The Clientuses the “DomainDownload” Program to manage and monitor the download of a domain at the Server.
The basic state model for the DomainDownload Programis presented in Figure A.2. The Programhas three primary states, Ready, Running, and Halted which are aligned with the standard states of a ProgramStateMachineType. Additionally, the DomainDownloadTypeextends the ProgramStateMachineTypeby defining subordinate State Machinesfor the Program’sRunning and Halted states. The subordinate states describe the download operations in greater detail and allow the Clientto monitor the activity of the download at a finer resolution.
An instance (Program Invocation) of a DomainDownload Programis created by the Clienteach time a download is to be performed. The instance exists until explicitly removed by the Client. The initial state of the Programis Ready and the terminal state is Halted. The DomainDownload can be temporarily suspended and then resumed or aborted. Once halted, the program may not be restarted.
Figure A.2– DomainDownload state diagram
The sequence of state transitions is illustrated in Figure A.2. Once the download is started, The Programprogresses to the Opening state. After the source of the data is opened, a sequence of transfers occurs in the Sending state. When the transfer completes the Objectsare closed in the Closing state. If the transfer is terminated before all of the data is downloaded or an error is encountered then the download is halted and the Programtransitions to the Aborted state; otherwise the Programhalts in the Completed state. The states are presented in Table A.1along with the state transitions.
The valid state transitions specified for the DomainDownload Program are specified inTable A.1.Each of the transitions defines a start state and end state for the transition and is identified by a unique number. Five of the transitions are from the base ProgramStateMachineTypeand retain the transition identifier numbers specified for Programs. The additional transitions relate the base Program states with the subordinate states defined for the DomainDownload. These states have been assigned unique transition identifier numbers that distinguish them from the base Programtransition identifiers. In cases where transitions occur between substates and the Program’sbase states, two transitions are specified. One transition identifies the base state change and a second sub-state change. For example, Ready to Running and to Opening occurs at the same time.
The table also specifies the defined states, causes for the transitions, and the effects of each transition. Program Control Methodsare used by the Clientto “run” the DomainDownload. The Methodscause or trigger the specified transitions. The transition effects are the specified EventTypeswhich notify the Clientof Programactivity.
Table A.1– DomainDownload states
|
No. |
Transition name |
Cause |
From State |
To State |
Effect |
|
2 |
ReadyToRunning |
Start Method |
Ready |
Running |
Report Transition 2 Event/Result |
|
3 |
RunningToHalted |
Halt Method/Error or Internal. |
Running |
Halted |
Report Transition 3 Event/Result |
|
5 |
RunningToSuspended |
Suspend Method |
Running |
Suspended |
Report Transition 5 Event/Result |
|
6 |
SuspendedToRunning |
Resume Method |
Suspended |
Running |
Report Transition 6 Event/Result |
|
7 |
SuspendedToHalted |
Halt Method |
Suspended |
Halted |
Report Transition 7 Event/Result |
|
10 |
OpeningToSending |
Internal |
Opening |
Sending |
Report Transition 10 Event/Result |
|
11 |
SendingToSending |
Internal |
Sending |
Sending |
Report Transition 11 Event/Result |
|
12 |
SendingToClosing |
Internal |
Sending |
Closing |
Report Transition 12 Event/Result |
|
13 |
SendingToAborted |
Halt Method/Error |
Opening |
Aborted |
Report Transition 13 Event/Result |
|
14 |
ClosingToCompleted |
Internal |
Closing |
Completed |
Report Transition 14 Event/Result |
|
15 |
SendingToSuspended |
Suspend Method |
Sending |
Suspended |
Report Transition 16 Event/Result |
|
16 |
SuspendedToSending |
Resume Method |
Suspended |
Sending |
Report Transition 17 Event/Result |
|
18 |
SuspendedToAborted |
Halt Method |
Suspended |
Aborted |
Report Transition 18 Event/Result |
|
17 |
ToOpening |
Internal |
Ready |
Opening |
Report Transition 19 Event/Result |
Four standard Program Methodsare specified for running the DomainDownload Program, Start, Suspend, Resume, and Halt. No additional Methods are specified. Thebase behaviours of these Methods are defined by theProgramStateMachineType. The Start Methodinitiates the download activity and passes the source and destination locations for the transfer. The Suspend Methodis used to pause the activity temporarily. The Resume Methodreinitiates the download, when paused. The Halt Methodaborts the download. Each of the Methods causes a Programstate transition and a sub state transition. The specific state transition depends on the current state at the time the Methodis called. If a Method Callis made when the DomainDownload is in a state for which that Method has no associated transition, the Methodreturns an error status indicating invalid state for the Method.
