On Oct 27, 10:15 pm, k...@rice.edu (Kenneth Marshall) wrote:
> Dear PostgreSQL Developers,
>
> This patch is a "diff -c" against the hashfunc.c from postgresql-8.3beta1.
> It implements the 2006 version of the hash function by Bob Jenkins. Its
> features include a better and faster hash function. I have included the
> versions supporting big-endian and little-endian machines that will be
> selected based on the machine configuration.
[snip]
I have some question concerning Bob Jenkins' functions
hashword(uint32_t*, size_t), hashlittle(uint8_t*, size_t) and
hashbig(uint8_t*, size_t) in lookup3.c.
Let k1 by a key: uint8_t* k1; strlen(k1)%sizeof(uint32_t) == 0.
1. hashlittle(k1) produces the same value on Little-Endian and Big-
Endian machines.
Let hashlittle(k1) be == L1.
2. hashbig(k1) produces the same value on Little-Endian and Big-Endian
machines.
Let hashbig(k1) be == B1.
L1 != B1
3. hashword((uint32_t*)k1) produces
* L1 on LittleEndian machine and
* B1 on BigEndian machine.
---------------------
The question is: is it possible to change hashword() to get
* L1 on Little-Endian machine and
* B1 on Big-Endian machine
?
Thanks.
Alex Vinokur
email: alex DOT vinokur AT gmail DOT com
http://mathforum.org/library/view/10978.html
http://sourceforge.net/users/alexvn
