Method and apparatus for incremental download from server to client

• US 6,490,616 B1
• Filed: 06/14/1999
• Issued: 12/03/2002
• Est. Priority Date: 06/14/1999
• Status: Expired due to Term

• Current Assignee: Wind River Systems Incorporated (Aptiv PLC)
• Original Assignee: Wind River International, Ltd. (Aptiv PLC)
• Inventors: Maryka, Stephen, Michaud, Bertrand, Dick, Greg
• Primary Examiner(s): Najjar, Saleh
• Application Number:
  US09/332,069
• Time in Patent Office: 1,268 Days
• Field of Search: 709/213, 709/222, 709/228, 709/232, 709/221, 713/1, 713/100, 370/229, 710/61
• US Class Current: 709/222
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 67/59 Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable

Abstract

A method and system for transferring objects between computers, especially a server and a device in a Java environment, is provided. A server connected to the device interrogates the device to determine whether the device has the available resources to accept a download, and to determine if any of objects included in the download are already resident on the device. Using a gateway object on the device, and a gateway managed-object on the server, the server passes an archive of the necessary objects, not presently available on the device, to the gateway via the gateway managed-object. The gateway then instructs a persistent storage repository on the device to commit the archive to persistent storage. A flag is set at the start of the archive-committing process, such that if the device loses power during the archive-committing process, upon re-initialization of the device, the device can determine that the archive-committing process failed and will instruct the persistent storage to free-up storage area used during the archive-committing process. The transferal of objects can then be recommenced once the server and device reestablish communication.

Claims

1. A method for transferring at least a portion of a group of objects to a first computer from a second computer, said first computer having a central processing unit, random access memory and a persistent storage means, said first and second computers connected by a communication medium, said method comprising the steps of:

interrogating said first computer for configuration information;

determining required objects for transfer based on an operation that considers, at least in part, said configuration information and said group of objects;

packaging said required objects into an archive;

transferring said archive to said random access memory;

setting an archive-commit flag on;

committing said archive to said persistent storage;

setting said archive commit flag off;

setting a list-commit flag on;

committing a list of said required objects to said persistent storage;

setting said list-commit flag off; and

activating said required objects in said random access memory.

2. The method according to claim 1 wherein said objects are JavaBeans beans based on the JavaBeans specification.

3. The method according to claim 1 wherein said archive is a Java ARchive.

4. The method according to claim 1 wherein said archive is committed to a repository area of said persistent storage.

5. The method according to claim 1 wherein said list is committed to a registry area of said persistent storage.

6. A system for transferring at least a portion of a group of objects between computers, comprising:

a first computer having a central processing unit, random access memory, a persistent storage repository for storing archives of objects, a persistent storage registry for storing a list of said objects, and a first network interface means, said first computer operable to execute said objects, and operable to execute a gateway object having privileges to interact with said repository and said register;

a second computer having a second interface means connectable to said first computer via a communication medium, said second computer having a file storage means for storing a group of objects, said second computer being operable to execute an application and a gateway managed object, said gateway managed object being a proxy for said gateway object so that said application can interrogate said gateway object for configuration information of said device and transfer an archive of at least a portion of said group via said gateway managed object to said gateway object, said archive packaged based on an operation that considers, at least in part, said configuration information;

such that when said gateway object receives said archive, said gateway object instructs said repository to commit said archive to said repository and a list of objects in said archive to said registry, said device setting at least one flag during said commission of said archive and said list to allow device recovery upon initialization if said device loses power during said commission.

7. The system according to claim 6 wherein said objects are JavaBeans beans based on the JavaBeans specification.

8. The system according to claim 6 wherein said archive is a Java ARchive.

9. The system according to claim 6 wherein said configuration information includes an inventory of available random access memory on said device.

10. The system according to claim 6 wherein said configuration information includes an inventory of available persistent storage on said device.

11. The system according to claim 6 wherein said configuration information includes a list of objects from said group of objects which are already resident in said device.

12. The system according to claim 6 wherein said gateway managed object is determined using the mogen tool from the Java Dynamic Management Kit.

13. The system according to claim 6 wherein said first computer is a Java-based intelligent device and said second computer is a Java-based network computing server.

14. The system according to claim 6 including a first flag set during said commission of said archive and a second flag set during said commission of said list.