Patent ID: 7346059

Claim:
A method for efficiently searching a hash table containing a plurality of ranges, the method comprising: performing one or more preliminary range checks on at least one target value, each preliminary range check generating an output value having a value dependent on whether the target value is included in a predefined range of values associated with the preliminary range check; combining signature information with the output values generated by the preliminary range checks to generate a modified signature; applying a predetermined function to the modified signature to derive an index that references a hash-table entry in the hash table; locating a searchable data structure associated with the hash-table entry referenced by the index, the searchable data structure comprising one or more search nodes, at least one of the search nodes configured to store one or more target-value ranges associated with the target value; searching the search nodes in the searchable data structure until a matching search node is found whose stored target-value ranges associated with the target value include the target value; and providing information associated with the matching search node.