Patent ID: 8862555
Filing Date: 2014-10-14
Classification: G06F

Abstract:
1. A computer-implemented method for generating difference data between reference and target files, the method being performed using a computer including at least a processor, data storage, and computer-readable instructions, and the method comprising: receiving the reference file and the target file by a difference engine implemented on the computer; and performing a first procedure by the difference engine to generate difference data representing the difference between the reference and target files if the reference and target files are both sorted according to a same lexical ordering, wherein the first procedure comprises a first stage that identifies copy and add instructions with incremented sequences of sorted records in the reference and target files and a second stage that packs and encodes a first difference file; and performing a second procedure to generate the difference data if the reference and target files are not sorted according to the same lexical ordering and the size of the reference file is less than a first threshold size, wherein the second procedure comprises a first stage that pre-processes the reference file to create a hash table, a second stage that identifies copy operations with sub-string matches, and a third stage that packs and encodes a second difference file.