File Coverage

blib/lib/Math/BigSimple.pm

Criterion	Covered	Total	%
statement	47	52	90.3
branch	20	26	76.9
condition	8	15	53.3
subroutine	5	5	100.0
pod	4	4	100.0
total	84	102	82.3

package Math::BigSimple;
require Exporter;
use Math::BigInt;
@ISA = qw(Exporter);
@EXPORT = qw(new);
@EXPORT_OK = qw(is_simple make_simple);
$VERSION = "1.1a";
$_DEFAULT_CHECKS = 4;
$_DEFAULT_RAND = sub { rand() };
sub new
{
	my $class = shift;
	my($LENGTH, $CHECKS, $RAND);
	my %param = @_ if(@_ % 2 == 0);
	if(exists $param{Length}) # Compability mode (with 1.0 version).
	{
		$CHECKS = $param{'Checks'};
		$LENGTH = $param{'Length'};
		$RAND = $param{'Random'};
	}
	else
	{
		($LENGTH, $CHECKS, $RAND) = @_;
	}
	if((!$LENGTH) || (int($LENGTH) != $LENGTH))
	{
		die "[error] " . __PACKAGE__ . " $VERSION : number length not specified.";
	}
	$CHECKS = $Math::BigSimple::_DEFAULT_CHECKS if((!$CHECKS) || (int($CHECKS) != $CHECKS));
	$RAND = $Math::BigSimple::_DEFAULT_RAND if((!$RAND) || (ref($RAND) != 'CODE'));

	my $ref = [$LENGTH, $CHECKS, $RAND]; # [$CHECKS, $LENGTH, $RAND] in 1.0.
	bless $ref, $class;
	return $ref;
}
sub make
{
	my $ref = shift;
	my($LENGTH, $CHECKS, $RAND) = @$ref;
	while(1)
	{
		my $p = &$RAND();
		if(int($p * 10) == 0)
		{
			my $repl = 0;
			while(!$repl)
			{
				$repl = int(rand() * 10);
			}
			$p += $repl / 10;
		}
		$p = int($p * (10 ** $LENGTH));

		return $p if(Math::BigSimple::is_simple($p) == 1);
	}
}
sub is_simple
{
	my($number, $CHECKS) = @_;
	return -1 if((!$number) || (int($number) != $number));
	$CHECKS = $Math::BigSimple::_DEFAULT_CHECKS if(!$CHECKS);

	my $_2 = Math::BigInt->new(2);
	my $coof = $number << 4;
	my $simple = 1;
	my $_p = Math::BigInt->new($number);
	my $_i1 = Math::BigInt->new($number-1);
	my $_i2 = $_i1->bdiv($_2);

	for(my $count = 0; $count < $CHECKS; $count++)
	{
		$simple = 0;
		last if($number % 2 == 0);
		my $x = Math::BigInt->new(int(&$Math::BigSimple::_DEFAULT_RAND() * $coof) % $number);
		next if($x->is_zero());

		my $func = $x->bmodpow($_i1, $_p);
		$func = $func->bstr();
		last if(($func != 1) && ($func != $number-1));

		$simple = 1;
	}
	if($simple == 1)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}
sub make_simple
{
	my $g = Math::BigSimple->new(shift);
	return $g->make();
}
__END__