Patent ID: 8653992

Claim:
A method comprising: performing a compression operation on a data file using an LZ77 compressor and Huffman coded entries and literals; storing intermediate results of the compression operation in memory; selecting a hashing technique for accessing the stored intermediate results, wherein the hashing technique is selected based on one or more features of the intermediate results; iteratively refining the compression operation via backward reference of the stored intermediate results of the compression operation, wherein the refining includes accessing stored intermediate results using the selected hashing technique and selecting one or more entries and literals associated with an increased compression based on cost estimates from a cost model, wherein the cost estimates are represented as floating point numbers; and stopping the refining when a termination condition is reached, the termination condition including one or more of performing a predefined number of iterations, selecting a candidate shortest path having a higher actual total bit cost than a current shortest path, and reaching a steady state of actual total path bit cost.