php - How to deal with integer max difference between 32 bit and 64bit servers?

Question

It takes a long time to figure out what was causing malfunctioning a website of mine when migrating to a better hosting subscription.

I use a 'self-made' uniqueId generator to generate everything that must be unique but this uniqueness is not random. I use this to communicate between several services, generate reproducible unique 'numbers' for files, articles and so on.

This is the function I have made and never had problems with (I think it never runs on a 64bit system before?) to generate an unique id. I know this uniqueness is limited (64.000) but never lead to a problem until now.

function suGetHashCode($s)
{
 $hash=0;
 $c=(is_string($s))?strlen($s):0;
 $i=0;
 while($i<$c) 
 {
   $hash = (($hash << 5)-$hash)+ord($s{$i++});
   //hash = hash & hash; // Convert to 32bit integer
 }
 return ( $hash < 0 )?(($hash*-1)+0xFFFFFFFF):$hash; // convert to unsigned int
} 

function suUniqueId( $s, $bAddLen = false )
{ 
  $i = base_convert( suGetHashCode( $s ), 10, 32 );
  if( $bAddLen && is_string($s) )
   { $i.=('-'.suGetLz( dechex( strlen($s)*4 ), 3 )); } 

  return $i; 
}

function suGetLz( $i, $iMaxLen ) // Leading zero
{
  if( !is_numeric( $i ) || $i < 0 || $iMaxLen <= 0 )
   { return $i; }
  $c = strlen( $i );
  while( $c < $iMaxLen )
   { $c++; $i='0'.$i; } 
  return $i;
}   

The max int value of an integer is on the new system:

PHP_INT_MAX = 9223372036854775807

On other system(s) it is:

PHP_INT_MAX = 2147483647

Well, I am not a math person, I think this is causing the problem because of the 0xFFFFFFFF increment when negative (I think it will be never negative on this new system).

But how can I change the function that it produces the same unique id's like on other systems?

For example: It produces the same id for different strings on the new hosting server:

 $sThisUrl = '<censored>';
 var_dump( suUniqueId($sThisUrl) ); // Produce: 1l5kc37uicb  
 $sThisUrl = '<censored>';
 var_dump( suUniqueId($sThisUrl) ); // Produce the same id as above: 1l5kc37uicb

But, this must be like on older systems:

 $sThisUrl = '<censored>';
 var_dump( suUniqueId($sThisUrl) ); // Produce: a46q6nd  
 $sThisUrl = '<censored>';
 var_dump( suUniqueId($sThisUrl) ); // Produce: 2mirj1h

Notice: The string is seperate into parts to avoid stackoverflow see this a link.

EDIT: Removed filenames

Does anyone how to deal with this problem?