Method and system for updating an archive of a computer file

• US 8,019,730 B2
• Filed: 03/16/2010
• Issued: 09/13/2011
• Est. Priority Date: 03/01/2000
• Status: Expired due to Fees

• Current Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Original Assignee: Computer Associates Think Inc. (Broadcom, Inc.)
• Inventors: Forster, Karl D.
• Primary Examiner(s): Truong; Cam Y T
• Application Number:
  US12/725,205
• Publication Number:
  US 20100174685A1
• Time in Patent Office: 546 Days
• Field of Search: None
• US Class Current: 707/667
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 2201/83 the solution involving signatures

Abstract

A method and system for updating an archive of a computer file to reflect changes made to the file includes selecting one of a plurality of comparison methods as a preferred comparison method. The comparison methods include a first comparison method wherein the file is compared to an archive of the file and a second comparison method wherein a first set of tokens statistically representative of the file is computed and compared to a second set of tokens statistically representative of the archive of the file. The method further includes carrying out the preferred comparison method to generate indicia of differences between the file and the archive of the file for updating the archive of the file.

Claims

1. A method for updating an archive of a computer file, the method comprising:

receiving an input selecting one of a first condition or a second condition to optimize archiving information stored on a client computer;

selecting one of a plurality of comparison methods as a preferred comparison method between a file resident on the client computer and an archive of the file resident on a server computer based on the input selecting one of the first condition or the second condition, wherein the plurality of comparison methods comprise;

comparing, in a first one of the plurality of comparison methods, individual bytes in the file resident on the client computer to corresponding individual bytes in a copy of the archive of the file, wherein the copy of the archive of the file resides on the client computer; and

partitioning, in a second one of the plurality of comparison methods, the file into a plurality of blocks, computing a first set of tokens that statistically represent the file from a cyclic redundancy code value computed for each one of the plurality of blocks, and comparing each one of the first set of tokens to a respective one of a second set of tokens that statistically represent the archive of the file, wherein the second set of tokens resides on the client computer; and

carrying out the preferred comparison method to generate one or more indicia of difference between the file resident on the client computer and the archive of the file resident on the server computer, wherein the carrying out the preferred comparison method includes conveying the one or more indicia of difference from the client computer to the server computer to update the archive of the file.

2. The method of claim 1, wherein carrying out the preferred comparison to generate the one or more indicia of difference comprises:

identifying, if the preferred comparison method comprises the first comparison method, any data words that are different between the file and the archive of the file; and

identifying, if the preferred comparison method comprises the second comparison method, any blocks of data words that are different between the file and the archive of the file.

3. The method of claim 1, wherein the first condition comprises minimizing local storage on the client computer and the second condition comprises minimizing transfer time to convey the one or more indicia of difference from the client computer to the server computer.

4. The method of claim 1, wherein selecting the one of the plurality of comparison methods as the preferred comparison method comprises evaluating one or more criteria associated with the client computer based on the selected condition, wherein a condition analysis subsystem associated with the client computer selects the first one of the plurality of comparison methods or the second one of the plurality of comparison methods as the preferred comparison method based on the one or more evaluated criteria and the selected condition.

5. The method of claim 4, wherein the one or more evaluated criteria include network bandwidth available to the client computer.

6. The method of claim 4, wherein the one or more evaluated criteria include a size associated with the file resident on the client computer.

7. The method of claim 4, wherein the one or more evaluated criteria include a type associated with the file resident on the client computer.

8. The method of claim 4, wherein the client computer conveys the one or more indicia of difference to the server computer over a network connection.

9. The method of claim 8, wherein the one or more evaluated criteria include a reliability or a cost associated with the network connection.

10. The method of claim 4, wherein the one or more evaluated criteria include storage space available on a hard disk associated with the client computer, operating efficiency associated with the hard disk, fragmentation associated with the hard disk, or information relating to an interface between the hard disk and a processor associated with the client computer.

11. The method of claim 1, wherein the copy of the archive of the file resides on the client computer in a compressed form and the plurality of comparison methods further comprise decompressing, in the first one of the plurality of comparison methods, the copy of the archive of the file and comparing each individual byte in the file resident on the client computer to corresponding individual bytes in the decompressed copy of the archive of the file.

12. A system for updating an archive of computer file, the system comprising:

a hard disk configured to store a file on a client computer;

a comparison subsystem configured to receive an input selecting one of a first condition or a second condition to optimize updating an archive of the file stored on a server computer;

a byte difference engine configured to compare individual bytes in the file stored in the hard disk to corresponding individual bytes in a copy of the archive of the file, wherein the copy of the archive of the file resides on the client computer;

a block difference engine configured to partition the file into a plurality of blocks, compute a first set of tokens that statistically represent the file from a cyclic redundancy code value computed for each one of the plurality of blocks, and compare each one of the first set of tokens to a respective one of a second set of tokens that statistically represent the archive of the file, wherein the second set of tokens resides on the client computer; and

a processor configured to;

select one of the byte difference engine or the block difference engine as a preferred difference engine based on the input selecting one of the first condition or the second condition;

generate one or more indicia of difference between the file stored in the hard disk and the archive of the file stored on the server computer using the preferred difference engine; and

convey the one or more indicia of difference from the client computer to the server computer to update the archive of the file.

13. The system of claim 12, further comprising a network interface configured to transfer the one or more conveyed indicia of difference from the client computer to the server computer over a network connection between the client computer and the server computer.

14. The system of claim 13, further comprising a condition analysis subsystem configured to evaluate one or more criteria associated with the client computer based on the selected condition, wherein the processor is further configured to select the byte difference engine or the block difference engine as the preferred difference engine based on the one or more evaluated criteria.

15. The system of claim 14, wherein the one or more evaluated criteria include available bandwidth, a reliability, or a cost associated with the network connection.

16. The system of claim 14, wherein the one or more evaluated criteria include a size or a type associated with the file stored in the hard disk.

17. The system of claim 14, wherein the one or more evaluated criteria include available storage space on hard disk, operating efficiency associated with the hard disk, fragmentation associated with the hard disk, or information relating to an interface between the hard disk and the processor.

18. The system of claim 12, wherein the copy of the archive of the file resides on the client computer in a compressed form and the byte difference engine is further configured to decompress the copy of the archive of the file and compare each individual byte in the file stored in the hard disk to corresponding individual bytes in the decompressed copy of the archive of the file.