The Start Methodspecifies three input arguments to be passed when it is called: Domain Name, DomainSource, and DomainDestination. The other Methodsrequire no input arguments. No output arguments are specified for the DomainDownload Methods. The resultant error status for the Programis part of theCall Service.
A ProgramTransitionEventTypeis specified for each of the DomainDownload Programtransitions. The EventTypestrigger a specific Eventnotification to the Clientwhen the associated state transition occurs in the running ProgramInstance. The Eventnotification identifies the transition. The SendingToSending state transition also includes intermediate result data.
The SendingToSending Programtransition Eventrelays intermediate result data to the Clientalong with the notification. Each time the transition occurs, data items describing the amount and percentage of data transferred are sent to the Client.
The DomainDownload Programretains final result data following a completed or aborted download. The data includes the total transaction time and the size of the domain. In the event of an aborted download, the reason for the termination is retained.
The UA model for the DomainDownload Programis presented in the following tables and figures. Collectively they define the components that constitute this Program. For clarity, the figures present a progression of portions of the model that complement the contents of the tables and illustrate the Program’scomposition.
The type definition for the DomainDownload Programprecisely represents the behaviour of the Programin terms of UA components. These components can be browsed by a Clientto interpret or validate the actions of the Program.
The DomainDownloadType is a subtype derived from the ProgramStateMachineType. It specifies the use or non-use of optional ProgramStateMachineTypecomponents, valid extensions such as subordinate State Machines, and constrained attribute values applied to instances of DomainDownload Programs.
Table A.2specifies the optional and extended components defined by the DomainDownload Type. Note the references to two sub State Machine Types, TransferStateMachineand FinishStateMachine. The DomainDownloadType omits references to the Reset Program Control Methodand its associated state transition (HaltedToReady), which it does not support.
|
Attribute |
Value |
||||
|
|
Includes all non-optional attributes specified for the ProgramStateMachineType |
||||
|
BrowseName |
DomainDownloadType |
||||
|
IsAbstract |
False |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
|
HasComponent |
Object |
TransferStateMachine |
|
StateMachineType |
Mandatory |
|
HasComponent |
Object |
FinishStateMachine |
|
StateMachineType |
Mandatory |
|
HasComponent |
Variable |
ProgramDiagnostic |
|
ProgramDiagnostic2Type |
Mandatory |
|
HasComponent |
Object |
ReadyToRunning |
|
TransitionType |
-- |
|
HasComponent |
Object |
RunningToHalted |
|
TransitionType |
-- |
|
HasComponent |
Object |
RunningToSuspended |
|
TransitionType |
-- |
|
HasComponent |
Object |
SuspendedToRunning |
|
TransitionType |
-- |
|
HasComponent |
Object |
SuspendedToHalted |
|
TransitionType |
-- |
|
HasComponent |
Method |
Start |
|
|
Mandatory |
|
HasComponent |
Method |
Suspend |
|
|
Mandatory |
|
HasComponent |
Method |
Halt |
|
|
Mandatory |
|
HasComponent |
Method |
Resume |
|
|
Mandatory |
|
HasComponent |
Object |
FinalResultData |
|
BaseObjectType |
Mandatory |
Table A.3specifies the Transfer State Machine typethat is a sub State Machineof the DomainDownload Program Type. This definition identifies the StateTypesthat compose the sub states for the Program’sRunning StateType.
