Cross-file pattern-matching compression
US6226628A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 24, 1998 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Jun 24, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99942
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of providing data files includes compressing the files using a cross-file compression technique. The technique makes use of ancillary files that are stored along with the data files. The ancillary files include lookup tables and indexes. A lookup table for a data file indicates the position of the last occurrence of individual data values within the data file. Each displacement index for a data file indicates displacements from respective data elements to prior strings of a particular match length that match strings of the particular match length begun by the respective data elements. Indexes corresponding to different match lengths are provided. In response to client requests for subsets of available data files, a server compresses each subset of data files using a pattern-matching compression scheme that attempts to represent given strings by referencing prior matching strings across file boundaries. To find a prior matching string for a string begun by a current data element in a current data file, the server finds a previous matching string in the current data file by referencing the displacement indexes associated with the current data file, and then searches for a la…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.