAttributes = new ScheduleActivityTaskDecisionAttributes()
{
ActivityType = new ActivityType()
{
Name = Constants.ActivityName,
Version = Constants.ActivityVersion
},
ActivityId = Constants.ActivityIdPrefix + DateTime.Now.TimeOfDay,
Input = evnt.WorkflowExecutionStartedEventAttributes.Input
}
});
}
if (evnt.EventType == EventType.ActivityTaskCompleted)
{
//ActivityState state = this.Deserialize<ActivityState>(evnt.ActivityTaskCompletedEventAttributes.Result);
//activityStates.Add(state);
decisions.Add(new Decision()
{
DecisionType = DecisionType.CompleteWorkflowExecution,
CompleteWorkflowExecutionDecisionAttributes = new CompleteWorkflowExecutionDecisionAttributes
{
Result = "We are done"
}
});
}
}
//if (decisions.Count == 0)
//{
// decisions.Add(new Decision()
// {
// DecisionType = DecisionType.CompleteWorkflowExecution,
// CompleteWorkflowExecutionDecisionAttributes = new CompleteWorkflowExecutionDecisionAttributes
// {
// Result = "We are done"
// }
// });
//}
return decisions;
}
void ProcessHistory(DecisionTask task, out string startingInput, out List<ActivityState> activityStates)
{
startingInput = null;
activityStates = new List<ActivityState>();
HistoryIterator iterator = new HistoryIterator(this.Client, task);
foreach (var evnt in iterator)
{
if (evnt.EventType == EventType.WorkflowExecutionStarted)
{
startingInput = evnt.WorkflowExecutionStartedEventAttributes.Input; //this.Deserialize<WorkFlowExecutionInput>(evnt.WorkflowExecutionStartedEventAttributes.Input);
}
if (evnt.EventType == EventType.ActivityTaskCompleted)
{
ActivityState state = this.Deserialize<ActivityState>(evnt.ActivityTaskCompletedEventAttributes.Result);
activityStates.Add(state);
}
}
}
/// <summary>
/// Process the history of events to find all completed activity events and the start event. Using that we can find out
/// what image is being resized and what images still need to be completed.
/// </summary>
/// <param name="task"></param>
/// <param name="startingInput"></param>
/// <param name="activityStates"></param>
void ProcessHistory(DecisionTask task, out Common.WorkflowExecutionStartedInput startingInput, out List<Common.ActivityTaskCompletedResult> activityStates)
{
startingInput = null;
activityStates = new List<Common.ActivityTaskCompletedResult>();
Dictionary<long, Common.ActivityTaskCompletedResult> timerActivityStates = new Dictionary<long, Common.ActivityTaskCompletedResult>();
Shared.HistoryIterator iterator = new Shared.HistoryIterator(this._swfClient, task);
foreach (var evnt in iterator)
{
if (evnt.EventType == EventType.TimerStarted)
{
timerActivityStates.Add(long.Parse(evnt.TimerStartedEventAttributes.TimerId), Common.Utils.DeserializeFromJSON<Common.ActivityTaskCompletedResult>(evnt.TimerStartedEventAttributes.Control));
}
if (evnt.EventType == EventType.TimerFired)
{
activityStates.Add(timerActivityStates[long.Parse(evnt.TimerFiredEventAttributes.TimerId)]);
}
if (evnt.EventType == EventType.WorkflowExecutionStarted)
{
startingInput = Common.Utils.DeserializeFromJSON<Common.WorkflowExecutionStartedInput>(evnt.WorkflowExecutionStartedEventAttributes.Input);
}
if (evnt.EventType == EventType.ActivityTaskCompleted)
{
Common.ActivityTaskCompletedResult state = Common.Utils.DeserializeFromJSON<Common.ActivityTaskCompletedResult>(evnt.ActivityTaskCompletedEventAttributes.Result);
activityStates.Add(state);
}
}
}
/// <summary>
/// Looks at the events on the task to find all the completed activities. Using the list of completed activites it figures out
/// what thumbnail hasn't been created yet and create a decision to start an activity task for that image size.
/// </summary>
/// <param name="task"></param>
/// <returns></returns>
List<Decision> Decide(DecisionTask task)
{
Console.WriteLine("Processing decision task ...");
List<Decision> decisions = new List<Decision>();
List<Common.ActivityTaskCompletedResult> activityStates;
Common.WorkflowExecutionStartedInput startingInput;
ProcessHistory(task, out startingInput, out activityStates);
//get the current request...
Request RequestCurrent = _tracker.GetRequestWithActions(startingInput.RequestId);
//if the request has no current state. initialize the request...
if (RequestCurrent.CurrentStateId == null)
{
_tracker.RequestInitialize(startingInput.RequestId);
//the request should have a new state and actions...
