# Fast 32 bit ints in ruby?

**URL:** <https://www.ruby-forum.com/t/fast-32-bit-ints-in-ruby/76749>\
**Category:** Ruby\
**Created:** [November 20, 2006, 9:42pm UTC](https://www.ruby-forum.com/t/fast-32-bit-ints-in-ruby/76749 "2006-11-20T21:42:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![devesh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/977dab/32.png) [@devesh](https://www.ruby-forum.com/u/devesh)\
**Post date:** [November 20, 2006, 9:42pm UTC](https://www.ruby-forum.com/t/fast-32-bit-ints-in-ruby/76749/1 "2006-11-20T21:42:12Z")

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Hi Folks,

I want an efficient implementation of an Ipaddress class. The ones I  
have seen (for eg: lib/ipaddr.rb) all represent things internally in  
the form of a Bignum. And that is turning out to be a bottleneck for  
me. Ideally I would want to create some kind of a class, in which I can  
wrap in a normal C int and then operate with it directly. Does anyone  
know of how to do this ?. Another way would be to create a struct  
wrapping this int and then access that from my C extension (Like it is  
done with the Jukebox example in the Pickaxe book). I am new to ruby  
and to mixing C and ruby. What would be a good way to achieve the  
following interface:

class IPAddress

```
# Some code to declare @magicCInt as a C type int
# magicCInt is a good'ol C type int (of full 32 bits)
# It is not a Bignum/Fixnum

def initizialize
	@magicCInt = 0
end
def & (other)
	p = self.clone
	p.magicCInt &= other.magicCInt
end
def == (other)
	return (other.magicCInt == self.magicCInt)
end
alias_method :== :eql?
#.. And other methods

```

end

Can I achieve this using RubyInline. It would be great if the more  
experienced of you could provide me with a code sketch to get me  
started ?

PS: My apologies if this question has been asked before, I would be  
grateful if you could point me to some other thread which seeks to  
answer this.

PPS: I am writing some networkingish code and comparing two ipaddress’s  
is sadly my biggest bottleneck (Bignum#==)

Thanks,  
-Devesh

---

<div class="post-metadata">

**Author:** ![devesh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/977dab/32.png) [@devesh](https://www.ruby-forum.com/u/devesh)\
**Post date:** [November 21, 2006, 12:12am UTC](https://www.ruby-forum.com/t/fast-32-bit-ints-in-ruby/76749/2 "2006-11-21T00:12:47Z")

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devesh wrote:

> and to mixing C and ruby. What would be a good way to achieve the  
> following interface:

What about packing the 4 bytes in a string:

p “192.168.1.2”.split(“.”).map{|d|Integer(d)}.pack(“C\*”)

# ==\> “\300\250\001\002”

Unfortunately, there’s no fast way to do & on strings of bits in pure  
ruby, AFAIK. Now, that might be a nice extension: bit operations on  
strings, including reading and writing bits n1 through n2 as a substring  
of bits, & ^ | on substrings of bits, etc.

Actually, maybe this will help:

[http://raa.ruby-lang.org/project/bitset/](http://raa.ruby-lang.org/project/bitset/)

never used it though…