Methods and apparatus for providing an extensible set of auxiliary services for objects in an object-oriented system

• US 5,581,761 A
• Filed: 07/20/1993
• Issued: 12/03/1996
• Est. Priority Date: 07/20/1993
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Radia, Sanjay R., Powell, Michael L., Nelson, Michael N.
• Primary Examiner(s): Kriess, Kevin A.
• Assistant Examiner(s): Banankhah, Majid A.
• Application Number:
  US08/094,455
• Time in Patent Office: 1,232 Days
• Field of Search: 395/700, 395/600, 395/200, 364/DIG. 1, 364/DIG. 2
• US Class Current: 717/108
• CPC Class Codes: G06F 9/4488 Object-oriented
• CPC Class Codes: Y10S 707/99931 Database or file accessing

Abstract

An extensible set of auxiliary services for objects in an object-oriented system. Every object in an object-oriented system is implemented by an associated object manager. Each object manager in the present invention has an associated object manager identifier that identifies the object manager. Each object manager in the system can optionally provide various auxiliary services for objects that the object manager implements. These auxiliary services are objects implemented by the object manager itself, or by another object manager. For a particular type of auxiliary service, different object managers may provide different auxiliary services. For example, two object managers may provide two different freeze-melt services. For each type of auxiliary service type, there is a well-known context in which auxiliary services of that type are associated with names. For each type of auxiliary service, there is also a well-known function that transforms an object manager identifier into a name. When a client of an object needs to access an auxiliary service for an object, the client first invokes an operation within the object that provides the object manager identifier for the object manager that manages the object. The client then passes the object manager identifier to the well-known function for the desired type of auxiliary service that transforms the object manager identifier into a name. The client resolves the transformed name within a well-known context for the type of auxiliary service desired to obtain a representation of the desired auxiliary service.

Claims

1. In an object-oriented system, said object-oriented system comprising first object manager, said first object manager managing a plurality of objects, a method providing an extensible set of auxiliary services for the objects in said object-oriented system, said method comprising the steps of:

creating a plurality of auxiliary service objects, each of said plurality of auxiliary service objects comprising at least one auxiliary service operation;

providing a name server, said name server comprising a plurality of context objects, each of said context objects comprising a plurality of name-to-object associations;

implementing a "get object manager identifier" operation in each of said plurality of objects, said "get object manager identifier" operation returning an object manager identifier associated with an object manager that manages said object;

transforming said object manager identifier into an auxiliary service object name having a desired auxiliary service;

resolving said auxiliary service object name associated with said desired auxiliary service in one of said plurality of context objects to receive a representation of said auxiliary service object; and

invoking one of the auxiliary service operations within said auxiliary service object using said representation of said auxiliary service object.

2. The method providing an extensible set of auxiliary services as claimed in claim 1, wherein said auxiliary service object name associated with a desired auxiliary service comprises a name that identifies said desired auxiliary service with said object manager.

3. The method providing an extensible set of auxiliary services as claimed in claim 1, wherein one of said auxiliary services is a freeze-melt service, said freeze-melt service used to make objects persistent.

4. The method providing an extensible set of auxiliary services as claimed in claim 1, wherein one of said auxiliary services is an object duplication service, said object duplication service used to create copies of objects.

5. The method providing an extensible set of auxiliary services as claimed in claim 4, wherein said object duplication service creates copies of objects with different access rights.

6. The method providing an extensible set of auxiliary services as claimed in claim 1, wherein a new auxiliary service is added by implementing said new auxiliary service object and binding at least one auxiliary service object name to said new auxiliary service object in one of said plurality of contexts.

7. In an object-oriented system, said object-oriented system comprising an object manager, said object manager managing a plurality of objects, a method providing a secure freeze-melt service, said method comprising the steps of:

creating a freeze-melt service object, said freeze-melt service object comprising a freeze operation and a melt operation, said freeze-melt service object having at least one freeze-melt service object name;

providing a name server, said name server comprising a context object, said context object comprising a plurality of name-to-object associations, one of said plurality of name-to-object associations comprising an association of said freeze-melt service object name to a representation of said freeze-melt service object;

implementing a "get object manager identifier" operation in each of said plurality of objects, said "get object manager identifier" operation returning an object manager identifier associated with said an object manager that manages the object;

implementing a transformation function that transforms said object manager identifier into said freeze-melt service object name;

obtaining for an object access to both said freeze operation and said melt operation by

invoking said "get object manager identifier" operation in said object to obtain said object manager identifier;

calling said transformation function to transform said object manager identifier into said freeze-melt service object name; and

resolving said freeze-melt service object name in said context object to receive a representation of said freeze-melt service object.

8. The method providing a secure freeze-melt service as claimed in claim 7, wherein said secure freeze-melt service comprises an object implemented by a second object manager.

9. In an object-oriented system, said object-oriented system comprising first object manager, said first object manager managing a plurality of objects, said first object manager having a first object manager identifier that identifies said first object manager, a method providing a duplication service that creates duplicates of said objects, said method comprising the steps of:

creating a duplication service object, said duplication service object comprising a duplication operation for duplicating objects, said duplication service object having at least one duplication service object name;

providing a name server, said name server comprising a context object, said context object comprising a plurality of name-to-object associations, one of said plurality of name associations comprising an association of a duplication service object name to a representation of said duplication service object;

implementing a "get object manager identifier" operation in each of said plurality of objects, said "get object manager identifier" operation returning an object manager identifier associated with an object manager that manages the object;

implementing a transformation function that transforms said first object manager identifier into a duplication service object name;

obtaining for an object access to said duplication operation by

invoking said "get object manager identifier" operation in said object to obtain said first object manager identifier;

calling said transformation function to transform said first object manager identifier into said duplication service object name; and

resolving said duplication service object name in said context object to receive a representation of said duplication service object.

10. The method providing a secure duplication service as claimed in claim 9, wherein said secure duplication service comprises an object implemented by a second object manager.