System and method for object oriented message filtering

• US 5,734,903 A
• Filed: 05/13/1994
• Issued: 03/31/1998
• Est. Priority Date: 05/13/1994
• Status: Expired due to Term

• Current Assignee: Apple Computer Incorporated (Apple Inc.)
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Saulpaugh, Thomas E., Szymanski, Steven J.
• Primary Examiner(s): TOPLU, LUCIEN
• Application Number:
  US08/242,259
• Time in Patent Office: 1,418 Days
• Field of Search: 364/DIG. 1, 364/DIG. 2, 395/683, 395/185.02, 395/200.09, 395/200.15, 395/481
• US Class Current: 719/316
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications

Abstract

A system for object oriented message filtering for selectively transferring a message between a client task and one or more server tasks for preprocessing, processing, and postprocessing comprises an object database having a filter object memory, an object management unit, a message transaction unit, and a locking unit. The object management unit creates a port object and one or more associated target message objects. The object management unit selectively creates one or more filter objects associated with a target message object, and selectively associates a preprocessor message object, a postprocessor message object, or both a preprocessor message object and a postprocessor message object with each filter object. The message transaction unit selectively routes a message sent by a client task and directed to a target message object to one or more associated preprocessor message objects prior to delivering the message to the target message object. After delivery to the target message object, the message transaction unit selectively routes the message to one or more associated postprocessor message objects. Server tasks receive messages from port objects associated with preprocessor message objects, target message objects, and postprocessor message objects, facilitating preprocessing, processing, and postprocessing operations.

Claims

1. A message filtering method for a computer system having a processing unit and a memory wherein a message filtering unit, a client task and a set of server tasks reside, the client task comprising a sequence of program instructions that require a service, each server task comprising a sequence of program instructions capable of providing a service, and the message filtering unit comprising a sequence of program instructions that manages the transfer of messages between client tasks and server tasks, the message filtering method comprising the steps of:

creating a first target message object with the message filtering unit, the first target message object corresponding to a first type of service provided by a server task within the set of server tasks, the first target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a first message processing service be performed upon a message;

creating a first filter object with the message filtering unit, the first filter object corresponding to the first target message object, the first filter object indicating whether a first message preprocessing service is associated with the first target message object;

issuing a send message request with the client task, the send message request directed to the first target message object and including a reference to a first message;

receiving the send message request with the message filtering unit;

examining the first filter object with the message filtering unit to determine whether a first message preprocessing service is required; and

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message preprocessing service in the event that a message preprocessing service is required.

2. The method of claim 1 further comprising the steps of:

creating a second filter object with the message filtering unit, the second filter object corresponding to the first target message object, the second filter object indicating whether a second message preprocessing service is associated with the first target message object;

examining the second filter object with the message filtering unit to determine whether a next message preprocessing service is required; and

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the second message preprocessing service in the event that a next message preprocessing service is required.

3. The method of claim 1, further comprising the step of transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message processing service.

4. The method of claim 3, wherein the first filter object also indicates whether a first message postprocessing service is associated with the first target message object, the method further comprising the steps of:

examining the first filter object with the message filtering unit to determine whether a message postprocessing service is required; and

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message postprocessing service.

5. The method of claim 1, further comprising the steps of:

creating a second target message object with the message filtering unit, the second target message object corresponding to a second type of service provided by a server task within the set of server tasks, the second target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a second message processing service be performed upon a message;

determining with the message filtering unit whether the server task performing the first message preprocessing service has issued a message forward request; and

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the second message processing service in the event that the server task performing the first message preprocessing service has issued a message forward request.

6. The method of claim 1, further comprising the steps of:

creating a second target message object with the message filtering unit, the second target message object corresponding to a second type of service provided by a server task within the set of server tasks, the second target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a second message processing service be performed upon a message;

creating a second filter object with the message filtering unit, the second filter object corresponding to the second target message object, the second filter object indicating whether a first message preprocessing service is associated with the second target message object;

determining with the message filtering unit whether the server task performing the first message preprocessing service associated with the first target message object has issued a message forward request;

examining the second filter object with the message filtering unit to determine whether a message preprocessing service associated with the second target message object is required; and

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message preprocessing service associated with the second target message object in the event that a message preprocessing service associated with the second target message object is required.

