uk.ac.sheffield.vtts.model

Class Operation

java.lang.Object

uk.ac.sheffield.vtts.model.Element

uk.ac.sheffield.vtts.model.Named

uk.ac.sheffield.vtts.model.Annotated

uk.ac.sheffield.vtts.model.Scope

uk.ac.sheffield.vtts.model.Operation

public class Operation
extends Scope

Operation represents an operation in the public interface of a service. An Operation represents a local Scope in which Input and Output variables may be declared. When included as part of a Protocol specification, an Operation maintains a collection of Scenarios, each representing a distinct path through the Operation. When an Operation is included in a TestStep, the Scenarios are not copied, but any Input and Output parameters will be bound to specific values. An Operation is a kind of Annotated element that may receive Warnings.

Version:

Broker@Cloud 1.0

Author:

Anthony J H Simons

Field Summary

Fields inherited from class uk.ac.sheffield.vtts.model.Scope

parameters

Fields inherited from class uk.ac.sheffield.vtts.model.Annotated

notice

Fields inherited from class uk.ac.sheffield.vtts.model.Named

name

Constructor Summary

Constructors

Constructor and Description
Operation() Creates a default Operation.
Operation(java.lang.String name) Creates a named Operation.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	accept(Event event) Reports whether this Operation accepts an Event in the current Memory state.
Operation	addScenario(Scenario scenario) Adds a Scenario to this Operation.
protected void	checkBindings(Notice topInfo, Notice opInfo) Checks that the Input values of this Operation are bound to some suggested values in the Binding clause.
Operation	checkCompleteness(Notice topInfo) Checks this Operation for completeness under all memory and input conditions.
boolean	fireEvent(Event event) Fires an event on this Operation.
java.util.Set<Failure>	getFailures() Returns the set of Failures of this Operation.
java.util.Set<Input>	getInputs() Returns the set of Inputs in this Operation.
java.util.Set<Output>	getOutputs() Returns the set of Outputs in this Operation.
protected java.util.Set<Predicate>	getPartitions(Notice opInfo) Returns the possible symbolic input partitions for this Operation.
Scenario	getScenario(Event event) Returns the Scenario corresponding to the supplied Event.
Scenario	getScenario(java.lang.String name) Returns the Scenario with the specified unique name, if it exists.
java.util.Set<Scenario>	getScenarios() Returns this Operation's Scenarios as an ordered Set.
boolean	isCreation() Reports whether this Operation is the initial service creation step.
boolean	isFailure() Reports whether this Operation represents an exceptional failure step.
Operation	resolve(Scope scope) Cause this Operation to resolve its global/local Parameter references.
java.lang.String	toString() Returns a printed representation of this Operation.

Methods inherited from class uk.ac.sheffield.vtts.model.Scope

addParameter, addScope, getParameter, getParameters, unbind

Methods inherited from class uk.ac.sheffield.vtts.model.Annotated

addNotice, getNotice

Methods inherited from class uk.ac.sheffield.vtts.model.Named

equals, getName, hashCode, setName, setName

Methods inherited from class uk.ac.sheffield.vtts.model.Element

safeEquals, safeHashCode, semanticError

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Operation

public Operation()

Creates a default Operation.

Operation

public Operation(java.lang.String name)

Creates a named Operation.

Parameters:

name - the name of this Operation.

Method Detail

isCreation

public boolean isCreation()

Reports whether this Operation is the initial service creation step. This test is used during grounding, to support bespoke code generation to create or initialise the service.

Returns:

true, if the name of this Operation is "create".

isFailure

public boolean isFailure()

Reports whether this Operation represents an exceptional failure step. This test is used during grounding, to support bespoke code generation to handle modelled service exceptions.

Returns:

true, if this Operation's result is bound to a Failure.

getInputs

public java.util.Set<Input> getInputs()

Returns the set of Inputs in this Operation. A convenience, to extract those Parameters from the Scope which are Inputs.

Returns:

the Inputs in this Operation.

getOutputs

public java.util.Set<Output> getOutputs()

Returns the set of Outputs in this Operation. A convenience, to extract those Parameters from the Scope which are Outputs.