//RequestCurrent = _tracker.GetRequestWithActions(startingInput.RequestId);
//code to tell SWF to fire activity for the new state
//decisions.Add(CreateActivityDecision(startingInput, RequestCurrent.RequestActions.Where(x => (x.ActionTypeId == Common.Constants.AWSActivityTypeId) && x.IsActive && !x.IsComplete).FirstOrDefault().RequestActionId ?? 0));
decisions = DecideHelper(startingInput, activityStates);
}
//compare the "active" SWF request actions that are not "complete" against the history
//this line finds the "intersection" of those two lists
//(filter this list down to only Simple Workflow actions)
List<Common.ActivityTaskCompletedResult> results = activityStates.Join(RequestCurrent.RequestActions.Where(x => (x.ActionTypeId == Common.Constants.AWSActivityTypeId || x.ActionTypeId == 2) && x.IsActive && !x.IsComplete).ToList(), a => a.RequestActionId, b => b.RequestActionId, (c, d) => c).ToList();
//mark any "active" but not "complete" request actions as "complete"
foreach (Common.ActivityTaskCompletedResult result in results)
{
_tracker.RequestActionComplete(result.RequestActionId);
}
//check whether the request's actions have reached a point where a transition can be followed...
Transition Transition = _tracker.GetCompletedTransitionForRequest(startingInput.RequestId);
//if a transition can be followed...
if (Transition != null)
{
//follow the transition
_tracker.RequestFollowTransition(startingInput.RequestId, Transition.TransitionId);
////the request should have a new state and actions now...
//RequestCurrent = _tracker.GetRequestWithActions(startingInput.RequestId);
//IEnumerable<RequestAction> ActiveNotComplete = RequestCurrent.RequestActions.Where(x => (x.ActionTypeId == Common.Constants.AWSActivityTypeId || x.ActionTypeId == 2) && x.IsActive && !x.IsComplete);
////if a request action was found that was "active" but not "complete" it must be run now
//if (ActiveNotComplete.Count() != 0)
//{
// //iterate through the active but not complete actions...
// foreach (RequestAction ra in ActiveNotComplete)
// {
// if (ra.ActionTypeId == 1) //if state completed...
// {
// //code to tell SWF to fire activity for the new state
// decisions.Add(CreateActivityDecision(startingInput, ra.RequestActionId ?? 0));
// }
// if (ra.ActionTypeId == 2) //if timer
// {
// // setup the input for the activity task.
// Common.ActivityTaskCompletedResult state = new Common.ActivityTaskCompletedResult
// {
// StartingInput = startingInput,
// RequestActionId = ra.RequestActionId ?? 0
// };
// Decision decision = new Decision()
// {
// DecisionType = DecisionType.StartTimer,
// StartTimerDecisionAttributes = new StartTimerDecisionAttributes()
// {
// Control = Common.Utils.SerializeToJSON<Common.ActivityTaskCompletedResult>(state),
// StartToFireTimeout = "3",
// TimerId = DateTime.Now.Ticks.ToString()
// }
// };
// decisions.Add(decision);
// }
// }
//}
//else
//{
// Console.WriteLine("Workflow execution complete for " + startingInput.RequestId);
// //code to tell SWF to complete workflow execution
// decisions.Add(CreateCompleteWorkflowExecutionDecision(activityStates));
//}
decisions = DecideHelper(startingInput, activityStates);
}
//// Loop through all the diffrent image sizes the workflow will create and
//// when we find one missing create that activity task for the missing image.
////
//// To keep the sample simple each activity is scheduled one at a time. For better performance
//// the activities could be scheduled in parallel and then use the decider to check if all the activities
//// have been completed.
//for (int size = 256; size >= 16; size /= 2)
//{
// if (activityStates.FirstOrDefault(x => x.ImageSize == size) == null)
// {
// decisions.Add(CreateActivityDecision(startingInput, size));
// break;
// }
//}
//// If there were no decisions that means all the thumbnails have been created so we decided the workflow execution is complete.
