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:
Dec. 10, 2019
Filed:
Oct. 31, 2013
Oracle International Corporation, Redwood City, CA (US);
David R. Chase, Belmont, MA (US);
Guy L. Steele, Jr., Burlington, MA (US);
Oracle International Corporation, Redwood City, CA (US);
Abstract
A lookup circuit evaluates hash functions that map keys to addresses in lookup tables. The circuit includes multiple hash function sub-circuits, each of which applies a respective hash function to an input key, producing a hash value. Candidate pairs of hash functions to be implemented by the hash function sub-circuits may be generated and tested for suitability in hashing a particular collection of keys. The suitability testing may include computing hash value bit vectors by applying each hash function in a candidate pair to a given key, and determining (using a modified union-find type operation that organizes objects in each set as a directed graph whose root points to itself) whether the resulting hash value bit vectors belong to the same set. The union-find type operation may include a limited distance-from-root test, path compression, or exception handling for special cases, but not a rank test.