Method and apparatus for generating and using short operation identifiers in object oriented systems

• US 5,640,564 A
• Filed: 06/06/1995
• Issued: 06/17/1997
• Est. Priority Date: 05/26/1994
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Kessler, Peter B., Hamilton, Graham
• Primary Examiner(s): Kriess, Kevin A.
• Application Number:
  US08/467,542
• Time in Patent Office: 742 Days
• Field of Search: 395/680, 395/683, 395/684, 395/182.02, 395/185.01, 395/185.02, 395/185.03, 395/185.04
• US Class Current: 719/315
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution
• CPC Class Codes: G06F 9/548 Object oriented; Remote method invocation [RMI] non-remote method invocation G06F9/449

Abstract

A distributed computer system in which a server application performs operations responsive to operation requests from a client application. The client application initially identifies an operation for the server application to perform with a short identifier of the operation. If the short identifier is ambiguous, the server application sends the client application a reply indicating that the short identifier was ambiguous. The client application responds by sending a long identifier which uniquely identifies the operation. Preferably, the short identifier of an operation is derived by performing a hash function on the long identifier of the operation. In object-oriented distributed systems, the operations are methods defined in objects supported by the server application.

Claims

1. A computer system comprising:

at least one processor executing

a client application; and

a server application, said server application being coupled to said client application;

wherein said server application executes a plurality of operations, each operation of said plurality of operations being identified by at least one operation identifier of a plurality of operation identifiers, each operation identifier of said plurality of operation identifiers identifying one or more operations of said plurality of operations;

wherein said client application issues a first request to said server application for said server application to perform a selected operation of said plurality of operations, said client application identifying said selected operation by transmitting a first operation identifier in said first request, wherein said first operation identifier is one of said plurality of operation identifiers, wherein said first operation identifier identifies said selected operation;

wherein said server application performs said selected operation when said first operation identifier identifies only said selected operation; and

wherein said server application transmits a notification to said client application notifying said client application that said first operation identifier was ambiguous and that said selected operation was not performed when said first operation identifier identifies more than one operation of said plurality of operations.

2. The computer system of claim 1 wherein said client application issues a second request to said server application for said server application to perform said selected operation when said client receives said notification from said server application, said client application identifying said selected operation by transmitting a second operation identifier in said second request, wherein said second operation identifier is one of said plurality of operation identifiers, wherein said second operation identifier identifies said selected operation, said second operation identifier being a different operation identifier than said first operation identifier.

3. The computer system of claim 2 wherein said plurality of operation identifiers include a plurality of short operation identifiers and a plurality of long operation identifiers, each operation of said plurality of operations being identified by a short operation identifier from said plurality of short operation identifiers, each operation of said plurality of operations further being identified by a long operation identifier from said plurality of long operation identifiers, wherein for each operation of said plurality of operations, the short operation identifier that identifies the operation is shorter than the long operation identifier that identifies the operation.

4. The computer system of claim 3 wherein said first operation identifier is one of said plurality of short operation identifiers, wherein said first operation identifier identifies said selected operation, wherein said second operation identifier is one of said plurality of long operation identifiers, wherein said second operation identifier identifies said selected operation.

5. The computer system of claim 4 wherein each short operation identifier of said plurality of short operation identifiers is derived by performing a hash function on a long operation identifier of said plurality of long operation identifiers, wherein a short operation identifier derived by performing said hash function on a given long operation identifier identifies the same operation as said given long operation identifier.

6. The computer system of claim 5 wherein said hash function is known to both said client application and said server application, wherein each of said client application and said server application independently derives said plurality of short operation identifiers from said plurality of long operation identifiers.

7. The computer system of claim 1 where said plurality of operations are a plurality of procedures.

8. The computer system of claim 1 wherein said plurality of operations are a plurality of methods that are to be performed on at least one object supported by said server application.

9. The computer system of claim 6 wherein said plurality of operations are a plurality of methods that are to be called on at least one object supported by said server application, said server application being aware of said plurality of long operation identifiers supported by said at least one object, said server application determining which short operation identifiers of said plurality of short operation identifiers are ambiguous when said at least one object is compiled.

