Re: fuzzy check sums

[http://dummy.us.eu.org/robert (Robert)]

Sorry about the "spam" thing.  I screwed up.

 > From: Michael Grant <http://www.grant.org/~mgrant>
 > Date: Tue, 02 Apr 2002 21:50:15 +0200
 >
 > I didn't post the code, nobody ever got back to me.  What do you think,
 > shall I post it to the list or what?  Having read the list the last few
 > days, it's more of a questions list and not a dev list so I wasn't sure
 > if it was the correct venu.  Are you one of the developers of dcc?

No, I'm not a DCC developer.  I was mainly interested in your algorithm
since I have my own fuzzy checksum program.  (See
http://dummy.us.eu.org/robert/software/fuzzysum/index.shtml .)

 > I've attached 2 files, essence4.c and essence6.c.  The main difference
 > is that essence6 is sensitive to line breaks.  It's been several weeks
 > since I looked at this stuff, I sure hope I'm sending you the correct
 > files!  I did most of my testing with essence6.  I have 9 different
 > functions I played with, so there's some room for confusion.
 > 
 > You'll need to get the gnu arbitrary percision math lib, libgmp from
 > your favorite gnu server.
 > 
 > I'd be happy to put one or both of these sums into a form that can be
 > included into the dcc project if there's interest.  At the moment, they
 > read stdin and print out a relatively long number on stdout.  Try adding
 > or deleting a line from the imput file and running it again.  The output
 > should be the same or very similar down to nearly the final digits.
 > Obviously these fuzzy sums work best with large files and few mods.  The
 > good news is that you can always chop the number at a certain number of
 > digits to make them fuzzier.  You'll have to do that anyway since dns
 > limits the overall length of a name which can be searched for.  Also
 > need to compact the number to use all available bits.  I'm perfectly
 > willing to do this, I just haven't yet since I was first experimenting
 > with fuzzy functions first.
 > 
 > Let me know what you think.

I'll look 'em over.

 > -Mike
 > 
 > p.s. also, please don't repost this with my email address, use
 > http://www.grant.org/~mg-dcc instead, cheers.

Right.  I understand.