Method and system for accessing chunks of data using matching of an access tab and hashing code to generate a suggested storage location
US5754844A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1995 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Dec 14, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99942
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In the tagged, hashed file system, each finite portion of a file of the user's data is tagged with a pathname (filename and path) and a logical offset of the data within the file. A hint, as to where the portion is located in storage in the THFS, is computed by hashing the pathname and the logical offset. Once the hint is provided, then the THFS commences to search storage from the location suggested by the hint until it finds a match between the tag on the portion with the pathname and logical offset. When a portion is to be written, the intended location for placement of the portion must be read to ensure that it is available for writing, i.e. empty. If the location is not available, then a search must be made for the closest available (empty) location, and the user data is written there. If during a read operation a matched tag is not found until an empty area is read, the search will terminate, and the user application will be notified that no file was found.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.