[Omake] SVN Commit: Mojave standard library (Rev. 12016)

[Jason J. Hickey]

Our hash was a little weak.  Specifically, any sequence of text where
the characters code sum up to 6229 can be pumped without changing
the hash.

Changed this:
            digest.(i) <- digest.(i) lxor (Array.unsafe_get hash_data (code + i))

To this:
            digest.(i) <- (digest.(i) * 3) lxor (Array.unsafe_get hash_data (code + i))

This is from the s-box implementation at http://bretm.home.comcast.net/hash/10.html

I did some performance analysis, checking build times for omake.  It is lost
in the noise at least on MacOS/Intel.

However, if performance is an issue we could to the shift and add (might be
faster than an multiply):

   x <- ((x lsl 1) + x) lxor y

BTW, this topic isn't entirely random.  I was working on a hash example
for the book.

----
Changes in libmojave/util:
    +2 -2       lm_hash.ml
 
A hyperlinked version of this commit is available at
http://svn.metaprl.org/commitlogs/libmojave/2007-08.html#07/08/23.15:13:20