Function

Description

ClientValidated()

A boolean function that returns TRUE only when the Client that is submitting a TransferSubscriptions request is operating on behalf of the same user and supports the same Profiles as the Client of the previous Session.

CreateNotificationMsg()

Increment the SeqNum and create a NotificationMessage from the MonitoredItems assigned to the Subscription.

Save the newly-created NotificationMessage in the retransmission queue.

If all available Notifications can be sent in the Publish response, the MoreNotifications state Variable is set to FALSE. Otherwise, it is set to TRUE.

CreateSubscription()

Attempt to create the Subscription.

DeleteAckedNotificationMsgs()

Delete the NotificationMessages from the retransmission queue that were acknowledged by the request.

DeleteClientPublReqQueue()

Clear the Publish request queue for the Client that is sending the DeleteSubscriptions request, if there are no more Subscriptions assigned to that Client.

DeleteMonitoredItems()

Delete all MonitoredItems assigned to the Subscription.

DequeuePublishReq()

De-queue a publishing request in first-in first-out order.

Validate if the publish request is still valid by checking the timeoutHint in the RequestHeader.

If the request timed out, send a Bad_Timeout service result for the request and de-queue another publish request.

ResetLifetimeCounter()

EnqueuePublishingReq()

Enqueue the publishing request.

InitializeSubscription()

ResetLifetimeCounter()

MoreNotifications = FALSE

PublishRateChange = FALSE

PublishingEnabled = value of publishingEnabled parameter in the CreateSubscription request

PublishingReqQueued = FALSE

SeqNum = 0

SetSession()

StartPublishingTimer()

IssueStatusChangeNotification()

Issue a StatusChangeNotification notificationMessage with a status code for the status change of the Subscription. The StatusChangeNotification notificationMessage type is defined in 7.25.4. Bad_Timeout status code is used if the lifetime expires and Good_SubscriptionTransferred is used if the Subscriptions was transferred to another Session.

ResetKeepAliveCounter()

Reset the keep-alive counter to the maximum keep-alive count of the Subscription. The maximum keep-alive count is set by the Client when the Subscription is created and may be modified using the ModifySubscription Service.

ResetLifetimeCounter()

Reset the LifetimeCounter Variable to the value specified for the lifetime of a Subscription in the CreateSubscription Service (5.14.2).

ReturnKeepAlive()

Create an empty NotificationMessage with the current SeqNum value.

ReturnResponse()

ReturnNegativeResponse()

Return a Service response indicating the appropriate Service level error. No parameters are returned other than the responseHeader that contains the Service level StatusCode.

ReturnNotifications()

CreateNotificationMsg()

ReturnResponse()

If (MoreNotifications == TRUE) && (PublishingReqQueued == TRUE)

{

DequeuePublishReq()

Loop through this function again

}

ReturnResponse()

Return the appropriate response, setting the appropriate parameter values and StatusCodes defined for the Service.

SessionChanged()

A boolean function that returns TRUE only when the Session used to send a TransferSubscriptions request is different from the Client Session currently associated with the Subscription.

SetPublishingEnabled ()

Set the PublishingEnabled state Variable to the value of the publishingEnabled parameter received in the request.

SetSession

Set the Session information for the Subscription to match the Session on which the TransferSubscriptions request was issued.

StartPublishingTimer()

Start or restart the publishing timer and decrement the LifetimeCounter Variable.

UpdateSubscriptionParams()

Negotiate and update the Subscription parameters. If the new keep-alive interval is less than the current value of the keep-alive counter, perform ResetKeepAliveCounter() and ResetLifetimeCounter().