url shortener modification

Question

Im working with a php url shortener and my problem is that it only creates the MAX number of shortening codes up to 2 characters (eg domain.com/XX). I want it to go up to 5 characters (eg domain.com/XXXXX)

I believe i found the relevant code, but im not sure how to change it to allow for this modification

function decode_url_id($code)
    { 
     $scheme = "abcdefghijklmnoprstuqwxvyz0123456789ABCDEFGHIJKLMNOPRSTQWXUVYZ";
     $scheme_size = strlen($scheme);

     $number  = 0;
     $code_size = strlen($code);
     $code = strrev($code);
     for($i = 0; $i < $code_size; $i++)
     {
      $digit_value = strpos($scheme, $code[$i]);

      $number += ($digit_value * pow($scheme_size, $i));
     }

     return $number;
    }

    function encode_url_id($number, $code="")
    {
     $scheme = "abcdefghijklmnoprstuqwxvyz0123456789ABCDEFGHIJKLMNOPRSTQWXUVYZ";
     $scheme_size = strlen($scheme);

     if ($number >= $scheme_size)
     {
      $c = $number % $scheme_size;
      $code .= $scheme[$c];
      $number = floor($number / $scheme_size);

      return encode_url_id($number, $code);
     }
     else 
     {
      $code .= $scheme[$number];
      $code = strrev($code);
     }

     return $code;
    }

Am i barking up the wrong tree?

Answer 1

Why not just encode the ID of the URL in the database with http://www.pgregg.com/projects/php/base_conversion/base_conversion.inc.phps.

Example usage:

$new_url = base_base2base($link_id, 10, 62);