perl API : idsession CRC32 vs ord function for test Apache::Session

[Brad Fitzpatrick]

Eric,

We recently discussed this on the list and agreed to switch it to CRC32.
(not sure if you were on the list then...)

Anyway, I just got around to checking it into CVS.  I'll probably do a new
CPAN release next.

- Brad


On Tue, 27 Jul 2004, eric GERMAN wrote:

> Hi , I keep  trying memcached +  perl API +  apache::Session
>
> the keys are  like this :
>
> stats cachedump 7 4
> ITEM 5ee71b9d6c06f42898a8854d9b085ea5 [43 b; 1090916693 s]
> ITEM b37ba939c5fdf9b47af27c4a5539c3b5 [43 b; 1090916693 s]
> ITEM df1506343dd4c87ef24af32b326ee19c [43 b; 1090916693 s]
> ITEM 1ff0a0b1df2c4f47be6eb5c2f604bb5e [43 b; 1090916693 s]
>
> (generated by Apache::Session:Generate::MD5.pm  function)
>
> with the original API perl (using ord function) with 2  servers my stats
> result are :
>
> [root@portable memcached-1.1.11]# telnet  10.75.237.156 11212
> Trying 10.75.237.156...
> Connected to 10.75.237.156 (10.75.237.156).
> Escape character is '^]'.
> stats items
> END
> quit
> Connection closed by foreign host.
> [root@portable memcached-1.1.11]# telnet  10.75.237.156 11211
> Trying 10.75.237.156...
> Connected to 10.75.237.156 (10.75.237.156).
> Escape character is '^]'.
> stats items
> STAT items:7:number 99
> STAT items:7:age 41
> END
>
> ==>  Only  bucker 0  is using .
>
> When I  use  String::CRC32  I have :
>
>
>
> [root@portable memcached-1.1.11]# telnet  10.75.237.156 11212
> Trying 10.75.237.156...
> Connected to 10.75.237.156 (10.75.237.156).
> Escape character is '^]'.
> stats items
> STAT items:7:number 43
> STAT items:7:age 25
> END
> quit
> Connection closed by foreign host.
> [root@portable memcached-1.1.11]# telnet  10.75.237.156 11211
> Trying 10.75.237.156...
> Connected to 10.75.237.156 (10.75.237.156).
> Escape character is '^]'.
> stats items
> STAT items:7:number 56
> STAT items:7:age 41
> END
>
> my  diff
> [root@portable Cache-Memcached-1.0.12]# diff Memcached.pm
> Memcached.pm.good
> 15c15
> <
> ---
>  > use String::CRC32;
> 602,604c602,605
> <     foreach (split //, shift) {
> <         $hash = $hash*33 + ord($_);
> <     }
> ---
>  > $hash = (crc32(shift) >> 16) & 0x7fff;
>  > #    foreach (split //, shift) {
>  > #        $hash = $hash*33 + ord($_);
>  > #    }
>
>
> thanks
> eric german
>
>
>