Dynamic information format conversion

• US 20040220982A1
• Filed: 05/28/2004
• Published: 11/04/2004
• Est. Priority Date: 09/21/1998
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Liu, Chao-Chia, Probert, David Bradley Jr.
• Granted Patent: US 7,747,594 B2
• Time in Patent Office: Days
• US Class Current: 707/205
• CPC Class Codes: G06F 16/258 Data format conversion from or to a database
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

A software layer (filter driver) residing between software components or application programs running locally or on a client across a network and a persistent store of an operating system provides on-the-fly conversions of persistent information formats. The filter driver determines which format a program expects, and dynamically converts the information from its storage format to the format expected by the program. Conversion includes both data format conversion, and conversion of access semantics. Loadable conversion modules are provided for converting application specific formats due to the potential large number of such formats which can be encountered. The filter driver may change the format that information is stored in based on access history or other system requirements. The software components or application programs may be ignorant of the true storage format used by the system, and thus the filter driver can be used to give old versions of software access to information stored in newer formats.

Claims

1. A method of accessing files stored in a different format than desired comprising:

receiving a request for access to portions of information in a first format;

retrieving the information which is stored in a second format; and

dynamically providing a view of requested portions of the information such that the information can be accessed as though it were stored in the first format.

2. The method of claim 1 and further comprising:

invoking a dynamically loadable conversion module to convert at least portions of the information to the first format.

3. The method of claim 1 and further comprising converting changes to the information made by an entity requesting access to the file in the first format, back to the second format.

4. The method of claim 1 and further comprising:

converting all the information to the first format.

5. The method of claim 4 and further comprising the step of creating an intermediate format including caching data to aid in providing views of the information in the first and second formats.

6. The method of claim 5 wherein the cache data is persisted.

7. The method of claim 1 wherein the first format comprises a single stream structured storage format and the second format comprises a multi stream structured storage.

8. A system for converting between storage formats, the system comprising:

a filter driver that intercepts requests to access information; and

a storage system that stores information in a native format, wherein the filter driver interfaces with the storage system to retrieve information in the native format and dynamically provides an operable view of the information in a different format consistent with an intercepted request.

9. The system of claim 8 and further comprising a plurality of loadable conversion modules invokable by the filter driver to provide format conversion capabilities.

10. The system of claim 8 wherein the received request comprises an identification of a docfile format, and wherein the native format comprises an NSS format.

11. The system of claim 8 wherein the receive request comprises an identification of an application sic format, and wherein the format of the information stored on the system is of a later, different version of the application specific format.

12. A system for converting between storage formats, the system comprising:

a filter driver that intercept requests to access information stored in a first application specific format; and

a storage system that stores information in a second, different application specific format and access the information in that format, wherein the filter driver interfaces with the storage system to provide a view of the information to a requestor which emulates the first application specific format.

13. The system of claim 12 wherein the first and second formats comprise different formats for different versions of the same application program.

14. The system of claim 12 wherein the first and second formats comprise different formats for different application programs.

15. The system of claim 12 wherein the first and second formats respectively comprise a non hypertext format and a hypertext based text format.

16. The system of claim 15 wherein the hypertext format comprises HTML, and the non hypertext format comprises a proprietary word processor format.

17. A data structure for use providing views of information which may be represented in different storage system formats, the data structure comprising:

a plurality of user data streams;

a block of synthesized metadata corresponding to a first format of the information; and

a block of native format specific metadata corresponding to a native format, wherein the blocks of metadata aid in the provision of different format views of the user data streams.

18. The data structure of claim 17 wherein the first format comprises a single stream structured storage format, and the second format comprises a multi-stream structured storage format.

19. A machine readable medium having instructions stored thereon for causing a computer to perform a method of accessing information stored in a different format than desired, the method comprising:

receiving a request for access to information in a first format;

retrieving the information which is stored in a second format; and

dynamically providing a view of the information such that the information can be accessed as though it were stored in the first format.

20. The medium of claim 19 and further comprising instructions for causing the computer to invoke a dynamically loadable conversion module to provide different views of the file.

21. The medium of claim 19 and further comprises instructions for causing the computer to maintain semantics of the second format.

22. The medium of claim 19 which the first format comprises a single stream structured storage format and the second format comprises a multi stream structured storage.

23. A method of storing information in a desired format, the method comprising:

monitoring requests to access information by format type;

determining frequency of such access by format type; and

storing the information in a format type based on such frequency.

24. A method of dynamically converting between file formats on a computer system comprising:

receiving a request from a program to access a file in a first format;

accessing the file in a second format; and

dynamically converting the file to the first format transparent to said program.

25. A machine readable medium having instructions stored thereon for causing a computer to perform a method of storing files in a desired format, the method comprising:

monitoring requests to access a file by format type;

generating statistics relating file types to the number of accesses per file type; and

storing the file in a format type which is selected based on such statistics.

26. A data structure for use in emulating a first format view of a data file which is stored in a second format, the data structure comprising:

a block of first format specific metadata; and

multiple blocks of user data identified by the mete said user data corresponding to blocks of user data stored in the second format.

27. A method of accessing files stored in a different format than desired comprising:

receiving a request for access to a file in a first format;

retrieving the file which is stored in a second format;

dynamically providing a view of the file such that the file can be accessed as though it were stored in the first format; and

concurrently providing a view of the file in the second format.

28. The method of claim 27 wherein the method is performed by instructions stored on a computer readable medium.

29. The method of claim 28 wherein the instructions are part of a kernel of an operating system on a computer.

30. A method of accessing files stored in a different format than desired comprising:

receiving a request for access to a file expressed in a first format related interface; and

dynamically mapping the request for access to the file into accesses of the file stored in the second format transparent to a requestor of the file.

31. A method of accessing binary data stored in a different format than desired comprising:

receiving a request for access to portions of the binary data in a first format;

retrieving portions of the binary data which is stored in a second format; and

dynamically converting retrieved portions of both a static layout of the binary data and dynamic rules for how to access the data to provide a view of such requested portions in the first format.

32. A machine readable medium having instructions stored thereon for causing a computer to perform a method of accessing binary data stored in a different format than desired, the method comprising:

receiving a request for access to portions of the binary data in a first format;

retrieving portions of the binary data which is stored in a second format; and

dynamically converting retrieved portions of both a static layout of the binary data and dynamic rules for how to access the data to provide a view of such requested portions in the first format.