Random\Engine\Xoshiro256StarStar::jump

(PHP 8 >= 8.2.0)

Random\Engine\Xoshiro256StarStar::jumpEfficiently move the engine ahead by 2^128 steps

Description

public Random\Engine\Xoshiro256StarStar::jump(): void

Moves the algorithm’s state ahead by 2128 steps, as if Random\Engine\Xoshiro256StarStar::generate() was called 2128 times.

The purpose of a jump is to facilitate the creation of a new Random\Engine\Xoshiro256StarStar engine from an existing seeded Random\Engine\Xoshiro256StarStar engine. The seeded engine acts as a blueprint, which can be cloned and repeatedly jumped to create 2128 non-overlapping sequences with 2128 values each.

Parameters

This function has no parameters.

Return Values

No value is returned.

Examples

Example #1 Random\Engine\Xoshiro256StarStar::jump() example

<?php
use Random\Engine\Xoshiro256StarStar;
use
Random\Randomizer;

$blueprintRng = new Xoshiro256StarStar(0);

$fibers = [];
for (
$i = 0; $i < 8; $i++) {
$fiberRng = clone $blueprintRng;
$blueprintRng->jump();

$fiber = new Fiber(static function () use ($fiberRng, $i): void {
$randomizer = new Randomizer($fiberRng);

while (
true) {
Fiber::suspend();
echo
"{$i}: " . $randomizer->getInt(0, 100), PHP_EOL;
}
});
$fiber->start();

$fibers[] = $fiber;
}


// Even though the fibers execute in a random order, they will print the same value
// each time, because each has its own unique instance of the RNG.
$randomizer = new Randomizer();

$fibers = $randomizer->shuffleArray($fibers);
foreach (
$fibers as $fiber) {
$fiber->resume();
}

$fibers = $randomizer->shuffleArray($fibers);
foreach (
$fibers as $fiber) {
$fiber->resume();
}
?>

The above example will output something similar to:

4: 89
3: 10
2: 63
1: 75
6: 41
5: 56
0: 16
7: 60
7: 34
6: 58
1: 74
4: 63
3: 3
5: 42
2: 45
0: 86

See Also

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