Then i find a corner case where LZ4 does not work so well. Having a sanity check on loong, a file created by Eugene Shelwien, initially to torture range coders with limit conditions, i discovered to my surprise that the decoding speed was not good enough, "only" 500MB/s; unexpected, as i was looking for something much closer to a few Gigabytes.
Looking back into the source, my understanding was that the code in charge of overlapping sequences was too cautious. With just a little more complexity, it could be made much faster.
Overlapping sequences are not too often, but they happen here and there, in each and every file. As a consequence, it resulted in a generic speed boost to all files for decoding.
Logical follow-up, here comes the release of a new LZ4 version, breaking some new decompression speed records. You can download them on LZ4 Homepage.
|LZ4 "Ultra Fast"||0.6||2.062||232 MB/s||805 MB/s|
|LZ4HC "High Compression"||0.9||2.345||38.2 MB/s||880 MB/s|
Talking about bragging around the world...