The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 2001
Filed:
Jun. 24, 1998
Jonathan Forbes, Bellevue, WA (US);
Microsoft Corporation, Redmond, WA (US);
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 larger matching string in previous data files by referencing the lookup tables and displacement indexes associated with the previous data files.