On Sun, Aug 10, 2014 at 04:51:44PM +0200, Jean-Pierre André wrote: > > I gather the crc polynomial you propose has proved > efficient in other compression algorithm, and is > supposed to be stable. Then a simpler way is to > compute the table once for all, and encode it as an > array of constants. Just comment out the encoding > function in case someone would like to test other > polynomials. >
The proposed hash function is borrowed from LZMA, the algorithm used by xz. The CRC polynomial is standard; it's widely used for checksums (Ethernet, PNG, zlib, bzip2, etc.). The main consideration is how to actually use the CRC32 table to hash 3 bytes. A true CRC would checksum all three bytes, but the current proposal only does a CRC on the first byte, then mixes the other two bytes into the hash, which is what LZMA does. I agree that a hard-coded table is the simplest solution if CRC32 is retained in the hash function. I'll post a patch for that unless I decide a different hash function is preferable. Eric ------------------------------------------------------------------------------ _______________________________________________ ntfs-3g-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ntfs-3g-devel
