Add DecisionTaskStartedEventID to workflowInfo (#1127)

internal/internal_event_handlers.go

@@ -818,6 +818,8 @@ func (weh *workflowExecutionEventHandlerImpl) ProcessEvent(
 		// Set replay clock.
 		weh.SetCurrentReplayTime(time.Unix(0, event.GetTimestamp()))
 		weh.workflowDefinition.OnDecisionTaskStarted()
+		// Set replay decisionStarted eventID
+		weh.workflowInfo.DecisionStartedEventID = event.GetEventId()
 
 	case m.EventTypeDecisionTaskTimedOut:
 		// No Operation

internal/workflow.go

@@ -793,18 +793,26 @@ type WorkflowInfo struct {
 	ParentWorkflowExecution             *WorkflowExecution
 	Memo                                *s.Memo             // Value can be decoded using data converter (DefaultDataConverter, or custom one if set).
 	SearchAttributes                    *s.SearchAttributes // Value can be decoded using DefaultDataConverter.
-	BinaryChecksum                      *string
+	BinaryChecksum                      *string             // The identifier(generated by md5sum by default) of worker code that is making the current decision(can be used for auto-reset feature)
+	DecisionStartedEventID              int64              // the eventID of DecisionStarted that is making the current decision(can be used for reset API)
 	RetryPolicy                         *s.RetryPolicy
 }
 
 // GetBinaryChecksum returns the binary checksum(identifier) of this worker
+// It is the identifier(generated by md5sum by default) of worker code that is making the current decision(can be used for auto-reset feature)
+// In replay mode, it's from DecisionTaskCompleted event. In non-replay mode, it's from the currently executing worker.
 func (wInfo *WorkflowInfo) GetBinaryChecksum() string {
 	if wInfo.BinaryChecksum == nil {
 		return getBinaryChecksum()
 	}
 	return *wInfo.BinaryChecksum
 }
 
+// GetDecisionCompletedEventID returns the eventID of DecisionStartedEvent that is making the current decision(can be used for reset API: decisionFinishEventID = DecisionStartedEventID + 1)
+func (wInfo *WorkflowInfo) GetDecisionStartedEventID() int64  {
+	return wInfo.DecisionStartedEventID
+}
+
 // GetWorkflowInfo extracts info of a current workflow from a context.
 func GetWorkflowInfo(ctx Context) *WorkflowInfo {
 	i := getWorkflowInterceptor(ctx)