Your IP : 216.73.216.97
<?php
namespace Laminas\Math;
/**
* Pseudorandom number generator (PRNG)
*/
abstract class Rand
{
/**
* @deprecated No longer used internally
*/
protected static $generator = null;
/**
* Generate random bytes using different approaches
* If PHP 7 is running we use the random_bytes() function
*
* @param int $length
* @return string
* @throws Exception\RuntimeException
*/
public static function getBytes($length)
{
try {
return random_bytes($length);
} catch (\TypeError $e) {
throw new Exception\InvalidArgumentException(
'Invalid parameter provided to getBytes(length)',
0,
$e
);
} catch (\Error $e) {
throw new Exception\DomainException(
'The length must be a positive number in getBytes(length)',
0,
$e
);
}
}
/**
* Generate random boolean
*
* @return bool
*/
public static function getBoolean()
{
$byte = static::getBytes(1);
return (bool) (ord($byte) % 2);
}
/**
* Generate a random integer between $min and $max
*
* @param int $min
* @param int $max
* @return int
* @throws Exception\DomainException
*/
public static function getInteger($min, $max)
{
try {
return random_int($min, $max);
} catch (\TypeError $e) {
throw new Exception\InvalidArgumentException(
'Invalid parameters provided to getInteger(min, max)',
0,
$e
);
} catch (\Error $e) {
throw new Exception\DomainException(
'The min parameter must be lower than max in getInteger(min, max)',
0,
$e
);
}
}
/**
* Generate random float [0..1)
* This function generates floats with platform-dependent precision
*
* PHP uses double precision floating-point format (64-bit) which has
* 52-bits of significand precision. We gather 7 bytes of random data,
* and we fix the exponent to the bias (1023). In this way we generate
* a float of 1.mantissa.
*
* @return float
*/
public static function getFloat()
{
$bytes = static::getBytes(7);
$bytes[6] = $bytes[6] | chr(0xF0);
$bytes .= chr(63); // exponent bias (1023)
$float = unpack('d', $bytes)[1];
return ($float - 1);
}
/**
* Generate a random string of specified length.
*
* Uses supplied character list for generating the new string.
* If no character list provided - uses Base 64 character set.
*
* @param int $length
* @param string|null $charlist
* @return string
* @throws Exception\DomainException
*/
public static function getString($length, $charlist = null)
{
if ($length < 1) {
throw new Exception\DomainException('Length should be >= 1');
}
// charlist is empty or not provided
if (empty($charlist)) {
$numBytes = ceil($length * 0.75);
$bytes = static::getBytes($numBytes);
return mb_substr(rtrim(base64_encode($bytes), '='), 0, $length, '8bit');
}
$listLen = mb_strlen($charlist, '8bit');
if ($listLen == 1) {
return str_repeat($charlist, $length);
}
$result = '';
for ($i = 0; $i < $length; $i++) {
$pos = static::getInteger(0, $listLen - 1);
$result .= $charlist[$pos];
}
return $result;
}
}