//if (decisions.Count == 0)
//{
// Console.WriteLine("Workflow execution complete for " + startingInput.SourceImageKey);
// decisions.Add(CreateCompleteWorkflowExecutionDecision(activityStates));
//}
return decisions;
}
List<Decision> Decide(DecisionTask task)
{
try
{
List<Decision> decisions = new List<Decision>();
var startEvent = task.Events.FirstOrDefault(x => x.EventType == EventType.WorkflowExecutionStarted);
if (startEvent != null)
{
var pollId = startEvent.WorkflowExecutionStartedEventAttributes.Input;
Logger.LogMessage("Processing decision task for poll id: " + pollId);
var poll = PollProcessor.Instance.GetPollAsync(pollId).Result;
if (poll != null)
{
if (poll.State == PollDefinition.POLL_STATE_UNSCHEDULE && DateTime.Now < poll.StartTime)
{
// Add second to compensate for the rounding
var timeDelay = (int)(new TimeSpan(poll.StartTime.Ticks - DateTime.Now.Ticks).TotalSeconds) + 1;
var decision = new Decision
{
DecisionType = DecisionType.StartTimer,
StartTimerDecisionAttributes = new StartTimerDecisionAttributes
{
StartToFireTimeout = timeDelay.ToString(),
TimerId = Guid.NewGuid().ToString()
}
};
decisions.Add(decision);
PollProcessor.Instance.UpdatePollStateAsync(pollId, PollDefinition.POLL_STATE_SCHEDULE).Wait();
Logger.LogMessage("Scheduled timer for {0} seconds till activating poll.", timeDelay);
}
else if (poll.State == PollDefinition.POLL_STATE_SCHEDULE)
{
Decision decision = new Decision()
{
DecisionType = DecisionType.ScheduleActivityTask,
ScheduleActivityTaskDecisionAttributes = new ScheduleActivityTaskDecisionAttributes()
{
ActivityType = new ActivityType()
{
Name = Constants.SWF_ACTIVTY_START_TIMER_EXPIRED,
Version = Constants.SWF_ACTIVTY_START_TIMER_EXPIRED_VERSION
},
TaskList = new TaskList
{
Name = Constants.SWF_ACTIVTY_START_TIMER_EXPIRED_TASKLIST
},
HeartbeatTimeout = Constants.SWF_TIMEOUT,
ScheduleToCloseTimeout = Constants.SWF_TIMEOUT,
ScheduleToStartTimeout = Constants.SWF_TIMEOUT,
StartToCloseTimeout = Constants.SWF_TIMEOUT,
ActivityId = string.Format("{0}:{1}", Constants.SWF_ACTIVTY_START_TIMER_EXPIRED, DateTime.Now.Ticks),
Input = poll.Id
}
};
decisions.Add(decision);
Logger.LogMessage("Start timer complete now deciding to run the {0} activity to activate poll.", Constants.SWF_ACTIVTY_START_TIMER_EXPIRED);
}
else if (poll.State == PollDefinition.POLL_STATE_ACTIVE && DateTime.Now < poll.EndTime)
{
// Add second to compensate for the rounding
var timeDelay = (int)(new TimeSpan(poll.EndTime.Ticks - DateTime.Now.Ticks).TotalSeconds) + 1;
var decision = new Decision
{
DecisionType = DecisionType.StartTimer,
StartTimerDecisionAttributes = new StartTimerDecisionAttributes
{
StartToFireTimeout = timeDelay.ToString(),
TimerId = Guid.NewGuid().ToString()
}
};
decisions.Add(decision);
Logger.LogMessage("Scheduled timer for {0} seconds till poll expires.", timeDelay);
}
else if (poll.State == PollDefinition.POLL_STATE_ACTIVE)
{
Decision decision = new Decision()
{
DecisionType = DecisionType.ScheduleActivityTask,
ScheduleActivityTaskDecisionAttributes = new ScheduleActivityTaskDecisionAttributes()
{
ActivityType = new ActivityType()
{
Name = Constants.SWF_ACTIVTY_END_TIMER_EXPIRED,
Version = Constants.SWF_ACTIVTY_END_TIMER_EXPIRED_VERSION
},
TaskList = new TaskList
{
Name = Constants.SWF_ACTIVTY_END_TIMER_EXPIRED_TASKLIST
},
HeartbeatTimeout = Constants.SWF_TIMEOUT,
ScheduleToCloseTimeout = Constants.SWF_TIMEOUT,
ScheduleToStartTimeout = Constants.SWF_TIMEOUT,
StartToCloseTimeout = Constants.SWF_TIMEOUT,
ActivityId = string.Format("{0}:{1}", Constants.SWF_ACTIVTY_END_TIMER_EXPIRED, DateTime.Now.Ticks),
Input = poll.Id
}
};
decisions.Add(decision);
Logger.LogMessage("End timer complete now deciding to run the {0} activity to expire poll.", Constants.SWF_ACTIVTY_END_TIMER_EXPIRED);
}
}
}
if (decisions.Count == 0)
{
Decision decision = new Decision()
{
DecisionType = DecisionType.CompleteWorkflowExecution,
CompleteWorkflowExecutionDecisionAttributes = new CompleteWorkflowExecutionDecisionAttributes
{
}
};
decisions.Add(decision);
Logger.LogMessage("Workflow execution complete for {0}", task.WorkflowExecution.WorkflowId);
}
return decisions;
}
catch(Exception e)
{
string message = string.Format("Error processing work flow execution {0} and is being aborted: {1}\n", task.WorkflowExecution.WorkflowId, e.Message, e.StackTrace);
Logger.LogMessage(message);
Decision decision = new Decision()
{
DecisionType = DecisionType.CompleteWorkflowExecution,
CompleteWorkflowExecutionDecisionAttributes = new CompleteWorkflowExecutionDecisionAttributes
{
Result = message
}
};
return new List<Decision> { decision };
}
}