Table A.3– TransferStateMachineType
|
Attribute |
Value |
||||
|
|
Includes all attributes specified for the FiniteStateMachineType |
||||
|
BrowseName |
TransferStateMachineType |
||||
|
IsAbstract |
False |
||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
|
HasComponent |
Object |
Opening |
|
StateType |
-- |
|
HasComponent |
Object |
Sending |
|
StateType |
-- |
|
HasComponent |
Object |
Closing |
|
StateType |
-- |
|
|
|
|
|
|
|
|
HasComponent |
Object |
ReadyToOpening |
|
TransitionType |
-- |
|
HasComponent |
Object |
OpeningToSending |
|
TransitionType |
-- |
|
HasComponent |
Object |
SendingToClosing |
|
TransitionType |
-- |
|
HasComponent |
Object |
SendingToAborted |
|
TransitionType |
-- |
|
HasComponent |
Object |
SendingToSuspended |
|
TransitionType |
-- |
|
HasComponent |
Object |
SuspendedToSending |
|
TransitionType |
-- |
|
|
|
|
|
|
|
|
HasComponent |
Method |
Start |
|
|
Mandatory |
|
HasComponent |
Method |
Suspend |
|
|
Mandatory |
|
HasComponent |
Method |
Halt |
|
|
Mandatory |
|
HasComponent |
Method |
Resume |
|
|
Mandatory |
Table A.3specifies the StateTypesassociated with the Transfer State Machine Type. All of these states are sub states of the Runningstate of the base ProgramStateMachineType.
The Opening state is the preparation state for the domain download.
The Sending state is the activity state for the transfer in which the data is moved from the source to destination.
The Closing state is the cleanup phase of the download.
Table A.4defines the states of the TransferStateMachineType.
Table A.4– Transfer State Machine – states
|
BrowseName |
References |
Target BrowseName |
Value |
Target TypeDefinition |
NOTES |
|
States |
|||||
|
Opening |
HasProperty |
StateNumber |
5 |
PropertyType |
|
|
|
ToTransition |
OpeningToSending |
|
TransitionType |
|
|
|
FromTransition |
ToOpening |
|
TransitionType |
|
|
|
ToTransition |
OpeningToSending |
|
TransitionType |
|
|
|
|
|
|
|
|
|
Sending |
HasProperty |
StateNumber |
6 |
PropertyType |
|
|
|
FromTransition |
OpeningToSending |
|
TransitionType |
|
|
|
ToTransition |
SendingToSending |
|
TransitionType |
|
|
|
ToTransition |
SendingToClosing |
|
TransitionType |
|
|
|
ToTransition |
SendingToSuspended |
|
TransitionType |
|
|
|
FromTransition |
ToSending |
|
TransitionType |
|
|
|
|
|
|
|
|
|
Closing |
HasProperty |
StateNumber |
7 |
PropertyType |
|
|
|
ToTransition |
ClosingToCompleted |
|
TransitionType |
|
|
|
ToTransition |
ClosingToAborted |
|
TransitionType |
|
|
|
FromTransition |
SendingToClosing |
|
TransitionType |
|
Table A.5specifies the Finish State Machine Typethat is a sub state machine of the DomainDownload ProgramStateMachineType. This definition identifies the StateTypesthat compose the sub states for the Program’sHalted StateType.
Table A.5– Finish State Machine Type
|
Attribute |
Value |
||||
|
|
Includes all attributes specified for the FiniteStateMachineType |
||||
|
BrowseName |
TransferStateMachineType |
||||
|
IsAbstract |
False |
||||
|
|
|
||||
|
References |
NodeClass |
BrowseName |
Data Type |
TypeDefinition |
Modelling Rule |
|
|
|
|
|
|
|
|
HasComponent |
Object |
Completed |
|
StateType |
-- |
|
HasComponent |
Object |
Aborted |
|
StateType |
-- |
Table A.6specifies the StateTypesassociated with the Finish State Machine Type. Note these are final states and that they have no associated transitions between them.
