Deterministic lookup using hashed key in a multi-stride compressed trie structure
US7827218B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 2007 |
| Grant date | Nov 2, 2010 |
| Priority date | — |
| Expiry date | Sep 1, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/2264
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An input lookup key is hashed and the hashed key divided into stride bits into a multi-level Trie structure. A compression function logically combines the stride bits to generate the compressed index bits into the stride tables. The bucket in the last stride table found by the hashed key may have several keys that collide at the same hash value. Discriminant bits are read from the key and select a stored key in the bucket table for verification of its result. Since the hashed key is a compression of the longer input key, more information is contained per bit of the hashed key than in the long key. The multi-stride lookup is performed first on the hashed key, allowing a faster convergence to the lookup result. The first stride can index a single hash table, with the remaining hash bits and discriminant bits used to select from among colliding keys.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.