From: Rob Biedenharn <Rob@...>
Date: 2010-08-10T12:13:46+09:00
Subject: Re: Error:  Bignum too big to convert into `long'

On Aug 9, 2010, at 6:09 PM, Matt Mencel wrote:
> Hi,
>
> I've got a bit of code that I borrowed from here http://www.ruby-forum.com/topic/77821 
> .  I use it to convert MS timestamps into a ruby Time object.
> It works fine on Mac/Linux, but not on a Solaris SPARC system.  The  
> error is "bignum too big to convert into `long'" and it occurs on  
> the line that begins...
> Time.at(.....)
>
> I'm wondering if it's because SPARC is Big-Endian that I get the  
> error?
>
>
>  def self.ad2time(timestamp)
>    ad_epoch = 116_444_736_000_000_000
>    ad_multiplier = 10_000_000
>
>    # DEBUG
>    ap ad_epoch.class
>    puts "TIMESTAMP:  #{timestamp}"
>    ap timestamp.class
>
>    Time.at((timestamp.to_i - ad_epoch) / ad_multiplier)
>  end
>
>
>
> On my Mac (Snow Leopard x86_64) the DEBUG output looks like this...

Ah, note the x86_64 part? That's a 64-bit system so Fixnum holds up to  
(2^62)-1

> Fixnum < Integer
> TIMESTAMP:  9223372036854775807
> Net::BER::BerIdentifiedString < String
>
> On Solaris SPARC it's this...
> Bignum < Integer
> TIMESTAMP:  9223372036854775807
> String < Object
>
>
>
> Looks like on Solaris it forces the 'ad_epoch' to a Bignum instead  
> of a Fixnum?  Should I try to cast it to a Fixnum on Solaris maybe?
>
> Matt

I suspect your SPARC system is only 32-bit where 2^30 and beyond  
becomes Bignum.

If your timestamp is a Net::BER::BerIdentifiedString, perhaps it has  
other properties that would help convert it into an Integer. (Notice  
that both Fixnum and Bignum are subclasses of Integer)

On a 32-bit system, the divide between Fixnum and Bignum is:

irb> 2**30-1
=> 1073741823
irb> _.class
=> Fixnum
irb> 2**30
=> 1073741824
irb> _.class
=> Bignum

So 910692730085 is far too big for a Fixnum and Time.at is likely  
wanting a number of seconds since 1970.  Maybe you can see a pattern  
if you compare Time.now.to_i on your platform with your expected  
timestamp value.

-Rob

Rob Biedenharn		
Rob@AgileConsultingLLC.com	http://AgileConsultingLLC.com/
rab@GaslightSoftware.com		http://GaslightSoftware.com/