<?php
/*
* This file is part of the PHPASN1 library.
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace FG\Utility;
/**
* Class BigIntegerBcmath
* Integer representation of big numbers using the bcmath library to perform large operations.
* @package FG\Utility
* @internal
*/
class BigIntegerBcmath extends BigInteger
{
protected $_str;
public function __clone()
{
// nothing needed to copy
}
protected function _fromString($str)
{
$this->_str = (string)$str;
}
protected function _fromInteger($integer)
{
$this->_str = (string)$integer;
}
public function __toString()
{
return $this->_str;
}
public function toInteger()
{
if ($this->compare(PHP_INT_MAX) > 0 || $this->compare(PHP_INT_MIN) < 0) {
throw new \OverflowException(sprintf('Can not represent %s as integer.', $this->_str));
}
return (int)$this->_str;
}
public function isNegative()
{
return bccomp($this->_str, '0', 0) < 0;
}
protected function _unwrap($number)
{
if ($number instanceof self) {
return $number->_str;
}
return $number;
}
public function compare($number)
{
return bccomp($this->_str, $this->_unwrap($number), 0);
}
public function add($b)
{
$ret = new self();
$ret->_str = bcadd($this->_str, $this->_unwrap($b), 0);
return $ret;
}
public function subtract($b)
{
$ret = new self();
$ret->_str = bcsub($this->_str, $this->_unwrap($b), 0);
return $ret;
}
public function multiply($b)
{
$ret = new self();
$ret->_str = bcmul($this->_str, $this->_unwrap($b), 0);
return $ret;
}
public function modulus($b)
{
$ret = new self();
if ($this->isNegative()) {
// bcmod handles negative numbers differently
$b = $this->_unwrap($b);
$ret->_str = bcsub($b, bcmod(bcsub('0', $this->_str, 0), $b), 0);
}
else {
$ret->_str = bcmod($this->_str, $this->_unwrap($b));
}
return $ret;
}
public function toPower($b)
{
$ret = new self();
$ret->_str = bcpow($this->_str, $this->_unwrap($b), 0);
return $ret;
}
public function shiftRight($bits = 8)
{
$ret = new self();
$ret->_str = bcdiv($this->_str, bcpow('2', $bits));
return $ret;
}
public function shiftLeft($bits = 8) {
$ret = new self();
$ret->_str = bcmul($this->_str, bcpow('2', $bits));
return $ret;
}
public function absoluteValue()
{
$ret = new self();
if (-1 === bccomp($this->_str, '0', 0)) {
$ret->_str = bcsub('0', $this->_str, 0);
}
else {
$ret->_str = $this->_str;
}
return $ret;
}
}