10. A server application for use in a computer system, the computer system including at least one processor executing said server application and at least one client application, the server application comprising:

an execution unit;

an input unit operatively coupled to said execution unit and said server application; and

an output unit operatively coupled to said execution unit and said server application;

wherein said execution unit executes a plurality of operations, each operation of said plurality of operations being identified by at least one operation identifier of a plurality of operation identifiers, each operation identifier of said plurality of operation identifiers identifying one or more operations of said plurality of operations;

wherein said input unit receives a first request from said at least one client application, said first request requesting said server application to perform a selected operation of said plurality of operations, said first request identifying said selected operation by a first operation identifier, wherein said first operation identifier is one of said plurality of operation identifiers, wherein said first operation identifier identifies said selected operation;

wherein said execution unit executes said selected operation when said first operation identifier identifies only said selected operation; and

wherein said output unit transmits a notification to said at least one client application notifying said at least one client application that said first operation identifier was ambiguous and that said selected operation was not performed when said first operation identifier identifies more than one operation of said plurality of operations.

11. The server application of claim 10 wherein said input unit receives a second request from said at least one client application for said server application to perform said selected operation when said client application receives said notification from said server application, said selected operation being identified by a second operation identifier in said second request, wherein said second operation identifier is one of said plurality of operation identifiers, wherein said second operational identifier identifies said selected operation, said second operation identifier being a different operation identifier than said first operation identifier.

12. The server application of claim 11 wherein said plurality of operation identifiers include a plurality of short operation identifiers and a plurality of long operation identifiers, each operation of said plurality of operations being identified by a short operation identifier from said plurality of short operation identifiers, each operation of said plurality of operations further being identified by a long operation identifier from said plurality of long operation identifiers, wherein, for each operation of said plurality of operations, the short operation identifier that identifies the operation is shorter than the long operation identifier that identifies the operation.

13. The server application of claim 12 wherein said first operation identifier is a short operation identifier of said plurality of short operation identifiers which identifies said selected operation, said second operation identifier being a long operation identifier of said plurality of long operation identifiers which identifies said selected operation.

14. The server application of claim 13 wherein said server application derives each short operation identifier of said plurality of short operation identifiers by performing a hash function on a corresponding long operation identifier of said plurality of long operation identifiers, wherein a short operation identifier derived by performing said hash function on a given long operation identifier identifies the same operation as said given long operation identifier.

15. The server application of claim 10 wherein said plurality of operations are a plurality of methods that are to be performed on at least one object supported by said server application.

16. The server application of claim 14 wherein said plurality of operations are a plurality of methods that are to be called on at least one object supported by said server application, said server application being aware of said plurality of long operation identifiers supported by said at least one object, said server application determining which short operation identifiers of said plurality of short operation identifiers are ambiguous when said at least one object is compiled.

17. A method for handling ambiguous identifiers in a computer system, the computer system including at least one processor executing a server application and at least one client application, said server application being capable of executing a plurality of operations, the method comprising the steps of:

identifying each operation of said plurality of operations by at least one operation identifier of a plurality of operation identifiers, each operation identifier of said plurality of operation identifiers identifying one or more operations of said plurality of operations;

at least one client application issuing a first request to said server application for said server application to perform a selected operation of said plurality of operations, said at least one client application identifying said selected operation by transmitting a first operation identifier in said first request, wherein said first operation identifier is one of said plurality of operation identifiers, wherein said first operation identifier identifies said selected operation;

said server application performing said selected operation when said first operation identifier identifies only said selected operation; and

said server application transmitting a notification to said at least one client application notifying said at least one client application that said first operation identifier was ambiguous and that said selected operation was not performed when said first operation identifier identifies more than one operation of said plurality of operations.

18. The method of claim 17 further including the step of at least one client application issuing a second request to said server application for said server application to perform said selected operation when said at least one client receives said notification from said server application, said at least one client application identifying said selected operation by transmitting a second operation identifier in said second request, wherein said second operation identifier is one of said plurality of operation identifiers, wherein said second operation identifier identifies said selected operation, said second operation identifier being a different operation identifier than said first operation identifier.

19. The method of claim 18 wherein said plurality of operation identifiers include a plurality of short operation identifiers and a plurality of long operation identifiers, said step of identifying each operation of said plurality of operations including the steps of:

identifying each operation of said plurality of operations by a short operation identifier from said plurality of short operation identifiers; and

identifying each operation of said plurality of operations by a long operation identifier from said plurality of long operation identifiers;

said first operation identifier being a short operation identifier of said plurality of short operation identifiers which identifies said selected operation, said second operation identifier being a long operation identifier of said plurality of long operation identifiers which identifies said selected operation, wherein said short operation identifier is shorter than said long operation identifier.

20. The method of claim 19 further including the step of deriving each short operation identifier of said plurality of short operation identifiers by performing a hash function on a corresponding long operation identifier of said plurality of long operation identifiers, wherein a short operation identifier derived by performing said hash function on a given long operation identifier identifies the same operation as said given long operation identifier.