Table A.6– Finish State Machine – states
|
BrowseName |
References |
Target BrowseName |
Value |
Target TypeDefinition |
NOTES |
|
States |
|||||
|
Aborted |
HasProperty |
StateNumber |
8 |
PropertyType |
|
|
|
FromTransition |
OpeningToAborted |
|
TransitionType |
|
|
|
FromTransition |
ClosingToAborted |
|
TransitionType |
|
|
|
|
|
|
|
|
|
Completed |
HasProperty |
StateNumber |
9 |
PropertyType |
|
|
|
FromTransition |
ClosingToCompleted |
|
TransitionType |
|
The Aborted state is the terminal state that indicates an incomplete or failed domain download operation.
The Completed stateis the terminal state that indicates a successful domain download.
Table A.7specifies the constraining behaviour of a DomainDownload.
Table A.7– DomainDownloadType Property Attributes variable values
|
NodeClass |
BrowseName |
Data Type |
Data Value |
Modelling Rule |
|
Variable |
Creatable |
Boolean |
True |
-- |
|
Variable |
Deletable |
Boolean |
True |
Mandatory |
|
Variable |
AutoDelete |
Boolean |
False |
Mandatory |
|
Variable |
RecycleCount |
Int32 |
0 |
Mandatory |
|
Variable |
InstanceCount |
UInt32 |
PropertyType |
-- |
|
Variable |
MaxInstanceCount |
UInt32 |
500 |
-- |
|
Variable |
MaxRecycleCount |
UInt32 |
0 |
-- |
A DomainDownload Program Invocationcan be created and also destroyed by a Client. The Program Invocationwill not delete itself when halted, but will persist until explicitly removed by the Client. A DomainDownload Program Invocationcannot be reset to restart. The Serverwill support up to 500 concurrent DomainDownload Program Invocations.
Figure A.3presents a partial DomainDownloadType model that illustrates the association between the states and the DomainDownload, Transfer, and Finish State Machines. Note that the current state number for the sub state machines is only valid when the DomainDownload active base state references the sub state machine, Running for the Transfer current state and Halted for the Finish current state.
Figure A.3– DomainDownloadType partial state model
Table A.8specifies the ProgramTransitionTypesthat are defined in addition to the ProgramTransitionTypes specified for Programs inTable 7. Thesetypesassociate the Transfer and Finish sub state machine states with the states of the base Program.
Table A.8– Additional DomainDownload transition types
|
BrowseName |
References |
Target BrowseName |
Value |
Target TypeDefinition |
NOTES |
|
Transitions |
|||||
|
|
|
|
|
|
|
|
ToSending |
HasProperty |
TransitionNumber |
10 |
PropertyType |
|
|
|
ToState |
Sending |
|
StateType |
|
|
|
FromState |
Opening |
|
StateType |
|
|
|
HasCause |
Start |
|
|
Method |
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
HasEffect |
AuditProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
SendingToSending |
HasProperty |
TransitionNumber |
11 |
PropertyType |
|
|
|
ToState |
Sending |
|
StateType |
|
|
|
FromState |
Sending |
|
StateType |
|
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
SendingToClosing |
HasProperty |
TransitionNumber |
12 |
PropertyType |
|
|
|
ToState |
Closing |
|
StateType |
|
|
|
FromState |
Sending |
|
StateType |
|
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
SendingToAborted |
HasProperty |
TransitionNumber |
13 |
PropertyType |
|
|
|
ToState |
Aborted |
|
StateType |
|
|
|
FromState |
Sending |
|
StateType |
|
|
|
HasCause |
Halt |
|
|
Method |
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
HasEffect |
AuditProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
ClosingToCompleted |
HasProperty |
TransitionNumber |
14 |
PropertyType |
|
|
|
ToState |
Completed |
|
StateType |
|
|
|
FromState |
Closing |
|
StateType |
|
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
SendingToSuspended |
HasProperty |
TransitionNumber |
15 |
PropertyType |
|
|
|
ToState |
Suspended |
|
StateType |
|
|
|
FromState |
Sending |
|
StateType |
|
|
|
HasCause |
Suspend |
|
|
Method |
