From: Tim Pease <tim.pease@...>
Date: 2007-01-17T04:51:42+09:00
Subject: Re: efficient access to a large int32 array

On 1/16/07, Christian Neukirchen <chneukirchen@gmail.com> wrote:
> "Martin DeMello" <martindemello@gmail.com> writes:
>
> > I have a file that is a dump of a large array of 32-bit unsigned ints
> > (bitvectors actually). All I need is to load this into memory and have
> > fast, efficient access to the array members, and a few bitmasking
> > operations - the array will never be written to, and ideally should
> > not need to be bounds-checked. Should I be looking at something like
> > mmap or narray to do this, or would I be better served by a custom C
> > extension?
>
> I think Ara has been hacking some package to use Narray on mmap'ed
> files, which works fast and is persistent.  Search the archives.
>

http://codeforpeople.com/lib/ruby/nmap/

You'll need to install Guy's mmap package ...

http://moulon.inra.fr/ruby/mmap.html

Blessings,
TwP