Deflate compression algorithm

摘要

A compression algorithm replaces duplicative strings with a copy pair indicating a location and length of a preceding identical string that is within a window from the duplicative string. Rather than a replacing a longest matching string within a window from a given point with a copy pair, the longest matching string may be used provide it is at least two bytes larger than the next longest matching string or is at a distance that is less than some multiple of a distance to the next longest matching string. In another aspect, the length of the window in which a matching string may be found is dependent on a length of the matching string. In yet another aspect, rather than labeling each literal and copy pair to indicate what it is, strings of non-duplicative literals are represented by a label and a length of the string.

主权项

1. A method for compression, comprising:
determining a longest candidate string for de-duplication starting at a current point in a data file that has a matching string preceding the current point subject to a condition; wherein the condition comprises the matching string having a length greater than a length of a previously determined matching string by at least one more unit than a minimum length parameter; and wherein the minimum length parameter comprises an integer.