7. The method of claim 1, wherein the first filter object additionally indicates whether a first message postprocessing service is associated with the first target message object, the method further comprising the steps of:

determining with the message filtering unit whether the server task performing the first message preprocessing service has issued a reply signal;

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message postprocessing service in the event that the server task performing the first message preprocessing service has issued a reply signal.

8. A message filtering method for a computer system having a processing unit and a memory wherein a message filtering unit, a client task, and a set of server tasks reside, the client task comprising a sequence of program instructions that require a service, each server task comprising a sequence of program instructions capable of providing a service, and the message filtering unit comprising a sequence of program instructions that manages the transfer of messages between client tasks and server tasks, the message filtering method comprising the steps of:

creating a first target message object with the message filtering unit, the first target message object corresponding to a first type of service provided by a server task within the set of server tasks, the first target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a first message processing service be performed upon a message;

creating a first filter object with the message filtering unit, the first filter object corresponding to the first target message object, the first filter object indicating whether a first message postprocessing service is associated with the first target message object;

issuing a send message request with the client task, the send message request directed to the first target message object and including a reference to a first message;

receiving the send message request with the message filtering unit;

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message processing service;

examining the first filter object to determine whether a first message postprocessing service is required; and

transferring the first message to a server task within the set of server tasks with the message filtering unit to perform the first message postprocessing service.

9. The method of claim 8, further comprising the steps of:

creating a second filter object with the message filtering unit, the second filter object corresponding to the first target message object, the second filter object indicating whether a second message postprocessing service is associated with the first target message object;

examining the second filter object with the message filtering unit to determine whether a next message postprocessing service is required; and

transferring the first message to a server tasks within the set of server tasks with the message filtering unit to perform a second message postprocessing service in the event that a next message postprocessing service is required.

10. A message filtering method for a computer system having a processing unit and a memory wherein a message filtering unit, a client task, and a set of server tasks reside, the client task comprising a sequence of program instructions that require a service, each server task comprising a sequence of program instructions capable of providing a service, and the message filtering unit comprising a sequence of program instructions that manages the transfer of messages between client tasks and server tasks, the message filtering method comprising the steps of:

creating a target message object with the message filtering unit, the target message object corresponding to a type of service provided by a server task within the set of server tasks, the target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a message processing service be performed upon a message;

creating a set of filter objects with the message filtering unit, each filter object within the first set of filter objects corresponding to the target message object, each filter object within the set of filter objects indicating whether a message preprocessing service and whether a message postprocessing service is associated with the target message object;

issuing a send message request with the client task, the send message request directed to the target message object and including a reference to a message;

receiving the send message request with the message filtering unit;

successively performing message preprocessing services by performing the substeps of;

examining each filter object within the set of filter objects; and

transferring the message to a server task within the set of server tasks with the message filtering unit, for each filter object within the set of filter objects that indicates that a message preprocessing service is associated with the target message object;

transferring the message to a server task within the set of server tasks with the message filtering unit to perform the message processing service; and

successively performing message postprocessing services by performing the substeps of;

examining each filter object within the set of filter objects; and

transferring the first message to a server task within the set of server tasks with the message filtering unit, for each filter object within the set of filter objects that indicates that a message postprocessing service is associated with the target message object.

11. The method of claim 10, wherein the substep of examining within the step of successively performing message preprocessing services occurs for a first through a last filter object within the set of filter objects, and wherein the substep of examining within the step of successively performing message postprocessing services occurs for the last through the first filter objects within the set of filter objects.

12. On a computer system having a processing unit and a memory wherein a client task and a set of server tasks reside, the client task comprising a sequence of program instructions that require a service, each server task within the set of server tasks comprising a sequence of program instructions capable of providing a service, a means for message filtering comprising:

means for creating a target message object, the target message object corresponding to a type of service provided by a server task within the set of server tasks, the target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a message processing service be performed upon a message;

means for creating a set of filter objects corresponding to the target message object, each filter object within the set of filter objects indicating whether a message preprocessing service is associated with the target message object;

means for receiving a send message request issued by the client task, the send message request including a reference to a message;

means for examining a filter object within the set of filter objects to determine whether a message preprocessing service associated with the target message object is required; and

means for transferring the message to a server task within the set of server tasks to perform the message preprocessing service in the event that the message preprocessing service is required.

