<?php
/**
* Zend Framework (http://framework.zend.com/)
*
* @link http://github.com/zendframework/zf2 for the canonical source repository
* @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
namespace Zend\Math\BigInteger\Adapter;
use Zend\Math\BigInteger\Exception;
/**
* Bcmath extension adapter
*/
class Bcmath implements AdapterInterface
{
/**
* Constructor
* Sets Bcmath scale factor to zero
*/
public function __construct()
{
bcscale(0);
}
/**
* Create string representing big integer in decimal form from arbitrary integer format
*
* @param string $operand
* @param int|null $base
* @return bool|string
*/
public function init($operand, $base = null)
{
$sign = (strpos($operand, '-') === 0) ? '-' : '';
$operand = ltrim($operand, '-+');
if (null === $base) {
// decimal
if (preg_match('#^([1-9][0-9]*)$#', $operand, $m)) {
$base = 10;
$operand = $m[1];
// octal
} elseif (preg_match('#^(0[0-7]+)$#', $operand, $m)) {
$base = 8;
$operand = $m[1];
// hex
} elseif (preg_match('#^(?:0x)?([0-9a-f]+)$#', strtolower($operand), $m)) {
$base = 16;
$operand = $m[1];
// scientific notation
} elseif (preg_match('#^([1-9]?\.?[0-9]+)[eE]\+?([0-9]+)$#', $operand, $m)) {
$base = 10;
$operand = bcmul($m[1], bcpow('10', $m[2]));
} else {
return false;
}
}
if ($base != 10) {
$operand = $this->baseConvert($operand, $base, 10);
}
$prod = bcmul($operand, '1');
if (bccomp($operand, $prod) !== 0) {
return false;
}
return $sign . $operand;
}
/**
* Add two big integers
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function add($leftOperand, $rightOperand)
{
return bcadd($leftOperand, $rightOperand);
}
/**
* Subtract two big integers
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function sub($leftOperand, $rightOperand)
{
return bcsub($leftOperand, $rightOperand);
}
/**
* Multiply two big integers
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function mul($leftOperand, $rightOperand)
{
return bcmul($leftOperand, $rightOperand);
}
/**
* Divide two big integers and return integer part result.
* Raises exception if the divisor is zero.
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
* @throws Exception\DivisionByZeroException
*/
public function div($leftOperand, $rightOperand)
{
if ($rightOperand == 0) {
throw new Exception\DivisionByZeroException(
"Division by zero; divisor = {$rightOperand}"
);
}
$result = bcdiv($leftOperand, $rightOperand);
return $result;
}
/**
* Raise a big integers to another
*
* @param string $operand
* @param string $exp
* @return string
*/
public function pow($operand, $exp)
{
return bcpow($operand, $exp);
}
/**
* Get the square root of a big integer
*
* @param string $operand
* @return string
*/
public function sqrt($operand)
{
return bcsqrt($operand);
}
/**
* Get absolute value of a big integer
*
* @param string $operand
* @return string
*/
public function abs($operand)
{
return ltrim($operand, '-');
}
/**
* Get modulus of a big integer
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function mod($leftOperand, $rightOperand)
{
return bcmod($leftOperand, $rightOperand);
}
/**
* Raise a big integer to another, reduced by a specified modulus
*
* @param string $leftOperand
* @param string $rightOperand
* @param string $modulus
* @return string
*/
public function powmod($leftOperand, $rightOperand, $modulus)
{
return bcpowmod($leftOperand, $rightOperand, $modulus);
}
/**
* Compare two big integers and returns result as an integer where
* Returns < 0 if leftOperand is less than rightOperand;
* > 0 if leftOperand is greater than rightOperand, and 0 if they are equal.
*
* @param string $leftOperand
* @param string $rightOperand
* @return int
*/
public function comp($leftOperand, $rightOperand)
{
return bccomp($leftOperand, $rightOperand);
}
/**
* Convert big integer into it's binary number representation
*
* @param string $operand
* @param bool $twoc return in two's complement form
* @return string
*/
public function intToBin($operand, $twoc = false)
{
$nb = chr(0);
$isNegative = (strpos($operand, '-') === 0) ? true : false;
$operand = ltrim($operand, '+-0');
if (empty($operand)) {
return $nb;
}
if ($isNegative && $twoc) {
$operand = bcsub($operand, '1');
}
$bytes = '';
while (bccomp($operand, '0', 0) > 0) {
$temp = bcmod($operand, '16777216');
$bytes = chr($temp >> 16) . chr($temp >> 8) . chr($temp) . $bytes;
$operand = bcdiv($operand, '16777216');
}
$bytes = ltrim($bytes, $nb);
if ($twoc) {
if (ord($bytes[0]) & 0x80) {
$bytes = $nb . $bytes;
}
return $isNegative ? ~$bytes : $bytes;
}
return $bytes;
}
/**
* Convert big integer into it's binary number representation
*
* @param string $bytes
* @param bool $twoc whether binary number is in twos' complement form
* @return string
*/
public function binToInt($bytes, $twoc = false)
{
$isNegative = ((ord($bytes[0]) & 0x80) && $twoc);
if ($isNegative) {
$bytes = ~$bytes;
}
$len = (strlen($bytes) + 3) & 0xfffffffc;
$bytes = str_pad($bytes, $len, chr(0), STR_PAD_LEFT);
$result = '0';
for ($i = 0; $i < $len; $i += 4) {
$result = bcmul($result, '4294967296'); // 2**32
$result = bcadd($result, 0x1000000 * ord($bytes[$i]) +
((ord($bytes[$i + 1]) << 16) |
(ord($bytes[$i + 2]) << 8) |
ord($bytes[$i + 3])));
}
if ($isNegative) {
$result = bcsub('-' . $result, '1');
}
return $result;
}
/**
* Base conversion. Bases 2..62 are supported
*
* @param string $operand
* @param int $fromBase
* @param int $toBase
* @return string
* @throws Exception\InvalidArgumentException
*/
public function baseConvert($operand, $fromBase, $toBase = 10)
{
if ($fromBase == $toBase) {
return $operand;
}
if ($fromBase < 2 || $fromBase > 62) {
throw new Exception\InvalidArgumentException(
"Unsupported base: {$fromBase}, should be 2..62"
);
}
if ($toBase < 2 || $toBase > 62) {
throw new Exception\InvalidArgumentException(
"Unsupported base: {$toBase}, should be 2..62"
);
}
$sign = (strpos($operand, '-') === 0) ? '-' : '';
$operand = ltrim($operand, '-+');
$chars = self::BASE62_ALPHABET;
// convert to decimal
if ($fromBase == 10) {
$decimal = $operand;
} else {
$decimal = '0';
for ($i = 0, $len = strlen($operand); $i < $len; $i++) {
$decimal = bcmul($decimal, $fromBase);
$decimal = bcadd($decimal, strpos($chars, $operand[$i]));
}
}
if ($toBase == 10) {
return $decimal;
}
// convert decimal to base
$result = '';
do {
$remainder = bcmod($decimal, $toBase);
$decimal = bcdiv($decimal, $toBase);
$result = $chars[$remainder] . $result;
} while (bccomp($decimal, '0'));
return $sign . $result;
}
}