From: John Johnson <johnatl@...>
Date: 2006-09-01T01:47:43+09:00
Subject: Re: Integer to byte string - Speed improvements

On Thu, 31 Aug 2006 12:20:32 -0400, Phrogz <gavin@refinery.com> wrote:

> I'm writing code that needs to store an integer as a sequence of bytes.
> Array#pack works for 1-, 2-, and 4-byte integers, but I want to be able
> to support Bignums as well.

s =  
Marshal.dump(0xCC8080808080808080808080808080808080808080808080808080808080AA)
bytes = s[5..-2]
bytes.each_byte { |b| print "%02x " % b }
aa 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80  
80 80 80 80 80 cc
(low byte first, as you mentioned)
or if you prefer:
rev_bytes = bytes.reverse
rev_bytes.each_byte { |b| print "%02x " % b }

As far as it being faster, dunno, probably. Here's the benchmark:
irb(main):041:0> Process.times  
{ s=Marshal.dump(0xCC8080808080808080808080808080808080808080808080808080808080AA)  
}

=> #<struct Struct::Tms utime=1.02, stime=0.54, cutime=0.0, cstime=0.0>

Regards,
   JJ

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