good news are always nice to hear! great work :) The incremental checksum feature sounds especially cool, instead of scanning from the start. It would be cool to watch the checksum changes continuously after every passing buffer. ;-)
Kobi Doug Coleman wrote: > Hi all, > > I wrote the MD5 and SHA1 checksums a very long time ago, before Factor > had all the great abstractions it has now. I just finished rewriting > them with all using modern coding style and more features. > > First, all of the state for the checksum computations is now kept in > tuples instead of in dynamic variables. Doing it this way should be a > lot faster when it's fully optimized sometime later. > > Also, the algorithms are now incremental, and there are new words to > add bytes/streams/files to the checksum without having to ask for the > answer immediately. You can call ``get-checksum'' at any time for the > current checksum, which clones the relevant state (very small > overhead) and returns the checksum at that point. You can resume > adding bytes to the same checksum state. > > Building HMAC and checksum interleave with the above features is now > trivial. The HMAC is a way of combining a key or password with the > data you want to checksum. You can transmit the HMAC'd checksum to a > server that has your key can verify that the data came from you. An > interleaved checksum hashes together all the odd bytes of the input, > and then all the even bytes, and then recombines them, alternating > bytes for a sequence of bytes that is twice the length of a regular > checksum. > > The SHA1 and SHA2 words are now in basis/checksums/sha. > > If someone wants to implement SHA-384 and SHA-512 for fun, go ahead. > Otherwise, I'll do it eventually. > > > Doug > > ------------------------------------------------------------------------------ > Crystal Reports - New Free Runtime and 30 Day Trial > Check out the new simplified licensing option that enables > unlimited royalty-free distribution of the report engine > for externally facing server and web deployment. > http://p.sf.net/sfu/businessobjects > _______________________________________________ > Factor-talk mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/factor-talk > ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Factor-talk mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/factor-talk
