If I understand it correctly, this implementation re-compresses the prefix 256 times, once for each possible byte continuation. It should be possible to save a

If I understand it correctly, this implementation re-compresses the prefix 256 times, once for each possible byte continuation. It should be possible to save a lot of work by saving the state of the compressor just before the predicted byte, and reusing it. Also, since gzip works on a limited sliding context window, it's probably pointless to give it a prefix much longer than the window... unless there's something about the algorithm that I'm missing. Same with bzip2 and its block size.