(PHP 8 >= 8.2.0)
Random\Engine\Xoshiro256StarStar::__construct — Constructs a new xoshiro256** engine
This function is currently not documented; only its argument list is available.
seed
How the internal 256 bit (32 byte) state consisting of four unsigned 64 bit integers is
seeded depends on the type used as the seed.
| Type | Description |
|---|---|
| null | Fills the state with 32 random bytes generated using the CSPRNG. |
| int |
Fills the state with four consecutive values generated with the SplitMix64 algorithm
that was seeded with seed interpreted as an unsigned 64 bit integer.
|
| string | Fills the state by interpreting a 32 byte string as four little-endian unsigned 64 bit integers. |
seed is
not 32 bytes, a ValueError will be thrown.
seed consists of
32 NUL bytes ("\x00"), a ValueError
will be thrown.
Example #1 Random\Engine\Xoshiro256StarStar::__construct() example
<?php
// Uses a random 256 Bit seed.
$e = new \Random\Engine\Xoshiro256StarStar();
$r = new \Random\Randomizer($e);
?>Example #2 Deriving a seed from a string
<?php
$string = "My string seed";
// Hash the string with SHA-256 using binary output to turn the
// $string into a 256 Bit seed. Using the same string will result
// in the same sequence of randomness.
$e = new \Random\Engine\Xoshiro256StarStar(
hash('sha256', $string, binary: true)
);
echo bin2hex($e->generate()), "\n";
?>The above example will output:
6e013453678388c2