From: Eleanor McHugh <eleanor@...>
Date: 2009-11-09T22:06:19+09:00
Subject: Re: FileString - request for comments

On 9 Nov 2009, at 13:54, apeiros@gmx.net wrote:
> Hi Joel
>
>> What would the advantage over mmap[1] be? FileString is pure ruby
>> (right?) and hence more portable, but probably mmap is much more
>> efficient? Any other tradeoffs?
>
> Interesting, I was looking if a solution existed already and didn't  
> find mmap. Yes, FileString is pure ruby and should therefore run on  
> all ruby implementations. And yes, I'd expect mmap to be more  
> efficient on the other hand. It'd be interesting to combine the two  
> (if that's at all possible).
> In a quick test it seems FileString is more complete too, e.g. Mmap  
> doesn't have #replace (should be trivial to add). But Mmap has the  
> feature to only tie a part of the file.

It would probably be fairly trivial for you to directly support mmap  
at the OS level using Ruby/DL, Ruby-FFI or even syscall (although  
that's ugly and fragile). Take a look at some of my Plumber's Guide  
presentations at the link in my signature and also at http://kenai.com/projects/ruby-ffi 
  for details of how to wrap these kinds of system calls such that  
they'll run identically on JRuby, Rubinius and MRI.


Ellie

Eleanor McHugh
Games With Brains
http://slides.games-with-brains.net
----
raise ArgumentError unless @reality.responds_to? :reason