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
HasEffect |
AuditProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
SuspendedToSending |
HasProperty |
TransitionNumber |
16 |
PropertyType |
|
|
|
ToState |
Sending |
|
StateType |
|
|
|
FromState |
Suspended |
|
StateType |
|
|
|
HasCause |
Resume |
|
|
Method |
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
HasEffect |
AuditProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
SuspendedToAborted |
HasProperty |
TransitionNumber |
18 |
PropertyType |
|
|
|
ToState |
Aborted |
|
StateType |
|
|
|
FromState |
Suspended |
|
StateType |
|
|
|
HasCause |
Halt |
|
|
Method |
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
HasEffect |
AuditProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
|
ReadyToOpening |
HasProperty |
TransitionNumber |
17 |
PropertyType |
|
|
|
ToState |
Opening |
|
StateType |
|
|
|
FromState |
Ready |
|
StateType |
|
|
|
HasCause |
Start |
|
|
Method |
|
|
HasEffect |
ProgramTransitionEventType |
|
|
|
|
|
HasEffect |
AuditProgramTransitionEventType |
|
|
|
|
|
|
|
|
|
|
Figure A.4through Figure A.10illustrate portions of the DomainDownloadType model. In each figure, the referenced tates, Methods, transitions, and EventTypesare identified for one or two state transitions.
Figure A.4– Ready To Running model
Figure A.4illustrates the model for the ReadyToRunning Programtransition. The transition is caused by the Start Method. The Start Methodrequires three input arguments. The Method Callservice is used by the Clientto invoke the Start Method and pass the arguments. When successful, the Program Invocationenters the Running state and the subordinate Transfer Opening state. The Serverissues two Eventnotifications, ReadyToRunning (2), and ToOpening (19).
Table A.9– Start Method additions
|
Attribute |
Value |
|||||
|
BrowseName |
Start |
|||||
|
IsAbstract |
False |
|||||
|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
ModellingRule |
|
|
HasProperty |
Variable |
InputArguments |
Argument[] |
PropertyType |
-- |
|
Table A.9specifies that the Start Methodfor the DomainDownloadTyperequires input arguments. Table A.10identifies the Start Argumentsrequired.
|
Name |
Type |
Value |
|
Argument 1 |
structure |
|
|
name |
String |
SourcePath |
|
dataType |
NodeId |
StringNodeId |
|
valueRank |
Int32 |
-1 (-1 = scalar) |
|
arrayDimensions |
UInt32[] |
null |
|
description |
LocalizedText |
The source specifier for the domain |
|
Argument 2 |
structure |
|
|
Name |
String |
DestinationPath |
|
dataType |
NodeId |
StringNodeId |
|
valueRank |
Int32 |
-1 (-1 = scalar) |
|
arrayDimensions |
UInt32[] |
null |
|
description |
LocalizedText |
The destination specifier for the domain |
|
Argument 3 |
structure |
|
|
name |
String |
DomainName |
|
dataType |
NodeId |
StringNodeId |
|
arrayDimensions |
UInt32[] |
null |
|
valueRank |
Int32 |
-1 (-1 = scalar) |
|
description |
LocalizedText |
The name of the domain |
|
|
|
|
Figure A.5illustrates the model for the Opening To Sending and the Sending to Closing Programtransitions. As specified in the transition table, these state transitions require no Methodsto occur, but rather are driven by the internal actions of the Server. Eventsare generated for each state transition (10 to 12), when they occur.
Figure A.5– Opening To Sending To Closing model
Notice that a state transition can initiate and terminate at the same state (Sending). In this case the transition serves a purpose. The ProgramTransitionEventTypeeffect referenced by the SendingToSending state transition has an IntermediateResultData Object Reference. The IntermediateResultData Objectserves to identify two Variableswhose values are obtained each time the state transition occurs. The values are sent to the Clientwith the Eventnotification. Table A.11defines the IntermediateResults ObjectTypeand Table A.13defines the Variablesof the ObjectType.
