NAME¶
Digest::JHash - Perl extension for 32 bit Jenkins Hashing Algorithm
SYNOPSIS¶
use Digest::JHash qw(jhash);
$digest = jhash($data);
# note that calling jhash() directly like this is the fastest way:
$digest = Digest::JHash::jhash($data);
DESCRIPTION¶
The "Digest::JHash" module allows you to use the fast JHash hashing
algorithm developed by Bob Jenkins from within Perl programs. The algorithm
takes as input a message of arbitrary length and produces as output a 32-bit
"message digest" of the input in the form of an unsigned long
integer.
Call it a low calorie version of MD5 if you like.
See
http://burtleburtle.net/bob/hash/doobs.html for more information.
FUNCTIONS¶
- jhash($data)
- This function will calculate the JHash digest of the "message"
in $data and return a 32 bit integer result (an unsigned long in the
C)
EXPORTS¶
None by default but you can have the
jhash() function if you ask nicely.
See below for reasons not to use Exporter (it is slower than a direct call)
SPEED NOTE¶
If speed is a major issue it is roughly twice as fast to do call the
jhash() function like Digest::JHash::jhash('message') than it is to
import the
jhash() method using Exporter so you can call it as simply
jhash('message'). There is a short script that demonstrates the speed of
different calling methods (direct, OO and Imported) in examples/oo_vs_func.pl
AUTHORS¶
The JHash implementation was written by Bob Jenkins <bob_jenkins [at]
burtleburtle [dot] net>.
This perl extension was written by Andrew Towers <mariofrog [at] bigpond
[dot] com>.
A few mods were added by James Freeman <airmedical [at] gmail [dot] com>).
SEE ALSO¶
http://burtleburtle.net/bob/hash/doobs.html
LICENSE¶
This package is free software and is provided "as is" without express
or implied warranty. It may be used, redistributed and/or modified under the
terms of the Artistic License 2.0. A copy is include in this
distribution.