Hash Function change between PHP4 and PHP5

php.internals

Stefan Esser

20 years ago
Hello, I just realised, that between PHP4 and PHP5 we changed the hash function used within zend_hash.h from DJBX33X to DJBX33A. The diff is here => http://cvs.php.net/diff.php/ZendEngine2/zend_hash.h?ws=0&r1=1.57&r2=1.58&ty=u Does anyone remember the exact reason for that? Or was the change done by accident when the loops were unrolled? I have no idea if there is a big difference for our hashing needs, but I am just curious if we changed it because of benchmarks... Stefan Esser
-- -------------------------------------------------------------------------- Stefan Esser sesser@php.net Hardened-PHP Project http://www.hardened-php.net/ GPG-Key gpg --keyserver pgp.mit.edu --recv-key 0x15ABDA78 Key fingerprint 7806 58C8 CFA8 CE4A 1C2C 57DD 4AE1 795E 15AB DA78 --------------------------------------------------------------------------

Marcus Börger

20 years ago
Hello Stefan, as said in private already. This pretty much looiooks like a take over problem. And as a sidenote, loop unwinding with string algorithmns should take care of byte alignment. Both said the code is damn wrong. marcus Sunday, November 20, 2005, 4:37:17 PM, you wrote:
> Hello,
> I just realised, that between PHP4 and PHP5 we changed the hash function > used within zend_hash.h from DJBX33X to DJBX33A. The diff is here => > http://cvs.php.net/diff.php/ZendEngine2/zend_hash.h?ws=0&r1=1.57&r2=1.58&ty=u
> Does anyone remember the exact reason for that? Or was the change done > by accident when the loops were unrolled? I have no idea if there is a > big difference for our hashing needs, but I am just curious if we > changed it because of benchmarks...
> Stefan Esser
> -- > -------------------------------------------------------------------------- > Stefan Esser sesser@php.net > Hardened-PHP Project http://www.hardened-php.net/
> GPG-Key gpg --keyserver pgp.mit.edu --recv-key 0x15ABDA78 > Key fingerprint 7806 58C8 CFA8 CE4A 1C2C 57DD 4AE1 795E 15AB DA78 > --------------------------------------------------------------------------
Best regards, Marcus