Random\Engine\Xoshiro256StarStar::jump
PHP function
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(PHP 8 >= 8.2.0)
Efficiently move the engine ahead by 2^128 steps
Description
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 Parameters
Return Values
Void
Examples
Random\Engine\Xoshiro256StarStar::jump() example
php
<?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), "\n";
}
});
$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:
output
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