Annotation validity using partial checksums

• US 20040111668A1
• Filed: 12/04/2002
• Published: 06/10/2004
• Est. Priority Date: 12/04/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cragun, Brian J., Rapp, William C.
• Granted Patent: US 7,392,267 B2
• Time in Patent Office: Days
• US Class Current: 715/512
• CPC Class Codes: G06F 40/169 Annotation, e.g. comment data or footnotes

Abstract

Embodiments of the present invention generally provide a system, method and article of manufacture for validating annotations describing one or more portions of a data object. In general, prior to displaying a requested annotation, a current change detection value may be calculated from current data extracted from portions of the data object described by the annotation. The current change detection value may be compared to a previously saved change detection value calculated from data extracted from the portions of the data object at the time the annotation was generated. A mismatch in the current change detection value and the previously saved change detection value indicates a change in the annotated portions of the data object, which may render the annotation invalid. The annotated portions of the data object may be continuous or discontinuous.

Claims

1. A method comprising:

creating an annotation for one or more portions of a data object;

calculating at least a first change detection value on data extracted from the one or more portions; and

creating an annotation record containing the first change detection value and the annotation.

2. The method of claim 1, wherein calculating at least a first change detection value on data extracted from the one or more portions comprises calculating a separate change detection value for each of the one or more portions.

3. The method of claim 1, wherein the one or more portions of the data object comprise discontinuous portions.

4. The method of claim 3, further comprising:

extracting data from the one or more portions of the data object into a buffer; and

calculating the change detection value from the extracted data in the buffer.

5. The method of claim 4, further comprising:

receiving a request for the annotation created for the one or more portions of the data object;

calculating a second change detection value on data extracted from the one or more portions after receiving the request for the annotation;

retrieving the first change detection value from the annotation record;

comparing the second change detection value to the first change detection value; and

providing an indication that the one or more portions of data have changed in response to determining the second change detection value and first change detection value do not match.

6. The method of claim 5, wherein providing an indication that the one or more portions of data have changed comprises displaying an error message.

7. The method of claim 5, wherein providing an indication that the one or more portions of data have changed comprises displaying the annotation and providing an indication the one or more portions of data described by the displayed annotation have changed.

8. The method of claim 7, wherein providing an indication the one or more portions of data described by the displayed annotation have changed comprises at least one of:

changing an appearance of the displayed annotation or related text relative to an appearance of the displayed annotation or related text when displayed when the one or more portions of data have not changed; and

adding, removing, or changing a graphical icon.

9. The method of claim 1, wherein the one or more portions of data comprise annotations.

10. The method of claim 9, wherein calculating the first change detection value comprises retrieving change detection values calculated for data associated with the other annotations and calculating the first change detection value based on the retrieved change detection values.

11. A method for determining validity of an annotation, comprising:

(a) calculating a current change detection value for data extracted from one or more portions of a data object referenced by the annotation;

(b) comparing the current change detection value to a previous change detection value calculated for data extracted from the one or more portions of the data object; and

(c) if the current and previous change detection values do not match, providing an indication to a user that the annotation is possibly invalid due to a change in the one or more portions of the data object.

12. The method of claim 11, wherein the operations (a)-(c) are performed in response to receiving a request, from a user, for the annotation.

13. The method of claim 11, wherein the operations (a)-(c) are performed periodically.

14. The method of claim 11, wherein providing an indication to the user that the annotation is possibly invalid comprises displaying the annotation with an indication the one or more portions of the data object referenced by the annotation have changed.

15. The method of claim 11, further comprising providing the user the option to overwrite the previous change detection value with the current change detection value.

16. The method of claim 11, further comprising providing the user the option to edit the annotation.

17. The method of claim 11, further comprising providing the user the option to delete the annotation.

18. A computer-readable medium containing a program which, when executed by a processor, performs operations comprising:

receiving, from a user, a request for an annotation for one or more portions of a data object;

calculating a current change detection value for data extracted from the one or more portions in response to receiving the request;

comparing the current change detection value to a previous change detection value calculated for data extracted from the one or more portions prior to receiving the request; and

if the current and previous change detection values do not match, indicating to the user that the requested annotation is invalid due to a change in the one or more portions of the data object.

19. The computer-readable medium of claim 18, wherein the operations further comprise providing the user with options comprising at least one of:

editing the annotation;

overwriting the previous change detection value with the current change detection value to reflect the change in the one or more portions of the data object; and

deleting the annotation.

20. The computer-readable medium of claim 18, wherein the operations further comprise, prior to receiving the request for the annotation:

creating the requested annotation;

calculating the previous change detection value; and

creating an annotation record containing an index to the one or more portions, the current change detection value, and the requested annotation.

21. The computer-readable medium of claim 20, wherein the one or more portions of the data object comprise discontinuous portions.

22. The computer-readable medium of claim 21, further comprising:

extracting data from the one or more portions of the data object to a buffer; and

calculating the change detection value on the data extracted to the buffer.

23. The computer-readable medium of claim 20, further comprising storing the annotation record in an annotation database.

24. An annotation system comprising:

an annotation database;

an annotation generation component configured to generate an annotation for one or more portions of a data object, calculate at least a first change detection value on data extracted from the on one or more portions of the data object, create an annotation record containing the first change detection value and the generated annotation, and store the annotation record in the annotation database; and

an annotation validation component configured to calculate at least a second change detection value on data extracted from the one or more portions of the data object in response to receiving a request for the generated annotation from a user, compare the first and second change detection values, and provide an indication to the user that the one or more portions of the data object have changed if the first and second change detection values do not match.

25. The annotation system of claim 24, wherein the one or more portions of the data object comprise discontinuous data elements.

26. The annotation system of claim 24, wherein the annotation generation component and the annotation validation component are configured to calculate change detection values for each of the one or more portions of the data object.

27. The annotation system of claim 24, wherein the annotation validation component is configured to provide an indication to the user that the one or more portions of the data object have changed by generating a message.

28. The annotation system of claim 27, wherein the generated message includes the requested annotation.

29. The annotation system of claim 27, wherein the annotation validation component is further configured to provide the user with the option of overwriting the first change detection value with the second change detection value.

30. The annotation system of claim 27, wherein the annotation validation component is further configured to provide the user with the options of editing or deleting the requested annotation.