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:
Jan. 05, 1999
Filed:
Jul. 19, 1996
Richard L Angle, Wellesley, MA (US);
Edward S Harriman, Jr, Bedford, MA (US);
Geoffrey B Ladwig, Chelmsford, MA (US);
Bay Networks, Inc., Santa Clara, CA (US);
Abstract
A computer implemented method for searching for a key in a radix search tree in a memory of a computer system. A table of keys is organized in a radix search tree stored in a memory of a computer system. The keys are divided into a string of symbols. Each node in the tree corresponds to a symbol. A path from a root node to a leaf node at level n in the tree represents a string of n symbols comprising a key. Each node is capable of having m possible entries corresponding to m possible symbol values. Each entry comprises a pointer to a son node and an existence map indicating which entries exist in the son node. In the preferred embodiment, the existence map is a bit mask that indicates, based on bit positions enabled and disabled in the bit mask, which entries exist in the son node pointed to by the pointer. By providing an existence map along with the pointer to a son node, m memory locations for m entries are allocated for the son node only if all of the m possible entries are used. Memory locations for entries that would otherwise be empty are not allocated, thereby minimizing memory resources required by a radix search tree.