Marshaling and unmarshaling framework for supporting filters in a distributed object system

摘要

In order to support filtering operations in a CORBA system, the marshaling and unmarshaling process is encapsulated in a server invocation object created from a class which contains data, including the request ID, the marshal buffer and the marshal and unmarshal methods. Filtering is supported by extending the class with a subclass that overrides the marshal and unmarshal methods to invoke the filters at the proper points. During operation, the CORBA object request broker examines the request to determine whether filtering is requested and instantiates a server invocation object either from the parent class, if filtering is not requested, or from the subclass, if filtering is requested.