Patent ID: 9632760
Date: 2017-04-25
CPC Classifications: G06F,G06T,H04L

Claim:
1. A computer-implemented method comprising: receiving a request to compute, for an overall range of indexes comprising set indexes having non-default values and unset indexes having default values, all contiguous ranges of unset indexes within the overall range of indexes, wherein the overall range of indexes is represented by a tiered array having a plurality of tiers, wherein each tier of the tiered array comprises one or more catalogs, wherein each catalog in each tier, except for a bottom-most tier, comprises (i) non-default elements that each identify a respective catalog at a lower tier and (ii) default elements that do not identify any catalogs, and wherein each bottom-most catalog in the bottom-most tier comprises one or more non-default elements having non-default values, each non-default value being stored at a respective index value in the bottom-most catalog; setting a reference index to be initially equal to a minimum index, the minimum index corresponding to an index that is first in an ordering of the overall range of indexes; performing a search, from the reference index, for a first range [a0, b0] of contiguously set indexes having non-default values, wherein a0 is a first index in the first range of contiguously set indexes and b0 is a last index in the first range of contiguously set indexes, wherein the index a0 is a first index in the tiered array having a non-default value; if a0 is greater than the minimum index, generating a range of indexes [0, a0−1] having default values, wherein a0−1 is a last index in the range of indexes having default values; repeatedly performing the following operations until an end of the tiered array is reached: providing, in response to the request, the generated pairs of index values representing the contiguous ranges of unset indexes within the overall range of indexes.