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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | PHP Version 4 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Dave Mertens <dmertens@zyprexia.com> |
// +----------------------------------------------------------------------+
//
// $Id: Basex.php,v 1.6 2003/06/04 14:48:44 et Exp $
require_once "PEAR.php";
if (!defined('MATH_BASEX_MATHEXTENSION')) {
if (PEAR::loadExtension('bcmath')) {
define('MATH_BASEX_MATHEXTENSION', 'bcmath');
} elseif (PEAR::loadExtension('gmp')) {
define('MATH_BASEX_MATHEXTENSION', 'gmp');
} else {
define('MATH_BASEX_MATHEXTENSION', 'none');
}
}
/**
* base X coding class
*
* I noticed that value of an int is different on most systems.
* On my system (linux 2.4.18 with glibc 2.2.5) i can use 8-byte integers
* (also called int64 or int8)
* On my laptop (Windows 2000) i only could use numbers up to 4-byte (32 bit)
* integers.
* So you might want to test this first!
*
* Note that you can without much effort also use the bcmath extentions to
* increase the length of your numbers.
*
* @author Dave Mertens <dmertens@zyprexia.com>
* @version 0.3
* @access public
* @package Math_Basex
* @category Math
*/
class Math_Basex
{
/**
* @var character base set
* @access private;
*/
var $_baseChars;
/**
* @var base length (for binair 2, dec 10, hex 16, yours ??)
* @access private;
*/
var $_length;
/**
* Constructor for class
*
* @param tokens string Character base set (Each character is only allowed
* once!)
* @return void
*/
function Math_Basex($tokens = "")
{
//set initial length
$this->_length = 0;
//if we did get already a character set, set it..
if (!empty($tokens)) {
$this->setBase($tokens);
}
}
/**
* Change the character base set. Behaves the same way the constructor does.
*
* @param tokens string Character base set (Each character is only allowed
* once!)
* @return void
* @access public
*/
function setBase($tokens)
{
if (!$this->_checkBase($tokens)) {
return PEAR::raiseError("Each character is only allowed once");
}
$this->_baseChars = $tokens;
$this->_length = strlen($tokens);
return true;
}
/**
* toBase translates a decimal (base 10) number into your base 'code'
*
* @param number (int64 or double without floats, both are 8-byte number
* types). This allows you to use numbers up to 18446744073709551616.
* @return string encoded 'code' of yout decimal number
*/
function toBase($number)
{
if (!is_numeric($number)) {
return PEAR::raiseError("You must supply a decimal number");
}
if ($this->_length == 0) {
return PEAR::raiseError("Character base isn't defined yet..");
}
if (is_float($number)) {
$number = ltrim(sprintf('%22.0f',$number));
}
$code = "";
do {
$this->_splitnumber($number, $full, $mod);
$code = $this->_getToken($mod) . $code;
$number = $full;
} while ($number > 0);
return $code;
}
/**
* toDecimal decodes the baseX 'code' back to a decimal number
*
* @param string code to decode
* @return int64 decimal (base 10) number
*/
function todecimal($code)
{
$length = strlen($code);
$total = 0;
if (strspn($code, $this->_baseChars) != $length) {
return PEAR::raiseError("Your Base X code contains invalid"
." characters");
}
for ($i=0; $i < $length; $i++) {
$sum = $this->_getNumber($code[$length - $i - 1]) *
$this->_pow($this->_length, $i);
$total = $this->_add($total,$sum);
}
return $total;
}
/**
* Returns the base scale. Note that this is onyl the count of the
* characters used for the encoding and decoding.
* Please do not use base_convert with this class, because it might result
* in rare results
*
* @access public
* @return integer
*/
function getBase()
{
return $this->_length;
}
/**
* Validates whether each character is unique
*
* @param string tokens Character base set
* @access private
* @return boolean true if all characters are unique
*/
function _checkBase($tokens)
{
$length = strlen($tokens);
for ($i=0; $i < $length; $i++) {
if (substr_count($tokens, $tokens[$i]) > 1)
return false; //character is specified more than one time!
}
//if we come here, all characters are unique
return true;
}
/**
* Helper function for encoding function.
