<?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;
/**
* GMP extension adapter
*/
class Gmp implements AdapterInterface
{
/**
* 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 === $base) {
// scientific notation
if (preg_match('#^(?:([1-9])\.)?([0-9]+)[eE]\+?([0-9]+)$#', $operand, $m)) {
if (!empty($m[1])) {
if ($m[3] < strlen($m[2])) {
return false;
}
} else {
$m[1] = '';
}
$operand = str_pad(($m[1] . $m[2]), ($m[3] + 1), '0', STR_PAD_RIGHT);
} else {
// let GMP guess base
$base = 0;
}
}
$res = gmp_init($sign . $operand, $base);
if ($res === false) {
return false;
}
return gmp_strval($res);
}
/**
* Add two big integers
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function add($leftOperand, $rightOperand)
{
$result = gmp_add($leftOperand, $rightOperand);
return gmp_strval($result);
}
/**
* Subtract two big integers
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function sub($leftOperand, $rightOperand)
{
$result = gmp_sub($leftOperand, $rightOperand);
return gmp_strval($result);
}
/**
* Multiply two big integers
*
* @param string $leftOperand
* @param string $rightOperand
* @return string
*/
public function mul($leftOperand, $rightOperand)
{
$result = gmp_mul($leftOperand, $rightOperand);
return gmp_strval($result);
}
/**
* Divide two big integers and return integer part result.
* Raises exception if the divisor is zero.
*
* @param string $leftOperand
* @param string $rightOperand
* @return string|null
* @throws Exception\DivisionByZeroException
*/
public function div($leftOperand, $rightOperand)
{
if ($rightOperand == 0) {
throw new Exception\DivisionByZeroException(
"Division by zero; divisor = {$rightOperand}"
);
}
$result = gmp_div_q($leftOperand, $rightOperand);
return gmp_strval($result);
}
/**
* Raise a big integers to another
*
* @param string $operand
* @param string $exp
* @return string
*/
public function pow($operand, $exp)
{
$result = gmp_pow($operand, $exp);
return gmp_strval($result);
}
/**
* Get the square root of a big integer
*
* @param string $operand
* @return string
*/
public function sqrt($operand)
{
$result = gmp_sqrt($operand);
return gmp_strval($result);
}
/**
* Get absolute value of a big integer
*
* @param string $operand
* @return string
*/
public function abs($operand)
{
$result = gmp_abs($operand);
return gmp_strval($result);
}
/**
* Get modulus of a big integer
*
* @param string $leftOperand
* @param string $modulus
* @return string
*/
public function mod($leftOperand, $modulus)
{
$result = gmp_mod($leftOperand, $modulus);
return gmp_strval($result);
}
/**
* 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)
{
$result = gmp_powm($leftOperand, $rightOperand, $modulus);
return gmp_strval($result);
}
/**
* 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, $rightOperand)
{
return gmp_cmp($leftOperand, $rightOperand);
}
/**
* Convert big integer into it's binary number representation
*
* @param string $int
* @param bool $twoc return in twos' complement form
* @return string
*/
public function intToBin($int, $twoc = false)
{
$nb = chr(0);
$isNegative = (strpos($int, '-') === 0) ? true : false;
$int = ltrim($int, '+-0');
if (empty($int)) {
return $nb;
}
if ($isNegative && $twoc) {
$int = gmp_sub($int, '1');
}
$hex = gmp_strval($int, 16);
if (strlen($hex) & 1) {
$hex = '0' . $hex;
}
$bytes = pack('H*', $hex);
$bytes = ltrim($bytes, $nb);
if ($twoc) {
if (ord($bytes[0]) & 0x80) {
$bytes = $nb . $bytes;
}
return $isNegative ? ~$bytes : $bytes;
}
return $bytes;
}
/**
* Convert binary number into big integer
*
* @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);
$sign = '';
if ($isNegative) {
$bytes = ~$bytes;
$sign = '-';
}
$result = gmp_init($sign . bin2hex($bytes), 16);
if ($isNegative) {
$result = gmp_sub($result, '1');
}
return gmp_strval($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"
);
}
if ($fromBase <= 36 && $toBase <= 36) {
return gmp_strval(gmp_init($operand, $fromBase), $toBase);
}
$sign = (strpos($operand, '-') === 0) ? '-' : '';
$operand = ltrim($operand, '-+');
$chars = self::BASE62_ALPHABET;
// convert operand to decimal
if ($fromBase !== 10) {
$decimal = '0';
for ($i = 0, $len = strlen($operand); $i < $len; $i++) {
$decimal = gmp_mul($decimal, $fromBase);
$decimal = gmp_add($decimal, strpos($chars, $operand[$i]));
}
} else {
$decimal = gmp_init($operand);
}
if ($toBase == 10) {
return gmp_strval($decimal);
}
// convert decimal to base
$result = '';
do {
list($decimal, $remainder) = gmp_div_qr($decimal, $toBase);
$pos = gmp_strval($remainder);
$result = $chars[$pos] . $result;
} while (gmp_cmp($decimal, '0'));
return $sign . $result;
}
}