Dynamic information format conversion

• US 6,745,176 B2
• Filed: 02/21/2003
• Issued: 06/01/2004
• Est. Priority Date: 09/21/1998
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Liu, Chao-Chia, Probert, David Bradley Jr.
• Primary Examiner(s): Rones, Charles
• Application Number:
  US10/371,492
• Publication Number:
  US 20030130999A1
• Time in Patent Office: 466 Days
• Field of Search: 709/230, 709/225, 707/100, 707/204, 707/10, 707/2, 707/203, 380/277
• US Class Current: 709/230
• 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 transparently give old versions of software access to information stored in newer formats.

Claims

1. A method of storing information in a desired format type that a program can handle, the method comprising:

monitoring requests from programs to access information by desired format type;

determining frequency of such access by desired format type; and

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

2. The method of claim 1, further comprising:

comparing the frequency of such access with a threshold frequency; and

storing the information in a format type based on such frequency as compared to the threshold frequency.

3. The method of claim 1, wherein the act of storing comprises:

calculating resource metrics for the information in a current format type;

selecting a candidate format type based on the determined frequency;

calculating resource metrics for the information in the candidate format type;

comparing the resource metrics for the information in the current format type with the resource metrics for the information in the candidate format type; and

storing the information in the candidate format type based on the comparison.

4. The method of claim 1, further comprising:

choosing one or more candidate format types from the frequency determination;

predicting an overhead prediction for computing resources required for dynamic conversion of the information to each of the candidate format types chosen;

comparing each overhead to select a desired format type;

calculating an amount overhead required to translate the information into the desired format type; and

storing the information in the desired format type based on the calculation.

6. The machine readable medium of claim 4, wherein the method of file storing further comprises:

evaluating the generated statistics against a statistical threshold; and

storing the file in a format which is selected based on the generated statistics if the threshold is reached.

7. The machine readable medium of claim 4, wherein the act of generating statistics comprises:

estimating a resource cost of dynamic conversion of the file in a current format to a new format;

estimating a resource cost of file translation of the file in the current format to the new format; and

comparing the resource cost of dynamic conversion of the file to the new format with the resource cost of file translation of the file to the new format.

8. The machine readable medium of claim 4, wherein the act of generating statistics comprises:

selecting a plurality of candidate storage formats based on the monitored requests;

predicting an overhead prediction for an amount of overhead required by dynamic conversion of the information to each of the candidate storage formats selected; and

comparing the overhead predictions to select a desired format.

5. 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 from programs to access a file in a desired format, each request desiring a format in which to access the file;

generating statistics relating desired formats to the number of accesses to the file per desired format type; and

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