Table A.11– IntermediateResults Object
|
Attribute |
Value |
||||
|
|
Includes all attributes specified for the ObjectType |
||||
|
BrowseName |
IntermediateResults |
||||
|
IsAbstract |
False |
||||
|
|
|
||||
|
References |
NodeClass |
BrowseName |
Data Type |
TypeDefinition |
Modelling Rule |
|
HasComponent |
Variable |
AmountTransferred |
Long |
VariableType |
Mandatory |
|
HasComponent |
Variable |
PercentageTransferred |
Long |
VariableType |
Mandatory |
|
|
|
|
|
|
|
Table A.12– Intermediate result data Variables
|
Intermediate Result Variables |
Type |
Value |
|
Variable 1 |
Structure |
|
|
Name |
String |
AmountTransferred |
|
dataType |
NodeId |
StringNodeId |
|
description |
LocalizedText |
Bytes of domain data transferred. |
|
Variable 2 |
Structure |
|
|
Name |
String |
PercentageTransferred |
|
dataType |
NodeId |
StringNodeId |
|
description |
LocalizedText |
Percentage of domain data transferred. |
The model for the Running To Suspended state transition is illustrated in Figure A.6. The cause for this transition is the Suspend Method.The Clientcan pause the download of domain data to the control. The transition from Running to Suspended invokes the Eventgeneration for TransitionEventTypes5 and 16. Note that there is no longer a valid current state for the Transfer State Machine.
Figure A.6– Running To Suspended model
The model for the SuspendedToRunning state transition is illustrated in Figure A.7. The cause for this transition is the Resume Method.The Clientcan resume the download of domain data to the control. The transition from Suspended to Running generates the Eventfor TransitionEventTypes6 and 17. Now that the Running state is active, the Sending state of the Transfer State Machine is again specified for the CurrentStateNumber.
Figure A.7– Suspended To Running model
The model for the Running To Halted state transition for an abnormal termination of the domain download is illustrated in Figure A.8. The cause for this transition is the Halt Method.The Clientcan terminate the download of domain data to the control. The transition from Running To Halted generates the Eventfor TransitionEventTypes3 and 15. The TransitionEventType15 indicates the transition from the Sending state as the Running State ends and then to the Aborted state as the Halted state is entered.
Figure A.8– Running To Halted – Aborted model
Figure A.9illustrates the model for the Suspended To Halted state transition for an abnormal termination of the domain download. The cause for this transition is the Halt Method.The Clientcan terminate the download of domain data to the control while it is suspended. The transition from SuspendedToHalted invokes the Eventnotifiers for TransitionEventTypes7 and 18.
Figure A.9– Suspended To Aborted model
The model for the Running To Completed state transition for a normal termination of the domain download is illustrated in Figure A.10. The cause for this transition is internal. The transition from Closing To Halted generates the Event for TransitionEventTypes3 and 14. The TransitionEventType14 indicates the transition from the Closing state as the Running state ends and then to the Completed state as the Halted state is entered.
The DomainDownloadType includes a component reference to a FInalResultData Object. This Objectreferences Variablesthat persists information about the domain download once it has completed. This data can be read by Clientswho are not subscribed to Eventnotifications. The result data is described in Table A.13.
|
Attribute |
Value |
||||
|
|
Includes all attributes specified for the ObjectType |
||||
|
BrowseName |
FinalResultData |
||||
|
IsAbstract |
False |
||||
|
|
|
||||
|
References |
NodeClass |
BrowseName |
Data Type |
TypeDefinition |
Modelling Rule |
|
HasComponent |
Variable |
DownloadPerformance |
Double |
BaseDataVariableType |
Mandatory |
|
HasComponent |
Variable |
FailureDetails |
String |
BaseDataVariableType |
Mandatory |
The Domain Download net transfer data rate and detailed reason for aborted downloads is retained as final result data for each Program Invocation.
DownloadPerformanceprovides the data rate in seconds for domain data transferred.
FailureDetailsprovides a descriptive reason for an abort.
Figure A.10– Running To Completed model
Figure A.11illustrates a normal sequence of service exchanges between a Clientand Serverthat would occur during the life cycle of a DomainDownloadType Program Invocation.
Figure A.11– Sequence of operations
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