Returns:

the Outputs in this Operation.

getFailures

public java.util.Set<Failure> getFailures()

Returns the set of Failures of this Operation. A convenience, to extract those Parameters from the Scope which are Failures.

Returns:

the Failures of this Operation.

resolve

public Operation resolve(Scope scope)

Cause this Operation to resolve its global/local Parameter references. Triggered when the Protocol owning this Operation is added to its owning Service. The Scope argument is the global Memory, which contains the global Constants and Variables. Constructs a new Scope, which contains all the global Parameters in the argument, to which are added all the local Parameters contained in this Operation. Delegates to each Scenario in turn, passing it the complete table of Parameters.

Parameters:

scope - a Scope containing global Parameters.

Returns:

this Operation.

addScenario

public Operation addScenario(Scenario scenario)

Adds a Scenario to this Operation. Each Scenario must be uniquely named using the format: "request/response". The "request" part must be equal to the name of this Operation. The table of Scenarios is only created when the first Scenario is added.

Parameters:

scenario - the Scenario to add.

Returns:

this Operation.

getScenario

public Scenario getScenario(java.lang.String name)

Returns the Scenario with the specified unique name, if it exists.

Parameters:

name - the name of the Scenario.

Returns:

the associated Scenario, or null if no such Scenario exists.

getScenarios

public java.util.Set<Scenario> getScenarios()

Returns this Operation's Scenarios as an ordered Set. If Scenarios were added, returns these; otherwise returns an empty set, rather than null.

Returns:

an ordered Set of this Operation's Scenarios.

getScenario

public Scenario getScenario(Event event)

Returns the Scenario corresponding to the supplied Event. Selects the Scenario from this Operation, whose name is equal to the Event's name. Raises a semantic error if no such Scenario exists.

Parameters:

event - the Event.

Returns:

the corresponding Scenario, which must exist.

accept

public boolean accept(Event event)

Reports whether this Operation accepts an Event in the current Memory state. Selects the Scenario from the Operation, whose name is equal to the Event's whole name. Reports whether this Scenario may be executed in the current Memory environment.

Parameters:

event - the Event.

Returns:

true, if the corresponding Scenario can be executed.

fireEvent

public boolean fireEvent(Event event)

Fires an event on this Operation. Selects the Scenario from this Operation, whose name is equal to the Event's name. Executes the Scenario and returns true, if the Scenario was able to execute with the current Memory state.

Parameters:

event - an Event.

Returns:

true, if this Operation was able to fire.

checkCompleteness

public Operation checkCompleteness(Notice topInfo)

Checks this Operation for completeness under all memory and input conditions. Seeks to determine whether there is a non-blocking and deterministic response to each partition in the symbolic input space of the Operation.

Parameters:

topInfo - the Notice to which global warnings are attached.

Returns:

this Operation.

getPartitions

protected java.util.Set<Predicate> getPartitions(Notice opInfo)

Returns the possible symbolic input partitions for this Operation. For each Scenario, extracts the atomic predicates over each pair of parameters, discovered by refining the Scenario's Condition and its complement. Partitions these predicates into sets, by indexing each set according to the pair of parameters governed by each predicate. Converts the partitioned sets into all possible combinations, taking one predicate from each set. Converts each combination into a logical -AND Proposition governing the Predicates in the combination, and adds this to the resulting set of Predicates. If an Operation has a single Scenario with no Condition, returns an empty set, indicating that the Operation accepts universal input. Otherwise, returns a set of predicates, each representing a different partition of the input space.

Parameters:

opInfo - the Notice reporting on this Operation.

Returns:

the partitions of this Operation's input space.

checkBindings

protected void checkBindings(Notice topInfo,
                 Notice opInfo)

Checks that the Input values of this Operation are bound to some suggested values in the Binding clause. Issues Warnings if some Inputs are not bound.

Parameters:

topInfo - the top-level Notice for the Protocol.

opInfo - the local Notice for this Operation.

toString

public java.lang.String toString()

Returns a printed representation of this Operation. Returns a String in the format "name(arg1, ... argN)", representing an invocation of this Operation.

Overrides:

toString in class Named

Returns:

the String representation of this Named element.