13. The means of claim 12, further comprising a means for transferring the message to a server task within the set of server tasks to perform the message processing service.

14. The means of claim 12, wherein at least one filter object within the set of filter objects indicates whether a message postprocessing service is associated with the target message object, the means further comprising:

means for examining a filter object within the set of filter objects to determine whether a message postprocessing service associated with the target message object is required; and

means for transferring the message to a server task within the set of server tasks to perform the message postprocessing service in the event that the message postprocessing service is required.

15. On a computer system having a processing unit and a memory wherein a client task and a set of server tasks reside, the client task comprising a sequence of program instructions that require a service, each server task within the set of server tasks comprising a sequence of program instructions capable of providing a service, a means for message filtering comprising:

means for creating a target message object, the target message object corresponding to a type of service provided by a server task within the set of server tasks, the target message object also corresponding to a message destination to which the client task issues a send message request for the purpose of requesting a message processing service be performed upon a message;

means for creating a set of filter objects corresponding to the target message object, each filter object within the set of filter objects indicating whether a message postprocessing service is associated with the target message object;

means for receiving a send message request issued by the client task, the send message request including a reference to a message;

means for transferring the message to a server task within the set of server tasks to perform the message processing service;

means for examining a filter object within the set of filter objects to determine whether a message postprocessing service is associated with the target message object; and

means for transferring the message to a server task within the set of server tasks to perform the message postprocessing service in the event that a message postprocessing service is required.

16. A system for message filtering, for selectively routing a message from a client task to a set of server tasks to perform message preprocessing operations, the object-oriented message filtering system comprising:

a memory having an input and an output for storing data and commands, the memory including a message filtering unit for creating a target message object to which a client task issues a send message request for requesting a message processing service;

creating a filter object indicating whether a message preprocessing service is associated with the target message object, receiving a send message request issued by a client task, examining the filter object to determine whether a message preprocessing service is associated with the target message object, and transferring a message to a server task to perform the message preprocessing service, the message filtering unit comprising program instructions that form a portion of a computer operating system; and

a processing unit having an input and an output, for processing data and executing commands under control of program instructions stored in the memory, the input of the processing unit coupled to the output of the memory, and the output of the processing unit coupled to the input of the memory.

17. A system for message filtering, for selectively routing a message from a client task to a set of server tasks to perform message postprocessing operations, the object-oriented message filtering system comprising:

a memory having an input and an output for storing data and commands, the memory including a message filtering unit for creating a target message object to which a client task issues a send message request for requesting a message processing service, creating a filter object indicating whether a message postprocessing service is associated with the target message object, receiving a send message request issued by a client task, transferring a message to a server task to perform the message processing service, examining the filter object to determine whether a message postprocessing service is associated with the target message object, and transferring the message to a server task to perform the message postprocessing service, the message filtering unit comprising program instructions that form a portion of a computer operating system; and

a processing unit having an input and an output, for processing data and executing commands under control of program instructions stored in the memory, the input of the processing unit coupled to the output of the memory, and the output of the processing unit coupled to the input of the memory.

18. A computer-readable medium storing program instructions for performing the steps of:

creating a target message object, the target message object corresponding to a type of service provided by a server task, the target message object also corresponding to a message destination to which a client task issues a send message request for the purpose of requesting a message processing service be performed upon a message;

creating a filter object, the filter object corresponding to the target message object, the filter object indicating whether a message preprocessing service is associated with the target message object;

receiving a send message request issued by a client task, the send message request including a reference to a message;

examining the filter object to determine whether a message preprocessing service is required; and

transferring the message to a server task to perform the message preprocessing service.

19. A computer-readable medium storing program instructions for performing the steps of:

creating a target message object, the target message object corresponding to a type of service provided by a server task, the target message object also corresponding to a message destination to which a client task issues a send message request for the purpose of requesting a message processing service be performed upon a message;

creating a filter object, the filter object corresponding to the target message object, the filter object indicating whether a message postprocessing service is associated with the target message object;

receiving a send message request issued by a client task, the send message request including a reference to a message;

transferring the message to a server task to perform the message processing service;

examining the filter object to determine whether a message postprocessing service is required; and

transferring the message to a server task to perform the message postprocessing service.