C++ Micro Services: PrototypeServiceFactory Struct Reference
PrototypeServiceFactory Struct Referenceabstract

A factory for prototype scope services. More...

Inheritance diagram for PrototypeServiceFactory:
Collaboration diagram for PrototypeServiceFactory:

Public Member Functions

virtual InterfaceMap GetService (Module *module, const ServiceRegistrationBase &registration)=0
 Returns a service object for a caller. More...
 
virtual void UngetService (Module *module, const ServiceRegistrationBase &registration, const InterfaceMap &service)=0
 Releases a service object created for a caller. More...
 
- Public Member Functions inherited from ServiceFactory
virtual ~ServiceFactory ()
 

Detailed Description

A factory for prototype scope services.

The factory can provide multiple, unique service objects.

When registering a service, a PrototypeServiceFactory object can be used instead of a service object, so that the module developer can create a unique service object for each caller that is using the service. When a caller uses a ServiceObjects to request a service instance, the framework calls the GetService method to return a service object specifically for the requesting caller. The caller can release the returned service object and the framework will call the UngetService method with the service object. When a module uses the ModuleContext::GetService(const ServiceReferenceBase&) method to obtain a service object, the framework acts as if the service has module scope. That is, the framework will call the GetService method to obtain a module-scoped instance which will be cached and have a use count. See ServiceFactory.

A module can use both ServiceObjects and ModuleContext::GetService(const ServiceReferenceBase&) to obtain a service object for a service. ServiceObjects::GetService() will always return an instance provided by a call to GetService(Module*, const ServiceRegistrationBase&) and ModuleContext::GetService(const ServiceReferenceBase&) will always return the module-scoped instance. PrototypeServiceFactory objects are only used by the framework and are not made available to other modules. The framework may concurrently call a PrototypeServiceFactory.

See Also
ModuleContext::GetServiceObjects()
ServiceObjects

Member Function Documentation

virtual InterfaceMap PrototypeServiceFactory::GetService ( Module module,
const ServiceRegistrationBase registration 
)
pure virtual

Returns a service object for a caller.

The framework invokes this method for each caller requesting a service object using ServiceObjects::GetService(). The factory can then return a specific service object for the caller. The framework checks that the returned service object is valid. If the returned service object is empty or does not contain entries for all the interfaces named when the service was registered, a warning is issued and NULL is returned to the caller. If this method throws an exception, a warning is issued and NULL is returned to the caller.

Parameters
moduleThe module requesting the service.
registrationThe ServiceRegistrationBase object for the requested service.
Returns
A service object that must contain entries for all the interfaces named when the service was registered.
See Also
ServiceObjects::GetService()
InterfaceMap

Implements ServiceFactory.

virtual void PrototypeServiceFactory::UngetService ( Module module,
const ServiceRegistrationBase registration,
const InterfaceMap service 
)
pure virtual

Releases a service object created for a caller.

The framework invokes this method when a service has been released by a modules such as by calling ServiceObjects::UngetService(). The service object may then be destroyed. If this method throws an exception, a warning is issued.

Parameters
moduleThe module releasing the service.
registrationThe ServiceRegistrationBase object for the service being released.
serviceThe service object returned by a previous call to the GetService method.
See Also
ServiceObjects::UngetService()

Implements ServiceFactory.