Performance of compression: The clone wars #8
Description
ribzip2 uses a very naive representation of Huffman codes and also writes them in a naive way: it uses dynamically allocated arrays of enums. Also at other places the habit of representing bits as arrays of enums has large costs, in total at least 5% are spent during clone operations of these arrays.
There are basically these places where this can be eliminated by a better internal representation, e.g. a 32 bit integer (bzip2 Huffman codes are length-limited to 17 bits writing and 20 bits reading anyway).
- replace representation of huffman codes by 32 bits integers to avoid cloning of arrays
- replace bitwriter internal representation by bytes or integers
- use bit array (represented by integers, for examples) instead of arrays of enums
- store block data more efficiently instead of just using arrays of
Bitenums