*
* @access private;
* @param number integer number to spilt for base conversion
* @param full integer non-float, unrounded number (will be passed as
* reference)
* @param modules float floating number between 0 and 1
* (will be passed as reference)
*
* @return void
*/
function _splitNumber($number, &$full, &$modules)
{
$full = $this->_div($number, $this->_length);
$modules = $this->_mod($number, $this->_length);
}
/**
* Helper function; Returns character at position x
*
* @param oneDigit integer number between 0 and basex->getBase()
* @return character from base character set
* @access private;
*/
function _getToken($oneDigit)
{
return substr($this->_baseChars, $oneDigit, 1);
}
/**
* Helper function; Returns position of character X
*
* @param oneDigit string Character in base character set
* @return integer number between 0 and basex->getBase()
* @access private;
*/
function _getNumber($oneDigit)
{
return strpos($this->_baseChars, $oneDigit);
}
/**
* Add two numbers, utilize Math extensions
*
* @param mixed a First operand
* @param mixed b Second operand
* @return mixed
* @access private
*/
function _add($a, $b)
{
switch (MATH_BASEX_MATHEXTENSION) {
case 'bcmath':
return bcadd($a, $b);
case 'gmp':
return gmp_strval(gmp_add($a, $b));
case 'none':
return $a + $b;
}
}
/**
* Multiply two numbers, utilize Math extensions
*
* @param mixed a First operand
* @param mixed b Second operand
* @return mixed
* @access private
*/
function _mul($a, $b)
{
switch (MATH_BASEX_MATHEXTENSION) {
case 'bcmath':
return bcmul($a, $b);
case 'gmp':
return gmp_strval(gmp_mul($a, $b));
case 'none':
return $a * $b;
}
}
/**
* Return the modulo of two numbers, utilize Math extensions
*
* @param mixed a First operand
* @param mixed b Second operand
* @return mixed
* @access private
*/
function _mod($a, $b)
{
switch (MATH_BASEX_MATHEXTENSION) {
case 'bcmath':
return bcmod($a, $b);
case 'gmp':
return gmp_strval(gmp_mod($a, $b));
case 'none':
return $a % $b;
}
}
/**
* Divide two integers, utilize Math extensions
*
* @param mixed a First operand
* @param mixed b Second operand
* @return mixed
* @access private
*/
function _div($a, $b)
{
switch (MATH_BASEX_MATHEXTENSION) {
case 'bcmath':
return bcdiv($a, $b);
case 'gmp':
return gmp_strval(gmp_div($a, $b));
case 'none':
return floor($a / $b);
}
}
/**
* Raise one number to the power of the other, utilize Math extensions
*
* @param mixed a First operand
* @param mixed b Second operand
* @return mixed
* @access private
*/
function _pow($a, $b)
{
switch (MATH_BASEX_MATHEXTENSION) {
case 'bcmath':
return bcpow($a, $b);
case 'gmp':
return gmp_strval(gmp_pow($a, $b));
case 'none':
return pow($a,$b);
}
}
/**
* Returns a common set of digits (0-9A-Za-z), length is given as parameter
*
* @param int length Optional How many characters to return, defaults to 62.
* @return string
* @access public
*/
function stdBase($n = 62)
{
return substr("0123456789"
."ABCDEFGHIJKLMNOPQRSTUVWXYZ"
."abcdefghijklmnopqrstuvwxyz", 0, $n);
}
/**
* Converts a number from one base into another. May be called statically.
*
* @param mixed number The number to convert
* @param int from_base The base to convert from
* @param int to_base The base to convert to
* @param string from_cs Optional character set of the number that is
* converted
* @param string to_cs Optional character set of the target number
* @return string
* @access public
*/
function baseConvert($number, $from_base, $to_base,
$from_cs = null, $to_cs = null)
{
if (isset($this)) {
$obj = &$this;
} else {
$obj = &Math_Basex::instance();
}
if (!isset($from_cs)) {
$from_cs = $obj->stdBase();
}
if (!isset($to_cs)) {
$to_cs = $obj->stdBase();
}
if (strlen($from_cs) < $from_base) {
return PEAR::raiseError('Character set isn\'t long enough for the'
.'given base.');
}
if (strlen($to_cs) < $to_base) {
return PEAR::raiseError('Character set isn\'t long enough for the'
.'given base.');
}
$from_cs = substr($from_cs, 0, $from_base);
$to_cs = substr($to_cs, 0, $to_base);
if ($tmp = $obj->setBase($from_cs) !== true) {
return $tmp;
}
$number = $obj->toDecimal($number);
if (PEAR::isError($number)) {
return $number;
}
if ($tmp = $obj->setBase($to_cs) !== true) {
return $tmp;
}
$number = $obj->toBase($number);
return $number;
}
/**
* Singleton method, call statically
*
* @return object
* @access public
*/
function &instance()
{
static $ins = null;
if (is_null($ins)) {
$ins = new Math_Basex;
}
return $ins;
}
}
?>
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