Re: Hash collision count

From: Petr Baudis <pasky@ucw.cz>
Date: Apr 26, 2005, 00:00 UTC
Message-ID: <20050426000017.GN13467@pasky.ji.cz>
In-Reply-To: <200504252350.QAA02241@emf.net>

Dear diary, on Tue, Apr 26, 2005 at 01:50:31AM CEST, I got a letter where Tom Lord <lord@emf.net> told me that...

Show 13 quoted lines

> 
>   From: Petr Baudis <pasky@ucw.cz>
> 
>   Pasky:
> 
>   > No, a collision is pretty common thing, actually. It's the main power of
>   > git, actually - when you do read-tree, modify it and do write-tree
>   > (typically when doing commit), everything you didn't modify (99% of
>   > stuff, most likely) is basically a collision - but it's ok since it
>   > just stays the same.
> 
> That is not the way people ordinarily use the word "collision".
> It's pretty much the opposite of the normal way, actually.

You need to quote me in the context of Jeff Garzik's

> > Third, a data check only occurs in the highly unlikely case that a hash
> > already exists -- a collision.  Rather than "trillions of times", more
> > like "one in a trillion chance."

I just wanted to point out that the data check would hahve to occur everytime you didn't modify an object.

Kind regards,

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor